The 9 micron sensor: Magic or Myth?

[Jack Flesher]

We got into a partial discussion surrounding the different "looks" generated by the different sensors we were comparing in the P65+ sneak peek thread (see here: http://forum.getdpi.com/forum/showthread.php?t=4333). A few folks commented on how the P25+ files with their "fatter" 9 micron pixels appeared to generate an image with more "pop." This is a fairly common reaction to 9 micron sensors from any of the manufacturers and most of us who look at a lot of digital files do see it, myself included. So I decided it might be worthwhile to start a thread about it where we can share some theories.

I say theories, because in trying to get my arms around the technical and mathematical aspects of cross-comparing many of the factors I believe contribute -- such as total DR, inter-pixel-contrast, Nyquist limits and lens performance -- I quickly realized I was going to have make too many assumptions to nail anything down in a concrete fashion. Moreover, I "see" what folks are talking about, so I know it is a "real" trait from that standpoint -- and can therefore look at it empirically. That conflicts with the mathematician-engineer in me, but is perfectly suited to my inner-artist, and since empirical is easier to compare visually, my inner-artist won out over my inner-mathematician . Here is an overview of some image comparisons I performed -- I used the series of "Across the Lake" test shots we already showed in full and crops from in the main thread.

Note these are my theories, observations and conclusions and presented here only to start the discussion -- I am *not* claiming them as facts.

For the first set of trials, I opened the three files that were as identical in framing as possible in C1 (4.5.1). My goals were to get the files as close to the same WB and overall color as possible, get them as close to the same exposure as possible, get as similar an inter-pixel appearance when viewed at 100% as possible and get the deepest blacks to the same point. This was attempted ALL in the raw converter, then the files were processed as 16-bit Profoto Tiffs for later working in Photoshop CS4 to finish the task. To accomplish the similar look, here is what was required in C1: I first matched WB as close as possible. The P25+ and P45+ were virtually identical when I was done, but the P65+ has a distinctly different color balance, so it only kind of close. Next I equalized local contrast (clarity) -- it is pretty obvious the P25+ has the most -- which required adjustments to the P45+ and P65+ files. In C1 I added 8 points clarity for the P45+ and 12 points for the P65+. Note that clarity also affects total contrast, and at this point most of the differences in perceived DR have evaporated from the files... Next I adjusted highlight exposures to the same level as the darkest image, in this case, the P25+. (It is important to note that none of the files had clipped highlights so I could have alternatively increased the two darker to match the lightest, P65+, but the slightly darker file showed better overall saturation, so I went that way.) I decreased the exposure on the P45+ file by 0.2 stop and on the P65+ by 0.4 stop. Finally I ratcheted the deepest black in the image to the same point in all three files. This required a minor levels adjustment to the each file -- I moved the black slider from zero to 6 on the P25+ file, zero to 4 on the P45+ file and zero to just 1 on the P65+ file. (Ironically, my gut tells me this indicates the P25+ may actually carry slightly MORE total DR than the other two backs!) At this point all of the images look very, very close save for a slight color difference in the P65+ and slight saturation differences (which I correct for in CS4 as explained below).

Once in CS4, I balanced saturation. I did it here because there was some differential saturation in the P65+ file I knew would get equalized by a vibrance adjustment, and C1 does not contain a vibrance slider as does LR/ACR. Here a 10 point bump in vibrance combined with a 10 point bump in saturation was given to the P65 file. The P45 got a 6 point bump in saturation only, and now all three files had pretty similar overall saturation. I then uprezzed ALL of the files to 24"x32" prints at 360 PPI. This required only a marginal 50% uprez on the P65+ file, but a significant 400% increase on the P25+ file. My goal here was to have ALL files uprezzed at least some amount, as we might do with each file in a real-world example for a larger print. The advantage of uprezzing to a print size of 24x32 at 360 PPI is it also serves double-duty as an identical print file for doing a 36"x48" print at 240 PPI.

The one thing that is very difficult to show online is how prints look comparatively. What I have found is that you can get a reasonable approximation of how final prints will compare by viewing the files side-by-side at 50% view in PS. This I did do and grabbed a screen-shot of all three "crops shown onscreen side-by-side. This is a full-screen cut off my 30" display, so is a large jpeg. I am linking to it instead of embedding it here, click on the thumbnail. You can easily tell which image is which by reading the titles. Note that these are *NOT* sharpened for output yet, but may show some jpeg compression artifacts:



~~~

A summary of my observations viewing all of these onscreen:

1) First, I feel I did get the 9 micron "look" in the other two files using my set of adjustments. IMO I would thus call the myth "busted," though admittedly I feel the 9 micron sensors deliver the better look without added work, so maybe there is something to the "magic" side.

2) You can definitely see the progressive additional detail as we move up in sensor resolution at 100%, but they are pretty slight and diminish to almost insignificant levels in the 50% view.

3) The P25+ has a propensity to generate visible moire in areas of repetitive fine detail like the mini-blinds in the windows seen in the screen capture. I conclude this tends to happen most often when the lens is sharper than the sensor, but also suspect the lens being sharper than the sensor is paramount to why the 9 micron sensors exhibit more inter-pixel contrast without added adjustments. Pick your poison.

4) The P45+ and P65+ 50% views are very, very close to my eyes, with an ever so slight advantage to the P65+ in the areas of really fine detail like the individual willow leaves, blades of tall grass and thinnest branches on the bushes and trees. Here the P25+ looks a bit softer for sure, but still resolves most of these same detail parts as well-defined individuals. I conclude here that the minor differences between the P45+ and P65+ may be because we are very near the limit of lens resolution already in the P45+.

Now for my summary after viewing actual prints.

1) In the 24x32 inch prints, the difference in discernible detail is IMO insignificant. In fact, I can only detect actual detail differences by viewing the print with a loupe. Using my reading cheaters at 12", I cannot see any significant differences -- really!

2) In the 36x48 inch prints... Here, with my nose in the prints, I can detect a slight loss of detail in the P25+ print -- it is very minor, but it is visible. However, it is not really noticeable unless you are comparing the P25+ directly to one of the others with your nose in the print. Between the P45+ and P65+, I see no difference. Again, if I use the loupe, I can see a slight edge to the P65+ print -- but even then it's a very tiny difference. From this observation I conclude the P25+ is starting to hit a limit on critical (very critical) detail at 36x48 inch print sizes. As photographers, I feel we are generally far more attuned to the minor nuances of detail than "normal" art viewing folk, so no doubt the P25+ could still go twice that large for most normal viewing situations.

3) Moire in the P25+ (not sure it carries through to other 9 micron pixel backs, but I assume it does) is a real issue and the user needs to learn/know how to deal with it. Note that the C1 software DOES contain a moire reducer (don't know about the others), but I did not run it for this test as it also kills very fine detail. My solution would be to run two conversions of the same file, one with and one without moire reduced, then layer them in CS and mask out the offending moire areas -- in this way the final image maintains the best from both conversions. Alternatively, if the uber-fine detail is not relevant to the image -- which in all honesty it often isn't -- then by all means save the masking hassle and use the moire tool (if available) during raw conversion.

A final thought: If you are regularly going to print larger than 24x36, then for sure the smaller pixel backs are probably worth looking at for their added ability to render very fine detail. However, understand you may become "lens limited" quickly and may need to consider an alternative camera system with digital-specific or high-resolution lenses to fully utilize the resolution the back is capable of.

Cheers,

[lance_schad]

Wow great report Jack.
I really liked the methodology along with the multiple print examples.
I am sure the readers will be enlightened by it.
I am glad that I was able to assist because it is hard to actually get all three backs for an evaluation like this in the same place with more importantly same camera position/type.
Looking forward to hearing some other observations.
L

[tashley]

Phew, Jack, that was an astonishing marathon of really useful information. I can't begin to question your methodology or conclusions: I'm simply grateful for them!

Tim

[mark1958]

Jack great piece of work. Was the moire result reproducible in multiple images? I had seen moire with my leaf aptus 65 that I did not see with my hasselblad H3DII and 35mm HC. In addition, I would say that my Leica 28mm R gives moire on my 1DsmkIII. In that case, I always thought it was possibly due to the adapter and the distance of the lens mount to the sensor being slightly different than what you normally get with a canon lens. If your theory is correct, perhaps it is due to the greater resolving power of the leica glass. However in that case more variables. I guess based on your data no need for the P65. M

[fotografz]

That's the longest post I've ever seen you write Jack ... and I read it all because he subject is indeed intriguing.

I do think that you are right in concluding "bigger isn't always better." However, it's a difficult pill to swallow because we have been hard-wired to believe the opposite.

What I find terribly interesting is how the backs started, and where they have migrated to in terms of application .... and the questions of appropriateness that may arise.

We forget that these were (and may still be?) primarily studio solutions. ISO selections other than 100, on board LCDs and CF card capture are relatively recent additions. Most backs were tethered to stationary cameras/computers shooting with powerful strobes. Even the first "portable" Kodak ProBack I owned still needed a huge Quantum battery, and only worked on a 555 ELD Hasselblad and my giant RZ Pro-II with a very expensive Kapture Group adapter. Portable it wasn't, in the current sense of the word.

Then came the Kodak ProBack 645 which @ $12,000. set the industry on it's ear. Totally portable, (and still the model for many MF digital back solutions.)

Back to the studio scenario ... it is here that the higher meg backs come into their own. When shooting available light outside, my 9 X 9 micron sensor CFV with legacy V lenses is fabulous ... move into the studio with all that sparkling and well controlled light, and it's still very good, but not so fabulous. The 39 meg back sings here. But as you say, it sings best with APO view lenses. I rarely use the 39 camera because the back is on the Rollei Xact 90% of the time.

Lastly, IMO, we tend to forget how images are viewed ... only other photographers press their noses against the image and whip out their Sherlock Holmes magnifier. People take it all in as a holistic experience .... and, besides content which is the most important aspect of the experience, color, tonal gradations, and the "impression" of clarity play a huge part in the overall emotional reaction to an image.

Just a few random thoughts.

[Guy Mancuso]

Well let me add Jack and I have talked at great length on this subject and last week we came to some of these conclusions and today on the phone he was describing all of this in print. I found his testing and such dead on in regards to what we already talked about with a few surprises on how well the P25 Plus holds it's own. Now as a owner of the P25 Plus I can address the moire issue as i have said in the past it is there and sometimes it is there often. It maybe the only issue i have seen with this back and I would assume other Kodak backs. Dalsa sensor backs i can only comment on the ZD which had the Aptus 22 inside it and i do remember moire but maybe not as frequent as my P25 Plus but obviously I had this back longer and shot a lot of many different subjects with it. Yes the Moire tool works and i have used it in C1 with great success and also even have a action for it. Now normally it shows up mostly with clothing which includes people so any softening with the Moire tool is not a big issue but when it hits window blinds and tile roofs than to get around it faster i use the Moire tool to rid the problem than sharpen a touch more than my base settings or I can do the masking as Jack describes. i will say if I shot fashion or clothing all the time I may have chosen or would maybe use a P30 plus or the P45 Plus . Micro lenses tend to be less a moire issue with the P21 plus and P30 plus at least from what I have seen it seems the case even though Micro lenses are not directly supposed to be related to moire reduction. It maybe a simply case of the smaller micron sensor and that is something we would have to test for to be sure. If we have DMR and or M8 shooters some of this comes through with those units as well. I have had both and run into several times. I will say the P25 plus may have more or it comes up more but at the end of the day it does not bother me because it is a easy fix and the workarounds are very simple and in C1 if you have a bunch of images of the same type than you can simply copy the settings from one and apply to others as well in a key stroke. Bottom line this is the price to pay for non AA filter camera's or backs. I accept that with open arms since i hate AA filters and there results from them.

Jack excellent report my friend, just great stuff.

[Jack Flesher]

Thanks for the kind words guys, and I'm impressed with you who taking the time to read it all!

Mark: Yes, the moire was reproducible and more common with the P25, but only with the best lenses mounted and in image areas containing high-frequency detail.

[jlm]

i find that medium format, the viewfinders and results suit my way of working just fine with the CFV or now, the P20. i do see more ducks in the 65 shot however

yesterday though i picked up a Lumix G1 and that baby for $700 has some features that should embarrass all the MFDB makers...like the live view and the amazing manual focus function, a histogram showing while taking the shot and the so convenient, high quality, positionable LCD screen. really shows what could be done to improve functionality

[Guy Mancuso]

That is one cool little camera John. I played with one for about 2 hours and it was just fun to shoot.

[mark1958]

Jack.. I guess it would be interesting to see how the 65, 45, 21 compare against some of your view camera digital lenses.

[Dale Allyn]

Jack,

I really appreciate this report, and the effort it took to compile it. Very practical info indeed. For me, the buck stops at the print (not peeping at files) and the fact that you saw this through to paper and ink lends so much more substance to the discussion.

All of this discussion and shared experience supports what conclusions I was beginning to come to, in that if one is to move up to the P45+ and P65+ backs s/he must also plan to give it the best glass. For me, the differences we're seeing between the P65+ and P45+ are not enough to make me hunger for the P65+... unless going for massive prints of images captured with the more specialized lenses (e.g. Schneider or Rodenstock optics, etc.). The P45+ (or other 39MP sensors) seems to be a sweet spot, with the P25+ holding up quite well. I'm very happy with the P25+ and your report adds even more support for that contentment (for now).

I'll also repeat my appreciation to the folks at C.I. and Phase who helped to make this comparison possible.

Cheers!

[fotografz]

RE: Moiré

dual process the file with and without moiré filtration, layer and paint out the bad effects.

[LJL]

Jack,
Very nice, detailed presentation and description of file treatment and thoughts about stuff. I would agree with your comment about the "myth" being busted, but maybe the "magic" remaining to some degree.....if I really thought the output from the 9x9 micron stuff was truly mythical ;-) Aside from the color variances you mentioned with the P65+, these results are demonstrating that the P25+ does hold its own quite nicely (despite moire issues), and the P45+ interestingly to me looks like it does land between the other two....color still seems just a teeny bit soft compared to the P25+. (The reds on the dock are my focus point here. To my eyes, there may still be a bit more black in the P25+ shot than the others, as the reds have a bit deeper/richer look. I know this is really splitting hairs, and as you say, nobody is ever going to tell them apart unless looking side-by-side-by-side.....and then make them "justify" what they think they are seeing.)

Guy,
You may want to hold on to that P25+ back, as I mentioned to you before. It is definitely holding its own for these kinds of outdoor/landscape type shots. Really more than "acceptable". It does produce some very nice files.

Marc,
I really think you are onto that other key point....the P65+ and probably the P45+ backs will do well in this landscape setting, but they will dazzle under the controlled studio lights....maybe more than the P25+ in this case. That could be the next iteration comparison....do them together under Elinchroms, Hensels, Profotos, Brons, or whatever one wants to use. I would guess, as you comment, that the bigger backs will really shine in that setting.

This is really nice to see, and frankly, it should help a lot of folks better understand what may or may not be going on, which is "better" or not, which may fill most needs, etc. Since the body, glass, set-up, etc., was out of the equation, and the processing was genuinely done to get as close to parity as is reasonable, AND the PRINT was actually part of the equation, it should be viewed as more than "fair" in comparisons.

Great stuff. Thanks to all involved with this effort.

LJ

[Bill Caulfeild-Browne]

Jack, let me just say "Thank You". I'm very impressed.
Bill

[EH21]

Jack,
Looks like you did a lot of work, however hate to say your test is near meaningless without using a scientific study that can provide quantitative results - something like Imatest to accurately check Dynamic range, Color accuracy, and sharpness. Sure you can see stuff like Moire and also that the p25 is picking up more detail in the shadows - look under the house for example. (But one would expect the p25 to have more DR as the kodak technical website specs it out as having more.)

Your test overlooks something important for a lot of shooters - diffraction. One would expect the smaller sensel chips to see diffraction limits at larger apertures than the 9micron chips. This is a really important test for people shooting landscapes and products that need big DOF.

Another area where I'd expect to see differences in these backs is that the newer Kodak chips have different color filters which should allow for better color accuracy. No way you are going to see this on a monitor with the kinds of tests you are doing. Imatest will give you the deviation vector for all the chips on your color chart in like 5 minutes worth of work. Same for DR.

There may be other programs out there besides Imatest, but that's what I've used and it's extremely accurate and much easier to get reliable results.

Then later down the road you can come back and test something else and make a fair comparison instead of judgement calls which don't do anyone any good.

Best of luck,
Eric

[Dale Allyn]

Originally Posted by EH21

Jack,
Looks like you did a lot of work, however hate to say your test is near meaningless without using a scientific study that can provide quantitative results - something like Imatest to accurately check Dynamic range, Color accuracy, and sharpness. Sure you can see stuff like Moire and also that the p25 is picking up more detail in the shadows - look under the house for example. (But one would expect the p25 to have more DR as the kodak technical website specs it out as having more.)

Your test overlooks something important for a lot of shooters - diffraction. One would expect the smaller sensel chips to see diffraction limits at larger apertures than the 9micron chips. This is a really important test for people shooting landscapes and products that need big DOF.

Another area where I'd expect to see differences in these backs is that the newer Kodak chips have different color filters which should allow for better color accuracy. No way you are going to see this on a monitor with the kinds of tests you are doing. Imatest will give you the deviation vector for all the chips on your color chart in like 5 minutes worth of work. Same for DR.

There may be other programs out there besides Imatest, but that's what I've used and it's extremely accurate and much easier to get reliable results.

Then later down the road you can come back and test something else and make a fair comparison instead of judgement calls which don't do anyone any good.

Best of luck,
Eric

Eric,

To say that Jack's report of his observations are "near meaningless" is an admission to having not read his original post with an open and considerate mind IMO. Perhaps they have little meaning for you, but that's not the same as "meaningless". As I read it, Jack did not post that his statements constitute theorem, but a theory, or even more so, personal observations. And furthermore, it appears that your interest is more intended towards a technical pissing-contest than a mutually beneficial conversation about a few of the digital backs available to us. Information in this thread seems geared toward practical, useful comparisons of available equipment in "real world" situations as they relate to a specific type of photography (as sampled). It does not appear to attempt to cover all situations. It is a conversation.

Your remarks regarding diffraction are valid and they do apply to certain applications (mine in particular), but that does not render Jack's (et al) observations invalid as you imply in your post. Why not contribute useful additions to the process rather than attempting to render someone else's contributions less useful to the group? A "winner" is not sought here, but shared growth is. Arrogance is the bane of internet fora, and an obstacle to shared learning and advancement.

Regards,

Dale Allyn

[fotografz]

IMO, in the end it IS subjective judgement regardless of scientific nit picking.

Obviously, photography is dependent upon science for it's very invention and existence ... and most certainly is an evaluative discipline to discover why something "is, or is not."

However, that aspect comes into play when subjective observation tells it to ... both for invention and for evaluation. I take it that Jack's post was done because many people have subjectively observed that the larger pixel pitch backs have "something" going for them that's logically hard to explain but relatively easy to see.

I've been doing photography for more years than I am willing to admit ... and one thing I've noticed is that we are a mixed lot ... many scientific minds with a creative streak, or "creative types" with some scientific curiosity.

With the advent and proliferation of digital, the balance has decidedly shifted to science, and the debates gather and disseminate huge amounts of data in support or denial of subjective observation.

My gripe is that subjectivity is generally becoming easy to dismiss with an overwhelming scientific tongue lashing. Yet in practice, I feel that clinical correctness has sucked the joy out of the creative process and subjective discovery. So many people are preoccupied with scientifically justifying and debating, that their inner child has been bound and gagged ... and they don't trust their own observations anymore.

I personally do not need to scientifically quantify my creative and subjective observations. I like occasionally reading those from others, but have, and will always trust my eyes in the end ... and embrace all the discriminatory creative prejudices inherent in that very personal creative process honed over the years and years of observing.

"I like, I don't like" ... and really don't give a healthy dump as to scientifically "why". The why is boring to me. I leave the "why" to nit pickers who derive joy from dissecting every pixel until it's all cataloged and neatly placed in it's proper column on the spread sheet of their minds.

In reality, I bet a 22 meg back will fulfill the requirement of 95% of most people's "real" needs. As Jack concluded, if you produce huge prints or shoot for excruciating detail, then up the game with both a bigger back and all other stuff you need to make use of that increased resolution. IMO, it's somewhat common sense.

[t_streng]

Are you saying its more relevant what is measured compared to what can be seen?

Originally Posted by EH21

Jack,
Looks like you did a lot of work, however hate to say your test is near meaningless without using a scientific study that can provide quantitative results - something like Imatest to accurately check Dynamic range, Color accuracy, and sharpness. Sure you can see stuff like Moire and also that the p25 is picking up more detail in the shadows - look under the house for example. (But one would expect the p25 to have more DR as the kodak technical website specs it out as having more.)

Your test overlooks something important for a lot of shooters - diffraction. One would expect the smaller sensel chips to see diffraction limits at larger apertures than the 9micron chips. This is a really important test for people shooting landscapes and products that need big DOF.

Another area where I'd expect to see differences in these backs is that the newer Kodak chips have different color filters which should allow for better color accuracy. No way you are going to see this on a monitor with the kinds of tests you are doing. Imatest will give you the deviation vector for all the chips on your color chart in like 5 minutes worth of work. Same for DR.

There may be other programs out there besides Imatest, but that's what I've used and it's extremely accurate and much easier to get reliable results.

Then later down the road you can come back and test something else and make a fair comparison instead of judgement calls which don't do anyone any good.

Best of luck,
Eric

[Guy Mancuso]

Originally Posted by fotografz

IMO, in the end it IS subjective judgement regardless of scientific nit picking.

Obviously, photography is dependent upon science for it's very invention and existence ... and most certainly is an evaluative discipline to discover why something "is, or is not."

However, that aspect comes into play when subjective observation tells it to ... both for invention and for evaluation. I take it that Jack's post was done because many people have subjectively observed that the larger pixel pitch backs have "something" going for them that's logically hard to explain but relatively easy to see.

I've been doing photography for more years than I am willing to admit ... and one thing I've noticed is that we are a mixed lot ... many scientific minds with a creative streak, or "creative types" with some scientific curiosity.

With the advent and proliferation of digital, the balance has decidedly shifted to science, and the debates gather and disseminate huge amounts of data in support or denial of subjective observation.

My gripe is that subjectivity is generally becoming easy to dismiss with an overwhelming scientific tongue lashing. Yet in practice, I feel that clinical correctness has sucked the joy out of the creative process and subjective discovery. So many people are preoccupied with scientifically justifying and debating, that their inner child has been bound and gagged ... and they don't trust their own observations anymore.

I personally do not need to scientifically quantify my creative and subjective observations. I like occasionally reading those from others, but have, and will always trust my eyes in the end ... and embrace all the discriminatory creative prejudices inherent in that very personal creative process honed over the years and years of observing.

"I like, I don't like" ... and really don't give a healthy dump as to scientifically "why". The why is boring to me. I leave the "why" to nit pickers who derive joy from dissecting every pixel until it's all cataloged and neatly placed in it's proper column on the spread sheet of their minds.

In reality, I bet a 22 meg back will fulfill the requirement of 95% of most people's "real" needs. As Jack concluded, if you produce huge prints or shoot for excruciating detail, then up the game with both a bigger back and all other stuff you need to make use of that increased resolution. IMO, it's somewhat common sense.

Well said . My clients are looking at reality and not the science of it. I can't sell a Imatest result. For me i will go what looks the best 100 percent of the time. The issue is lens testing never shows what the look of the lens actually does or what the final results look like. Tests are great for some things but in the end we sell results or print results for the wall or clients needs.

Also one issue right now is we can't test the P65 for color and noise floor since the firmware is NOT correct and it is off right now and we are talking to Phase about our testing and the needed final firmware for shipping.

[asabet]

Originally Posted by Jack Flesher

We got into a partial discussion surrounding the different "looks" generated by the different sensors we were comparing in the P65+ sneak peek thread (see here: http://forum.getdpi.com/forum/showthread.php?t=4333). A few folks commented on how the P25+ files with their "fatter" 9 micron pixels appeared to generate an image with more "pop."

In any size format, from small sensor to medium format, there always seem to be similar schools of thought, that the fatter pixels produce an image with more pop. From what I have seen when tests are done properly, such as yours were, the results are always in line with what you found. Nothing magic about larger pixels in terms of crispness or pop. With a given high quality lens, a greater number of smaller pixels gets you a little more resolution and a little less moire. The idea that the fat pixels hold some magic in this regard is probably rooted in a subconscious impression that comes from viewing the pixels onscreen at 100%, where the fat ones look crisper.

The two areas in which I'd expect that fatter pixels may hold an advantage are dynamic range and colors. These were not the focus of your test though.

As for Eric's comments about diffraction, I think it's worth pointing out that diffraction limits are never a weakness of a sensor, but a property of the optics. A small pixel sensor is diffraction-limited at a lower f-stop only because a fatter pixel sensor is unable to "see" the effects of diffraction at that f-stop. Diffraction never causes the higher res sensor to resolve less than a lower res sensor with a given format size and lens.

[Jack Flesher]

Originally Posted by EH21

Jack,
Looks like you did a lot of work, however hate to say your test is near meaningless without using a scientific study that can provide quantitative results - something like Imatest to accurately check Dynamic range, Color accuracy, and sharpness.

Hi Eric:

Sorry you found it all meaningless, though it wasn't a "test" as you indicated but rather a comparison... Indeed Imatest is great for pixel-peep tests, and I used to do that kind of testing, however I now prefer drawing my conclusions by viewing real-world shots since at the end of the day that's how most *paying clients* judge my images. Thus I will leave scientific analysis for other folks to perform. And please feel free to post any of your own scientific test findings on the forum!

Cheers,

[Bob]

The philosophical question is:
If something cannot be seen does it exist?
Perhaps it does, but does it matter?

OTOH, I was thinking of posting last night the Fourier convolutions necessary to properly describe the relationship between the lens MTF surface and the spatial frequency comb filter characteristics of the sensor as well as the transformations necessary to put it on paper assuming inkjet technology, with comparisons, of course, with the resolving capability of the human eye with a side dissertation on viewing distance and how spatial excitation frequency is modified by the effects of subject magnification caused by attempts to match subject height to various sensor sizes. Anyway I wrote the damn thing down in the margin of the book I was reading, but somehow this morning I find that I have misplaced it.
-bob

[Guy Mancuso]

Damn Bob how about some bloody English . Good or Bad.


I could not resist

[Bob]

Guy,
I thought I would leave out the bits about frequency dependent sharpening and my opinions on the characteristics of various printing media and surface characteristics and their effects on imaging system MTF to the standard observer, and comparisons of several de-Bayering algorithms just to simplify things a bit.

Or, you could take the approach of looking at the damn thing and seeing if it looks good or not.
-bob

[LJL]

Bob,
Careful, you have egregiously omitted the differential characteristics of color in the spectrum and how that is/is not successfully resolved ;-)

(Honestly, your description of your marginal annotations had me laughing also....great sense of humor and perspective.)

LJ

P.S. Eric, I for one am NOT beating up on your comments over Jack's testing, but it sure did feel like cold water being tossed on a comfy glowing fire. I would rather see the glowing flames than all the thick choking smoke ;-)

[Guy Mancuso]

Originally Posted by Bob

Guy,
I thought I would leave out the bits about frequency dependent sharpening and my opinions on the characteristics of various printing media and surface characteristics and their effects on imaging system MTF to the standard observer, and comparisons of several de-Bayering algorithms just to simplify things a bit.

Or, you could take the approach of looking at the damn thing and seeing it it looks good or not.
-bob

Scary thing is I understood it to a point than you lost me on spatial frequency comb filter . In which case i use a brush

[Bob]

Originally Posted by LJL

Bob,
Careful, you have egregiously omitted the differential characteristics of color in the spectrum and how that is/is not successfully resolved ;-) -- snip --

LJ
-- snip --

OOPS.
Yes, you are right, you must consider the power spectrum of the illuminant as well as effects of discontinuous spectra not to mention atmospheric effects.
-bob

[Bob]

Originally Posted by Guy Mancuso

Scary thing is I understood it to a point than you lost me on spatial frequency comb filter . In which case i use a brush

Guy,
I am rapidly approaching the point where I need neither brush nor comb.
-bob

[Guy Mancuso]

Just shot this a hour ago with the 55mm 2.8 Mamiya 500 dollar used special. LOL

At F11 on a 12 ft ladder handheld

[Guy Mancuso]

An image i may expect Moire but seems like nothing there after a quick check through the image.

[Digitalcameraman]

Originally Posted by Jack Flesher

We got into a partial discussion surrounding the different "looks" generated by the different sensors we were comparing in the P65+ sneak peek thread (see here: http://forum.getdpi.com/forum/showthread.php?t=4333). A few folks commented on how the P25+ files with their "fatter" 9 micron pixels appeared to generate an image with more "pop." This is a fairly common reaction to 9 micron sensors from any of the manufacturers and most of us who look at a lot of digital files do see it, myself included. So I decided it might be worthwhile to start a thread about it where we can share some theories............



Cheers,

Jack:

I enjoyed reading your findings and observations between the variuos backs. I just wanted to point out a few details that need to be understood when one attempts to make this comparison both visually and in printing that I have discovered during this process.

First, each chip sees color a little differently as we have seen. Each chip has a default ICC camera profile that is automatically loaded when you open a Phase One file in Capture One software. This ICC camera profile is the recipe for the color and contrast that is going to be rendered when the original image comes into Capture One. That being said you can slide the white balance, contrast and exposure before you process the images to get them closer to each other. But as we see one file may show more saturated reds than the other files. One file may show more punch due to the contrast being a little steeper. One file may show more DR than another file due to the camera profile being applied. Once again each chip sees color differently and each chips has a different profile.

Color Editor is a very powerful tool that will allow you to tweak each profile and get them closer. But in the end we really only want the camera we use to have what we perceive as the best color and range.

My very brief testing of the new Phase One P65+ also showed that the files were a little different color and contrast due to the different camera profiles being use. I have always been a firm believer that I should use the profile that was designed for the chip being used and then make changes to it if I want to modify the way my camera is seeing color based on the camera profile being loaded in Capture One or Capture 4. Sure you could select the same camera profile for all three images but my experience has been that the color gets a little weird. The shadows may shift and have a color cast when using a profile from say a P25+ on a P65+ Raw file.

On many occasions I have been asked by people who were testing new cameras and of course comparing them to their old camera that they have built much of their confidence and trust on, why does each camera not match in color when tested side by side on the same camera body and lens? With this high end level of color we are seeing captured from most MF digital backs, we notice that one looks different than the other. And that's okay.

I truly feel we are just scrapping the surface on the quality and color levels of these new technologies.

And good observations on the pixels size and ability to see morie or not to see morie. There is not doubt that the P25+ still produces a great image and one with great range, color, and contrast. But when challenged by textiles such as clothes and fabrics or printed materials, the smaller pixels wins hands down by eliminating most of it up front before the workflow starts. There are many factors that help dictate what digital back is best suited for one's specific application. And output size is one of the main factors.

Subject matter also plays a big role. If I take a picture of a purse and it fills the frame, that image may be just a good on either of the MP backs. But when I have a picture of a model holding a purse, you really start to appreciate the fine detail that the bigger MP backs can resolve.

Optics also play a very important role here. But as Guy has just posted a shot with the P25+ and 55mm Mamiya lens($500) has great detail and edge sharpness. Now the real question is, if the new 45mm D Lens resolves detail from edge to edge as well as the 80mm and 150mm D Sekors do, we are in for a real treat.

Just wanted to share this because I think it has a lot to do with how we perceive the color and dynamic range of new products and I really feel that the camera profile is controlling much of this. On the other hand I still feel like many do that Capture One and Capture 4 produce a better rendered image so use the profile you like the best that is recommended for your chip.

Good work.



Chris Snipes
Image Production, Inc
Phase One Resller
Phase One Test Studio


www.imageproduction.com
chris@imageproduction.com

[Jack Flesher]

Chris,

Excellent point re profiles. I did not mention it because I know the P65 is a pre-production sample and as such I doubt the profiles are finalized. (In fact, I will go so far as to say if they are finalized, then "we have a problem Houston!" )

The best testing option probably would have been for me to shoot the MacBeth under controlled conditions and then built dedicated test comparison profiles for each back myself... But for anyone who has ever built camera profiles, fun it aint. Been there, done that, have the tee-shirts and don't need another one --- moreover, I like my P45+ profile set just fine as is, thank you very much

Cheers,

[Digitalcameraman]

Originally Posted by Jack Flesher

Chris,

Excellent point re profiles. I did not mention it because I know the P65 is a pre-production sample and as such I doubt the profiles are finalized. (In fact, I will go so far as to say if they are finalized, then "we have a problem Houston!" )

The best testing option probably would have been for me to shoot the MacBeth under controlled conditions and then built dedicated test comparison profiles for each back myself... But for anyone who has ever built camera profiles, fun it aint. Been there, done that, have the tee-shirts and don't need another one --- moreover, I like my P45+ profile set just fine as is, thank you very much

Cheers,

I agree. I have tried to make camera profiles with many different products on the market and I must say I have never been able to make one as good as P1 does. Printer and monitors are easy compared to camera profiles. The only place I have seen it work well is in fine art. Doing copy work you can make a camera input profile that seems to work across the board. I have always felt that this may be due to the controlled lighting environment and color temperature. When we do various types of photography under different conditions I think the canned Phase One cameras profiles are the best, even though we use different temperature lights and the sun changes the temperature for us.

Over the years we have also seen how Phase One can make new profiles or lets say improve the camera profiles that may have released earlier in a products life. The P25+ profile is much better than the original P25. They made it much smoother in the shadows. I have got good results swapping these profiles between the 2 cameras because the chips are from similar batches.

But as you point out the P65+ is just being released and I do expect to see a better profile for it when that occurs. That chip is manufactured by Dalsa and not Kodak so it is going to see color a little differently. We went through the exact same motions when the P45 and P45+ were released. And now look at what we have.


Chris Snipes
Image Production, Inc
Phase One Reseller
Phase One Test Studio


www.imageproduction.com
chris@imageproduction.com

[robsteve]

Originally Posted by Guy Mancuso

At F11 on a 12 ft ladder handheld

How do you hand hold a 12 foot ladder

[Jan Brittenson]

It could be related to the spectral filtration of the mosaic. Narrower filters with limited overlap, that produce a linear response (so that for any point on the spectrum the sum of all channels is constant) have superior color reproduction. But wider filters can obtain better sensitivity - there is more overlap, so there is response in more channels for any given point on the spectrum. Then this is cleaned up in processing to retain accuracy in key hues (like skin). Going to a finer pitch reduces sensitivity and a simple recourse might be to recover it using less steep filtration on the mosaic. (This also sacrifices apparent dynamic range since steeper filtration changes the saturation behavior - requiring more exposure for the same number of channels to clip. And as long as at least one channel hasn't clipped some luminance gradation/shoulder can be recovered.)

[Guy Mancuso]

Originally Posted by robsteve

How do you hand hold a 12 foot ladder

I'm a Pro wrestler in my spare time. LOL

[Guy Mancuso]

Originally Posted by Digitalcameraman

Jack:

I enjoyed reading your findings and observations between the variuos backs. I just wanted to point out a few details that need to be understood when one attempts to make this comparison both visually and in printing that I have discovered during this process.

First, each chip sees color a little differently as we have seen. Each chip has a default ICC camera profile that is automatically loaded when you open a Phase One file in Capture One software. This ICC camera profile is the recipe for the color and contrast that is going to be rendered when the original image comes into Capture One. That being said you can slide the white balance, contrast and exposure before you process the images to get them closer to each other. But as we see one file may show more saturated reds than the other files. One file may show more punch due to the contrast being a little steeper. One file may show more DR than another file due to the camera profile being applied. Once again each chip sees color differently and each chips has a different profile.

Color Editor is a very powerful tool that will allow you to tweak each profile and get them closer. But in the end we really only want the camera we use to have what we perceive as the best color and range.

My very brief testing of the new Phase One P65+ also showed that the files were a little different color and contrast due to the different camera profiles being use. I have always been a firm believer that I should use the profile that was designed for the chip being used and then make changes to it if I want to modify the way my camera is seeing color based on the camera profile being loaded in Capture One or Capture 4. Sure you could select the same camera profile for all three images but my experience has been that the color gets a little weird. The shadows may shift and have a color cast when using a profile from say a P25+ on a P65+ Raw file.

On many occasions I have been asked by people who were testing new cameras and of course comparing them to their old camera that they have built much of their confidence and trust on, why does each camera not match in color when tested side by side on the same camera body and lens? With this high end level of color we are seeing captured from most MF digital backs, we notice that one looks different than the other. And that's okay.

I truly feel we are just scrapping the surface on the quality and color levels of these new technologies.

And good observations on the pixels size and ability to see morie or not to see morie. There is not doubt that the P25+ still produces a great image and one with great range, color, and contrast. But when challenged by textiles such as clothes and fabrics or printed materials, the smaller pixels wins hands down by eliminating most of it up front before the workflow starts. There are many factors that help dictate what digital back is best suited for one's specific application. And output size is one of the main factors.

Subject matter also plays a big role. If I take a picture of a purse and it fills the frame, that image may be just a good on either of the MP backs. But when I have a picture of a model holding a purse, you really start to appreciate the fine detail that the bigger MP backs can resolve.

Optics also play a very important role here. But as Guy has just posted a shot with the P25+ and 55mm Mamiya lens($500) has great detail and edge sharpness. Now the real question is, if the new 45mm D Lens resolves detail from edge to edge as well as the 80mm and 150mm D Sekors do, we are in for a real treat.

Just wanted to share this because I think it has a lot to do with how we perceive the color and dynamic range of new products and I really feel that the camera profile is controlling much of this. On the other hand I still feel like many do that Capture One and Capture 4 produce a better rendered image so use the profile you like the best that is recommended for your chip.

Good work.



Chris Snipes
Image Production, Inc
Phase One Resller
Phase One Test Studio


www.imageproduction.com
chris@imageproduction.com

Well said Chris . I have been very happy with the profiles for the P25 Plus very good all around and not much i have to do to a file. The 55 is a nice lens but i want the 45 mm since I have the 28 and sell the 35 and 55 . I like the manual override on the lens and not have to resort to the body mode for M. The new 45 is supposed to have it on board. In regards to the P65 yes the profile needs work, no question about it but the folks at Phase will have it ready for production units. Jack and I have a conference call coming with some of the folks at Phase to talk about the P65. Hopefully we can give some good input as others that may have tested it also. I like the idea of getting pre-production units out to folks and get feedback from it, just makes the end result better in my view.

[EH21]

Originally Posted by Jack Flesher

Hi Eric:

Sorry you found it all meaningless, though it wasn't a "test" as you indicated but rather a comparison... Indeed Imatest is great for pixel-peep tests, and I used to do that kind of testing, however I now prefer drawing my conclusions by viewing real-world shots since at the end of the day that's how most *paying clients* judge my images. Thus I will leave scientific analysis for other folks to perform. And please feel free to post any of your own scientific test findings on the forum!

Cheers,

Hey I'd be happy to do some testing - you know DR, Color fidelity, sensor resolving power, diffraction limit stuff... BUT you'd have to lend me the p65+ first. I'd probably need it for a while to do the scientific tests, then another while for subjective tests. It's just the thing I need to finish my series of underwater nudes with too so hopefully I could fit that in as well.

[Guy Mancuso]

Well if that is the case need a assistant than. LOL
I can swim pretty good.

[carstenw]

Especially with a nice carrot, eh?

[dfarkas]

Guy,

I've noticed that your shots are running cyan/blue and slightly desaturated. It may be time for a refresh on the monitor calibration. Just a friendly observation.

I took the liberty of doing a quick correction in PS. Before and after.

David

[dfarkas]

Relating to this thread....

If Jack wasn't able to discern much difference in a 3' x 4' print between 39 and 60 MP and we suspect that the lenses are limited in resolving this extra detail, where does this leave the Leica S2? At 37.5MP it should resolve at least as much as the P45+, and the lenses should be a lot better across the board versus the Mamiya lenses. Not saying the Mamiya D lenses are bad, but even with the 80mm D and the 150mm D Sekkors we are seeing limits on resolving power. If the Leica S lenses can seriously outresolve the current competition and the sensor is in line (6um pixels) with what is coming out of the P65+, I'm expecting pretty phenomenal results in a smaller, faster, and fully weather-sealed package. Anyone else thinking the same?

David

[Guy Mancuso]

Originally Posted by dfarkas

Guy,

I've noticed that your shots are running cyan/blue and slightly desaturated. It may be time for a refresh on the monitor calibration. Just a friendly observation.

I took the liberty of doing a quick correction in PS. Before and after.

David

Thanks David yes a couple things have changed on my box and need to check that. Thanks Guy

[Greg Seitz]

Jack,

Nice work on the comparison, pretty interesting results.

On a somewhat related note, I've done a comparison of per pixel sharpness for the D700, 5D Mk II, and 450D all of which have different pixel pitches. Here's the thread if your interested:

http://forum.getdpi.com/forum/showthread.php?t=4470

Thanks,

Greg

[Jack Flesher]

Originally Posted by dfarkas

If Jack wasn't able to discern much difference in a 3' x 4' print between 39 and 60 MP and we suspect that the lenses are limited in resolving this extra detail, ~~~ If the Leica S lenses can seriously outresolve the current competition and the sensor is in line (6um pixels) with what is coming out of the P65+, I'm expecting pretty phenomenal results in a smaller, faster, and fully weather-sealed package. Anyone else thinking the same?

David, here is my take:

If we look at theoretical sensor resolution limits, Nyquist aside, the absolute best we can hope for is as follows: 9 micron sensors will resolve at most 55 line pairs per mm; 6.8 micron sensors (P45+) will resolve 74 line pairs per mm; and 6 micron sensors (P65+ and S2) will resolve at most 83 line pairs per mm.

Looking at the percentage of change on LP/mm rendering, the P45+ has a 26% gain over the P25+ while the P65+ has only an 11% gain over the P45+. Since I did see "some" improvement from the P65+ sensor, I can only assume my lowly Mamiya glass is rendering at least some of that 11% potential advantage. How much exactly is tough to say for certain, but 11% over 26% is less than half, and I can say with some certainty that relative to the change between the P45 and P25, the change between the P65 and P45 seemed somewhere between 1/3 and 1/2 as significant -- or right in line with the actual difference in possible resolutions.

Thus I would conclude that even if Leica's MF lenses resolve 200 line pairs, the most they put to the digital sensor will be 83, so even if Mamiya's best lenses only resolve 80 line pairs, the difference in resolution recorded at the sensor is going to be essentially moot...

Finally add one more factor -- getting 80 line pairs of resolution to the imaging surface. Here I will go on record stating it is *VERY* difficult to get more than even 60 line pairs of resolution into a real-world image, and probably one reason the 9 micron sensor holds its own so well! To achieve these levels of resolution you first need the best optics and a sensor that is perfectly parallel to the mounted lens plane, and then you need to use rigorously methodical capture technique; a sturdy tripod, perfect focus, limit camera movement and limit subject movements. Combine all of that and you are on your way.

So while I anxiously await the S2 and think it will be a cutting-edge digital camera on many levels, I do not think it is going to represent a "phenomenal" increase in image quality over current high-end MF digital systems. That said, IMHO there are many other optical qualities beside resolution that lead to a "phenomenal" image, and historically the total "look" *has been* one area where Leica has always excelled. This is an area I hope we'll see some of that Leica phenomenon

Cheers,

[shakeshuck]

Originally Posted by Jack Flesher

6.8 micron sensors (P45+) will resolve 74 line pairs per mm; and 6 micron sensors (P65+ and S2) will resolve at most 83 line pairs per mm.

Here I will go on record stating it is *VERY* difficult to get more than even 60 line pairs of resolution into a real-world image

Cheers,

Shoot me down if I'm wrong here, but for the 65+ to show a visible improvement over the 45+ (which it does), then either:

1) Your focussing was better on the 65+ shot, or

2) Your lens is resolving considerably more than 74 lp/mm across the entire frame, in which case

[Guy Mancuso]

Focus never changed when shooting the test which i actually shot the images and Jack surpervising. Exactly the same camera and same lens locked down, mirror up and used self timer. Only change was shifting the backs out. Absolute best solution, almost no variables. Only time there was a change is when I had to move in the P65 back to capture the same framing as the P45 and P25 than same procedure but obviously had to make the correct focus and framing adjustments. Pretty much no other choice here if wanting to use the exact lens. We shot from the same spot on one test all 3 backs and than the extra P65 move in framing to match.

My body and lens also if that means anything but we certainly seen many images with it.

[Jack Flesher]

Originally Posted by shakeshuck

Shoot me down if I'm wrong here, but for the 65+ to show a visible improvement over the 45+ (which it does), then either:

1) Your focussing was better on the 65+ shot, or

2) Your lens is resolving considerably more than 74 lp/mm across the entire frame, in which case

Yes, 2 is a sound conclusion, along with the other components of technique I mentioned

Guy and I did the shooting and all modesty aside, we know proper technique... We used a known good lens for our system, the new AFD 80. We confirmed focus via the excellent electronic focus confirmation in the Phase/Mamiya AFD3 body for the shots -- we know it works from previous testing and it eliminates the variable of your #1. We used a sturdy tripod, the Gitzo 3541 XLS with only the first two legs extended, so it was low to the ground. Finally, we used mirror-up and cable release to fire.

[Guy Mancuso]

Yea lowered the camera to my bloody height actually lower. LOL

He is almost a whole foot taller at least it seems that way my neck hurts from looking up for three days. LOL

[PeterA]

You guys are mad. I am selling all my MF stuff and buying a Sony!!