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HOW DO YOU FOCUS WITH YOUR ALPA

jotloob

Subscriber Member
High to all ALPA users .

I am new to ALPA since half a year and would very much like to know :
How do you ALPA users focus with your camera .
Does anyone use the ALPA ground glass and the leather type bellow with the loupe ? ? ?
What is your experience with the method you use ? ? ?

I currently use the HASSELBLAD SWC screen adapter ground glass with the split image ACUTE MATTE , but I think there must be a better way to focus .
I use only WA lenses and a HASSELBLAD CFV-39 digital back up to now and find focussing not as easy as I expected .

Jürgen
 

VICTOR BT

Member
jurgen...
the best is simply to practice on guessed focusing. really, it is not very difficult.
one trick...
a normal-size person needs two steps of normal easy-walk to do 1 meter walk. or really easy walk = 1 foot if u prefer feet.
it most "accuracte" to imagine that u "walk" from camera position to the object in focus. this is good even if u have a good eye mesurement of the distance, because in many cases, the surrounding may be missliding... with doing imaginative steps u get enough accuracy even for medium size distances... and it is very quick to do.
the "accuracy" in this way is no issue for wide lens, medium distances, optimum aprture
 
O

Optechs Digital

Guest
Hi Jurgen,

I usually only ever use two methods for focus. Either by estimation or by Ground Glass. I really Use the Ground Glass more for composition than for focus though and I use it with the newer small focus bellows from Alpa. This one is nice because it lets you look at the screen with both eyes or you can stick any focus loupe in it for magnification.

One thing i have noticed about some of the "bright screens" is that they are very bright but very difficult to actually focus with. They can tend to make things appear sharp even when they are not. Similar to a glossy screened monitor. If you can get a chance to try the Alpa Pro Grid Screen I would strongly recommend it. I bet it would resolve your problems. It is not as bright as some but it is very easy to focus with. It also has nearly no grain in the glass so you can use a fairly high powered magnifier to make sure you are in focus at a critical focus point.

Also, make sure to focus on the Ground Glass with the lens wide open rather than at the shooting aperture. Otherwise you will be trying to focus through depth of field which is almost impossible.

It has always been my experience that wider lenses are harder to focus on a ground glass than long ones. Long lenses will pop in and out of focus more distinctly. On the other hand, wide lenses will most often end up being shot at infinity ( at least in my experience). Have you done a shim adjustment to your back. This can also greatly affect your results. I know some people think this is BS but I have seen many times where this makes a huge difference.

I hope some of this will help.

Best,
Paul

High to all ALPA users .

I am new to ALPA since half a year and would very much like to know :
How do you ALPA users focus with your camera .
Does anyone use the ALPA ground glass and the leather type bellow with the loupe ? ? ?
What is your experience with the method you use ? ? ?

I currently use the HASSELBLAD SWC screen adapter ground glass with the split image ACUTE MATTE , but I think there must be a better way to focus .
I use only WA lenses and a HASSELBLAD CFV-39 digital back up to now and find focussing not as easy as I expected .

Jürgen
 

Don Libby

Well-known member
First let me say up front that I don't use an Alpa; however I do shoot with a Cambo WRS 1000. I also don't use a Hasselblad but instead I use a Phase One P45+. My choice of lenses are Schneider (35,72, and 120mm); I also have a groundglass. Even with my camera setup being completely different than yours, I still believe the basic principals will apply. I also need to add the caveat that I only shoot landscape so my experiences may differ.

I think the best way is to experiment using know distances. Set up the shot using a know object at a measured distance and shoot it. I've found that most of my lenses are accurate "to a degree" on distance; when shooting infinity I'll normally nudge the setting back just off the mark. My 10' 20' are normally spot on. However this has taken countless hours of experimentation to get use to and know my lenses.

I'd suggest you begin with the experimentation mode before doing anything else. The next step is to follow Pauls advice on shimming.

Regarding groundglass - I have one however I rarely use it and when I do it isn't for focusing rather I use it for filter placement. My thought on using a groundglass is that it's all but useless for me as it's just too small; I can see the use of a groundglass on a 4x5.

I thought the hardest thing I'd end up doing was critical focus when I made the move to technical camera shooting - I quickly learned that wasn't the case. My two biggest mistakes when I first started shooting was to remember to remove the lens cap and remembering to cock the shutter.

Again I don't have any experience with an Alpa or Hassy however I wanted to add my experiences as they relate to focusing.

Don

 

darr

Well-known member
Hey Jürgen,

I use the leather bellows with loupe on ground glass to focus after I compose using the Hasselblad magnifying hood. I find this works best for me. IMO, the bellows and loupe give an excellent view of the scene and is easy to use. I come from using a 4x5 for over 20 years, and I use a similar leather bellows and loupe on my Arca Swiss. I find this method to be the easiest to store and use. I shoot an Alpa Max with a 47mm.

Kind regards,
Darr
 

thomas

New member
I use a GG and a focussing hood (in my case Cambo, not Alpa).
I use the focusing hood without exception for composition. For focussing on the GG I use a 6x loupe.
However I am only focussing on the GG at relatively close distances (when the magnification of the motif in question is high enough).
For wider distances but not quite infinity I use a laser distometer (I also have taped marks for some distances on my lens).
For infinity… well I set the lens to infinity (slightly adjusted WRT to the aperture/DOF).
I agree with Don that you have to "learn" your lenses as there is still a lot to handle with feeling/experience.
I mostly shoot at f11 and f16… rarely at f8 and practically never at f5.6. I think for critical work with narrow DOF (i.e. large apertures) I would always tether…
 

PeterA

Well-known member
Not too difficult to estimate distance by looking at the scale between F8 -F11 eg


@F11 - I have acceptable focus on the 35mmSchneider digitar from about 1.5meters to infinity. The Alpa is used only for wide angle shooting either hand held or on tripod. At F8 - I get sharp focus from 1 meter to 3 meters.
I dont use any other Fstops as they are suboptimal.

I have tried shooting tethered in studio and yes one can get verified sharp focus using this method - but there are better tools for such work - like a Hasselblad. haven't bothered with a GG and Loupe as ( again) there are better systems with sliding backs available for this purpose - and I am not as patient as others and wary of dust etc in the whole procedure.

Makes sure you take the trouble to calibrate your back to adaptor via shims that come with your chosen adaptor when purchasing an Alpa - or get your dealer to do it - if they have a clue.
 

Mike M

New member
Hi Jurgen,

I usually only ever use two methods for focus. Either by estimation or by Ground Glass. I really Use the Ground Glass more for composition than for focus though and I use it with the newer small focus bellows from Alpa. This one is nice because it lets you look at the screen with both eyes or you can stick any focus loupe in it for magnification.

One thing i have noticed about some of the "bright screens" is that they are very bright but very difficult to actually focus with. They can tend to make things appear sharp even when they are not. Similar to a glossy screened monitor. If you can get a chance to try the Alpa Pro Grid Screen I would strongly recommend it. I bet it would resolve your problems. It is not as bright as some but it is very easy to focus with. It also has nearly no grain in the glass so you can use a fairly high powered magnifier to make sure you are in focus at a critical focus point.

Also, make sure to focus on the Ground Glass with the lens wide open rather than at the shooting aperture. Otherwise you will be trying to focus through depth of field which is almost impossible.

It has always been my experience that wider lenses are harder to focus on a ground glass than long ones. Long lenses will pop in and out of focus more distinctly. On the other hand, wide lenses will most often end up being shot at infinity ( at least in my experience). Have you done a shim adjustment to your back. This can also greatly affect your results. I know some people think this is BS but I have seen many times where this makes a huge difference.

I hope some of this will help.

Best,
Paul
Thanks for the run-down on the pro grid screen and the new bellows. I was originally thinking of getting the bellows with attached loupe but never considered that it would be difficult to use both eyes. It sounds like the new bellows would be much better for my purposes.

Also, I wanted to say thanks for the videos about shimming. Those particular videos are what got me interested in Alpa again. I had seen a lot of pictures taken by Alpas on the web and something looked "off"...Just couldn't quite figure it out. It made me not trust the system. But as soon as I saw your videos with the misaligned sensor then I knew exactly what was bothering me before and how to fix it. So anyway, it renewed my interest in Alpa.


jurgen...
the best is simply to practice on guessed focusing. really, it is not very difficult.
one trick...
a normal-size person needs two steps of normal easy-walk to do 1 meter walk. or really easy walk = 1 foot if u prefer feet.
it most "accuracte" to imagine that u "walk" from camera position to the object in focus. this is good even if u have a good eye mesurement of the distance, because in many cases, the surrounding may be missliding... with doing imaginative steps u get enough accuracy even for medium size distances... and it is very quick to do.
the "accuracy" in this way is no issue for wide lens, medium distances, optimum aprture
Thanks for reminding me of this method. I haven't done that since I was a teenager and totally forgot about it. What was old is new again for me :)
 

etrump

Well-known member
Jurgen,

The best advice I can give is to learn hyperfocal focusing. It sounds much more difficult than it is. Once you learn it, you will wonder what took you so long.

For example, if I am shooting with my 35mm, I set f11 and the hyperfocal focus distance for that aperture and start shooting. As long as no part of the scene is closer than 4' Everything is in focus. I just keep composing and shooting without concern for the focal point. If I have a foreground element that is closer than half the hyper focal distance I either stop down or take two exposures and stack them.

At f11 I am at the sweet spot for all my glass. The only time I stop down is if I need it more DOF but even then it is strictly by the numbers. I use PhotoCalc on my iPhone to calculate the focusing distances and it has been very accurate for me.

I have a laser distance finder and small tape measure for more critical work but hardly ever have to use them.

An important point is that you have to test your kit. On the cambo and 645 kits I find i have to adjust two stops from the scale on the lens with my p65. Doug who is tech support for capture integration explained why but I don't really understand it. I just know at f11 I set the hyper focal scale to f5.6, at f16 set it to f8 and it works. I know it has something to do with the resolution of the back but haven't really caught on to why the scale on the lens is off.
 

tjv

Active member
I'm enjoying this thread, even if it is basic technical info. What would make it better though is pictures!

I'm interested in seeing how practical the Alpa / Cambo / Horseman tech camera is in everyday use, put to various tasks.
 

jotloob

Subscriber Member
Thank you all for your valuable feedback and postings .

A little bit to my photographic background .
I am working with HASSELBLAD cameras and an SWC for more than 20 years and with an ARCA SWISS 4x5 field camera for more
than 12 years now .
Using all available accessories for proper focusing for both camera systems , including the hyper focal method for the SWC , I obtained the desired sharpness in most cases . If not , I found , that I did something wrong . But that was , when I was still shooting with film .

Now , I have taken the plunge into digital for MF since the CFV-16 is on the market .
The desire for real WA digital photography made me end up with an ALPA12SWA + a CFV-39 + a RODENSTOCK DIGARON-S 4,5/28mm about half a year ago .
I also got a RODENSTOCK APO-GRANDAGON 45mm + a SUPER ANGULON XL 72mm adapted to use with the ALPA .

The digital back adapter is shimmed by an ALPA technician to perfection and I use the ALPA , up to now , only from a tripod and for WA lenses .

For focusing , I currently use the HASSELBLAD SWC screen adapter (split screen ACUTE MATTE) + HM2 or RMfx viewer or a little RF from chinese manufacturer FOTOMAN .
I am not very happy with the HASSELBLAD screen adapter solution , and therefore will have a look to the ALPA GG + loupe solution .
But it is very expensive .

The distance scale of the DIGARON-S 28mm lens , for example , just shows
for longer distances 5m and the next is infinity .
Between these two positions is only very little space , and I find it very difficult to transfer an estimated or measured value to that scale , if the distance is within that range . It is simply estimation as well .

On the other side , I found , that focusing for a digital MF device is much more critical than for film .

Therefore , you might now understand , why I asked :
HOW DO YOU FOCUS WITH YOUR ALPA .

Here an example :
View attachment 32219

The bricks of the building are sharp , while the tiled roof of the little "tower" on the left is tack sharp .
The difference in distance will be about 2-3meters .
I used aperture f16 and according to the hyper focal method , all objects are within the DOF .
Should the tiles and bricks be of the same sharpness ? ? ?
The image is taken with the 4,5/28 DIGARON-S .

Here an example taken with the APO-GRANDAGON 4,5/45mm .
(even not beeing a "digital" lens , that lens is superb)
The focus is on the grey bricks in the middle of the modern building and turns out to be tack sharp , but the foreground is not as sharp , although within DOF .

View attachment 32220

What is your experience ? ? ?

Best regards . Jürgen
 

jotloob

Subscriber Member
Jurgen,

The best advice I can give is to learn hyperfocal focusing. It sounds much more difficult than it is. Once you learn it, you will wonder what took you so long.

For example, if I am shooting with my 35mm, I set f11 and the hyperfocal focus distance for that aperture and start shooting. As long as no part of the scene is closer than 4' Everything is in focus. I just keep composing and shooting without concern for the focal point. If I have a foreground element that is closer than half the hyper focal distance I either stop down or take two exposures and stack them.

At f11 I am at the sweet spot for all my glass. The only time I stop down is if I need it more DOF but even then it is strictly by the numbers. I use PhotoCalc on my iPhone to calculate the focusing distances and it has been very accurate for me.

I have a laser distance finder and small tape measure for more critical work but hardly ever have to use them.

An important point is that you have to test your kit. On the cambo and 645 kits I find i have to adjust two stops from the scale on the lens with my p65. Doug who is tech support for capture integration explained why but I don't really understand it. I just know at f11 I set the hyper focal scale to f5.6, at f16 set it to f8 and it works. I know it has something to do with the resolution of the back but haven't really caught on to why the scale on the lens is off.

Ed

Honestly , I must say , I try to understand your posting , but up to now , I have not got the clue about the sweet point and f-steps and why the scale is off .
Might be Doug can give more hints or an explanation .

Jürgen
 

jlm

Workshop Member
jotloob:

"sweet spot" means the aperture at which the lens perfoms best; for him it is f11
the way i would use hyperfocal focusing is to set the farthest distance of interest in the subject to the hyperfocal mark for the next smaller f-stop you are using.

next smaller because of the tighter demands placed on the digital image compared to film.
 

jotloob

Subscriber Member
jotloob:

"sweet spot" means the aperture at which the lens perfoms best; for him it is f11
the way i would use hyperfocal focusing is to set the farthest distance of interest in the subject to the hyperfocal mark for the next smaller f-stop you are using.

next smaller because of the tighter demands placed on the digital image compared to film.

Ahhhh , John

The sweet point is the recommended working f-stop (as per definition of the RODENSTOCK documentation) .
Yes , that is understood now , as well as adjusting the distance ring to the next smaller f-stop .

But , why for two stops ? ? ?

That all helps me very much , because I really thought , that the use of WA lenses with digital backs need a 100% focusing .

Thank you all a lot .
I wish Dough would explain his two f-stop adjustment a bit in more detail .

My home is my castle .

View attachment 32221

Regards . Jürgen
 

jlm

Workshop Member
oops! the f stop used for hyperfocal should be the next larger aperture, next smaller f-number, than you are using for the exposure
 

PeterA

Well-known member
I'm enjoying this thread, even if it is basic technical info. What would make it better though is pictures!

I'm interested in seeing how practical the Alpa / Cambo / Horseman tech camera is in everyday use, put to various tasks.
Hyperfocal focusing - just make use of the extreme depth of field the Schneider and Rodenstocks deliver between F8-11 their sweet spots..
this one example of a snap using es than 1 meter to 10 meters all acceptable focus



street snap hand behind my back as I walked by the scene - this time lens preset at 4 meters @ f8..



the 12W series so easy to handhold at insanely low shutter speeds...
 

steflaurent974

Active member
I use the ALPA with the SK 24mm and 47mmXL apoDigitar. In 95% of the cases, I am working at F11, hyperfocal and when a closer subject is in the frame then it's guess estimation !
I am working with a P25+ wich may be more tolerant than the 39MP backs, that I don't know ; but the focus achieved with these methods is enough good for me.
 

tjv

Active member
Thank you all for your valuable feedback and postings .

A little bit to my photographic background .
I am working with HASSELBLAD cameras and an SWC for more than 20 years and with an ARCA SWISS 4x5 field camera for more
than 12 years now .
Using all available accessories for proper focusing for both camera systems , including the hyper focal method for the SWC , I obtained the desired sharpness in most cases . If not , I found , that I did something wrong . But that was , when I was still shooting with film .

Now , I have taken the plunge into digital for MF since the CFV-16 is on the market .
The desire for real WA digital photography made me end up with an ALPA12SWA + a CFV-39 + a RODENSTOCK DIGARON-S 4,5/28mm about half a year ago .
I also got a RODENSTOCK APO-GRANDAGON 45mm + a SUPER ANGULON XL 72mm adapted to use with the ALPA .

The digital back adapter is shimmed by an ALPA technician to perfection and I use the ALPA , up to now , only from a tripod and for WA lenses .

For focusing , I currently use the HASSELBLAD SWC screen adapter (split screen ACUTE MATTE) + HM2 or RMfx viewer or a little RF from chinese manufacturer FOTOMAN .
I am not very happy with the HASSELBLAD screen adapter solution , and therefore will have a look to the ALPA GG + loupe solution .
But it is very expensive .

The distance scale of the DIGARON-S 28mm lens , for example , just shows
for longer distances 5m and the next is infinity .
Between these two positions is only very little space , and I find it very difficult to transfer an estimated or measured value to that scale , if the distance is within that range . It is simply estimation as well .

On the other side , I found , that focusing for a digital MF device is much more critical than for film .

Therefore , you might now understand , why I asked :
HOW DO YOU FOCUS WITH YOUR ALPA .

Here an example :
View attachment 32219

The bricks of the building are sharp , while the tiled roof of the little "tower" on the left is tack sharp .
The difference in distance will be about 2-3meters .
I used aperture f16 and according to the hyper focal method , all objects are within the DOF .
Should the tiles and bricks be of the same sharpness ? ? ?
The image is taken with the 4,5/28 DIGARON-S .

Here an example taken with the APO-GRANDAGON 4,5/45mm .
(even not beeing a "digital" lens , that lens is superb)
The focus is on the grey bricks in the middle of the modern building and turns out to be tack sharp , but the foreground is not as sharp , although within DOF .

View attachment 32220

What is your experience ? ? ?

Best regards . Jürgen
It's so hard to see what you are talking about on such low screen res jpgs, but I take your word for it. Maybe you could post some crops?

As an aside, have you personally rested the calibration of the back re the shimming? Also, could it be possible that the Hasselblad screen you're using is not 100% in spec with the entire system? Either way, I'm no expert. I have never shot with an Alpa but have been lusting after your exact setup for quite some time!
 
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