Lars
Active member
Stefan -@ lars
I am not an Astronomy specialist, but these could give you the full details about optical finders, resolution of the human eye and human viewing physiognomy. But it is already quite enlighting to see what the real resoltion can be at max (exerpt from Wikipedia/eye):
"Visual acuity
Visual acuity, or resolving power, is "the ability to distinguish fine detail" and is the property of cones.It is often measured in cycles per degree (CPD), which measures an angular resolution, or how much an eye can differentiate one object from another in terms of visual angles. Resolution in CPD can be measured by bar charts of different numbers of white/black stripe cycles. For example, if each pattern is 1.75 cm wide and is placed at 1 m distance from the eye, it will subtend an angle of 1 degree, so the number of white/black bar pairs on the pattern will be a measure of the cycles per degree of that pattern. The highest such number that the eye can resolve as stripes, or distinguish from a gray block, is then the measurement of visual acuity of the eye.
For a human eye with excellent acuity, the maximum theoretical resolution is 50 CPD(1.2 arcminute per line pair, or a 0.35 mm line pair, at 1 m). A rat can resolve only about 1 to 2 CPD. A horse has higher acuity through most of the visual field of its eyes than a human has, but does not match the high acuity of the human eye's central fovea region.
Spherical aberration limits the resolution of a 7 mm pupil to about 3 arcminutes per line pair. At a pupil diameter of 3 mm, the spherical aberration is greatly reduced, resulting in an improved resolution of approximately 1.7 arcminutes per line pair.[33] A resolution of 2 arcminutes per line pair, equivalent to a 1 arcminute gap in an optotype, corresponds to 20/20 (normal vision) in humans....."
Now what does this tell ?
lets assume the maximum resolution of an optical finder with 1m virtual distance is 3000 linepairs - if you are young, have perfect vision and the scene is bright.
As finders are quite often working at a virtual distance shorter than 1 m this number is reduced further. Second the optimum resolution is also only reached if the light on the subject/Image is bright -the darker the scene becomes resolution of the eye dwindles away.
A resolution of 1024pixel on a viewing distance (I don´t know the simulated /real okular focal lenght and size of the Sony finder- so that are only estimations)) of maybe 50 cm will equal 500 x 2 linepairs (compared to the 1 m resolution) which is already matching your vision at dim light and open pupil. When your vision is less than perfect and it gets even darker this resolution already is BETTER than your eye. And finally you can lighten up the scene electronically and automatic + you can zoom electronically any time..........
So I guess this finder already is a gamechanger having higher resolution than any comparable finder on the (consumer)market - the Arri Alexa has 1280 X 768 pixels.
regards
Stefan
That's just inconsistent with reality. A logical conclusion from your estimate above would be that full HD resolution on a display or TV is a waste of pixels - not to mention a 24 megapixel camera, or any prints from it, since nobody would be able to see more than one megapixel. Or perhaps the whole cinematography industry is mistaken in its quest for 4K digital resolution?
Clearly that's not true. For example, I'm sitting here with a 1920x1200 pixel 24" display at 60 cm distance, and I can clearly see individual pixels and jagged diagonal lines. It's not even close to what my eyes can resolve.
And when I look at a well-exposed 8x10 transparency on my light table, taking in the full 200+ megapixels of detail (an experience that is impossible in the digital realm, short of producing 6ft high-res prints, which according to your estimate is a complete waste anyway), I am just imagining the extreme detail? Clearly that's not the case, as you well know from your days shooting 8x10.
-Lars