Can your camera see better than you?

[daniel_taylor]

"So we need a 6.8MP camera but with real pixels not red blue green together, because we do not want the interpolation"

 

Why not? That's how the human eye works to.

[peter_smirnoff]

Thanks for the charts. I think the answer to the original question is: "No, current [consumer] cameras can't see better than humans".

 

Whetever.

[leonard_richmond7]

Wow, thanks Jochen. I took your image, doubled its size so that I wasn't limited by my monitor's pixels, then sharpened it. The 20/15 line is clearly readable. The 20/13 line is almost - the last letter O could be a C. The 20/10 line is almost - the last letter D can't be determined. Looking around on the internet, I think that qualifies for 20/10 "vision".

 

Of course, this was an underexposed jpeg. Would be nice to see what a properly exposed (I assume the paper was white) TIFF would blow up to be.

 

And you said "35mm lens wide open". The lens gets sharper if you close the aperture 2 or 3 stops. If the image gets any sharper, it will certainly be better than I can see.

[Jochen_S]

O.K. about the pic I posted: Well stopping down would be nice, but according to the 20ft distance and the limited power of built in flashes... I had to do it this way. - No I didn't mess up my workflow, I shot RAW, converted to TIF, and saved as big JPG for posting. I doubt I got many mistakes in. The Pentax 35mm f2.0 should be a quite good lens. We are looking at single pixels here so I doubt stopping down would gain significantly more information. By the way the 35mm is a rather long standart lens on my 6.something MP chip, so the math wizards are right, our actual consumer DSLRs see less than helthy eyes.

[mark_jacoby___raleigh__nc]

I prefer to use manual focus on my D100. But I wear eyeglasses.

 

I bought a real rubber eyecup for the camera and sometimes I take off the glasses, compose in the viewfinder and let the camera autofocus do it's work and in that case my camera does see better than these old eyes.

[leonard_richmond7]

<i>"35mm is a rather long standart lens on my 6.something MP chip,"</i>

<p>

The Pentax *istD sensor is 23.5 x 15.7 mm. So the mulitiplication factor is 1.53. So the 35mm lens is equivalent to 53.55mm in full frame (35mm film) format, about 7% longer than the "standard" 50mm lens (for full frame).

<p>

That's close enough - the picture wouldn't look much different.

<p>

20/20 is the average corrected vision. 20/15 is sharper than average. 20/10 is about the best that even the sharpest eyes can see.

<p>

So the majority of people, even wearing corrective contacts or glasses, cannot see quite as sharp as your 6 MP digital camera with a "normal" lens. The best eyes may be ever so slightly sharper.

<p>

Of course, your eye's resolution is much less away from the center of vision. Your camera/lens is MUCH sharper away from the center of the image than your eye is.

[yakov_fradkin]

One can't compare a human eye vs a still camera. Your eye is constantly moving collecting more details about the subject. A proper comparison is a human eye vs a video camera. Because of a rapid succession of frames, a moving picture device (eye, video camera) doesn't require all that high resolution that a still picture needs.

[rayfraser]

No matter how much you move your eye, I'll bet you can't see the 20/10 line any better. Even while driving at high speed, you still benefit by having 6-7 million cones giving you an ability to read signs. While your brain depends on some minor eye movement even while staring, an ability to read a distant sign is primarily dependent on number and sensitivity of light receptors. Also many digital camera's can take video - or at least several frames per second. The Canon PowerShot Pro1 can shoot 2.5 frames per second, but any advantage of merging information from multiple shots would diminish after just 2-3 frames and only 1 frame may be needed to clearly identify the 20/10 line.

 

I will concede I currently trust my 2 human eyes more than any manufactured sensor, but how many of us will be willing to allow electronic decisions by our cars based on cmos imagers? http://www.smalcamera.com/pressreleases/acm100.html

[vasilis]

You cannot easily replace human eyes to a camera for a variety of reasons. One of these, is that the human eyes (and most eyes in the animal kingdom) are logarithmic sensors. That is why your camera (which is linear) cannot see as good as you in bright sunlit scenes. But I have a question, is there anything like a logarithmic sensor or film?

[rayfraser]

For a 500 times extended dynamic range look at SMaL Technology

<a href="http://www.smalcamera.com">smallcamera.com</a>. For an amazing hacking effort on $20 dollar "Pure Digital" single use cameras which use SMaL imagers check out

<a href="http://www.linux-hacker.net/cgi-bin/UltraBoard/UltraBoard.pl?Action=ShowBoard&Board=cameras&Idle=&Sort=&Order=&Session=">linux-hacker cameras</a>.