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Can your camera see better than you?

Ray Fraser , Nov 10, 2004; 09:15 p.m.

My 1.3 Meg camera can barely see at 20/40. By that I mean when I take a picture of a standard eye chart from 20 feet with a standard lens (no zoom or telephoto) the lowest line that is readable is just one down from the top. Some Humans (7 million cones and 120 million rods) can clearly see the 20/10 line. Can a 9 megabyte digital camera "see" the 20/10 line? With a standard lens this would imply a cropped chart size of approximately 120x180 pixels. Please post a photo if you can demonstrate a 20/10 capability without any zooming.


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Ray Fraser , Nov 10, 2004; 09:38 p.m.

I can't seem to edit my original question. Too many years dealing with kilobytes, megabytes, gigabytes and terabytes - what I meant to type was "9 megapixel". Also 120x180 probably should be closer to 200x260.

Jeff Spirer , Nov 10, 2004; 09:49 p.m.

Why should a photograph replicate human eyesight? That's not what photography is about at all.

Michael Darnton , Nov 10, 2004; 10:11 p.m.

I don't happen to have a standard eyechart handy at the moment, for some reason (let me look. . . . no there's not one under the sofa, either) but yesterday I took delivery of my new Canon Powershot Pro1 (8mp) and where my Olympus E-10 (4mp) fell about even with 35mm/Tri-X, I think I've moved up to 35mm/Pan-X, or maybe even a bit better.

Jeff, maybe sharpness doesn't matter to you (how are things on the Lomo forum?), but for what I do with my camera, it's essential. There's more to photography that just what YOU do with it, believe it or not.

Jeff Spirer , Nov 10, 2004; 10:16 p.m.

If people comment that my photos are "sharp", I look to see what I did wrong. Photography transcends any specific technical parameter. If your job is photographing eyecharts, then it matters. Otherwise, it's just more technobabble from technoweenies rather than anything from photographers. I have yet to meet a photographer who spent any time photographing, printing, or framing eyecharts.

Brad - , Nov 10, 2004; 10:24 p.m.

Yeah, I buy all that, but how about having good bokeh?

Bill Mitchell , Nov 11, 2004; 12:46 a.m.

Good question, but what do you mean by a "standard lens?"

Beau Hooker , Nov 11, 2004; 08:32 a.m.

Hi Ray, Just a guess on my part, but I suspect that a 1.3 Mp camera might not have the best lens in the world. The quality of the lens you use can come into play more than the sheer number of megapixels in your camera. Best wishes . . .

Ray Fraser , Nov 11, 2004; 09:54 a.m.

To test your camera just print chart at - http://www.leftseat.com/pdffiles/eyed20.pdf, and take a picture from 20 feet away.

If you want only soft pictures with no sharp focus anywhere, replace your lens with a pinhole! Requiring an eye chart at 20 feet to be in focus (only a tiny portion of image) takes nothing away from ability to create artistic blur.

Mark Richards , Nov 11, 2004; 11:33 a.m.

If you put the best lens in the world in front of a 16 pixel digital sensor, you are not going to get very detailed pictures!

A good pair of (human) eyes can resolve X - I don't know what X is in absolute terms; you can talk about rods and cones etc., but our eyesight doesn't work in the way that lenses and digital sensors do.

A good lens can resolve Y - I can measure Y in absolute terms, but I have no idea how that compares to a decent pair of (human) eyes (X). The amount of Y that gets translated into film information or digital sensor information depends on the density of that medium. In the example above, nearly all of Y gets discarded because the sensor is only able to record 16 pixels of information.

A 1.3 megapixel camera simply doesn't have the ability to record all of the information that a decent lens can capture. I have an old (Fuji) 1.3 megapixel camera too; the fixed hyperfocal lens is probably ok (similar quality to a decent disposable 35mm camera probably), but the sensor is lousy.

A decent 6-8 megapixel DSLR is capable of recording most (if not all) of the useful information from a decent lens. I seen some posts here arguing that Canon's latest CMOS sensor (16.7 megapixels) is capable of recording more information than a decent lens can deliver.

Now, whether that is as good as or better than a decent pair of (human) eyes is anyone's guess. However, depending on your view of the whole film v digital carnival, it's as good as any other (35mm) film camera with a decent lens. If an 6-8 megapixel DSLR sensor cannot resolve see your 20/10 line, then I doubt that a 35mm sized piece of colour print/slide film can too.

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