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Old Apr 17, 2006, 12:45 AM   #1
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Hi everyone! This is my first post.

I'm kinda curious. Why is digital photography done in the same manner as conventional photography and is inhibited by the same limitations that a conventional film camera comes with?

For a film camera, a certain amount of light must hit a frame of film for a specific amount of time for the a chemical reation to happen on the celluloid for an exposure to come out properly. Since digital cameras do not have the physical/chemical limitations of film, I'm kinda wondering why the image sensor can't do more, take some things like aperture and shutter spd out of the equation. I know that statement is probabley heretical to photography buffs, hehe.

Heres my neat concept for a future digicam. When the shutter button is pressed, have the sensor record EVERYTHING all at once. Every aperature, every point of focus, every shutter spd. And then have a program be able to adjust each parameter with a bunch of sliders. And let you designate where the focus is going to be. Some sort of a dynamic image if you will
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Old Apr 17, 2006, 1:44 AM   #2
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It's physical/electrical.

Actually CCD's do have "electronic shutter".

But aperture /shutter speeds can't be removed, because if there isn' enough light hitting CCD there isn't enough data to get image, or if there's too much light everything overexposed.
And there's thing called as bracketing when camera takes multiple shots with differing exposure.

Also camera which records also angle of light rays hitting photosites in addition to luminance has been tried but I think resolution of that was enough for postage stamp. And despite of low resolution it has to record very big amount amount of data which requires very heavy processing to get final picture, including selecting focusing distance so in that aspect it wouldn't be very "digital" considering speed you can see results.
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Old Apr 17, 2006, 6:54 AM   #3
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Photography is all about counting photons at a certain point or pixel. In the old analog photography that was done in a chemical way and in the new digital photography this is done with semiconductors. The same rules of optics apply with one modification: the electronic sensor is usually smaller than the chemical sensor, i.e. film, though for a DSLR the sensor has about half the size of 35mm film.
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Old Apr 17, 2006, 7:20 AM   #4
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There are, indeed, plenty of people thinking outside the box as you suggest.

One area I personally have hope for is the "plenoptic system" (read from the initial releases last year here: https://graphics.stanford.edu/papers/lfcamera/or Google for more info and images ... be sure to look at their videos at http://graphics.stanford.edu/papers/lfcamera/refocus/).

The full abstract states it is a modified digital camera and sensorthat "samples the 4D light field on its sensor in a single photographic exposure. This is achieved by inserting a microlens array between the sensor and main lens, creating a plenoptic camera. ... To the photographer, the plenoptic camera operates exactly like an ordinary hand-held camera." More: http://graphics.stanford.edu/papers/...era-150dpi.pdf

The end result is a digital image that is in focus at ALL distances, near and far, which can then be manipulated in the computer to perfect the end result, layer of focus, etc.
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Old Apr 17, 2006, 9:02 AM   #5
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The Stanford multi focus camera is an example of a trade-off of resolution against focus. The same kind of trade-off could be made with exposure against resolution byinterspersing sensors with different sensitivity. So what you are suggesting could be done, albeit at low resolution with today's technology. With sensors begining to out perform lenes, I expect someone to start using the "extra" sensors in that way.

So if you are willing to give up resolution, what you are suggesting can be done. A key "word" to remember is TANSTAFL - There Ain't No Such Thing As a Free Lunch.
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Old Apr 17, 2006, 10:59 AM   #6
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I'm kinda curious. Why is digital photography done in the same manner as conventional photography and is inhibited by the same limitations that a conventional film camera comes with?

The simplest explaination is that the cameras and lenses have not changed, we simply put an electrical sensor where the film belongs, and a computer to translate the signal into a digital file. The mechanics of photography have not changed.

In medium format, you actually do use the same camera as before but buy a "digital back" to use in place of film. Digital SLR's are very similar to 35mm SLR's. The compact cameras look more different, but it all still works about the same.
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Old Apr 18, 2006, 8:28 PM   #7
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Thanks for all taking the time to respond, folks!

The reason I decided to pop the question is that I took several photography courses in school and of course we had to use manual cameras. After the photographer adjusts the focus, all the camera asks of you is "give me enough light!" And then the little indicator turns green, and click.

I bought a Canon S2 recently and have been playing with the manual controls and kinda wished the camera would do some of the thinking for me. Exposure levels, white balance, etc. Of course, the auto modes don't give perfect results.

Photoshop can only do so much to touch up a picture. I made an analogy to audio recording. I enjoy multitrack audio recording and a lot of outboard effects are required during mixing to get a good sound when playing back on your stereo. When you record, you can either add effects (the most common to consumers being an equalizer) to a track afterwards or, if desirable, you can have the track recorded with the effect active on the way in, so a vocal for example gets recorded to tape (nowadays, hard drive) already equalized. Of course, with the latter the equalization is somewhat irreversible. Same with photoshop.


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