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Old Jul 30, 2002, 7:06 PM   #1
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Default digital vs SLR

I would like to know what the image size in Megapixels which will give the same image quality as an SLR film camera.
Issues such as S/N and Resolution obviously have to be considered.
I heard somewhere that 27 Megapixels are required to generate the same image quality as an SLR Film . Any comments?

Thank you
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Old Jul 30, 2002, 7:48 PM   #2
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I presume you mean a 35mm SLR as opposed to a 6x6cm Hassleblad or a 6x7cm Mamiya SLR.

That said it's all in how you define quality. A grid of pixels is not the same as random grain structure in chemical film dye layers. Does equal quality mean two prints that don't display jagged pixels or grain? Not hard to do that all depending on your print device. Does equal quality mean no difference in an enlargement that shows grain in film? Much harder to duplicate that digitally. Is your standard something sterile like lines of resolution or subjective image qualities that may be harder to define.


Define your terms and you'll be on the track to finding your answer.
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Old Jul 30, 2002, 7:51 PM   #3
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thats a hotly debated subject. when i started shooting with digital the debate started. i use kodachrome 25/64 and deal with kodak. now this info is old and again debated. it was put to me at approx 25 mega pixal to come anywhere close to that of the information on a k64 image. when i scan a slide on a nikon coolscan 4000d. each scan is approx 65-68 MB. now the question is what can be resolved by the human eye and judged acceptable
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Old Aug 1, 2002, 1:38 AM   #4
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sjms is giving you the correct answer ... but let me add to it. Pixels can also be "empty" If you have more opixels then are needed to create an 8X10, then thos epixels are wasted. Another way of looking at this is find out from a phor mag what the resolution of a good camera lens is. A pixel counht better than that will not do you any good.

Bottom line, it seem form what I have seen that at full frame, the coolpix 5700 probably will produce images at 8X10 that are indistinguisheable from film.

That said, there are other issues. Film is inferior to pixels because you have (esp in color) very little control over contast and color balance. So imge qulaity with pixels may be superio. Even though a film image can be digitized, the ability of color film to "hold" cotrast is very limited compared to pixels so some information may be lost with film! Film i vastly superior to pixels in fine detail. Even though this may be below the resolution you would use in a full from 8X10, there are said to be subtle effects of fine deatail and of course the effects get very real at higher mags.

My guess is that for all practicila purposed digital; images made with a 5mpix camera will be superior to film images unless the image is enlarged beyound 11X14.
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Old Aug 3, 2002, 7:08 AM   #5
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Default Digita vs SLR

Padeye
Sorry, your post is not very convincing...
There are objective technical evaluation criteria like:
S/N
Resolution
which you can measure...this kind of stuff has been around for decades

Steve
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Old Aug 3, 2002, 9:05 AM   #6
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Sorry, but you need to re read what I wrote.

First, resolution ... pixel count or grain density ... greater than what will be visible is wasted. So, while film is still "better" than chips, at %Mpix, the adavanatge is meaningless at *X10.

Second, dynamic range. Color film, esp slides, has a very short dynamic range and lacks any of the compensation possible with digital. Uisng the zone system, one needs to be very, very careful in color not to exceed the range of the film. This is not as great a problem in digital.

Third, film/paper are essentially limited to one correct exposure because burnig and dodging run afoul of the density response curves for the different colors.

So, as I said, for limited enlargement size, all things being equla ... pixels are better than film,
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Old Aug 3, 2002, 10:06 AM   #7
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Default Digital Cam. vs film

Sorry. I was not refering to your post...but the one before..Padeye...
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Old Aug 10, 2002, 11:21 AM   #8
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"Pixels can also be "empty" If you have more opixels then are needed to create an 8X10, then thos epixels are wasted."


i beg to differ about those wasted. in analog they all are used. they increase the perception capability of the image to the eye. it's the equivelent of analog recording in sound. ambiance is necessary. the first digital recording were inadequate due to the lack of ambiance. it's the infinite filler between the 0/1 that gives a photo done on film that exquisite quality and depth. to produce a good image is as much art as science. fixing it in the mix is more limited at this time in digital then in analog though it is improving. we as the individual image maker must decide how much is enough.

on the 11x14 statemement i'll agree. that is about the limit. the darned things do make a reasonable 8x10. if we could just get the camera, monitor, and printer to truely see the same information and not "color" it. icc profiles and products need to work for that sort of precision.

[Edited on 8-10-2002 by sjms]

[Edited on 8-10-2002 by sjms]
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Old Aug 11, 2002, 7:17 AM   #9
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I have a Fuji S2pro & an F80. I must say I find the film has the edge. Side by Side in terms which is best the films are better!

Fuji produces the smallest grain films. The negatives resolution is around 7000-8000ppi depending on who you figure you use.

Having said that this is not the only factor. Otherwise why have medium format carmeras not taken over?

35mm is very sucessful because you can get many lens and carry them about! Films have improved over the last 5 years and made 35mm SLR quality good enough for nearly all pro use.

Digital has not got that far yet though it getting there fast, it;s good enough for most of uses. With my F80 costing $450 and the S2pro cost $2400, I guess you cant say cost effective yet!

Having said that I can product final prints same day with the digital adjustments I want.
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Old Aug 20, 2002, 1:55 PM   #10
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Being a serious amateur for over 30 years, though admittadly not technically talented, I have been amused and chagrined at arguments about lenses, film, and now digital images. There is no end to the technical arguments.

My digital images look pretty darn good to me, whatever the technical comparisons. It's technique and creative talent I lack, not technically better equipment.
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