DSLR Scanning - Signal / Noise
Hello,
How many images can i stitch from a 4x5 negative - before signal/noise ratio drops significantly?
Subject to DOF restrictions would seem I can do a fair amount, however expect at some point the DSLR images dont get any better at picking up details
Cheers
Re: DSLR Scanning - Signal / Noise
I think you are referring to the number of exposures in the mosaic for which the limit would be resolution of the grains or dye clouds. Those are the details. However there can be actual noise in the high density areas that might be overcome via multiple exposures at each mosaic element such as in astrophotography.
Re: DSLR Scanning - Signal / Noise
I used to do 25 frames per 4x5 at 1x magnification. I found that going higher lead to better results on a high resolution test target, but it didn't lead to better results with regular negatives.
Re: DSLR Scanning - Signal / Noise
Check out this page: https://www.largeformatphotography.i...scanning/page4
I don't think many CMOS based camera capture systems will have a significant amount of noise, especially those that eliminate the debayering altogether.
Re: DSLR Scanning - Signal / Noise
I never found noise to be a problem, even with quite dense negatives. As sperdynamite points out, this should be even less of a problem with pixel-shift/averaging systems. Using HDR exposure blending increases the density range that can be captured, but my old D200 could already do about a stop more than an Epson scanner when scanning a Stouffer step wedge, and so it might only be called for in the most extreme cases.
Re: DSLR Scanning - Signal / Noise
Quote:
Originally Posted by
Peter De Smidt
my old D200.
Peter, out of curiosity, had you removed the AA filter from your D200 for scanning? FWIW, I'm mulling over a DSLR for scanning relatively big negatives (5x7) for fairly small prints, and was wondering if that's where the inflection point is (versus FF or "gross" megapixels) in terms of basic performance.
Re: DSLR Scanning - Signal / Noise
No, and I recommend a newer camera than the D200. Modern cameras have better dynamic range, as well as more resolution. A D600 or newer would be better. The best would be a pixel shifting mirrorless camera, especially one with electronic first curtain shutter to minimize vibration.
Re: DSLR Scanning - Signal / Noise
Sony mirrorless cameras 42 mp and greater (a7r ii, a7r iii and a7r iv) do not have AA filters. This is probably true of some other brands of high resolution FF cameras.
Sandy
Re: DSLR Scanning - Signal / Noise
I like and use the Panasonic S1R even though the Sony has a better sensor. The reason being that Panasonic has pretty great tethering software, a variety of shooting ratios (1:1, 4:3, 3:2), and the pixel shifted scans do not require an extra piece of software to open them in LR or ACR. IIRC the Sony files need proprietary Sony software. Not a huge deal but an extra step. Nothing can beat the Sony sensor though. The Panasonic comes close but it's not as high res.
Re: DSLR Scanning - Signal / Noise
CreationBear, if you're talking 5x7 prints from a 5x7 negative, then a 50-80mm enlarging lens + extension tube + most fairly recent cameras should work great. Honestly, at that size I bet my phone would work well. After this week of tests and grading, I'll give it a try.