Hello,
I really love the idea of the DSLR scanner. But, I'm really struggling with something ...
Film Grain and Aliasing:
http://www.photoscientia.co.uk/Grain.htm
The above link pretty much sums up the issues I am having with my own DSLR scanner. Thus, the idea of using a DSLR scanner sounds great at first. But, this method seems to suffer from the problem of scanner aliasing. And to be honest, I'm not sure what to do about it. And, I'm also still trying to understand it...so bare with me.
From that perspective, I can see the attraction to drum scans for the best of scans. However, my hope, was that a DSLR scanner could at the very least match a drum scanner if not surpass it. Why? Drum scanners are highly expensive (easily a few thousands dollars), bulky, have fewer companies producing them today then in years past, and all around not cost effective for the average Joe. Not all film merits that of being drummed scanned, but when I do, I'd like to be able to have them done in a feasible way. And this is where, I thought, the DSLR scanner would come in and help the average person out. For me, I already have a DSLR and lenses....and that's why I'm testing the waters with it.
What makes the drum scanner most effective over that of a flat bad scanner, DSLR scanner, or otherwise is the PMT and the ability to control the aperture. This is discussed here:
http://www.karimsahai.com/2010/08/sc...-drum-scanner/
Drum scanners fulfill the same role as any other film scanning device, while relying on an entirely different technology: photomultipliers, or PMTs. In essence, PMTs are extremely sensitive particle detectors tuned to respond to uv, infrared and visible light (photons). The principles at the heart of a drum scanner were derived from research in the field of nuclear physics, in which scientists observe and measure the results and effects of particle collisions. In the case of drum scanners, several photomultipliers are combined to offer the very best scanning device for photographic film. PMTs act as photon collectors and bypass the methodology used in CCD scanners which is to amplify an electrical current. Drum scanners do not suffer from the CCD side-effects that we know: noise & limited dynamic range, specially in shadow areas of your film. The ability for drum scanners to vary their built-in aperture to match the grain size of the film you’re scanning; their ability to scan all film formats including very large exotic sizes and their ability to offer superior batch scanning capability (you can fit a LOT of images on a single drum. Some drum scanners are sold with multiple drums) make them the very best scanner there exists for quality-conscious photographers who want to capture all the range that is encapsulated in their film, at very high resolution.
This ability of the drum scanner to adjust the aperture to match that of film grain seems to be the overriding advantage that it would have over flat bed scanners, DSLR scanners, or otherwise.
My question out there who may know this better than I, is if there is a way for DSLR scanners to overcome the problem of scanner film grain aliasing that drum scanners seem to have the ability to overcome? Using a DSLR scanner, is there any techniques that can be employed that would help to minimize the scanner aliasing issue and therefore pull out more of the picture/image from the film?
Wiki has a section on this called "Grain effect with film and digital":
http://en.wikipedia.org/wiki/Film_grain
In there are two images:
http://en.wikipedia.org/wiki/File:Ma...Norway1991.jpg
http://en.wikipedia.org/wiki/File:Ma...y1991Grain.jpg
The zoomed in detailed one is pretty much the result of what 'I see' in my own images scanning with the DSLR scanner. You get what looks like colorful noise in the image with a lot of grain. Again, this is what I also see and suffer from.
Apparently, if a drum scanner were used, it would be able to pull out more of the image from the picture than the grain. But, I have yet to see some comparisons of this.
For example, controlling the aperture on a drum scanner to match the film grain, what would the resulting image look like over that of a slide/negative scanned by a flat bad or a DSLR scanner?
Anyway, this is what I am struggling with: how to overcome the scanner aliasing issue that drum scanners seem to have over DSLR scanners? Or, if there are any techniques that DSRL scanner users can apply to effectively match the same quality that a drum scanner can perform? Or, for all I know, DSLR scanners by their very nature just can't compete with the drum scanner regardless of how many megapixels the DSLR scanner has? For example, can I conclude that even a Hasalblad H5D-60 with a 60 Mpixels (8956 x 6708) sensor and a good lens could not pull out as much detail from film than that of a drum scanner due to scanner aliasing issues?
Here's a blog that touts the ability of the DSLR scanner:
http://jamiemphoto.com/blog/2013/12/...t-film-scanner
The title is, ""Yes, Your DSLR Really Is the Best Film Scanner". Hmm, but is a DSLR really the best film scanner? I'm not entirely sure if DSLR scanners suffer from scanner aliasing issues as that is what I have run into as my problem with DSLR scanning approach. Or, maybe the author of this article is applying techniques that are well know by others to overcome this but that I am not aware of. If so, I'd love to hear what those techniques are.
Thoughts?
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