Re: Does MF color slides scanning in 24 bit still make sense
Mike, you are certainly right on what you state about the intended purpose of DSLR captures versus PMT drum scans. However, I hope I'll be surprised in good with the results obtained with the DSLR arrangement. CMOS have evolved, as well as software, and together, with fully coated lenses designed for digital cameras, they master flare and glare quite well, provided the whole light funnel is treated with a non reflective paint, which is not always the case with those lenses adapters, or when a lens sits on a long extension tube. If certainly not on par with drum scans, those scans from 120 film and larger should be hopefully good enough for low to mid-range productions. There is no question that the Micro-Nikkor will capture the film grain if the lighting is directive enough. It's performances are close to the Apo-Rodagon D. Still, it's a retro-focus design and a Sony macro lens designed for the short captor distance could do theoretically even better (the old Leica's effect). The distance from the diffusing glass to the slide can be set a means to reproduce the PMT oil mounting effect, which really is a way to diffuse the light all around the film grain in order to minimize the sand paper effect in the clear parts, such as the sky, and of wiping small scratches and blemishes away by making the rough surface more translucent. I did once some comparison scans when I worked with a drum scanner (a mid range one), wet and dry, and as far as super fine grain films are concerned, the gain was there when peeping at pixels, but at sight distance it was anecdotal. But the trouble of wet mounting is considerable. I thought it was better to scan dry, not to soak my precious slides into gels and solvents that might alter their life span. So, yes the process needs to be mastered and I am just supposing, but I'm expecting results that will please. Kind regards Paul Schilliger
CMOS have evolved, as well as software, and together, with fully coated lenses designed for digital cameras, they master flare and glare quite well
To 11 stops linearity, if the lenses and sensor are sterile clean, and camera chamber does not bring flare like some D750 Nikons do. -- Best regards, Iliah Borg LibRaw, LLC www.libraw.org www.rawdigger.com www.fastrawviewer.com
Nice detail and useful tip. How many f-stops would correspond to a density of D0 to D4.2, which is the number of high-end scanners if I recall? Kind regards Paul Schilliger Iliah Borg wrote on 18.01.16 19:54:
CMOS have evolved, as well as software, and together, with fully coated lenses designed for digital cameras, they master flare and glare quite well To 11 stops linearity, if the lenses and sensor are sterile clean, and camera chamber does not bring flare like some D750 Nikons do.
-- Best regards, Iliah Borg LibRaw, LLC www.libraw.org www.rawdigger.com www.fastrawviewer.com
4.2D corresponds to 4.2*log2(10) = 14 stops. On Jan 18, 2016, at 2:07 PM, Paul Schilliger wrote:
Nice detail and useful tip. How many f-stops would correspond to a density of D0 to D4.2, which is the number of high-end scanners if I recall?
Kind regards Paul Schilliger
Iliah Borg wrote on 18.01.16 19:54:
CMOS have evolved, as well as software, and together, with fully coated lenses designed for digital cameras, they master flare and glare quite well To 11 stops linearity, if the lenses and sensor are sterile clean, and camera chamber does not bring flare like some D750 Nikons do.
-- Best regards, Iliah Borg LibRaw, LLC www.libraw.org www.rawdigger.com www.fastrawviewer.com
Wow! But I think, even the black crushed shadows of Velvia aren't that deep. A Tango scanner doesn't boast that number and it's a reference. For normally exposed slides, the useful D-Max is probably around 3.0D. Iliah Borg wrote on 18.01.16 20:15:
4.2D corresponds to 4.2*log2(10) = 14 stops.
On Jan 18, 2016, at 2:07 PM, Paul Schilliger wrote:
Nice detail and useful tip. How many f-stops would correspond to a density of D0 to D4.2, which is the number of high-end scanners if I recall?
Kind regards Paul Schilliger
Iliah Borg wrote on 18.01.16 19:54:
CMOS have evolved, as well as software, and together, with fully coated lenses designed for digital cameras, they master flare and glare quite well To 11 stops linearity, if the lenses and sensor are sterile clean, and camera chamber does not bring flare like some D750 Nikons do. -- Best regards, Iliah Borg LibRaw, LLC www.libraw.org www.rawdigger.com www.fastrawviewer.com
On 18 Jan 2016, at 18:47, Paul Schilliger <pschilliger@sunrise.ch> wrote:
I did once some comparison scans when I worked with a drum scanner (a mid range one), wet and dry, and as far as super fine grain films are concerned, the gain was there when peeping at pixels, but at sight distance it was anecdotal. But the trouble of wet mounting is considerable. I thought it was better to scan dry, not to soak my precious slides into gels and solvents that might alter their life span. So, yes the process needs to be mastered and I am just supposing, but I'm expecting results that will please.
Oil mounting isn’t about reducing grain — you do that on a drum by opening the aperture manually and/or adjusting the focus point :) You oil mount to stop light scattering when it hits the uneven (and scratched) surfaces of the film. Reducing scatter as light passes through the film means you get more contrast and more detail. It also gives you a very clean scan with no clean up required. Also, oil and film cleaner don’t “soak” film — water is far more penetrating. -- Martin Orpen Idea Digital Imaging Ltd
participants (3)
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Iliah Borg
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Martin Orpen
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Paul Schilliger