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ShannonG
27-Oct-2015, 08:45
here is a diagram made for consistency for my set up when i copy my darkroom prints to go digital for the internet.the lighting kit is a Speedatron with large diffusion panels.I do a lot of copying of my prints and this set up seems to work best.The diffusion panels eliminates the glare on glossy prints. 141473

Nicolasllasera
27-Oct-2015, 08:56
Thanks for sharing. Im about to start doing something similar and your setup will help a lot.

John Olsen
27-Oct-2015, 09:21
here is a diagram made for consistency for my set up when i copy my darkroom prints to go digital for the internet.the lighting kit is a Speedatron with large diffusion panels.I do a lot of copying of my prints and this set up seems to work best.The diffusion panels eliminates the glare on glossy prints. 141473
Obviously, this works for you, but the diffusers are limiting the contrast you can achieve. You've already got a polarizer on the camera; however, the lights themselves should also have polarizers. Ditch the diffusion panels and get a large polarizer sheet for one Speedo head on each side. Hang the sheets with the polarization arrow the same for both sheets. My old Roscoe polarizers work best with the arrows vertical when the lights are as you have. (Other manufacturers may have the polarization marked differently.) Then use the modeling lights to adjust the polarizer on the camera for maximum contrast. Use barn doors on the lights to limit stray light bouncing around the room and hang dark cloth on the wall behind, again to limit stray bounces.
With this arrangement, you'd be able to shoot your prints, even if they're framed behind glass.
141474

Tin Can
27-Oct-2015, 09:53
John, looks like good advice on Rosco Polarizing sheets which I was unaware of. They are way more affordable than other options

I will be getting a couple at $50 each.

Also thanks Shannon, for this useful thread. I do a fair amount of color pencil drawing copy work and it has been a steep learning curve.

brucetaylor
27-Oct-2015, 12:13
Polarizing the light is the way to go. I knew of this technique but never bothered to buy the needed materials until recently. I had to copy a whole bunch of family photos. Using hot lights (that's what I have) Rosco sheets and a polarizing filter on the camera all reflections were eliminated when all was aligned properly. Even shooting through glass. Freestyle has the sheets btw.

Drew Wiley
27-Oct-2015, 12:31
Polarizing gels are not completely color neutral if you are copying onto color film. They seem to have a slightly greenish bias, which I offset with a 5CC Magenta lens filter. For gross color temp changes, like accommodating daylight film to tungsten hot lights, I prefer to sandwich the appropriate blue conversion gels with
the polarizing ones. Too many stacked filters on the lens can affect resolution, and you're already going to need a polarizing filter on the lens too, to cross-polarize
the light aimed at the table.

Bob Salomon
27-Oct-2015, 12:55
Polarizing gels are not completely color neutral if you are copying onto color film. They seem to have a slightly greenish bias, which I offset with a 5CC Magenta lens filter. For gross color temp changes, like accommodating daylight film to tungsten hot lights, I prefer to sandwich the appropriate blue conversion gels with
the polarizing ones. Too many stacked filters on the lens can affect resolution, and you're already going to need a polarizing filter on the lens too, to cross-polarize
the light aimed at the table.

The color and quality of the foils depends on the brand. The Heliopan foils that we sold for almost 30 years were color neutral. They are available in a choice of thicknesses and sizes, up to 14 x 14". But are only available on special order. They are not optical grade foils so they should not be used as a lens polarizer. Same for any other lighting polarizing foils.

ShannonG
27-Oct-2015, 15:18
Obviously, this works for you, but the diffusers are limiting the contrast you can achieve. You've already got a polarizer on the camera; however, the lights themselves should also have polarizers. Ditch the diffusion panels and get a large polarizer sheet for one Speedo head on each side. Hang the sheets with the polarization arrow the same for both sheets. My old Roscoe polarizers work best with the arrows vertical when the lights are as you have. (Other manufacturers may have the polarization marked differently.) Then use the modeling lights to adjust the polarizer on the camera for maximum contrast. Use barn doors on the lights to limit stray light bouncing around the room and hang dark cloth on the wall behind, again to limit stray bounces.
With this arrangement, you'd be able to shoot your prints, even if they're framed behind glass.
141474
thanks for the reply,yup i use a black BG and barn doors,and turn the overhead lights in my studio off. I have the polarizing sheets but not a big fan of the color temp of them. The contrast in my copied image captures is as strong as the prints.with a little post production my prints look as close as they can as they do in person.but they are always better in person.

Drew Wiley
28-Oct-2015, 09:51
It is impossible to get perfect color rendering with polarized light, even if you do correct for minor color balance issues. It's even a bigger problem with paintings, especially where impasto is part of the intended effect. I printed on Cibachrome. By removing the glare, I also compromised the look. Blues can become blackish with excessive polarization, just like when shooting a blue sky with a polarizing filter. That's one reason pictures of painting in art books never ever look quite right, much less over the web. In effect, you're translating the image into a different dialect, and not everything comes across correctly. With black and white copying a lot depends on just how much is truly monochrome versus to what extent hue differentiation is critical to image, like the presence of toner nuances. We just do the best we can. I found it fairly easy to keep clients happy, but never with reference to presenting my personal work in any secondary fashion.

John Olsen
28-Oct-2015, 12:55
Polarizing gels are not completely color neutral if you are copying onto color film. They seem to have a slightly greenish bias.
Back when people wanted 4x5 transparencies, the color seemed to be fine even for art publications. Mine have aged over the years and now give small color cast. It doesn't matter for the digital world, except for making a color temp change when you process the file. However a slight filter on the lens is easy as a correction, if you were shooting for transparencies. In that case also, you would want to use film that wasn't known for dramatic colors.

As for corrections for hot lights to daylight film, that's just way to much to ask for color accuracy. Besides, the hot lights tend to damage the polarizer sheets pretty quickly. I don't do that anymore.

Drew Wiley
29-Oct-2015, 08:54
Not much choice out there anymore. Tungsten balanced chromes were more accurate for color copying than daylight balanced ones, even with temp conversion
filters in place. The exception was Fuji Astia and esp Astia 100F, which was a wonderful repro film in general.