Re: Color photography with black and white film
Sounds like you are looking for an old Devin Tricolor camera. Purpose built for technicolor-like still photography, that is, three separate 6.5 x 9 cm glass plate negatives (had to use glass plates to ensure good registration between the three negatives), all the filters and mirrors built into the camera. See the diagram on the manual's page 8.
If I read the manual correctly they used Wratten A, B, and C5 filters. I think you'll find a number of interesting things in the manual. My personal favorite is that it took two different emulsions to get the wave lengths right, so the plates aren't all interchangeable. Very interesting -- like nearly all of photography, it's never as easy as it looks.
Re: Color photography with black and white film
Quote:
Originally Posted by
Incoherent Fool
So does anybody have any experience with this? Is this more trouble than it's worth? Am I crazy?
I've been wanting to do this, but I have yet to find the right blue filter. It would be great for unusual film sizes, like my little 9x12 plate cameras. You can even print directly if you use three different coloured processes (like cyanotype layered with red & green gum bichromate prints). I wonder if anyone has done this with ULF negatives?
Re: Color photography with black and white film
Quote:
Originally Posted by
jbannow
Silly question - how do you all differentiate which sheet is which color? Trial and error later, or are you marking them some how?
Take notes, same as with anything else.
Of course with only three colours to align it can't be that hard to sort out later anyway.
Re: Color photography with black and white film
Quote:
Originally Posted by
jbannow
Silly question - how do you all differentiate which sheet is which color? Trial and error later, or are you marking them some how?
you just remember what order you shot them in :)
http://photo-utopia.blogspot.com/200...om-b-film.html
Re: Color photography with black and white film
Quote:
Originally Posted by
Joanna Carter
No, treat all the films the same - N development. Don't forget, although the "effective speed" of each colour is a lot less, you are "adding" three exposures together to make the final print. Any area of white will be the sum of the "1/3" red, "1/3" green and "1/3" blue.
Couldn't you, instead, compensate in scanning (assuming a digital post-capture workflow)? That way you could optimize your exposure for each of the three colours? I guess scanning underexposed film is easier anyway.
Re: Color photography with black and white film
Quote:
Originally Posted by
Joanna Carter
To translate another part of his article on tests that he did, he recommends allowing the following ISO ratings for the three exposures, assuming you are using 100 ISO film
Red : 32 ISO
Green : 20 ISO
Blue : 20 ISO
I've just read more of the "Test" article; Henri appears to go on to say that he finally settles on :
Red : 10 ISO
Green : 10 ISO
Blue : 16 ISO
Re: Color photography with black and white film
Quote:
Originally Posted by
walter23
Couldn't you, instead, compensate in scanning (assuming a digital post-capture workflow)? That way you could optimize your exposure for each of the three colours? I guess scanning underexposed film is easier anyway.
If you have exposed the films at an appropriate level, you should have straight scans, although, of course, you can alter whatever you want. If I know Henri well enough, his methodology is usually to do as much in the camera and as little digitally, as possible.
I thoroughly recommend trying to translate http://www.galerie-photo.com/test-trichromie.html, with Google or BabelFish, to see what Henri has to say what someone, who is acknowledged as an accomplished practician in his field, has to say.
Re: Color photography with black and white film
Ok, I am fascinated. I have a lee filter pack, might even have those filters. I'd take it that one would want to vary the shutter speed only to avoid strange aliasing issues with changing DoF (if accuracy was the desire, anyway). Assuming digital reconstruction, I am not sure I understand the effective ISO; outside of filter factors, I don't see the need. I expect analog reconstruction would be different, but one would think that less exposure would be wanted, not more. What am I being dumb about here?
Re: Color photography with black and white film
I did this in a traditional darkroom using a technique we called dye transfer. You would make three B&W negs through filters and then project each one on to a matrix film which held you dyes. After that it was like tricolor graphic arts printing. Took a group class in this and really only scratched the surface of it's potential.
Sid
Re: Color photography with black and white film
Quote:
Originally Posted by
Paul Kierstead
I'd take it that one would want to vary the shutter speed only to avoid strange aliasing issues with changing DoF
Correct; you certainly don't want to change the aperture :o
Quote:
Originally Posted by
Paul Kierstead
Assuming digital reconstruction, I am not sure I understand the effective ISO; outside of filter factors, I don't see the need.
The effective ISO is due to the fact that, without filters, you would have uninterrupted passage of light. But, with the interposition of a filter, there is a loss of light transmission which has to be compensated for.
If we take the example of wanting to separate out the red light on a scene, without a filter, a sheet of film that is, theoretically, only sensitive to red light would respond to a theoretical 1/3 of the available light.
However, filters are not perfect transmitters of all the light that strikes them, thus interposing a red filter would attenuate, not only unwanted green and blue light, it would also attenuate some red light due to its very presence.
Quote:
Originally Posted by
Paul Kierstead
I expect analog reconstruction would be different, but one would think that less exposure would be wanted, not more. What am I being dumb about here?
Just as, if you were to use a red or orange filter for enhancing skies, you would need to increase your exposure by three or two stops, you still have to compensate for the presence of a trichromie filter. The filters really are quite dense to try and remove as much of the unwanted (parasitic) colours as possible.