Jump to content

Printing 16mm Colour Neg on B&W Print Stock?


Zoe Allsop

Recommended Posts

In the UK, it is getting virtually impossible to process and print B&W 16mm film. One solution (for cost purposes) might be to shoot colour neg, and then have it printed to B&W print stock. Has anyone tried this? Is the image compromised at all? Did you have to light with more contrast? Or just as you would normally for B&W? Or aim for thicker/thinner negs? Any stories, good or bad much appreciated!

Link to comment
Share on other sites

Printing colour negative onto B&W positive stock is not a very good idea: B&W positive is orthochromatic and sensitive to blue light, a colour negative has an orange mask and this acts as a safelight.

We still do a considerable amount of traditional 16 and 35mm B&W work, mainly for artists such as Marcel Broodthaers (his widow places the orders), and many others in the art gallery environment.

Link to comment
Share on other sites

Printing colour negative onto B&W positive stock is not a very good idea: B&W positive is orthochromatic and sensitive to blue light, a colour negative has an orange mask and this acts as a safelight.

We still do a considerable amount of traditional 16 and 35mm B&W work, mainly for artists such as Marcel Broodthaers (his widow places the orders), and many others in the art gallery environment.

Actually B/W positive stock is not orthochromatic (sensitive to green and red) it is as you say blue sensitive only. This means that you will only get a print of the yellow layer which happens to be the layer with the most grain. Many years ago Ilford use to make a panchromatic b/w print stock just for this purpose. I have attached some images made via Photoshop that will give you an approximation to what you would get. The first is an Eastman colour print, the second the equivalent of a panchromatic print and finally a blue sensitive print.

 

Brian

Link to comment
Share on other sites

  • Premium Member

You may try printing on Eastman High Contrast Panchromatic Film 3369, around ISO 32, grey polyester base. I believe overall contrast can be tamed. Same goes for Kodak Panchromatic Sound Recording Film 2374, around ISO 20, grey polyester base

 

If a lab holds 7369 you have colourless acetate base.

 

http://www.cinematography.com/index.php?showtopic=33389#ixzz1bvFRjU5T

Link to comment
Share on other sites

Brian,

 

I should have said 'not panchromatic' instead of orthochromatic but you understand.

 

Simon,

 

I have worked on 5369, it is a very expensive stock, makes beautiful 35mm prints from B&W negatives. It is designed for bluescreen separation work and similar jobs and I have never seen it in 16mm. For information it is more expensive than 35mm colour intermediate so the producer was complaining about the price of his prints until he started winning awards in festivals.

Link to comment
Share on other sites

  • Premium Member

Just how is the orange mask overcome in colour printing? Using cyan or other subtractive colour filters?

It is not "overcome" as much as just in the background. I have only played with printing still colour, where the typical filtration needed is Yellow and Magenta. so the mask is just "there" anyway. The printing material is designed to have a "white balance" such that it is not a problem. remember that the Mask is correcting for dye imperfections so it is not uniform.

Link to comment
Share on other sites

Just how is the orange mask overcome in colour printing? Using cyan or other subtractive colour filters?

 

The answer to your question is that the masking is filtered out during printing.

 

The masks are there to correct for unwanted absorptions in the dyes. The couplers that produce the magenta and cyan dyes are coloured; the magenta coupler is coloured yellow and the cyan coupler is coloured magenta. Together they make the orange colour seen in a colour negative. The amount of coloured coupler visible is inversely proportional to the amount of dye present. If there is the maximum amount of dye present then there is no coloured coupler. If you have a highlight that is white, then there would be no dye and the maximum amount of coloured coupler.

 

It is common practice in many labs that if you want to grade a black and white negative and then print it onto colour print stock you used a piece of unexposed, processed colour negative as a filter, firstly in the colour analyser and then in the printing machine. If you don’t do that then a large chunk of your correction goes in trying to get a neutral colour. With the film base filter your ‘normal’ exposure will lie somewhere in the middle of the light range of the printer.

 

If you want to know a bit more about masking you can find some information on my website including some unique samples of single layers of colour negative with and without masks. http://www.brianpritchard.com/why_colour_negative_is_orange.htm

 

Brian

Link to comment
Share on other sites

You would have to be sure to use a panchromatic B&W stock for making the interpositive, in this case it would be 5234 instead of the usual 5366. The processing times would have to be increased to get a higher gamma. Then make the duplicate B&W negative onto 5234 stock with the standard 0.65 gamma. At one time I tried the 5235 B&W separation negative but it was nearly impossible to dry.

Link to comment
Share on other sites

  • Premium Member

If you are using 35mm you could use Orwo DP31 ...Unfortunately it is not available in 16mm.

Brian

 

Of course, It would be very tempting to bump up to 35mm for the conversion, and then bump down, if only to avoid a build up of grain and such in 16mm.

Link to comment
Share on other sites

Of course, It would be very tempting to bump up to 35mm for the conversion, and then bump down, if only to avoid a build up of grain and such in 16mm.

 

Or I suppose you could use one of the remaining camera stocks, (7222 or 7266 X-Processed), to create a B&W positive in a more DIY situation. But just how would the orange mask work in this situation? Would it add contrast similar to an orange filter on a camera? Or can it be just compensated for in the printer lights?

Link to comment
Share on other sites

I don't believe that it has any effect on contrast provided you give sufficient exposure to ensure that the blacks are black. You would not normally find it necessary to filter the light when exposing the dupe positive. The orange mask doesn't act like an orange filter on B/W negative because of the way that it is inversely proportional to the amount of dye present, if you had an area of deep blue in the colour negative there would be no mask present to hold back the colour. When an orange filter is used on a camera it is holding back the light reaching the film that it is not transmitting i.e mainly blues and blue greens, so they would appear light in the negative and dark in a print.

 

You could use 5222 and then make the negative on dupe pos stock, that would bring the contrast back to the correct contrast. In the early days of the cinema (around 1927 onwards) there was only one duplicating stock that was used for the master pos and the dupe negative. They were both processed to a gamma of 1.0. Excuse the self promotion but you will find a transcript of the booklet 'Eastman Duplicating Film - its Properties and uses' from 1927 on my website here:

 

http://www.brianpritchard.com/Eastman_Duplicating_Film_1927.htm

 

Brian

Link to comment
Share on other sites

  • Premium Member

Brian, your posts never seem to be self promotion. And I for one always read them carefully as they often touch on many topics.

 

I enjoyed reading the booklet you transcribed. Is that the first mention of the now Ubiquitous D-76? (Ubiquitous in still Photography anyway), also the mention of the filter to control contact reminded me so much of Varigram, Polycontrast and Multidrade Printing paper, I wonder if this is the start of that technology?

Link to comment
Share on other sites

Thank you for your kind remarks Charles.

 

I believe that D76 was invented by Capstaff of the Eastman Kodak Research Labs in 1926, it was specifically designed as a motion picture developer but, of course, became used universally.

 

I think that the use of yellow dyed films and a violet filter is not quite the same as the multigrade printing papers where the papers have two different emulsions that are sensitive to different colours, one being a low contrast emulsion and the other a higher contrast emulsion. Filters allow you to vary the contrast of the paper by varying the proportion of each emulsion. I presume that the violet filter holds back the exposure of the negative highlights more than the shadows and therefore reduces the contrast and also the maximum density.

 

The original booklet has frame samples of nitrate film and although I took a lot of care scanning them it is not the same as looking at the actual films.

 

Brian

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...