Bleach bypass on the print film

Zagorchinov · Nov 13, 2005

Greetings,

As a student cinematographer, I was wondering about the process of bleach bypassing the print film. Since I am going to test this process this week I want to ask for some advice.

I have the sensitometric charts from the local Kodak approved Boyana Film Lab - both from normal print and bleach bypass print film. The film is Kodak Color Print Film 2383.

From the charts and the curves, I can see that, regardless of the increased contrast and Dmax, the bleach bypassed print is about a stop denser in the area of the middle gray density (around D 1.0). This means that the bypassed print will be a stop darker on the screen.

So the question is: How do I compensate for this - increasing exposure or lowering the print lights?

I assume that increasing exposure with about 2/3 stops will give me better shadow detail, but it may be crushed down anyway by the denser print film. The increased exposure also tends to saturate the color and I want the image to be as much desaturated as possible.

On the other side, the print lights from normal exposed negavtive have to be around 15-18, which is a scary idea.

Please, if anyone have some expirience with this, I will be glad to learn about the details.

Thanks in advance,
Dian Zagorchinov
Student Cinematographer, Bulgaria

David Mullen ASC · Nov 14, 2005

Don't change your method of exposing the negative to compensate for bleach bypass to the print -- you just change your printer lights. Having to print "up" (lower numbers) to make the midtones lighter is not going to be a problem since your blacks will be rich enough from the silver retention.

However, since bleach bypass to the print causes a loss of shadow detail, if your MAIN reason for doing a bleach bypass is to lower color saturation rather than increase contrast, the best thing would be to wash out the contrast on the negative (which will also help reduce saturation) either with contrast-lowering filters, smoke, flashing, pull-processing, or using low-con negative stock. Or a mix of techniques. This will lift up your shadow detail and milk up your blacks, which the skip bleach will restore to the print.

You can read here about some of these techniques that I used for "Northfork":

http://www.cinematography.com/articles/northfork/

Zagorchinov · Nov 14, 2005

Thank you, Mr Mullen.

I think I am prety much clear now about how to proceed with the test.

The image I am looking for has to be as much desaturated as possible, with a little bit higher contrast, but definately not blocked blacks and burned whites.

Since I can't afford a flashing device, I plan to use heavy low contrast filters on the wide shot exteriors. The thing that I don't know is, can the UltraCon and LowCon filters raise the negative black level enough to give me a flashed look? May be grade #3 to #5?

Also, do you have experience with print film flashing with bleach bypass?

Kind regards,
Dian Zagorchinov
Student cinematographer, Bulgaria

David Mullen ASC · Nov 14, 2005

No, I've never flashed a print or IP, but the problem is that flashing a positive lowers contrast by darkening the highlights, which doesn't help much when doing a skip bleach to the print where the shadows and blacks are what need the contrast-lowering, hence why flashing the negative is better when you are skip-bleaching the print. You want to lift up shadow detail and blacks.

A heavy UltraCon (like a #4 or #5) would give you a flashing effect, although it varies in strength by how much ambient light is in the frame so it's not as consistent as flashing. Plus any stray hard light hitting the filter just washes out everything. But UltraCons would be a good choice if you want to lower the contrast without softening the image nor getting halation. If you want some softening and halation, then regular LowCons would be better.

There is also an interesting filter called Smoque by Tiffen that resembles a cross between an UltraCon and Double-Fog. It also reacts to the bright areas in the image.