Jump to content

7222 contact print on PF2


Recommended Posts

I just have to toot my own horn here. I have an old Uhler Cine Printer and have started dialing in 7222 on PF2 in D97. Dilution tests were done today and one was spot on. Details in lights and darkest darks show projected. They show the same on a light box, too. I didn't like clear areas on my negatives. I had trouble printing black parts of negatives. Lots of work has been done and now I am finally getting somewhere. What I do is documented on my Facebook home page, https://www.facebook.com/michael.studiocarter no longer in the group I started called, Home movie film lab. I could use some help or a kind word from time to time. This hasn't been easy. I do not have a densitometer. I look at the ceiling light through black leader and guess. D97 was diluted 1:3 today in great results. I have a 100 foot spiral tank that I can afford to fill now. Anyway, that is me in the darkroom.

Edited by Michael Carter
Link to comment
Share on other sites

  • Premium Member

You’re doing the right thing, Michael, train your eye and brain on negatives and positives. Not many people are alive who can give you a match. I once met and worked together with a grader, back in the eighties, and he was able to combine Wratten gelatin filters off snippets of a colour negative over a light well. He would look at the image, one hand on the filter drawer, and say 0.025 minus blue, 0.05 minus green. He would then pick a log 0.025 yellow and a log 0.05 magenta filter, punch a compensating circular hole in the Leatheroid band used with an ARRI step printer, and staple the filters over the hole. Whole films were corrected like that.

 

You might want to make scales, perhaps with a camera. Expose in regular increments, either in intensity or in time, no lens, flashlight onto a white wall. Orwo PF 2 reacts like most other print films with a relative linear response to time differences but towards very short times you will have an ever increasing fall-off. When printing on Orwo TF 12 you will have linear response down to 1/100,000 second and great densities at the same time. I can sell you contact strips of a grey wedge from log 3.0 to 0, one foot long, 35 and 16. Short wedges from log 4.0 to 0.1 are possible in 16.

 

If you want to upgrade your equipment, let me know about. I sell the most modern film printer light control, Memochrome. With that system you can run up to 32,000 frames at 50 steps per primary colour (RGB), freely programmable. Middle setting is 25-25-25. At 0-0-0 no exposure takes place. As far as I know you have a continuous Uhler. They made step printers also. Some projectors can relatively easily be adapted to printing purposes. I like and appreciate your activity. Do keep going on.

Link to comment
Share on other sites

Wow, thanks Simon. I would not know what to do with a gray wedge. Yes, my printer is continuous. I worry about the light bulb burning out and dread looking for a replacement. I would swap the sound lamp. I only do black and white. It is complicated enough! It is great to know that D97 works diluted. My next task is to repeat what was just done to prove it works. Only with longer film that has close up shots of details like white textured things and dark areas. I thought to include some sky out of focus on each film to get a solid area of tone that could be measured or compared from one film to another. Leader on negatives is clear. Even a gray card could be shot up close out of focus like Zone tests. But then, I am making this up as I go.

Link to comment
Share on other sites

A grey wedge is a piece of film of continuously varying density. It would take the place of your OOF sky, which of course would only be a single reference point. You would splice it into each printer run and know what density range you were achieving. But you would need a densitometer to get the most out of it.

Edited by Mark Dunn
Link to comment
Share on other sites

  • Premium Member

If I can explain something that is complicated as simple as possible, let me try.

 

The entire calculation of contrast, density, veil, shadows and highlight details, graininess, and whatnot begins with a matte white surface in the dark. Assuming a gain or albedo of 0.9 we have the starting point. From here we go backwards through all conditions right up to camera (shutter open angle, frame rate, film speed, lens aperture (to be quite correct: figure of transmission), filters, and the light on a scene.

 

Black-and-white positive print film has a gamma of around 2.8 when processed after the recommended formulae and a max. density of around log 3. In other words contrasts up to 1,000 to 1 are transmitted by the print. We want an overall contrast or gamma of 1.5 to 1.6 in the projector which leads us to a negative contrast of 1.55/2.8 = 0.55. The print gamma higher than 1 has to do with the Callier effect of the illumination system of the projector combined with the reflections within the lens. Its value generally lies at around 1.2. Arc lamps are more powerful than incandescent bulbs, 16mm prints therefore are slightly different from 35mm ones. The screen gain influences overall density.

 

Camera negatives are often developed somewhat harsher than to the 0.55 mentioned above. In turn the prints need to be made a little softer. We can reckon with negative gamma between 0.65 and 0.75. Denser or lighter negatives were religious subjects in the golden age of cinema before the advent of colours. Tastes differ but we can out ourselves as technicians capable of reproducing an image of a scene on a cinema screen at the contrast factor of 1.

Link to comment
Share on other sites

My current project is to film a new negative that will show me the lightest tone in a print that is projected. I will measure the gray card, set the aperture according to my personal EI already derived in earlier tests, then increase exposures up to 4 more stops. Single frames, two at a time, will be exposed of the lightest tone, then the gray card will be flipped over to the white card, two frames will be made, repeat, exposing the gray card, alternating the white card, until about a foot or more has been done. In-between will be a few exposures of the gray card as gray, without any increase in the iris. That will separate one value from the other. If any tone prints, it will be seen projected as a flickering light. I could not see light tones printed all the same, they all looked clear to me. A Minolta spot meter could not read them. Animated flickering tones I can do.

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...