Flashing Paper

[inthedark]

I concur with less. I have tried flashing variable contrast papers and films with various colors and the only difference will be the flashing exposure time. Otherwise, as with Les, my unscientific but usual method of evaluation notes no end difference.

 

[Les McLean]

glbeas wrote:
That's quite interesting Les. Any idea why this happens to be so?


The object of flashing is to sensitize the paper so it seems to me that the "grade" of the light source is irrelevant just so long as it is consistent.

 

[inthedark]

As I was drifting off to sleep, it occured to me that with VC paper, I often do a form of what I think you all call "split filitering" with different contrast and color filters, also I have often dodged with a color filter to control contrast in just one area. But as Les once again has commented, once you take away the negative, it becomes simply a matter of how dark the flash will be.

 

[Flotsam]

I have seen this thread topic but haven't been following the posts until today.
Last night I was working on a negative that happened to be perfect for this technique. It is a shot taken straight up through the branches of a Magnolia tree. The branches and flowers were backlit and, on a #2 grade, the sky was paper white. A brief flash added an even, grainless, minimal density to the sky, vastly improving the print. I used the, "just yank out the carrier" method. This is a good technique to keep handy in a printer's toolbox.

 

[Alex Hawley]

Les and Don, I have a question about flashing VC paper.
What are the qualitative difference between flashing with the 3 filter or no filter, just the 5 filter or just the 0 filter?

OOPS! I did my first pre-flashing with VC paper and it worked. Many thanks to Les for sharing his knowledge with me. I guess I didn't pick up on using the technique with only graded paper.

I can attest to the fact that the filter grade makes no difference. I tried it it with 0, 2, 4, 5, and no filter. Tried split filtering on the same print with pre-flashing but saw no improvement.

Here's the one I tried all this with. In the final outcome, I pre-flashed for a couple seconds then exposed with a #1 filter.

(there was a url link here which no longer exists)

 

[mobtown_4x5]

Don-

Thanks for the informative reply to my side question (just got back in town from sunny Fla. and catching up on my APUG)

-Matt

 

[gainer]

I have an easel densitometer that I use, with proper calibration, to set the exposure for each negative. I can set it to read Zones instead of density. I designed and built it myself, so don't ask where you can buy one. Along with this contraption, I have an adjustable light source that is wired to be on (by switch) when the enlarger lamp is on. I use this light for "while flashing" by setting the enlarger for highlights with the flasher off and adjusting the flasher for shadows with both lights on. The object is to add just enough light to the enlarger's that the lightest part of the image is at the paper's shadow threshold. Highlights are NOT affected by any visible amount.

The result is as if the film had had a long toe with upsweeping curve.

I don't use this setup very much because I use mostly VC paper.

 

[gainer]

I should have added that the printing exposure is made with both lights on.

 

[gainer]

I have to apologize. I not only got it backwards, but emphasized my mistake. I set the exposure for the SHADOWS (Zone 2 or 3) with the flashing light off, then turn the flashing light on and adjust it to give Zone 8 0r 9 in the highlights with both lights on. The highlights thus have an amount of light about equal to the threshold. The reading in the shadows is practically unchanged because the flashing illumination is a small percentage of the illumination from the enlarger in the shadows, and the Zone readings are logarithmic. The shape of the paper's H&D curve is changed so that the highlights are flattened, so it is not good to make major adjustments by flashing. This is true whether it is done in two separate exposures or in one combined exposure.