Flashing

dancqu said:

The above quoted puzzled me. Flashing and post exposure
bleaching do not necessarily produce prints of "little or no
difference".

Ferricyanide is a strong oxidizer. EXTREMELY little is used.
The presence of any foreign reducible material may
entirely kill the bleach. I've an example of what
can happen.

Use distilled water in it's preparation and use. The little
additional work involved in using a post exposure latent
image bleach can pay big dividends. Very modest to
substantial corrections are possible. Dan

Click to expand...

I said I found little or no difference. My tests were done soon after the article on SLIMT appeared in Darkroom and Creative Camera Techniques magazine. If I had not accounted for all the possible errors you describe, there would have been great differences.

In point of fact, when one sets up the flashing to be done at the same time as the imaging exposure, the brightest and darkest points of the resulting print can be measured with the appropriate spot meter and the flashing illumination can be set so that white is the unexposed paper white and black is the maximum paper black. Furthermore, a properly designed flashing source will allow for predictable selective flashing. Try that with SLIMT.

lynettemax said:

I have ruled out safe light fog. I've left paper out on the table for a period of time and my photos are not fogged. I'm not sure I was properly taught how to do this however.
I would post a jpeg of it but i dont have the money to use my schools scanner... I'm broke enough buying paper haha

Click to expand...

THe proper way to test your safelight for fogging is to know what a decent base exposure for a print for a certain neg is, lets say to get some grey in a sky shot, then stop down about stops, give it the exposure time (now at 3 stops down though( and them place an opaque object in that grey sky area and wait about 3 to 6 minutes. Develope normally. if you see a mark like the opaque thing, you've got safelight fog. You cannot just put paper out and something on it and expect proper results...you need to give it a slight exposure first.

BTW, I've always found the 2nd enlarger flashing system to be controllable, ideal, predictable and the easiest flashing method there is bar none. Like I said earlier, just watch your results and you'll do fine.

Alexis

Hi Lynette,

If you expose paper for just a few seconds at the smallest aperture of your enlarging lens, you will see that the paper is still pure white. Paper has a small lagtime before anything happens. Like a cartoon character running but not moving for the first few seconds.

I pre-expose the paper with the enlarger head all the way up to the very top. Enlarging lens at it's smallest aperture. Contrast filter 0.
I make 5 small test strips with the time written right on the face of the paper (2,3,4,5,6 sec.) Before exposure, I place a small coin on top of the number, expose to indicated time and develop all together.
Once the strips are dry, lay them side by side and it is easy to see when the shape of the coin appears on one of them faintly. The correct pre-exposure time is the longest time where the coin is not visible.
You can pre-expose any paper out of that batch of paper the same amount of time.
This is simple and consistent and works well for me.