Newbe with pre flashing paper

[norm123]

Hi all
I think I have a good experience in the darkroom but I have a 4x5 negative with a nice range of tones in the middle and lower tones. The scene is some farm installation, barn with the sky at the top of the picture. I see separation between clouds and the sky on the negative but when I expose it on paper, the sky is washout. I read a bit about preflashing paper in the darkroom. I figure to expose the paper (Ilford FB Classic glossy) without negative and without grade filter under the light (150 watt 212 bulb) of the enlarger (Omega D2V) and make a strip test (maybe 1-2 seconds interval). I'll decide the tone I want for the sky, expose paper and make another strip test with the negative and grade 4 or 5 filter in place. Is it a good way to do it? I
know my light is not "white". Is it an obligation to get a...saying 4500 or 5000 K daylight to have a good result or a tungstene bulb can do the job? Sorry for my weak English.

Norm

 

[Doremus Scudder]

Check out Les McLean's article on flashing if you haven't already: http://www.lesmcleanphotography.com/articles.php?page=full&article=27

My comments/advice:

Your enlarger light source is "white light" as far as your paper is concerned. Don't worry so much about color temperature. With VC paper, you have the choice of flashing at whatever contrast setting you prefer. Low-contrast flashing will give you tonality without a lot of contrast; high-contrast flashing does the opposite.

Split-grade printing techniques may work better for your purpose here. Burning the sky with a 00 filter is really not much more than selective flashing at low contrast. I find this tool works well for me in cases similar to yours to get a basic tonality. Then burning selective areas with high-contrast to get some snippets of detail darkened down while avoiding areas you don't want to darken works well many times.

But, try burning with normal contrast first. Any flashing or burning with low-contrast settings is a contrast killer. If you can get the tonality you want without these, the contrast will be better. Often dodging the objects that are not bright in the area you later plan to burn helps even things out.

Bright skies with lots of intruding objects are difficult, however, so flashing or low-contrast burning may be the best choice.

Best,

Doremus

 

[norm123]

Check out Les McLean's article on flashing if you haven't already: http://www.lesmcleanphotography.com/articles.php?page=full&article=27

My comments/advice:

Your enlarger light source is "white light" as far as your paper is concerned. Don't worry so much about color temperature. With VC paper, you have the choice of flashing at whatever contrast setting you prefer. Low-contrast flashing will give you tonality without a lot of contrast; high-contrast flashing does the opposite.

Split-grade printing techniques may work better for your purpose here. Burning the sky with a 00 filter is really not much more than selective flashing at low contrast. I find this tool works well for me in cases similar to yours to get a basic tonality. Then burning selective areas with high-contrast to get some snippets of detail darkened down while avoiding areas you don't want to darken works well many times.

But, try burning with normal contrast first. Any flashing or burning with low-contrast settings is a contrast killer. If you can get the tonality you want without these, the contrast will be better. Often dodging the objects that are not bright in the area you later plan to burn helps even things out.

Bright skies with lots of intruding objects are difficult, however, so flashing or low-contrast burning may be the best choice.

Best,

Doremus

Thank you Doremus

In my case I have a sky with a lot of intruding objet. I'll try flashing paper with grade 1 and I'll see.

 

[Alan9940]

You might be interested in this video, too:

 

[Andrew O'Neill]

Keep the negative in place. Insert a piece of translucent plexi glass in your filter holder. Do a test strip. Find the lightest tone that you can visually see from paper white. The proper exposure for flashing will be slightly less than this time. Do it for real on another strip of paper, then pull the plexi and do another test strip with image light. You may have to do a bit more tweaking. Also try it with a soft contrast filter with the plexi in place.
Since I started develoingp film with pyrocat-hd, and print with unsharp masks, preflashing has become a rare occurance in my darkroom.

 

[David Allen]

For pre-flashing paper there is absolutely no need to remove the negative or a second enlarger. The simplest way is to buy a thin piece of semi-opaque acrylic and hold this (or fix it with some BluTac / tape / etc) under the lens and do your pre-flash. No need to remove the negative, no need for an extra enlarger or light source, etc.

Also, if only the sky is your problem (and despite the fact that you have intruding objects) then you can simple pre-flash the sky. The central idea to pre-flashing is that all papers have a threshold for exposure that has to be overcome (think along the lines of how hard it is to start pushing a car but, once moving, it becomes easier). By pre-flashing you give the area that you have pre-flashed a head start over the un-flashed parts of the paper.

This technique is quite different to split-contrast exposure which (with the #00 + #5 method) puts a low contrast veil over the whole images that, to my eyes at least, reduces micro-contrast throughout. Pre-flashing is a very easy technique to learn and a powerful one for certain negatives:

• Mark your test strip with a pen (so that later you can accurately judge the change in exposures).
• Expose the test strip.
• Develop, fix and rinse the test strip.
• View the test strip at a level of light similar to where you show your prints (for fibre-based Baryta paper it is important that the print is fully dry before assessing the test strip - I have an old microwave in my darkroom to dry test strips).
• Identify which exposure gives a slight tone darker than the paper base.
• The exposure to select is not the one with a slight tone but the previous section of the test strip (i.e if your exposures are increasing from left to right and the third exposure has a slight tone then use the time from the adjacent - to the left - section of the text strip).
• Use this pre-flash on your paper and then do a normal test strip to assess you post pre-flash exposure.

Bests,

David.
www.dsallen.de