Paper Flashing - the 5 W's

Colin Corneau · Aug 21, 2008

What is paper flashing?

What is it used for, and when would a person want to employ it?

What are good techniques for doing it?

Many thanks for the advice, all...

climbabout · Aug 21, 2008

Colin Corneau said:
What is paper flashing?
Paper flashing is exposing paper to raw, non image forming light. The theory is that it takes a certain amount of exposure before your paper will record tone. You can determine that by exposing a test strip of your paper under your enlarger, then develop it and determine the maximum amount of time you can expose it before it records tonality - that is your paper threshold. For the paper I use, its 10 seconds at f16 at a height of 40 on my beseler 23c with 50mm lens. I like to find a time that I can vary if I don't want to flash fully.

What is it used for, and when would a person want to employ it?
It is generally used when you want to lessen the contrast of paper(usually when using graded paper). I.e - if you have highlight areas that are hard to print.

What are good techniques for doing it?
All you need is a controllable, repeatable light source - here's what I do. I have 2 enlargers, side by side in my darkroom. A beseler 23c and an omega 5x7 that I do most of my printing with. They are both hooked up to a common timer. This way I can leave the neg in the 5x7 and flash with the beseler. If you only have 1 enlarger, you can pre flash a bunch of paper ahead of time before you start printing.
Hope thishelps.
Tim
Many thanks for the advice, all...

Hope this helps
Tim

Stoo Batchelor · Aug 21, 2008

Colin Corneau said:
Colin Corneau said:

What is paper flashing?

What is it used for, and when would a person want to employ it?

What are good techniques for doing it?

Many thanks for the advice, all...

Click to expand...

Hi Colin

Have a read of this article by les McLean, it will answer most of your questions.

http://www.lesmcleanphotography.com/articles.php?page=full&article=27

Best

Stoo

P.s If you havn't got his book 'Creative Black and White Photography' Its a must have for all dark room users and can be found at very reasonable prices at Amazon.

Colin Corneau · Aug 21, 2008

Thanks to you both!

The addiction continues...

climbabout · Aug 21, 2008

Excellent link Stoo - more info there than I had time to type in my post.
Tim

Neil Souch · Aug 22, 2008

Hi,

For easy paper flashing obtain a PAPER FLASHER from RH Designs (jointly designed by Les with RH Designs) which takes care of all the calculations for you and can be used as a creative tool -to falsh small parts of the paper as well as the whole sheet. I have has one in my darkroom since they came out and it is one of my favourite gadgets.

Cheers,

Neil.

Thomas Bertilsson · Aug 22, 2008

Just one more good link. This is from RH Designs home page:
http://www.rhdesigns.co.uk/darkroom/html/flashing_and_fogging.html

- Thomas

Monophoto · Aug 22, 2008

Colin -

There is a trick I learned a number of years ago that makes flashing very simple.

Start with a sheet of heavy cardboard. I found an old vinyl looseleaf binder that was being thrown away, and stripped the vinyl from the front and back covers to reveal a pair of very heavy cardboards. 8-ply mat board should also work. I cut a rectangular opening in one leaving a border about an inch wide on all four sides. Then I glued a sheet of translucent velum drafting paper over the opening in the cardboard.

With this flashing card, it isn't necessary to have a second enlarger, or even to remove the negative from the carrier. Just hold the card under the lens of the enlarger and turn on the light for a short interval, keeping the card moving to prevent the texture of the velum from being projected onto the print. The velum diffuses the projected image so that all that actually strikes the print is diffuse white light.

I find that a typical flashing exposure is 5 to at most 10% of the basic enlarging exposure. The result is a reduction of paper contrast by about 1/4 to 1/2 grade (this works well even with VC paper and filters), and helps put texture into otherwise blank white highlights.

Thomas Bertilsson · Aug 24, 2008

Upon Bob Carnie's recommendation, I have employed pre-flashing as a means of controlling contrast with lith printing.

Bob suggested to have a standard development time, say 4 minutes, and then the duration of the pre-flash determines the contrast when you stop development at 4 minutes. It's an approach that seems a lot more reproducible than regular lith printing where you snatch the print when it looks good.
I haven't done it all the way as Mr Carnie suggests, but I pre-flash when I can't get any highlight detail regardless of how much I expose the negative. I still control contrast with standard enlarger exposure time, and use pre-flash to compress the tonal scale somewhat. It works great for me, and I'm able to do it with a single enlarger.
For standard black & white printing, the approach is similar to Bob's lith printing technique. If you want your prints to look really old, preflash the paper without putting it into the easel first. It'll 'tone up' the rebate on the paper too. It looks pretty cool, actually.

- Thomas

pentaxuser · Aug 25, 2008

Thomas Bertilsson said:
If you want your prints to look really old, preflash the paper without putting it into the easel first. It'll 'tone up' the rebate on the paper too. It looks pretty cool, actually.

- Thomas

Thomas. I take it that this is pre-flashing to the point of putting tone in the paper as opposed to pre-flashing to that point immediately before any tone is established.

If I have got this right then is there a means of squaring a correct no tone pre-flash for the print with the tone required for the old look, or do you simply have to sacrifice the correct pre-flash for the sake of getting the old look and tone in the borders? I think you may be saying that it is not in fact a sacrifice because the benefits of the old look and borders are what is being aimed at.

I have never tried pre-flash but have read about it. To give me some idea of look, how would you describe the effect on the print and the borders of your technique?

Thanks

pentaxuser

Thomas Bertilsson · Aug 25, 2008

Thanks Pentax,

you are correct. I should have mentioned that with getting the paper exposed to that degree prior to illuminating via the negative actually brings you over the threshold of the paper and affects the tone in the actual print area as well, not just the rebate.

- Thomas

pentaxuser · Aug 25, 2008

Thomas Thanks. So overall the rebate looks a pale grey. I say pale because I assume that if you wanted a darker grey this would be at too much of a cost to the print quality? I always associate the "old look" with a brown sepia type of look and you can even buy an antique dye in the UK to get this nicotine stained look, especially in the rebates but I think that your stated "old look" is probably different from this effect .

Can you elaborate on this "old look" part?

Thanks

pentaxuser

Thomas Bertilsson · Aug 25, 2008

I'll scan a print when I come home tonight. (I'll dig up the APX400 negs too )

- Thomas

pentaxuser · Aug 25, 2008

Thomas Thanks A picture or better still two and covering another post of mine is worth 2 thousand words and kills two birds with one stone. That's metaphorically speaking folks, of course. I am not part of the hunting fraternity. I leave that to Elmer Fudd!

pentaxuser

ic-racer · Aug 25, 2008

With VC paper I get results identical to just using a lower grade filtration. Perhaps someone can post a step wedge exposure or graph to show otherwise, but each time I have tried it the flash results can be matched with lower grade filtration. I don't have an ANSI testing lab, so I'm curious as to other's results.

Paper Flashing - the 5 W's

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