Paper flashing question

PVia · Jun 27, 2008

I've used flashing to get some tone into blown out areas when the rest of the exposure otherwise looks good, however, sometimes other areas, esp skintones get too depressed and lose the nice modeling effects of natural light.

Short of making a mask, is it possible (or conventional) to flash for a shorter period of time and achieve a better balance?

For example, my paper flashing threshold is .9 seconds (where tone first appears on my flashing test strip), and I am using .6 seconds (the strip before the .9 seconds one). Will I still get the effects of flashing (and possibly find a better balance) if I decrease the time of the pre-flash, say, to .4 seconds?

Ian Grant · Jun 27, 2008

The simple answer is probably yes. My flashing exposures are always done using a second enlarger, and I use the lens stopped well down & flash for 0.5 seconds, sometimes giving 2 flash exposures. In fact the threshold for my paper is 5 flashes, and the most I'd ever give is 3.

On that basis you are giving quite a heavy flashing exposure, so try 0.2 seconds and 0.4 seconds.

Ian

edtbjon · Jun 27, 2008

A couple of links for you:
Les McLean on Flashing and Fogging
and also check RH Designs on the same subject, where there's also additional info in the links provided on that page, e.g. the manual for that device.

//Björn

VesaL · Jun 28, 2008

It would be good to make yourself a flash test-stip pattern. Start from 0.1 and advance to 0.6 with F 11 for example.

From there you will be able to judge your flashing better. Remember of course that flashing time wary from different papers.

glbeas · Jun 28, 2008

It would be good to use a large sheet stepped in one direction with a flash exposure and stepped in small increments the other direction with a suitable image to see how the two exposures interact. Center the image steps around a "proper" exposure for the mid and dark tones.

Jim Jones · Jun 28, 2008

I use a small flashlight with the light diffused with masking tape for flashing small areas of a print.

jeroldharter · Jun 29, 2008

Flashing for fractions of a second? I think that the startup and turnoff of the bulb would introduce some error because of those short periods of time. That would account for inconsistency. I use the RH Designs flasher (expensive but works well) and usually have flash times of 10-15 seconds depending on paper and enlarger height (the flasher is mounted to my lens board).

Apart from the selective flashing with the flashlight device noted earlier, you can dodge parts of the print that you do not want affected by the flashing exposure.

DocPhibes · Jun 29, 2008

I have been using fog masks which I learned from a contrast masking kit with great success. It's easy to locally flash very detailed areas of the photograph without affecting other areas. Works beautifully for me. I used to use other flashing techniques but this is much more controllable and accurate. Lyn Radeka has some information about it at www.maskingkits.com. The other kinds of masks are really helpful too. The flashlight with the diffused light works good for very broad simple flashing in a pinch.

Gary Holliday · Jun 30, 2008

jeroldharter said:
Flashing for fractions of a second? I think that the startup and turnoff of the bulb would introduce some error because of those short periods of time. That would account for inconsistency. I use the RH Designs flasher (expensive but works well) and usually have flash times of 10-15 seconds depending on paper and enlarger height (the flasher is mounted to my lens board).

Apart from the selective flashing with the flashlight device noted earlier, you can dodge parts of the print that you do not want affected by the flashing exposure.

I agree with jerold...

I was working on a print this afternoon which needed some extra highlight detail. I liked the tones on the face and wedding dress, so flashed the print with a 00 filter for 2 seconds and dodged the face during the flash.

jfish · Jul 1, 2008

Pre or post flash? Makes a difference which you use, and you can even use them in combination to really fine tune your print. Dodging, as Gary pointed out, is very easy to do.

dancqu · Jul 5, 2008

Jim Jones said:
I use a small flashlight with the light diffused with
masking tape for flashing small areas of a print.

I wonder of the usefulness of such a technique. Flashing
or even very light fogging affects only the otherwise purely
white or thinest of highlight areas of the print. Your technique
seems to me to be more of a non-image small area burning.
Is that actually the effect you are after? Dan

RobC · Jul 5, 2008

After some advice from this site, I made up a diffussion sheet which I just place under the lens with the neg still in it. Its very fast to use and you can work out your flash times as a percentage of total time so that it works at any enlarger height. And of course you can adjust the flash time for more or less effect. And just because you are flashing doesn't mean you can't at the same time dodge the print so that the flash only affects the parts of the print you want it to.

dancqu · Jul 5, 2008

rob champagne said:
After some advice from this site, I made up a
diffusion sheet which I just place under the lens
with the neg still in it.

I probably worry too much but wonder if the
possible image pass through might not slew the
results. Image pass through is greatest just where
addition exposure is not wanted, the shadows. Where
additional exposure is wanted, the highlight areas,
the least amount of light is reaching the paper.
In fact the very dense areas of the negative
may pass so little light as to not affect the
paper at all.

My technique eliminates the image pass through
issue. After exposure I stop the lens down to f45
then carefully remove the negative with carrier.
With timer set to some very short time the
paper is wholly exposed to the enlarger's
even light. Dan

df cardwell · Jul 5, 2008

Testing showed that a plastic cup mixed an image perfectly.

A filter holder beneath the lens and a sheet of Tough Rolux is perfect,
and doesn't need to be held. Milk Glass, plain paper, almost anything works.

Simple doesn't exclude sound technique; rationalism's weakness is that we can convince ourselves of anything.
Testing proves what works.

Printing an edition justifies a special lightsource for flashing if you have room. A small enlarger is perfect.

RobC · Jul 5, 2008

dancqu said:
I probably worry too much but wonder if the
possible image pass through might not slew the
results. Image pass through is greatest just where
addition exposure is not wanted, the shadows. Where
additional exposure is wanted, the highlight areas,
the least amount of light is reaching the paper.
In fact the very dense areas of the negative
may pass so little light as to not affect the
paper at all.

My technique eliminates the image pass through
issue. After exposure I stop the lens down to f45
then carefully remove the negative with carrier.
With timer set to some very short time the
paper is wholly exposed to the enlarger's
even light. Dan

I wondered about that BUT this is a diffusion sheet and that means light from the whole image is diffused over the whole of the paper and not just the light from the bit of the negative you want to flash. A diffusion sheet evens everything out so what hits the paper is non image forming and NOT dependant on one part of the negative. But you do need the right amount of diffusion. I don't have it to hand but I think I used four 4 or 5 layers of Lee lighting diffusion sheet which for which I use 10% of print time (+ or - if necessary). It works very well and is a breeze to use.

Jim Jones · Jul 6, 2008

Originally Posted by Jim Jones
I use a small flashlight with the light diffused with
masking tape for flashing small areas of a print.

dancqu said:
I wonder of the usefulness of such a technique. Flashing
or even very light fogging affects only the otherwise purely
white or thinest of highlight areas of the print. Your technique
seems to me to be more of a non-image small area burning.
Is that actually the effect you are after? Dan

I use it both for reducing unwanted highlights and for darkening skies a bit around the edges of the image.

Feketefeher · Jul 7, 2008

Flashing gives the whole image a dull look. You can burn in the area with a lower contrast filter, you can make shapes with your hand or you can cut out the shape from a cardboard, just make sure you are moving your hand or the board so the edges are not sharp. Put the blown out part of the picture in warm water for few seconds and go back to the dev.(this method is not working for RC paper)
Practice to see what works for you. Good luck.

Ed Sukach · Jul 7, 2008

Feketefeher said:
Flashing gives the whole image a dull look.. Put the blown out part of the picture in warm water for few seconds and go back to the dev.

... As in a two stage process..? I've done a LOT of "pre-flashing" to control (reduce) contrast ... but always independent of development. I can't see where an intermediate water bath would have an effect - ANY effect - but, I'll have to try it.

(this method is not working for RC paper)

Strange - I've always used "pre-flashing" on both RC as well as fiber papers - and EXTENSIVELY with RA-4 Color - all with great success.

hka · Jul 8, 2008

Ed Sukach said:
Strange - I've always used "pre-flashing" on both RC as well as fiber papers - and EXTENSIVELY with RA-4 Color - all with great success.

Ed,
Can you explain how you do that on RA-4 Color??

Ed Sukach · Jul 8, 2008

hka said:
Ed,
Can you explain how you do that on RA-4 Color??

Oh, boy.... I've done this so many times ... yet, I never have had to write it down.

Here goes... I use the ColorStar 3000 extensively ...

First, the "pre-flash":

Either using some sort of diffusion media - or possibly ... nothing ....in the negative carrier of the enlarger, analyze a complete frame of light ... adjusting Cyan, Magenta and Yellow filters to produce a "neutral gray." Adjust the aperture to the produce a ten second (suggested) exposure. For the pre-flash exposure, reduce the TIME and expose for two seconds (~20%) Note 1.

Remove and secure the pre-flashed paper.

For the main exposure, analyze the frame to be printed. Adjust cyan, magenta and yellow filtration. Set the aperture to ten seconds - place the pre-flashed paper in the easel, and complete the exposure with an actual time of eight (8) seconds.

Process as normal.

This has worked wonders in a situation as photographing girls in white Wedding Gowns - and "colored" Bridesmaid's dresses ... in *BRIGHT*, direct, July sunlight. With care, the texture of the white fabric is THERE (!!) and the shadows are NOT blocked.

This will take an amount of trial-and-error... but in my book it is well worth the effort.

Note 1; Yeh, I know it is not theoretically 20%. It's somewhere around there ... good enough for f/63. You might need more - 30% or so.

I hope this makes sense .. at least enough to get you started. It has been a rough day of medical procedures. Questions will be gladly answered - later.

hka · Jul 9, 2008

Ed,
Thanks for the explanation that's a very interesting way to keep extremely contrast under control.
I will give it a try and do some experiments the next few weeks as I have some days off.
I had never heard about it before. This is a real eye opener for me.

Trevor Crone · Jul 9, 2008

It's good to see so many 'flashers' about I was begining to think we were a dying breed.

nworth · Jul 14, 2008

Flashing both raises the toe values and reduces the contrast of the print. Tim Rudman gives an excellent explanation of the process in his "Master Printing Course" book. It is important to find the time for the flash exposure. This usually involves making a test strip of just flash exposures and choosing the time just before the first visible density on the strip. There are a lot of variations, however, depending on the effect you need.

RobC · Jul 14, 2008

Yes Tims book expalins it very well. But the technique does require removing the negative from the carrier or having a second enlarger. Using a diffusion sheet under the lens doesn't and therefore makes the technique much simpler and a lot quicker to do.

CBG · Jul 14, 2008

rob champagne said:
... But the technique does require removing the negative from the carrier or having a second enlarger ...

Or having some other second light source on a timer, say, a dim and diffused ceiling mounted light that could flash a sheet or two sitting on the counter.

C

Paper flashing question

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