Combining split-grade printing techniques with paper flashing

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David Brown

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I love this website because before comeing here...if Fred Picker didn't teach me something (ok, and St. Ansel too), I didn't know it existed. I'm learning things about staining developers, sprlit-grade, f-stop printing, pre-flashing papers, etc., etc. that are quite a revelation to me.

Similar experience for me. However, I am more grateful to this site for the people I've met. Reading about flashing is one thing. Seeing a Les McLean or a Lee Carmichael DO IT and the difference it can make, is the revelation!:surprised:

And I wouldn't dismiss post-flashing as a "band-aid" until you've seen it in action. :wink: (Or, done it yourself.)
 

Bob Carnie

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I think Lees point about using a 5 filter alongside the post flash is a critical point.
I use post flashing at times to define a white sky and the paper white borders. When I can see a hint of edge tone I have flashed enough. To me there is nothing worse in a print than to have the borders and the edge of the image blending together to white. Unless it is a deliberate close crop fade to white.
 
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Pre or post flashing?

If post-flash = fogging (remedial addition of tone to a blown-out highlight), and preflash is a non-remedial method of overcoming the emulsion's inherent inertia to achieve better local contrast, then I understand what's going on. If that's the case, then I'm more interested in pre than post, though I am not dismissive of the need for bandaids in certain situations.

Can anyone tell me whether there's really a difference between flashing before the main exposure (pre-flashing) and flashing afterwards (post-flashing), as long as one uses the same filtration and exposure time? i.e. is there really some special chemical process involved in "overcoming the emulsion's inertia" when the paper hasn't had any previous exposure at all? Or is exposure just exposure, regardless of what order you give it in?
 

Dave Miller

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Can anyone tell me whether there's really a difference between flashing before the main exposure (pre-flashing) and flashing afterwards (post-flashing), as long as one uses the same filtration and exposure time? i.e. is there really some special chemical process involved in "overcoming the emulsion's inertia" when the paper hasn't had any previous exposure at all? Or is exposure just exposure, regardless of what order you give it in?

Yes, there really is a difference in results, the best way to understand it is to try it for yourself.
 

tim rudman

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They are different techniques with different outcomes and objectives Paul.
The split grading is really IMO to quickly get both the exposure time and contrast grade (filtration) matched to the negative. From there you can interpret the final print the way you want it without having to cope with unnecessary dodging and burning from having the contrast & filtration mismatched (what you might call rescue dodging/burning, as opposed to interpretative or creative dodging/burning).
It also gives you the option of dodging during either the Gr.)).) exposure or the Gr.5 exposure, or a combination - thus altering local contrast too.

Flashing is useful to raise the threshold of the paper to exposure so that it is much more 'sensitive' at the highlight end, where little light is getting through. This makes burning in either unnecessary or much easier when it is required. It also alters contrast and so can be used with graded papers for in-between grades.

The two techniques can be used separately of together as required.

Various flashing tools have been discussed here. The RH flasher has its own timer, which can be useful. It is commonly used on the enlarger though, near the lens. I find this less convenient as its distance from the paper - and hence the flashing time - changes as the enlarger is moved. I like to get a 'max-flash' time for a whole box of paper, which I can then repeat without re-testing for diferent enlargers. I also found that blu-tacking it onto the base plate tending to cause alignment shifts on my enlargers so be aware and avoid using pressure to hold it in place - elastic bands might be better. I find it simpler to use a second enlarger for flashing or a distant low wattage night light (I use both for different applications) - connected to my timer (I use the second channel on my R H Designs Stopclock Pro for this - very easy to toggle back and forth)

Another point to be careful of: If your flasher is not exactly in the negative light path (e.g. a distant flasher, or one alongside the lens or lens board, it will shine obliquely on the paper and if the paper is in the easle you will probably see an unflashed 'flash shadow' strip along one or two sides on the image. Don't flash in the easle unless you can exclude this.
Tim
 

jstraw

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Flashing all paper from the same, fixed distance makes good sense to me. It's got me thinking about a means to put an RH flasher on a swing-away arm next to my enlarger.
 

Lee L

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I can think of two alternate ways of getting consistent flashing when you need to raise and lower the enlarger.

1) With the flashing source mounted by the enlarging lens it will change distance as you change enlargement factors, but you can use an enlarging meter like the Ilford EM-10, Beseler Analyte 500, or a regular meter that reads low light like a Gossen LunaPro to set the light level or time from the flasher to be consistent with the needs of the paper.

2) Mount the flasher at a fixed height over a second easel for a consistent flasher to paper distance. Obviously you need to do the flashing either before or after all other exposures with this method.

When I was making 2000 custom B&W prints a month in a lab 20 years ago, I used an Ansel Adams style pre-exposure tool* under the enlarger lens with the negative still in place. I found that about 20% of the main exposure would do the job on the overdeveloped negs I was often given to print. I didn't have an enlarging meter in that lab. You could run the aperture up and down with this method to adjust flashing intensity. Place a black card over the paper if you need to meter at the baseboad without exposing it, or make the reading before you get paper out. A styrofoam cup over the enlarger lens could also work in the same fashion.

Lee

* See Ansel Adams "The Negative" for this. It's basically two pieces of translucent plastic spaced with thin cardboard around three sides, taped together, and sized to accept either 75 or 100mm Wratten gels in the space between the plastic through the gap in the fourth side.
 
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