Pre Flashing Film - Anyone Do It?

[Colorado CJ]

As winter is here, and many days have very flat light, with white skies, and snow on the ground, I am wondering if I should try to pre-flash some film.

Has anyone done this, does it really make a difference in such low contrast scenes? What are the positives and negatives of pre flashing? Lastly, what is your technique when pre flashing film?

Here's one example of where I might like to try pre flashing. I don't know what exactly it would do, or if it would help, as I have no experience with it. This scene spot metered between 14.5 EV - 16 EV.

Winters First Snow by Andrew Marjama, on Flickr

[Jac@stafford.net]

Preflashing lowers contrast. Is that what you want? Grey snow?

[Michael E]

Or more detail in the deep shadows? That's the reason I use it sometimes.

[TrentM]

I've pre-flashed, as described in Ansel Adams' "The Negative". It is a method that boosts shadow detail in high contrast scenes to a higher zone (the norm here in south FL). For low contrast, I would expose for an N+1 to create more separation between grey scale tones and boost pure white (zone VIII+).
For your beautiful snow scene like your original post, with very low contrast , you could add sparkle to the snow by slightly over-developing the film...but be careful. you might want to go out and shoot several sheets under your low con conditions and try raising development time by a few percentage points for each. If you are printing in a traditional darkroom, you could them determine the correct expose on your selected paper

[Colorado CJ]

I definitely don't want grey snow. I guess I had it backwards what preflashing does.

I'll try some N+ development times and see what I can come up with.

Just trying to get a little more "pop" from these very low contrast scenes.


It does sound like pre flashing might be a good idea when the skies clear up and there is a high contrast range between the snow, shadows and sky though.

Looks like I need to reread "The Negative" since I got it completely backwards of what preflashing does.

[Michael R]

Exposure of film (or paper) to non-image forming light (pre-exposure/flashing, flare) raises the densities of low exposure areas, but decreases contrast in those areas. Generally speaking it does the opposite of what you want when you are trying to maximize contrast.

Nice photo, by the way!

[Jerry Bodine]

[QUOTE=Colorado CJ...Looks like I need to reread "The Negative" since I got it completely backwards of what preflashing does.[/QUOTE]

You'll find it under "Pre-Exposure" in the index (p. 119 in my copy). Read it very carefully, as there are important precautions to heed.

[Jac@stafford.net]

Or more detail in the deep shadows? That's the reason I use it sometimes.

An amusing tip: if your image doesn't have sky in the frame, shoot with a blue filter. The shadows will fill as if you used a small second sun for fill.

[Jim Jones]

For sunlit snow, a red filter deepens shadows which boosts texture and contrast a little.

[Drew Wiley]

I never flash except once in awhile to correct a color cast in shadows using color film. It muddies up the shadows, though some people might still do it. I'd rather
just use a film properly matched to the anticipated contrast range of typical scenes, then develop as needed for printing contrast. In this case, just plus develop.