Flashing

T

Tokarsky

Active member
I have a very basic knowledge of the technique, but I'm interested in learning specifics about both how they do it and more in depth about it's effect of the film's characteristices like EI latitude ect. I would be shooting in 16mm on color neg. stock, what exact stock I have no idea yet, and if one color neg. stock is effected this way and another effected that way, that is going to be useful when choosing what film to shoot.
 
The best way to know how it will effect a particular film stock is to test. Test. Different stocks can react different ways. There are also different ways to flash. There are two (ok three) ways of doing it. Either in camera with something like a Varicon, or either before (preflashing) by % or after, which is the riskiest and rare method. The lab will have to do a pre or post flash, but some will refuse to do it as it's quite the risk.
 
Ryan Patrick O'Hara said:
The best way to know how it will effect a particular film stock is to test. Test. Different stocks can react different ways. There are also different ways to flash. There are two (ok three) ways of doing it. Either in camera with something like a Varicon, or either before (preflashing) by % or after, which is the riskiest and rare method. The lab will have to do a pre or post flash, but some will refuse to do it as it's quite the risk.
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I've heard about this for movies... with still sheet film, it seems almost 'doable' but for movies, does the lab sort of have a continous feed of the film, 'flash'ing s the film moves by, then when used, the frames endup
where ever they are in terms of sprocket alignment?
 
There is actually a fourth way, which is from my understanding was the most prevalent, which is from the inter-positive to inter-negative stage. However, this is not a modern 16mm workflow solution. My question is, outside of a very specific look, why would you want to do this with 16mm film? Modern motion picture color negative film stocks have such a high dynamic range and latitude that I really can't image a situation, exposure wise, that could not be handled with a fast stock and push processing. Most modern stocks. if properly exposed should be able to handle a 2 stop push without too much of a problem. Well, without too much of a problem that can't be handled in post anyways. If you are anticipating situations where you think that flashing a 16mm stock may be needed, I would suggest maybe increasing the light level, using a higher speed stock, and maybe pushing the stock a stop or two. Then you can control the images contrast in video post, which will give you much more control.
 
David G. Smith said:
Modern motion picture color negative film stocks have such a high dynamic range and latitude that I really can't image a situation, exposure wise, that could not be handled with a fast stock and push processing. Most modern stocks. if properly exposed should be able to handle a 2 stop push without too much of a problem.
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I've never 'pre/post-flashed' my film, but I was under the impression the 'flashing' was to boost low lit areas, to give more 'density' which then could be 'boosted' with either plus development, or in the case of stills, a contrastier paper. I recall it be used by news people who had to get an image, any image, and there wasn't enough light. Since it was for ephemeral news work, no one was going to worry about shadows that had a blank flat look, if there wasn't enough light for details to be boosted.

Pushing doesn't boost shadows as much as mid to high values.
 
For some examples:
The Summer of Sam by Ellen Kuras was pre-flashed
Kaminski used a Panaflasher (during shooting) set at 15% on Saving Private Ryan... the reason he flashes is because when he does a custom process such as ENR, the picture gets contrasty and he uses flashing to bring the image back. He did the same on Amistad.


About percentages: Christopher Probst, a great writer for AC magazine and AMAZING DP wrote a famous article years ago called Soup De Jour... there he explains:

"It's like when people talk about a percentage of flashing," he elaborates. "A client may ask for a 10 percent flash. Well, what does that mean? In the lab, a 10 percent flash is the addition of a .10 density over a simple D-min [or clear reading] in each color. For instance, if you have a D-min reading of .06, .06, .12 [R-G-B], then a "10 percent flash- would result in subsequent readings of .16, .16, .22 respectively."
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In the 16mm world of reversal films "in the olden days", flashing was primarily used to lower the contrast of Ektachrome EF film. This 125 ASA Tungsten stock was used both as a news film, (where the camera original film was projected in the film chain) and for broadcast documentaries where high quality prints had to be made. Flashing in the lab (essentially a controlled, low level fog) lowered the contrast enough to print from. It was quite reliable and widely used at the time. Quite obsolete today, of course.

Also, there were some feature films in the late '60s,early '70s where it was used for effect.

Ken
the Screen Skins guy
 
Did you pre-flash or do it before developing? That would make the most sense considering the Panaflasher and Varicon are the only devices I know and they both are not 16mm friendly. Flashing is almost always before development.
 
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It is most effectively used to lower the contrast on very high contrast film but it is used for other methods as well like raising the sensitivity of the negatives black range. Some would argue that this is is the same as lowering the contrast.
 
I always had the lab flash before development. The cameraman who actually started this trend in the '60s did it in camera BEFORE shooting (pretty risky, but it worked for him). When the local labs began offering the service, flashing before development became the norm.

Wow, I had almost forgotten about the Panaflash. An interesting tool that provided unique results. As with any new tool, testing was required (shoot, develop, print) for repeatable results. You couldn't just fire it up, eyeball it and expect "WYSIWYG".
Ken
the Screen Skins guy
 
Flashing is the technique of subjecting the negative to a controlled uniform exposure prior to developement, usually to reduce the contrast of the image
by affecting the toe (shadow) of the sensitometric curve of the film. Sometimes it is used to achieve matching contrast between different films. Most requests
for flashing are between 15%-30%. The only way to know how it will affect a certain stock is to run tests, or to talk with someone who has flashed the same stock
you will be using.
 
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