Flashing

Wanted to know why and how is flashing done? What are the results of flashing on the contrast and is there any different kind of light used for flashing?

Thanking you
Saurabh Goswami
India

Flashing involves exposing the film to an overall weak amount of light, like fogging the film evenly. The light can be white or it can be coloured. The effect is to lift some minor detail buried in the shadows and to lift the blacks, lowering contrast. It also softens color saturation. Using coloured light for the flash will tint the shadows and the blacks that color.

You can flash in-camera using the VariCon in front of the lens in a 6x6 mattebox -- or with a Panaflasher on a Panaflex or you can have the lab flash the film. Or you can do it yourself by exposing the film twice, but that's a real pain. You shoot an underexposed grey card that fills the frame (just shoot it out of focus) and then rewind and reload the film and shoot the scene. In 35mm, you'd have to make sure you re-exposed starting on the same perfs.

I've found that a 5% to 7% flash will improve shadow detail but anything higher than that and you are just lifting the blacks without gaining any more shadow detail. But you still keep lowering the color saturation and the PERCEIVED contrast (although not gaining any more shadow information beyond a certain point.) A light flash is good at "unburying" detail just on the verge of visibility (like around 4 stops under) but doesn't help stuff that is really underexposed (more than 5 stops under).

Mark Woods wrote a good article on the subject for ICG Magazine :

http://mywebpage.netscape.com/markwoods9/Flasher.html

David Mullen, ASC
Los Angeles

I would add that I am talking about flashing the negative here. Flashing the positive (print or IP) lowers contrast by darkening the whites and bringing in some overexposure detail (but mostly it is just greying out your whites.)

"Heaven's Gate" flashed both the negative and the prints. I had heard a rumour that the prints for "Reds" both used the ENR silver retention process and were slightly flashed. "Tootsie" had their IP flashed. But positive flashing is much more rare.

David Mullen, ASC
Los Angeles

I wonder if flashing will become more common with the onset of DI. Theoretically one could add a flash to bring out shadow detail and then restore the blacks somewhat in digital timing such that there's more shadow detail but the image isn't completely washed out at all.

Art Adams, DP [film|hidef|video]
San Francisco Bay Area - "Silicon Valley"
http://www.artadams.net/
Local resources : http://www.artadams.net/local

>I wonder if flashing will become more common with the onset of DI.
>Theoretically one could add a flash to bring out shadow detail and then >restore the blacks somewhat in digital timing

A good idea but I sort of think the opposite will happen -- flashing will become even less common with DI since (1) we now have lower-contrast negative stocks anyway; (2) we can digitally simulate the flashed look; and (3) we can adjust the gamma curve of the negative with digital color-correction to allow more shadow information to appear in the final print made off of the digital negative. So flashing probably becomes more bother than its worth at that point.

David Mullen, ASC
Los Angeles

David Mullen writes:

>we can digitally simulate the flashed look

Wouldn't it still be better to flash the original negative? Wouldn't you have cleaner blacks that way because you wouldn't be forcibly bringing up the grain and grunge?

Dan Drasin
Producer/DP
Marin County, CA

>Wouldn't you have cleaner blacks that way because you wouldn't be >forcibly bringing up the grain and grunge?

Well, by definition a flashed image doesn't have clean blacks but greyed blacks. I suspect that simply lifting the video black level a little to simulate a light flash isn't going to lead to much grain and grunge -- after all, one plays with the black levels all the time in digital post to match shots that vary in contrast and black level, like scenes shot with smoke in the air. Both flashing and digitally milking up the image a little will unbury some low-end detail and also bring out the grain structure in the shadows a little more, either way. I think the question is whether the digital method would also bring up noise in the shadows. I suspect if the lifting is mild, probably not.

Anyway, I think low-con negative stocks have better shadow detail than flashed regular-con negative stocks. My own experience on "Northfork", where I flashed F-125T slightly more to match the look of the less-flashed F-400T showed me that while I could match the blacks this way, the F-400T still had more shadow detail.

My point is just that while a light flash may improve shadow detail on the regular negative stocks, which could be helpful in the telecine bay, using a low-con stock would probably be simpler. So the need for flashing as a method of improving shadow detail is less strong now that we have lower contrast stocks and DI's.

David Mullen, ASC
Los Angeles