Home of Professional Cinematography since 1996

Blue Fog Waves

Published : 19th November 2003


Waiting to hear back from the lab inspecting the neg, but...

We had intermittent blue fogging on 2 consecutive B-Camera rolls B97 & B98. The picture is pristine, then a gradual blue fog evenly fades-up and overtakes the picture - after 3 seconds it peaks then fades out again to a pristine picture.

I do not suspect the SR3 cameras/mags since :

- Looks nothing like a camera/mag light-leak (its too even and fades up too perfectly and slowly).
- Camera did not light-leak onto other mags used.
- Same 2 mags did not leak with other rolls (M#7773 & 2364)
- Seems unlikely that 2 adjacent mag rolls would leak so similarly

It's not the Loader since :

- Does not look like a flashed roll where you'd have edge fogging on one side or throughout the reel.
- She's really solid and experienced.

I do not suspect the film manufacturer or storage since its unlikely that two entirely different emulsion batches would have the same problem on 2 consecutive camera rolls.

Due to all of the above I am suspecting an isolated problem at our Lab since :

- It's the same problem on 2 adjacent camera rolls assembled at the tail of the lab reel.
- It looks like it could be a problem in the yellow dye developer layer (or fixer?)...perhaps the machine slowed down and the rollers dipped in that tank got overdeveloped ?
- Otherwise it would have to be some overall light exposure that could only occur when the film was unspooled (the anti-halation layer wasn't helping here - it was a very even fogging).
- The frequency of the intermittent fog waves is too long to be a camera issue - it seems to come and go on a larger scale than what's possible in a camera, and seems to fit the scale of the lab developer machines.

If anyone has any experience with this sort of problem, let me know on or off list.

Mark Doering-Powell
LA based DP



Mark,

Although this end of the business is no longer my specialty, it sure sounds like lab to me.

I'll bet there was a break during processing. The film after the break point stopped moving and they had to turn on the overhead lights to fix the break. The film that was looped over the roller at the top of the tank got most exposed by the overhead lights - the most blue fog - and the exposure gradually fades away on the film on either side of the roller as the film descends deeper into the tank...or something pretty similar.

Have you talked to the lab?

Hope this helps!

Andy Coradeschi
President
Straight Shoot'r Cranes, Inc.



If your film stock is Kodak, contact your marketing rep who can have a length of the negative sent back to Rochester for examination.

They should be able to ascertain if the blue fog is pre exposure, during exposure or post-exposure.

Paul Maibaum
DP/LA



Hi,

Out of interest, just exactly how do they do that? It strikes me as Very Clever.

And on an unrelated topic, well, a slightly related topic, where does the word "Kodak" actually come from?

Phil Rhodes
Video camera/edit
London



>where does the word "Kodak" actually come from?

If I can recall correctly from my high school days (or was it primary school?), it comes from nowhere actually. George Eastman thought a commercial name should be short and with a strong sound (that was where the use of repeated K's came from) and also should have no meaning; and, as a result he produced KODAK (instead of Eastman, or Photox, or Supercalifragilisticoexpialidoso).

Arturo Briones-Carcaré
Filmmaker
Madrid (Imperial Spain)



>We had intermittent blue fogging

The exact frequency of the fogging is the smoking gun clue here.

You need to measure the exact distance from one peak to the next. That may well correspond to the exact length of the roller racks in the developing tanks. Also, how many times does it happen altogether? It sounds as though it starts in one reel and continues through to the next. All the clues point to the processing machine. The blue colour would be due to daylight fogging affecting the top layer before or during development. Not fixer, the film is no longer light sensitive at that point. A slow-down or stop wouldn't give you the blue - more likely that someone opened a tank lid when they shouldn't have done, or possibly the darkroom door was opened too soon.

Of course your lab should be able to work this out if they examine the negative. Try to get you production office to let them do this - so often we are unable to properly investigate problems because the negative is (a) "useless" but (b) mustn't be handled or examined or cut up or sent to odak or anything "in case we need that take".

Dominic Case
Atlab Australia