trouble shooting in 65mm

[Delorme Jean-Marie]

hi all

 

i was filming recently an IMAX documentary about van gogh and we had a strange trouble shooting

 

a roll shot in 3 diferent locations shows the same problem : a light leek coming from the inside of the perforation ang going sometime in the direction of the edge and sometime in the direction of the frame.

and from both edges but not on every perf.

i beleive it's not a camera problem as in between we shot other rolls and we shot time laps as well as 24fps.

for me it could come from the perforetion machine at kodak.

it'c can't come from the lab as it was processed with other rolls the same day.

 

note that we had other cans with the same roll number stock was 5205

 

finaly we had to reshoot thoses takes

 

as anyone had a similar problem

[John Sprung]

The first thing that comes to mind is pressure latensification. If you squeeze undeveloped emulsion hard enough, it gets exposed by the pressure. Were there any really tight rollers holding the film to a sprocket? Any signs of mechanical damage in the light leak region?

 

 

 

 

-- J.S.

[Delorme Jean-Marie]

a total of 4 perfs dameged for a 1000 ft roll and some marks of a wrong pitch adjust on the first time laps....

maybe it helps to understand

[John Sprung]

Now that you've re-shot, talk to Kodak. If you send them the damaged film, they're quite helpful and honest in researching the problem.

 

It's a shame that John Pytlak is no longer with us. He knew much more than I do about this.

 

 

 

-- J.S.

[Delorme Jean-Marie]

yes i agree

John! we miss you

a shame they don't have internet up there