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Xavier Cunilleras

Light Leak. Camera or lab ?

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Hello everyone, 

We just received the scanner from a 35mm project shoot with Moviecam compact 3 perf camera. The lab says the camera or the magazine might have a light leak. 

It is a small burn with greenish color on the left hand side of the frame thru all the footage with different magazines. Sometimes that has happened to me in either stills cameras or motion picture cameras it always results in a much larger fogging or a yellowish burned color.

I am confused since the color is strange and also it happens all over the footage. Any ideas would be greatly appreciate it. could be the lab ? or could be from the black magic cintel scanner ?

Many Thanks

I have included a still from the scans as examples.

frame1.jpg

frame2.jpg

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Nice frames! 

Have you been able to check the camera reports to see if you can narrow the light leak down to specific mags? If it’s happening across all mags, then it could be the body or the lab/scan. 

How about examining the negative - can you see the light leak on the actual film? If so, then it’s unlikely to be the lab, though not impossible. If it’s not on the film, then it’s probably from the scanner. 

If it’s a green light leak on the positive image then it should be magenta light on the negative, right?

Was the film factory fresh stock? Or re-cans and short ends? 

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Hi Satsuki,

I has happened all across the magazines, and the body I tested prioir to the shoot and it had no problems.

I am waiting to recieve the negative to be able to evaluate it there; and yes as you mention iI think t should be magent on the negative.

The stock was a fresh new one from Kodak 5219. the curious note is that it is always on the same side, same position with pulsating movement, so I am not sure what could be.. in any case I didn't knew it could be from a problem or defect in the scanner:I will call the lab tomorrow to ask about it.

When I was a loader, I always kept a piece of film of about 5 cm that went already thru the magazine in case something happened in the negative I always had my safety card on that piece of film that could be develope afterwards and if it was different from the original negative I could probe is a lab problem, shame I didn't ask it to do it this time...

Thanks

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Is the fogging on the perforations as well or only in the image area?

Since its on the left side of the image it would have originated on the right side of the negative. Maybe the top magazine port had a small leak or something in the video tap assembly or eyepiece was introducing stray light? 

Thankfully its small and subtle enough that you still have a large useable image area if you decide to crop.

 

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If it’s a camera light leak it’s a pretty odd one, consistently green and bright even when you shot in what looks like a red light dark room..

Sometimes the glow from a ground glass glow mask can mistime or otherwise hit the film, but the Moviecams I’ve dealt with (Compact 2) have the glow light in the viewfinder, removed from the ground glass area. 

I’m curious to hear if it’s on the neg, until then we’re just speculating.

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Yes inded is a weird one, and since right now to send the camera to service in LA would be difficult I want to understand if it comes from any of the parts of the camera or the Lab.

The camera is moviecam compact MKII

Yes the light leak is on the negative but curuious enough is just on either side of the perforation but not affecting it. Very consitent thru all the magazines and always on the same spot with the same intensity and color.

I am attaching 2 stills from the frames I previously uplaod.

thanks

WhatsApp Image 2020-07-29 at 10.15.34.jpeg

WhatsApp Image 2020-07-29 at 10.19.57.jpeg

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The only thing in the camera I can think of that could create a consistent green patch at each frame would be the glow mask. Just looking at the manual, there is an “LCD Movielite module” that the manual says is not compatible with S35 (I don’t know why, the cameras I used to know only had the later mask style Movielite module, which were S35 compatible). 

Is it possible your camera has the earlier module? Were you using a glow mask to see the framelines in the viewfinder?

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The fogging is at 4 perf interval while the format is 3 perf.

Sorry,

Need to remove my facemask, I miscounted.

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38 minutes ago, Dirk DeJonghe said:

The fogging is at 4 perf interval while the format is 3 perf.

No it’s in the same spot on each frame, every 3rd perf.

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From a lab perspective I would say that it would be hard for a processor to make a consistently repeating exposure like that, as the film on the load side of the Processor is on a flange then into a load elevator and then the prebath/remjet then developer all in the dark.

Typically if there is a light leak in the processor before the developer it would be a streak not a repeating pattern.

 

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My processing machines don't even use the perforations, I can process unperforated stock just as easily. Those processors that use sprockets will most likely be multiples of 4 perf interval as well.

On the other hand, the perforators at Kodak only work in 4 perf, so that is excluded as well. Remains only the camera as a suspect;

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16 minutes ago, Dirk DeJonghe said:

My processing machines don't even use the perforations, I can process unperforated stock just as easily. Those processors that use sprockets will most likely be multiples of 4 perf interval as well.

On the other hand, the perforators at Kodak only work in 4 perf, so that is excluded as well. Remains only the camera as a suspect;

Almost all processors are demand drive not sprocket, the sprocket drive processors were usually made for high speed print processing like the TFS 1500ft/min machines they used at Tecnicolor and DeLuxe in the days of film prints. PhotoMec / Allen / Treise / Calder processors are no sprocket demand drive.

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I have two demand drive and one sprocket Treise machine. The second Treise was 35mm only and was dismantled.

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Many thanks to everyone.

Yesterday I did some more test with 50D and 500T and will develope today to check if the problem in different camera speeds and magazines still persists.

I think that yes, might be some very small leak or led in the camera that is fogging the image slightly. I did run the camera with the door open in a totally dark room and I didn't see any dim light like a glow mask or LCD movielite module, which I double check and is the MKII version one.

What is really strange to descipher is that there is one take that the leak is more prominent with a very sharp round burn ( picture attached ) that just last for that specific scene and then return to the usual leak every 3 frames.

IMG_5202--.jpg

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Posted (edited)

All six of our 35mm machines are Triese sprocket drive machines...  The very last machines Tom ever made...

Edited by Frank Wylie
update
  • Like 1

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I was going to ask if the camera has a film timecode system installed, it should be a little matrix of LEDs in the gate, the placement of the fogging/mark seems outside of where that would normally write into to the film but maybe if there was something off about it this could be a cause?

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Odd that it’s a small round circle and then a sideways dash next to it, every third sprocket hole in the same place. And sometimes the burn is fairly defined and other times it’s blurred, even as the film is moving in both cases. So it must be a light source that can move slightly in the vertical dimension, but can also be static.

Given the orientation of the film image, it should be on the left side of the film gate, near the film door, no? Or on the right side of the ground glass.

Have you pulled the film gate to see if there might be any irregularities there? Pressure plate? 

Is there a video tap on the camera, and have you tried removing it from the optical path? 

The burns around the sprocket holes are also odd. Maybe connected?

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Posted (edited)

When you shot your tests did you have a lens on and in a lit environment?

Might be worth running a bit of film with no lens, eyepiece closed and the camera covered in a dark room to rule out it originating from inside the camera somehow.

Edited by Evan Walsh

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Try running the camera without a lens, in a dark room and look towards the filmgate through the lens mount.

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