Problem seen in scan - my fault?

Jesse Haycraft · April 29, 2015

Project background: short film shot on 7219 with an SR3.

Just got back our 2k DPX from the lab. One of the rolls has double images in every frame, like ghosting. There's a primary image and then a half-opacity secondary image that appears identical but slightly above the primary image. Similar to ghosting from a filter but there were no filters used on this roll. There were multiple lenses used on the roll and the problem is consistent between the lenses. The same lenses were used on other rolls that do not exhibit this problem.

The roll in question was almost entirely shot wide open on Ultra Primes.

This roll was our only roll shot exterior and was pushed two stops. The lab says it's in the negative. What could I (or my AC) have done wrong to cause this? I can't think of anything. Is there anything that can be done?

I attached an example from our slate.

Edited April 29, 2015 by Jesse Haycraft

Jeff L'Heureux · April 30, 2015

This tends to be caused by a problem with the perfs not lining up properly on the registration pin between frames, or the film was shaky in the gate somehow. It's strange that it would happen on an SR3 though, as I've only had this happen on smaller hobby 16mm cameras.

I don't think it's the lenses though, and there's not much that can be done with this problem, unfortunately.

Josh Gladstone · April 30, 2015

How many different mags were you using? Have you used the mag that this roll was in before? Did you notice if the camera was any noisier while you shot that roll?

Edited April 30, 2015 by Josh Gladstone

Satsuki Murashige · April 30, 2015

Bad registration? Could be a mag that needs service. Check the camera report for the mag # and see if whomever provided the camera can repeat the problem. Probably also worth checking the negative roll in question with a loupe to see if it really is on the negative or not.

Jesse Haycraft · April 30, 2015

How many different mags were you using? Have you used the mag that this roll was in before? Did you notice if the camera was any noisier while you shot that roll?

We had three mags and I'm pretty sure we never used this mag again. I'll double check. The camera sounded the same to me while shooting the mag and roll in question.

Bad registration? Could be a mag that needs service. Check the camera report for the mag # and see if whomever provided the camera can repeat the problem. Probably also worth checking the negative roll in question with a loupe to see if it really is on the negative or not.

I will do all these things, thanks!

Jesse Haycraft · April 30, 2015

This tends to be caused by a problem with the perfs not lining up properly on the registration pin between frames, or the film was shaky in the gate somehow. It's strange that it would happen on an SR3 though, as I've only had this happen on smaller hobby 16mm cameras.

I don't think it's the lenses though, and there's not much that can be done with this problem, unfortunately.

It just seems to me that bad registration would cause jumping and weaving of the image, not double exposure? I'm really hoping it's the labs problem because if it's my fault it can't be fixed :unsure:

Edited April 30, 2015 by Jesse Haycraft

Satsuki Murashige · April 30, 2015

Hard to tell from a single frame. Definitely check the negative yourself ASAP, you want to rule out a telecine operator error first.

Simon Wyss · April 30, 2015

Were you in the cold with the camera, I mean on an evening or in the night?

Possibly a relatively warm mag and film (from a car or the case) were exposed to a cooler surrounding causing humidity to make the film stick in the gate. Traces of gelatine deposit can brake the film to a degree that the movement is overstrained.

Have a close look at the camera gate. It must not have the tiniest scratch or burr anywhere, else you have a gelatine deposit there instantly and that is sticky. Go over the races with the finger nail and feel whether they are really smooth.

Telecine error only when film is transported intermittently. In case of telecine fault, go on the them. Those idle rollers must turn freely and without much play. Film tension and capstan drive should be under constant control.

Film perforators function safely. Samples are constantly inspected. Least probable cause

Mark Dunn · April 30, 2015

If the lab say it's on the neg, then they've already looked at it, presumably.

Nicholas Kovats · April 30, 2015

Jesse,

I have replicated such a ghosting effect in my Bolex regarding film transport with b/w Orwo UN54 film stock. I ended up utilizing the footage for artistic purposes. The color portions are Kodak V50D color negative. Perforation quality? FIlm thickness? Same camera was used for both stocks. The transported Orwo appears to have a "sticky" quality to it. Some may point out I am comparing apples (Arri) with oranges (Bolex) regarding transport. C'est la vie. I hope this helps. Cheers!

Jeff L'Heureux · April 30, 2015

It just seems to me that bad registration would cause jumping and weaving of the image, not double exposure? I'm really hoping it's the labs problem because if it's my fault it can't be fixed :unsure:

It's certainly not your fault overall, unless it was a deliberate mistake with loading the mag, but it's an unfortunate risk that's taken when shooting film. It's not necessarily a double exposure that you see so much as if the film were moving in the gate as it is exposed, it would create a ghosting/smear effect similar to if you held the shutter open on a still camera and whip-panned around quickly. Nicholas' post above with the video is exactly the effect I got on my small 16mm camera on one roll that wasn't running through the gate properly. The likely culprit is that instead of the frame locked in place when the shutter came around to expose, for whatever reason it was already in motion towards the next frame, which causes the vertical smearing.

Josh Gladstone · April 30, 2015

It's certainly not your fault overall, unless it was a deliberate mistake with loading the mag, but it's an unfortunate risk that's taken when shooting film. It's not necessarily a double exposure that you see so much as if the film were moving in the gate as it is exposed, it would create a ghosting/smear effect similar to if you held the shutter open on a still camera and whip-panned around quickly. Nicholas' post above with the video is exactly the effect I got on my small 16mm camera on one roll that wasn't running through the gate properly. The likely culprit is that instead of the frame locked in place when the shutter came around to expose, for whatever reason it was already in motion towards the next frame, which causes the vertical smearing.

Right, this. It very well could be a timing issue, but I'm not sure about how the sr3 works, so I'm not sure it's possible for mags to cause movement timing issues. But that said, it's a safe bet that the mag needs servicing. I definitely wouldn't use that one again without having it looked at. This is why you name your mags and record that info on the camera report.

If it were me, curiosity would get me so the first thing I'd do is get some dummy stock, load that mag up, and run it open. See if anything is weird. You can also check the timing by making a mark on the film with a sharpie as it's in the gate, then advance one frame and see if the mark is still there. It should be gone since that frame should be advanced while the shutter is covering it. And again, since the other mags performed properly, it might not be the timing as I'm not sure that's possible on an sr3.

Robert Houllahan · June 25, 2015

It could also be a loop that is too short or when the mag was put on the body the loop was asymmetric relative to the gate aperture i.e. more loop after the gate than before.

Tyler Purcell · June 25, 2015

Yep, I just saw this thread and Robert is right. I've had lots of problems with the SR's if the loops aren't big enough. It's a common problem on that particular camera because you can't check the loop's when it's running like manual thread cameras. My guess is whoever loaded the mag's, didn't leave enough film hanging out for good loops OR didn't have enough slack on the return side of the mag.