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Help diagnosing a 16mm print issue.


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#1 Nima Khazaei

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Posted 05 December 2015 - 04:35 AM

Hello everyone,

I just had 16mm film printed for the first time, and noticed a strange anomaly in the print. I'm wondering if you guys could help me figure out what it is... Here's a picture of the print, taken through a loupe. The two thin white lines are obviously scratches in the negative, but I'm very confused about what the more diffuse line to their right is. I checked the negative, and it's nowhere to be found- it appears only in the positive.

 

When projected, it doesn't look perfectly straight- more wavy and with varying thickness.

 

Sincerely appreciate any ideas you might have :) Thanks in advance!

 

—Nima

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#2 Simon Wyss

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Posted 05 December 2015 - 04:51 AM

It is possible that the raw stock was not up to full expectation.

 

Perhaps a hair behind the printing aperture


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#3 Nima Khazaei

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Posted 05 December 2015 - 05:00 AM

Hi Simon,

 

Do you mean the raw print stock, or the raw camera stock?

 

Is it possible there's an issue with the negative that I'm not seeing?


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#4 David Mullen ASC

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Posted 05 December 2015 - 11:01 AM

Looks like an abrasion in the negative... a diffuse scratch-scuff rather than thin one.


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#5 Simon Wyss

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Posted 05 December 2015 - 12:49 PM

Nima, one usually prints from processed film, so the negative cannot be in question. You say you find nothing with the negative.

 

It might help, if you had a little more information about the lab, the printer, the staff. I have worked at several labs and know

very well what can happen in the dark and in the light. What I can tell from your picture is the type of printer, a continuously

exposing one, very likely a Bell & Howell model J.


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#6 Dirk DeJonghe

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Posted 05 December 2015 - 02:00 PM

Looking at it, I think it is a bit of dirt stuck in the printer gate. If it is not on the negative, the lab should reprint this reel.

Is it during the entire length or just a section? On a Model C printer there is air pressure at the gate to prevent dust sticking in the gate, but it could still happen.

Because the film is moving continuously, what would be a camera hair in a camera and show up as a dark spot near the edge of the frame, in a contact printer this would show up as a 'D-line' (technical term the lab people will understand). 

It would be helpful to examine the negative first, there is still a possibility it might be pressure sensitization (exposure by pressure on the emulsion).

 

The white scratches to the left of the D-line would probably disappear if printed wet-gate.


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#7 Nima Khazaei

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Posted 05 December 2015 - 09:24 PM

Thanks so much for your input everyone, this is incredibly helpful.

 

Dirk, it's for the duration of this reel, but it's not on other reels printed in the same order. Do you know if a wet-gate print would improve the appearance of scratches on the base side of the film, rather than the emulsion side?

 

I may ask the lab to reprint wet-gate. I just scratch-tested the camera and magazine again, and I'm quite certain the film wasn't scratched when I sent it in.


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#8 Gregg MacPherson

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Posted 05 December 2015 - 09:51 PM

 

.....I just scratch-tested the camera and magazine again, and I'm quite certain the film wasn't scratched when I sent it in.


If there is a scratch on the negative, the thing that made it may not still be sitting there.
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#9 Dirk DeJonghe

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Posted 06 December 2015 - 02:04 AM

Wetgate printing would completely eliminate any base-side scratches. These show up as white on the print. Any colored scratches are on the emulsion side and will not be affected by wetgate printing.

The lighter density unsharp area, to the right of the base scratches, appears to be a printing defect (D-line) and is a reason to reprint free of charge. If you have the same defect on a telecine transfer of the same negative then it is a pressure mark due to something in the camera touching but not scratching the emulsion side.

I would ask the lab to examine the negative and if the D-line is a printing defect, offer to pay the difference between dry and wetgate printing. You would then get a new print without the camera scratches.


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#10 Nima Khazaei

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Posted 07 December 2015 - 05:05 AM

Thanks everyone!

 

I'm going to give the lab a phone call tomorrow and hopefully get this resolved.

 

Gregg, I'm becoming more certain the scratches were not on the negative I sent in- they appear across this entire reel, which was composed of rolls from different magazines. The camera is an Aaton, so the camera body never touches the base side of the film, only the magazine does. Both of my magazines also passed scratch tests both before and after this shoot. Is there anything I could be missing?


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#11 Simon Wyss

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Posted 07 December 2015 - 10:38 AM

Yes, unfortunately a full catalogue of things

  • Fresh factory packed camera stock or recans?
  • Really no burrs and dings with mags? How about the magazine passage ways?
  • Really no mineral particles present with loading bag? Dark bag really clean?
  • Camera: gate never bumped by anything? Cleanliness upon attaching mags, camera parts above gate really clean? Hands? Gloves can be dangerous! Draft while loading, wind carrying particles? Yes, I know, this sounds ridiculous, but I know what it takes to process and dry a film that’s free from dust. The shot you show is made at dawn or dusk, so one can presume there was not too much daylight for a final inspection of camera and mag. Mag covers? Sometimes pressure air brings right in the unwanted.

 

  • How about processing machine mags and throats? Staples can dwell in the most unwanted places.
  • Squeegees? They can become terrible scratchers.

 

I leave you now with that. Quality prints are step prints. Continuous printers destroy the physical reference between positioning element and aperture or in other words, they don’t transfer the camera’s precision. DIN ISO 69 defines the datum edge and the +3 perforation hole counted from the optical axis as reference point. Don’t listen to the large talks on websites. Each lab is the best lab on the planet.


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#12 Gregg MacPherson

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Posted 07 December 2015 - 03:02 PM

 

  • Really no burrs and dings with mags? How about the magazine passage ways?


Nima said there was no change in the print with the camera mag changes, so it's unlikely to be them.
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#13 Simon Wyss

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Posted 08 December 2015 - 06:43 AM

You are right.

 

Burrs and dings with mags

 

Shift of emphasis towards laboratory


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#14 Nima Khazaei

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Posted 08 December 2015 - 05:53 PM

I talked to the lab- they were incredibly courteous and professional, and they appear to be taking this quite seriously.

The diagnostic they proposed was looking at the staple splices between the rolls. I examined one of them and it appears that the scratch goes over the splice rather than under it, indicating that it happened in the processing machine. This seems so simple, but I would never have thought of it myself.

I'm going to ship it back today for their staff to examine.
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