Mystery artifact

[dourbalistar]

Not sure if this is the right subforum, but just digitized a roll of film, and saw this interesting artifact. This is the worst example, and the artifact doesn't extend beyond the image area onto the rebate in this frame. Some frames are unaffected, but smaller and lighter artifacts, all around the same location about appear in about 25% of the frames.

Any ideas what it might be? Pinhole in the shutter? Thanks in advance!

Leica CL, Nikkor-H.C 5cm f/2, Ultrafine Xtreme 400 (bulk rolled), developed in LegacyPro L110 at 1:31 for 5.5 minutes.


2020.02.29 Roll #238-04454-positive.jpg by dourbalistar, on Flickr

 

[Pál_K]

Since the light doesn't extend into the rebate area, I'll eliminate a light leak from the side or back of the camera.

What kind of camera is it - a folder, solid body, rangefinder, SLR?

The light I think is coming from somewhere in the area between the rear element and the front of the film gate (or film aperture). That's why it doesn't leak into the rebate area.

It seems too sharp and well defined to be a shutter or bellows pinhole. There must be some missing baffle, perhaps at the top, the viewfinder, or near the lens mount that let's light in when the camera is at an angle to sunlight.

Perhaps hold the shutter open at B and move the camera around near a bright light with the back open to spot stray light coming in.

 

[Mr_Flibble]

My first impression is that is a pinhole in the shutter.

Check both the curtains.

 

[TenEleven]

Seconding that this very much looks like a shutter pinhole.

From my experience the irregular shape is due to the light hitting the film at various angles when the camera and lens moves around as you walk.

 

[Beemermark]

I've had pinholes in shutter curtains and they always show up as a very define round dot on the film. Nothing like the OP
s picture.

 

[Freakscene]

Looks more like static electricity to me than a pinhole. If film is handled too quickly but without Being earthed, especially if it is very dry and/or very cold, it generates static electricity and when it discharges it makes marks that look exactly like this. It happened to us all the time in antarctica until we realised how slowly we needed to roll the cassettes and that everything needed to be properly earthed.

Have you tried developing any of the film straight off the bulk roll, or out of the cassette before exposure? It could have happened when the film was rolled into the 100’ bulk rolls, or when it was rolled into the cassettes.

Marty

 

[TenEleven]

I've had pinholes in shutter curtains and they always show up as a very define round dot on the film. Nothing like the OP
s picture.

I've had both kinds of leaks.



In my experience the distance of the shutter curtain to the film plane plays a role. Also how long the frame "sat" in the film chamber behind the holed curtain. Imagine a light source shining through a hole from various angles, it won't be so defined after a while.

 

[Malcolm M]

If it's a shutter curtain pinhole, it should show up holding the camera up to a bright light (the Sun) with the back open. If it only shows on some frames, it would depend on whether or not the shutter was left cocked.

 

[Pál_K]

Being that the artifact is generally in the same spot each time rules out static - though I agree the look is similar.

Which camera is this?

 

[dourbalistar]

Thanks for all the helpful responses, everyone! The camera is a newly acquired Leica CL, otherwise in very good cosmetic condition, with a functioning meter - vertically traveling rubberized cloth shutter, I believe. In any case, I think I've pinned down the source of the artifact (pun intended). After shining a bright light through the curtains, I indeed have a small pinhole in the shutter. 😡

TenEleven seems to also have nailed why the artifact is so uneven. I took this shot on a bright, sunny day, but the shutter was cocked and film wound for a bit while I framed the shot, and waited for some people to get out the way. Artifacts on other affected frames are more regular, slightly circular blob shaped.

Now the question is, what's the best way to repair? I've read liquid electrical tape, but any particular brand recommended? Do I need to paint the pinhole on both sides of the curtain, or just the back side closer to the film?

 

[Beemermark]

If it's really small a drop of liquid electrical tape put on with a toothpick works great.


Thinking about my earlier comment about what light leak would look like I realized mine were with a SLR (Pentax 67). So the mirror would have blocked the light except when I pressed the shutter and the mirror went up. With a RF the film will be exposed while the camera is moved around making a blob. One should always think before speaking -🙂

 

[Rob-F]

I've had pinholes in shutter curtains and they always show up as a very define round dot on the film. Nothing like the OP
s picture.

Agreed. pinholes tend to look like pinhole-sized dots on the negative.

 

[farlymac]

Thanks for all the helpful responses, everyone! The camera is a newly acquired Leica CL, otherwise in very good cosmetic condition, with a functioning meter - vertically traveling rubberized cloth shutter, I believe. In any case, I think I've pinned down the source of the artifact (pun intended). After shining a bright light through the curtains, I indeed have a small pinhole in the shutter. 😡

TenEleven seems to also have nailed why the artifact is so uneven. I took this shot on a bright, sunny day, but the shutter was cocked and film wound for a bit while I framed the shot, and waited for some people to get out the way. Artifacts on other affected frames are more regular, slightly circular blob shaped.

Now the question is, what's the best way to repair? I've read liquid electrical tape, but any particular brand recommended? Do I need to paint the pinhole on both sides of the curtain, or just the back side closer to the film?

After owning a few Zorki and FED cameras that seem to burn much easier for some reason, I can attest that it definitely is a pinhole. I've had this type, and the round dot type as it does pertain to how long the film was subjected to being in the area of the hole, and how long light was admitted into the film chamber. I used to always cap my lens immediately after each exposure to minimize the occurrence of pinholes, but then learned to keep the lens pointed away from any bright light sources.

I always used the LET on the lens side of the shutter as that way you shouldn't have to worry about the possibility of the shutter then dragging on the film. Make sure you let it air dry for a minimum of 24 hours before letting the shutter cycle. Otherwise it might stick to itself, and then you have a larger problem.

PF

 

[rfaspen]

Hole in shutter curtain. Count me as another certain vote. Seen it before..... unfortunately.