Black mark on film

[Fly Ricky the Wine T]

Hi,Hi,

I've got a problem with my Contax T3, there is a small black mark, a small sharp curved line on a lot of my frames (in negative). It happened many times. It's on the same spot, and on a majority of frames. I don't understand why it's not on all the frames ! I tested the camera with all the apertures two times. One time, it was on all frames. I cleaned the camera, I retested it, and it was on none. But the problem reappeared on the next films ! The intensity of the mark varies depending on the received light, a picture of a wall doesn't have it, but a picture of a street with the sky have it, cloudy scenes don't have it neither.
What can it be ?
Thanks

 

[farlymac]

From the way you describe it, I would guess you've got something caught up in the shutter guides that comes out every so often, casting a shadow on the negative. Unless you are saying it's a black mark on the negative, then that would be a light leak. But without any photos of the problem, it's hard to diagnose.

PF

 

[mikemc_photo]

Could be loose light trapping, or static discharge. Post up a print of the flaw

 

[Fly Ricky the Wine T]

Here are some examples. The mark is allways on the same place.

 

[farlymac]

That's light. Could be a flare when the lens is pointed in certain angles to the sun. That would explain why you don't get it every time. Problem with most P&S cams is no where to mount a hood. Some of the earlier Canon and Nikon models did have filter threads, and Ricoh put a clip-on hood on their later versions of the GR1.

PF

 

[Fly Ricky the Wine T]

That's light. Could be a flare when the lens is pointed in certain angles to the sun. That would explain why you don't get it every time. Problem with most P&S cams is no where to mount a hood. Some of the earlier Canon and Nikon models did have filter threads, and Ricoh put a clip-on hood on their later versions of the GR1.

PF

Thanks for the answer, I found people that have what seems to be the same problem with the Contax T2
https://www.flickr.com/photos/27897439@N03/5804978157/in/photostream
Actually, there is a hood for the Contax T3 and it's pretty pretty pretty expansive. I could try to make a fake hood for the moment just to test that hypothesis.
I planned to sell the Contax so it's really bugging me.

 

[Fly Ricky the Wine T]

But I don't see anyone who talk about having flare with the Contax T3... What could be causing this on mine ? A coating problem ? A metallic part inside that reflects on the film ?

 

[Steve M.]

Open the back, put the shutter on B, and look to see if there isn't some sort of debris sticking up from one of the bottom corners, from the looks of it. I've had this sort of mark show up on old folders and it's usually a bit of the bellows threading coming loose.

 

[j j]

As per Steve M. this looks to me like an object in the camera.

I struggle to see how flare could be so consistent in effect and the middle picture with the camera pointing at the ground looks an unlikely candidate for flare.

The on-off nature of the effect may be due to aperture: I had a hair on the sensor of a DSLR that was well-defined when I used a very small aperture and far from obvious at wider settings.

 

[Rob-F]

The streak looks dark on two of the negatives, and light on the third. (I assume all three are negatives, as I can see sprocket holes on each. And they look like negatives.) This might be a clue: of what, I'm not sure, but I tend to agree it is something inside the camera.

 

[k__43]

I had a mark on my frames with my M2 - always at the same location same size etc .. independent of aperture, focus and focal length (although it appeared more often with wides) .. it was always there when the light came from a specific direction.
I always suspected a scratch on the surface of my RF coupling so I took it apart and painted some black paint over it. It disappeared.
Check for something that could reflect light behind or in the lens

 

[farlymac]

First of all, the first and third photos are negatives, while the second is a print. Something inside the camera blocking light to the negative will leave a white mark on the negative, creating a black mark on the print. A light leak or flare will create a dark place on the negative, thus creating light areas on the print.

If this was something inside the camera blocking the light, I would think it would also show all the way to the edge of the negative. There is the possibility of an internal reflection too, which I forgot to mention. I don't understand why it would disappear after a cleaning (the level of which I would assume was just opening the back of the camera, and swiping the lens with fluid), then reappear.

I think it's just going to take a bit of perseverance by the OP to figure this one out.

PF

 

[DNG]

I too think is a hair, or felt...

check the right-upper corner in the camera...
The image is recorded upside-down and flipped in the camera.

 

[B.J.Scharp]

Since the mark is black on the negative, it's excess light, not lack of it. So it can't really be something in the camera. From the look of it in the second (non-negative) picture, it's probably flare. Have you tried shooting a roll of color, to see what it looks like then?

 

[ottluuk]

It does look like flare/reflection, especially the one in the Flickr link in post #6. It could be a reflection off the outer edge of a lens element that is not blackened properly or perhaps from a worn inner edge of a diaphragm blade.

A light leak would show up as a fuzzy blob, not a well-defined line like that (unless the "hole" was very close to film).

 

[Rob-F]

First of all, the first and third photos are negatives, while the second is a print.
PF

I'm not sure about that. I see a sprocket hole and a frame line in the picture. Could be, but could the OP verify this?

 

[farlymac]

I'm not sure about that. I see a sprocket hole and a frame line in the picture. Could be, but could the OP verify this?

The middle one appears to be a contact print, or a reversal of the scan. That's why the sprocket holes are black, as opposed to the first and third being white.

PF

 

[Fly Ricky the Wine T]

Yes, it's the reversal of a scan, sorry I hould have mention it.
Thanks for all the answers !
So, there are two possibilities :
- a particle inside the camera (which seems unlikely to some of you)
- a reflection inside the camera

I'm gonna test the first one, since it's the easiest. Cleaning the camera, watching closely for anything inside and develop a test film. And if the problem's still there, I'm gonna try to disassemble the lens. Hoping to not break anything...

 

[farlymac]

Before you take it apart, shine a flashlight into the lens from both directions to see if the reflection is visible. You might see a shiny spot.

PF

 

[Photo_Smith]

Looks like internal reflection, I've seen similar in the mirror box of a camera near the film plane where the matt black paint was damaged.
Also note the mark looks to be in the same place on two different shots and is consistent, that is it varies in density about 1/3 of the way along in both images.

I doubt it's a bit of 'fluff' as that would be the the inverse density of what we are seeing and would need to touch the film plain-it can't be though as it would need to be black in the positive shot.

Is it more prominent on outdoor shots? Ones with sky in particular.

Look for damage to the internal light baffles or missing scraped matt black paint.