Anyone know for sure what causes this?

[dmr]

I'm talking about the blue-greenish stuff between some of the sprocket holes.

(Over on APUG, or whatever they are calling it now, I keep forgetting, PE appeared to be stumped!)

 

[sepiareverb]

Does this appear on your B&W films as well? I ask because I sometimes see this on some of my B&W films. I have always thought it was a light leak of some sort maybe in the felts? It has almost always on those polyester backed films with warnings of light piping, but I have had it appear on HP5+. Hope someone chimes in with an answer.

 

[dmr]

Does this appear on your B&W films as well?

Uh {blush} do you know how long it's been since I shot any true B&W film, let alone processed it? {looking for a place to hide ...}

This was Svema color, done in the Jobo.

I have always thought it was a light leak of some sort maybe in the felts? It has almost always on those polyester backed films with warnings of light piping, but I have had it appear on HP5+.

I would think that if it were a true light leak it would have spoiled the images, but they are all fine. It only affects the sprockets on the sides.

It may have been light piping, since the sprocket-hole shaped marks kind of go in and out of alignment with the actual holes. I'm trying to think of the handling of the roll after I shot it.

Since I got the Jobo I'm trying to get in the habit of rewinding slowly and leaving a tail out. That particular roll would have been at the beginning of a weekend trip and it may have been exposed to hotel room light for a couple of days. I do remember having the rolls I shot out on the table by the TV in the room.

 

[Highway 61]

I have always thought it was a light leak of some sort maybe in the felts? It has almost always on those polyester backed films with warnings of light piping, but I have had it appear on HP5+. Hope someone chimes in with an answer.

I have had it appear on lford PAN 400 135-36 too (all films of the same batch, with all my cameras, so the cameras are not the culprits and a friend having bought some Ilford PAN 400 135-36 from the same batch has this with his Leica M4-2 too), but always from frame 0 to frame 12 only (same for the friend). From frame 12 to the end of the roll it totally disappears and the film strip looks normal 100%.

If you look at the color negative pictured above, there is also a dark line along the edge of the film strip.

I too think of light piping through some defective felts or something like that.

As soon as it doesn't protrude into the images frames, no concerns. But it's quite close sometimes...

Below is a pic of what I get with Ilford PAN 400 :

Note : I have been processing my BW films at home for 35 years. I know how to do it. I always use clean steel reels and steel tanks and the same routine process. This is the first time I experience such a strange thing.

 

[PKR]

There isn't a lot I know "for sure"! But, those might be Surge Marks caused by a Nitrogen burst system. That section of film may have been near one of the jets.

If you're doing your own processing, I would think the Surge Marks may have to do with your processing methods and the location of that portion of film on your reels.

 

[x-ray]

I suspect it's caused mechanically when the film is being rewound or wound in the camera. I suspect the film is riding up and over the sprocket. It would be similar to the crescent marks from linking the film when loading it on processing reels. Film is sensitive to mechanical damage.

 

[brbo]

...nevermind...