Hard shadow on hasselblad negatives

[Dr Dik]

I just took a close look at my camera and back, and I can't figure it out. It's definitely not the clamp. Why the shadow areas are on both sides of the negative is a mystery. The problem looks nothing like a light leak, which would be bright and scattered in my experience. It's more of a very precise "dark leak", and only on two of the edges.

Does every frame have exactly this problem? And do different films show this issue the same way? Do the darker areas move at all from frame 1 to frame 12?

I'm trying to think of how this effect could happen after the film leaves the camera but that seems a dead end too because problems outside of the camera tend to add light to the film. And if the problem was in the developing tank I'd not expect the problem to be on both sides of the negatives and with such precise lines.

Edit: I wonder if this is a minor light leak from the sides that is slightly overexposing the film everywhere except the shadow areas? (I doubt it, but still.) You can check this by exposing a roll of film with the perimeter of the film back taped with light blocking tape. If you try this, be careful with the tape which could damage the camera if it's too tacky. If this test yields the same dark strips on the negatives then the problem is between the lens and the film, rather than a typical light leak.

This problem occurs sporadically and the shadow line area can appear on either side of the negative. It’s most obvious in sky tones. I’ve looked at the 501 and SWC bodies for weirdness that might be casting this shadow but don’t see anything. I’ve dealt with many light leaks on LF and 120 cameras but nothing like this.

 

[Eric Rose]

I wish I could help. I have been shooting blads since 76 and have never seen this issue.

 

[warden]

This problem occurs sporadically and the shadow line area can appear on either side of the negative. It’s most obvious in sky tones. I’ve looked at the 501 and SWC bodies for weirdness that might be casting this shadow but don’t see anything. I’ve dealt with many light leaks on LF and 120 cameras but nothing like this.

Since the problem is sporadic I'm thinking @Photomultiplier might be right. Are you using a lens hood?

 

[Dr Dik]

I wish I could help. I have been shooting blads since 76 and have never seen this issue.

Thanks.

 

[Dr Dik]

Since the problem is sporadic I'm thinking @Photomultiplier might be right. Are you using a lens hood?

I use a lens hood when I remember to put it on. I’ll try to leave it off and see what happens. Sure can’t hurt! Thanks.

 

[Dr Dik]

Could the problem lie in the body rather than the back? Is there some sort of auxiliary shutter/baffle that opens when the mirror tilts up? I only have an SWC, no mirror or anything there, but my Rolleis have some sort of baffle between the film and the mirror.

Pieter, it occurs with both the SWC and 501.

 

[Dr Dik]

@Dr Dik this must be the most fascinating "help me investigate the problem" thread I've seen online. I am now as motivated to find the cause as you are Do you mind clarifying a few things:

* Does every shot has a shadow?
* You said it shows up on both sides. At the same time i.e. on a same negative?
* Do you have another film back which doesn't have this problem?
* Is the width of the shadow consistent?
* Do you keep the camera loaded with film for extended periods of time? What do you think would happen if you load a film and quickly expose all 12 frames and then develop it?

Thanks.

[EDIT] Basically I'm thinking of a camera being stored for some time near a source of a weak radiation which slightly fogs the entire negative (or even the entire roll). But a single frame under the pressure plate would be shielded by the thick film back frame which is almost half inch of metal if penetrated sideways. If you store the camera in one of two orientations (one side towards the radiation source vs another) this would explain the shadow only on one side at a time, and only on some frames.

The width off the shadow is consistent. It doesn’t happen on every exposure on a roll and it can happen on either side of the negative but I haven’t seen it on both sides at the same time. It happens with more than one back. I don’t know where I’d be getting weak radiation exposure but anything is possible I suppose.

 

[Dr Dik]

The "clamp" lies outside the film gate and is therefore not visible.

The attached picture (low quality handheld DSLR shot with light box) shows the same kind of shadow. I already mentioned this shot some time ago in an similar discussion.
Here it was caused by an internal reflection of bright objects, in that case the sun, from the inner wall of the body. This leads to a diffuse light coming from outside the film gate and
is therefore able to cause this kind of shadow.

Root cause in my case was not using a lens hood. Blocking out the sun with a hand, body or other objects also works.
The sun was not in the picture, but within the image circle of the lens and got projected on the inner wall of the camera.

Same issue! Wow. This is the most helpful suggestion yet. Thanks. I’m not religious about using my lens hoods and I’ll try that. Onward!

 

[Eff64]

That is the image from the film clamp on the edge of the film back. Nothing to be concerned about and nothing that you can eliminate. Just crop the edge of the negative when you print it in an enlarger. A slide holder will cover this area anyway.

Yeah, but that is in his live area, on both sides.

 

[Eff64]

I just took a quick look at some of my contact scans. Notches, yes. Clamp shadow, no.

View attachment 311934

This is a normal full frame.

This discussion about the clamp, and cropping out the shadow, is confusing the issue.

Having shot literally thousands of frames with a Hasselblad, there was never anything affecting the live image like the OP is showing.

 

[Dr Dik]

Thanks for clarifying this Pieter.

 

[reddesert]

The thing casting the shadow is the film gate itself. The notches prove that. It's not an obstruction between lens and film. The question is, where is the extra light coming from. That is likely from outside the image, reflecting off the side of the body chamber. Here is a diagram of the suggested cause. This is most likely to happen when there's a lot of bright stuff like sky or sun outside the field of view. Use a more restrictive lens shade, shade the lens from the sun with your hand or the dark slide, etc.

 

[Mike Lopez]

This discussion about the clamp, and cropping out the shadow, is confusing the issue.

The clamp is a red herring that should not have entered the discussion. It was never going to be the cause of what's shown. Misinformation.

 

[warden]

The thing casting the shadow is the film gate itself. The notches prove that. It's not an obstruction between lens and film. The question is, where is the extra light coming from. That is likely from outside the image, reflecting off the side of the body chamber. Here is a diagram of the suggested cause. This is most likely to happen when there's a lot of bright stuff like sky or sun outside the field of view. Use a more restrictive lens shade, shade the lens from the sun with your hand or the dark slide, etc.

View attachment 311998

Nice work! I agree with your assessment.

 

[Arthurwg]

The clamp is a red herring that should not have entered the discussion. It was never going to be the cause of what's shown. Misinformation.

Not the first time.

 

[brbo]

@Photomultiplier's shot explained it all. It's not a shadow band that is a problem, but a reflection that is effecting the rest of the area of the negative. Just goes to show that showing entire film area helps troubleshoot the problem.

What is interesting is that this problem is not discussed more often. When I had Hasselblad I never encountered this problem and I shot my 50mm without a hood (I didn't have the hood). Although, the lens was the early "C" type and not the cleanest to begin with so maybe the already high internal reflections of the lens masked the problem. I shot the 80mm always with the hood attached. Or maybe Hasselblad improved the internal flocking at some point and only older bodies are effected?

 

[Dr Dik]

The thing casting the shadow is the film gate itself. The notches prove that. It's not an obstruction between lens and film. The question is, where is the extra light coming from. That is likely from outside the image, reflecting off the side of the body chamber. Here is a diagram of the suggested cause. This is most likely to happen when there's a lot of bright stuff like sky or sun outside the field of view. Use a more restrictive lens shade, shade the lens from the sun with your hand or the dark slide, etc.

View attachment 311998

Thanks so much for this cogent and well illustrated explanation Red. It makes perfect sense and I’ll send it to the HB tech in NJ who’s been puzzled by this. I’ll be using my lens hoods religiously for now on.

 

[pentaxuser]

It would be one hell of a design flaw if Hasselblad had produced backs/inserts with that clamp in the film area, requiring cropping of the negative in printing (you'd no longer even have a square, unless you were to crop the frame elsewhere). But the clamp is clearly not the culprit, as is obvious from your posted examples.

What a head-scratcher (very irritating, as you say). Good luck with this.

Yes, I agree and that was the very point I was trying to make many posts ago but the answer from one poster seemed to be that this was normal for HBs and cropping the actual negative and thus removing some of the picture was the only answer.

I had even made a "post-it " note as a reminder to stick with my other make MF and never buy a HB

pentaxuser

 

[Mike Lopez]

Yes, I agree and that was the very point I was trying to make many posts ago but the answer from one poster seemed to be that this was normal for HBs and cropping the actual negative and thus removing some of the picture was the only answer.

I had even made a "post-it " note as a reminder to stick with my other make MF and never buy a HB

pentaxuser

Yes, that was an absurd assertion and it's unfortunate that anyone took it "seriously." As noted above, this ain't the first time.

 

[Sirius Glass]

Yes, I agree and that was the very point I was trying to make many posts ago but the answer from one poster seemed to be that this was normal for HBs and cropping the actual negative and thus removing some of the picture was the only answer.

I had even made a "post-it " note as a reminder to stick with my other make MF and never buy a HB

pentaxuser

Great, that is one less buyer I have to compete against when I buy lenses or accessories!

 

[pentaxuser]

Great, that is one less buyer I have to compete against when I buy lenses or accessories!

Give us other reasons and you might not have any competition for HBs at all

pentaxuser

 

[Pieter12]

Great, that is one less buyer I have to compete against when I buy lenses or accessories!

I find it difficult to comprehend that a true believer like you would just accept the fact that the camera you worship has an innate, major design flaw with a clamp that creates a shadow on the film. Maybe you should take a closer look at the problem and your conclusion.

 

[brbo]

Give us other reasons and you might not have any competition for HBs at all

But if that helps him finally get a Hasselblad that doesn't leave a clamp shadow in the image area...

On a more @Sirius Glass note, can you circle the shadow area left on the negative in the #40 post us?

 

[Sirius Glass]

I find it difficult to comprehend that a true believer like you would just accept the fact that the camera you worship has an innate, major design flaw with a clamp that creates a shadow on the film. Maybe you should take a closer look at the problem and your conclusion.

The two tiny spots that get automatically cropped out, are so small that they are not a problem. Sometimes I have to remind a photo finisher to raise the enlarger head enough to leave them out.

 

[Sirius Glass]

But if that helps him finally get a Hasselblad that doesn't leave a clamp shadow in the image area...

On a more @Sirius Glass note, can you circle the shadow area left on the negative in the #40 post us?

That would be really had to do, since there is not shadow area in that negative. As I pointed out before I have never had a shadow area like that. Nor has anyone other than the OP had the shadow area. Why do not you ask everyone who posted on this thread to circle the nonexistent shadow areas of their photographs to? Will you now post your nonexistent shadow areas of your photographs?