Negative Dark Patches

[Borris63]

Hello , Could I kindly ask if somebody could offer any advise to the following two images their thoughts to the patches I am getting on the negatives. I don't think they are light leaks but possible developing agitation/fixer issues. But I am not sure. Any advice would be greatly appreciated

Kind Regards

Andy

[MartinP]

Light-leaks. Are they at the end of the filmholder where you insert the darkslide> It could be that you accidentally move the back as you do so. Alternatively, the leaks may be at the other end suggesting that there is a leak on the filmholder, through the tape 'hinge' for example.

To diagnose, try another filmholder, and keep the back firmly closed with one hand while withdrawing the slide. Good luck.

[Borris63]

Light-leaks. Are they at the end of the filmholder where you insert the darkslide> It could be that you accidentally move the back as you do so. Alternatively, the leaks may be at the other end suggesting that there is a leak on the filmholder, through the tape 'hinge' for example.

To diagnose, try another filmholder, and keep the back firmly closed with one hand while withdrawing the slide. Good luck.

Thank you for your reply, the film holders are quite old. I will have to do tests on each one I think.

[nitroplait]

Give a unique number to each of your film holders with indication of the two sides (for example 01A and 01B, 02A and 02B). In your exposure notebook you include this data, and it makes it a piece of cake to ID leak issues.

[Borris63]

Give a unique number to each of your film holders with indication of the two sides (for example 01A and 01B, 02A and 02B). In your exposure notebook you include this data, and it makes it a piece of cake to ID leak issues.

Thank you, will do. The thing is though is I'm not sure if this is light leaks as they do not run all they way through. One of the negatives has a faded square shape inside, or do you think these are indications of light leaks?

Thank you

[koraks]

I'm not sure if this is light leaks
Rest assured: they are.

[paulbarden]

Thank you, will do. The thing is though is I'm not sure if this is light leaks as they do not run all they way through. One of the negatives has a faded square shape inside, or do you think these are indications of light leaks?

Thank you

These marks are absolutely the result of light leaks somewhere in your process.

[Tobias Key]

On the second image it looks like a light leak in the middle but that hard line on the each edge looks like an internal reflection being partially blocked by the holder, although it could be a very small leak where the bellows meets the rear standard. Anyway, it is probably worth double checking there aren't any areas inside the camera that could do with a coat of black paint. Always bear in mind there may be more than one fault with the camera.

[Doremus Scudder]

Borris,

These are definitely light leaks. The most likely culprit is the spring back being pulled away from the camera body when you pull/insert the dark slide or the holder not seating correctly in the grooves in the camera back.

The next most likely things are: a camera back that doesn't fit correctly onto the camera body (warpage, missing gaskets, cracks, etc.).bellows that has separated from the frame/camera body (or not attached correctly in the case of removable bellows), film holders with bad light traps or cracks.

Note that the condition of the hinge tape on the filmholder really makes no difference as long as the flap is held on and positioned correctly. The hinge tape is just a hinge; it doesn't do any blocking of light.

So, make sure you pinch the spring back to the camera body when you pull/insert the darkslide and make sure your holders are seated correctly in the grooves in the back.

Inspect the back-body fit carefully, check bellows, etc. A light inside the camera in a darkened room helps find leaks.

Best,

Doremus

[Borris63]

Thank you to all for your replies. I have taken the camera (Toyo Monarail) apart, checked the bellows as well the front 7 rear standards and all seem ok. As its pretty conclusive they are light leaks, I will do tests for each of my film holders.

Kind Regards

Andy

[Doremus Scudder]

Filmholder testing methods:

Load your holders (with photo paper for economy) and leave them sitting out in the sunlight for a while. Flip them around making sure all the sides/edges get exposed to the sunlight for a while.

Develop those exposures. I usually do tests like this when printing, so even if I used film, I can just toss them in print developer in total darkness for speed/economy. Any light leaks will show up as dark fogging/streaks on the neg (or paper).

If these turn out completely clear (no leaks), then load another holder, place it in the camera in portrait orientation (light-trap end up). Cover the bellows with your dark cloth but leave the light trap side of the holder exposed to the light and make sure the shutter is closed. Carefully pull the slide, making sure that the back doesn't pull away from the camera body. Leave the whole thing exposed to light for a while with the dark slide out. Replace the dark slide and develop and see if there is any fogging.

Hope this helps,

Doremus

[Borris63]

Ok, just doubled checked with my wife and it seems the bellows have a very small pinhole tear on both sides. The images above were taking in a field in bright daylight, so I think I have found my problem. So one final question can you repair bellows or is it best to replace?