Tijmendal
Young photog
Hi,
I recently acquired a 60mm CF lens for my beloved 'Blad. I tested it quite thoroughly and everything seemed to be working correctly. Now, I shot my first roll with it and there's something very weird going on with my negs.
Here's a (crappy) picture of it:
As can be seen, there's a purple streak/haze about 90% of the way down and after that, the negs look perfectly fine. This is the same for every exposure. One of the photo's on the roll was taken with my 150mm C and that picture looks perfect. I know it's not the A12 back, because I've never had any problems with that either.
Could anyone elaborate what the culprit might be? I'm imagining it's some sort of light leak?
Thanks a lot
I recently acquired a 60mm CF lens for my beloved 'Blad. I tested it quite thoroughly and everything seemed to be working correctly. Now, I shot my first roll with it and there's something very weird going on with my negs.
Here's a (crappy) picture of it:
As can be seen, there's a purple streak/haze about 90% of the way down and after that, the negs look perfectly fine. This is the same for every exposure. One of the photo's on the roll was taken with my 150mm C and that picture looks perfect. I know it's not the A12 back, because I've never had any problems with that either.
Could anyone elaborate what the culprit might be? I'm imagining it's some sort of light leak?
Thanks a lot
mfogiel
Veteran
To begin with, the bright line at the bottom indicates, that you may have a slightly leaky light seal in your film back. Was the good shot from the 150 at the beginning or the end of the roll? I am guessing, while you had the 60mm on, you kept the camera for a long time with the dark slide removed, and this is why you have fogged the film. BTW, 60mm is a great lens.
Tijmendal
Young photog
Thanks for the help. The shot with the 150mm was the last shot of the roll.
The rest of the pictures were all made in a timespan of about an hour, if not less. Most of the time the darkslide was in it's designated slot.
Also: can it be established that it's not a problem with the lens? I'm so confused right now...
The rest of the pictures were all made in a timespan of about an hour, if not less. Most of the time the darkslide was in it's designated slot.
Also: can it be established that it's not a problem with the lens? I'm so confused right now...
mfogiel
Veteran
If the lens has whatever issue, it normally results in a uniform effect. Check the bayonet and the helicoid, if they look OK, I would not worry. If you want to check again, shoot a quick roll with various lenses in interiors, with the slit of your dark slide covered by a piece of tape. BTW, at closer look at your film, it seems that you have a slight fogging at the top and bottom of the frames, which could mean that there is a slight distancing between the body and the back going on when you wind the film. This is typically an issue with a film back that needs servicing.
Tijmendal
Young photog
Here a scan of the same pic as above.
I see what you're saying about the fogging at the top/bottom, but seeing how I haven't had any problems with other lenses, I don't think that's a problem.
It's so weird that the problem seems to come from the lens though. That's the thing I don't understand. Like why in the hell would it give these non-uniform problems?
About the bright line at the bottom: that's something weird going on in the picture. There's nothing noticeable on the actual slides.
Here a picture taken with the same body/back not long ago. Looks perfectly fine to me.
I see what you're saying about the fogging at the top/bottom, but seeing how I haven't had any problems with other lenses, I don't think that's a problem.
It's so weird that the problem seems to come from the lens though. That's the thing I don't understand. Like why in the hell would it give these non-uniform problems?
About the bright line at the bottom: that's something weird going on in the picture. There's nothing noticeable on the actual slides.
Here a picture taken with the same body/back not long ago. Looks perfectly fine to me.
mfogiel
Veteran
The double VV mark is on the side opposite the dark slide slit, so your fogging is consistent with light getting in through the slit. There is always a beginning when things start wearing out - how long ago have you had your magazine serviced?
EDIT: I've changed my mind - the side through which the light came in has to be the one close to the winding gears, in fact, it looks like when you wind, the back gets distanced slightly from the body, so the light penetrated along that side, and exposed also the borders - could be due to a slight difference in film flatness at the edges and an oblique angle at which the light came in. Put the camera on a tripod, and shoot a few frames, carefully looking at the right side of the body as you wind, where the magazine joins the main box. If you see the magazine move, it means it is ripe for service.
EDIT: I've changed my mind - the side through which the light came in has to be the one close to the winding gears, in fact, it looks like when you wind, the back gets distanced slightly from the body, so the light penetrated along that side, and exposed also the borders - could be due to a slight difference in film flatness at the edges and an oblique angle at which the light came in. Put the camera on a tripod, and shoot a few frames, carefully looking at the right side of the body as you wind, where the magazine joins the main box. If you see the magazine move, it means it is ripe for service.
ZeissFan
Veteran
I'm not going to say that I am 100% certain, but I don't believe that a lens can cause that type of fogging. Simply because of the circular nature of lenses to create an arc-shaped flare or flare that will run diagonally but not vertically. Plus, there is no light source seen streaming in from the top.
It just doesn't look like something that would be caused by the lens.
Has this camera ever been serviced? Particularly the back?
It just doesn't look like something that would be caused by the lens.
Has this camera ever been serviced? Particularly the back?