Odd flare in some frames

[peter_gilbert3]

I use a 500C/M with two backs. It seems about half the shots I took

recently have flare similar to this example, shot with a 50mm CF. I

have replaced the seals in both backs about a year ago (and note the

flare is not on the frame edge) so I don't think that is an issue.

I was using a Cokin P filter adapter and Cokin polaroid filter; do

you think this is simply sun reflections through to the film?

 

http://www.photo.net/photodb/member-photos?user_id=2063965

[bueh]

Looks like a light leak to me. Isn't the light also on the lower edge of the film (where the frame numbers are)?

[peter_gilbert3]

Bueh:

 

yes, the flare goes to the bottom of the frame, and seems to be roughly in the same area on all affected frames, although it is worse in some than others (seems to be worse in frames 9-12 on the roll). In my past experience, light leaks from the seals have been on the left or right. Do you think this is a seal leak? Thanks Peter

[bueh]

Peter, I am not familiar with Hasselblad cameras, but I think I can recognize a light leak -- I have seen my fair share of them with all kinds of cameras. If there is light on the film's edge, it MUST be a light leak, not some stray light (flare, glare, ghosting) that comes through the lens. If the film's edge is exposed, it did not happen where the film was regularly exposed by the opening of the shutter, but at some other place inside the film holder, because the 6x6 mask (pressure plate and frame) would have protected the edges.<p>

Again, I don't know where the light could have entered the back, usually it is at the hinges left or right, but it could really be anywhere. Light leaks often differ in shape and intensity from frame to frame.

[peter_gilbert3]

Bueh:

You are most likely correct, now I have to find out which back is the culprit. The thing that got me thinking though was that the flare seems to be heavier away from the frame edges - I would have thought a light leak would be heaviest at the edges. I plan to run some b/w film through both backs, and check everything out carefully.

 

Thanks

 

Peter

[tarashnat]

Peter,

 

Looking at the type of flare, it is either coming from the top (most likely) or bottom of the

camera (remember that the image on the film itself is upside down when in the back. I

would suspect that the fit of one of your backs may be loose and the light is leaking from

between the back and the body. This is my best guess, but it could be from other places

as well.

 

Taras

[peter_gilbert3]

Taras:

 

Thanks,

I'll check the fit carefully while winding on with film loaded. I've seen other messages in this forum where it is claimed the pressure of the cogs can force the back to separate momentarily from the body while winding on. The flare/light leak is on that side and towards the bottom of the frame. I'm still puzzled why there is such a sharp cut-off in the overexposed section towards the left side as viewed however.

 

Cheers,

 

Peter

[desmond_kidman]

Look how the flare stops along a straight line on the left edge. I had a similar occurance, with a couple of backs, nearly new, shooting one day with a lot of side-light (low sun) and a lot of open bright sky. I was using a shade, and no light was hitting the front element. There were no light sources in the shot. I never got to the bottom of this. They were the latest backs, and, as I said, nearly new.

 

I used Hassy for 20 or 25 years and never had the problem before or since. Since then I have read a number of threads where folks had flare that they just could not track down. I know it drove Diego Buono crazy, I don't know if he ever tracked his down. Am I correct tht there seem to be more of these threads with Hassy than other MF cameras? Maybe I'm just more interested in them and it only seems that way due to my long experience with Hassy. But I do not remember reading such threads, say, for RZ.

 

Peter, I'd love to know if you are able to duplicate the problem and then track it down.

[peter_gilbert3]

Armando:

 

I've pretty much concluded that the flare I've seen is through the lens, and not a leak from the backs. As you say, the flare does not go to the frame edge (in some frames I have it does, but the flare is much stronger away from the frame edge, and not outside the picture area either).

 

I was using a 50mm with a Cokin P holder and pola filter; I had one section of Cokin holder lens hood (to avoid vignetting) but I cannot say for sure I was not getting direct sun on the front element (or, filter). I use a PM5 prism, which I thought would have shown any flare, maybe I need to be more careful in future. Also, the Cokin holder has gaps around the edges, so I'm suspecting that some light was bouncing around through those gaps and found its way to the film surface. The film was Reala 120 btw.

 

I have not yet had the chance to try and duplicate this, I'll repost when I do.

 

Several years ago I owned a Bronica GS-1 with three backs, and I did have some problems with those - they are difficult to mount correctly - I had one instance when the back did not latch fully yet I was able to remove the darkslide. That resulted in the first 2-3 frames washed out. Also, the hinged back was a cause of some light leaks after several years. The Hassie backs seem to me much better constructed (but complicated).

 

Peter