Topic: light leak - in a bad way

[gregor]

I'm having issues with the film back on my bronica sq-a.  Intermittent leaks in either low light shots (as attached) or in bright light. I'll post another example of the latter after scanning the last roll.  The seal looks fine and I'm thinking that it's one from one of two possible sources:  the body or back is getting worn and when attached the join isn't tight enough to prevent light from getting in, or it's coming in through the dark slide slot.

I'd rather not invest in a new back if I can't identify it as a problem with the back only and not the hinges on the back or hinge slots on the body being worn out and letting light in (I do switch out backs frequently from 120 to 220 to polaroid....). I've been using the 120 back as my other film backs need resealing and this back worked perfectly up until the last 4 or 5 rolls.

Thoughts?

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[Francois]

I would probably start by taping up the side you think it's coming from...
But I'm surprised to see such a leak in low light... I would have expected to see it more for outside shots!

[gregor]

Thanks Francois:  I would have expected the same.

Here's a couple of more.  keep in mind these not my 'art photography' work, but are personal shots at a reunion of folks from seattle who volunteered to go to Biloxi Mississippi last summer to help rebuild or repair homes destroyed by hurricane katrina. 

Film: fomapan 400 scanned as ilford hp5 as Silverfast doesn't have a fomapan profile....

The 1st shot is f16 @500. The second is f11 @ 500.  I've scanned the whole negative to the borders so you can see the progression. In  shots 1 & 2 below the day is bright sun, coming in over my left shoulder.

The third shot is f4 or 5.6 (can't recall which) @ 500 with no sun hitting the camera.....

My initial assumption was that it was the dark slide shot.  However looking at these and seeing leaks on both the left & right makes me feel the hinges no longer hold the back tight against the body.

I'm not technically astute when it comes to these matter so I'm open to any thoughts suggestions. I'd love to keep this camera going but it looks kaput to me.....

Some shots on the roll came out fine in cases where there was no sun hitting the camera @ f8 and above.

[fortunately I had a couple of cameras w/me so I not all was lost from this reunion !]

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[moominsean]

does it have a bulb mode? if so, you can open the shutter and shine a flashlight through the front of the camera. you may be able to see pinpoints of light along the back edges or hinges.

the first leak, the line across the film, looks like the kind you get while advancing the film.

[gregor]

no bulb mode per see but I can keep the mirror with the dark slide out. I'll check into that one. Thanks Sean.

[gregor]

correction - mirror open but shutter closes.  a fall back of the sq-a - no B setting.....

It is worth noting that the polaroid back has no leaks except on fuji peel apart films - a line of three light spots above the exposed area (polaroid films do not have this).  But then the pola back is bigger than the body and could be blocking out potential leaks due to it's size...

[sheetshooter]

I suspect it is worth checking the latches and not the hinges - maybe they are sitting too proud of the unit and not forming as snug a fit as they should.


Cheers,

[gregor]

not sure of the difference - hinges would be the upper connection to the body and latches the lower?  The negs look like it's primarily the upper..... which could also explain the light specs in the fuji peel apart films w/the pola back.

[gregor]

ah, I'm sure you're all dying to know:  Sean I was able to get in with a pen light with the lens off. No light coming through but I did discover three things. The front of the lens was filthy. The back of the lens was filthy and the mirror was filthy ;-)

I did detect some slight looseness in the seam where the back closes after film is loaded (as opposed to the seam where body and back meet) but given that the seal is good and seeing where the leaks are in the photos above, I don't think this is the cause.

[Francois]

I'm not very experienced with Bronica backs but am wondering if the backs can be opened (like for loading film) and still be mounted to the camera. Some backs use a small window to see the markings on the film before you close the whole thing so maybe you could light this things from the inside like that...

Other way would be to go to an electronics store and get a flat battery holder (like the large watch battery on your computer's motherboard) and a simple white LED. Just solder them together (the diode is polarized so it it doesn't work one way, just flip it around) and put them inside an empty film holder before closing it... That way, you could see if light is leaking to the outside and from were.

Or, if you don't want to solder anything, there's probably some toy at the dollar store which you could break apart to get the same result...

[gregor]

I'm not very experienced with Bronica backs but am wondering if the backs can be opened (like for loading film) and still be mounted to the camera.

Excellent suggestion. The bronica can backs be opened while attached. I'll run off and get a LED or small penlight to fit inside.  I'll let you know the results !  Thanks.

[gregor]

Didn't see anything with the LED, but I did find a good reference on APUG. I didn't realize the Bronica back has foam seals in several places.  I thought there was only 1 strip along the top....  Fortunately one of my backs is good on all but 1 of the locations and I just resealed that (the top strip).

As a reference for any other Bronica users:

http://www.apug.org/forums/forum51/51945-light-leak-bronica-sq-ai-back.html

[Francois]

Good to know even if I don't have one

[reiki_]

Today I had my 2 c-41 rolls developed and they both showed some sort of light leak on random photos. Damn. I'll just have to duct tape my poor om-2n.


Anyway , this is my first post. Cheers everyone.