Hasselblad A12 back, light leak?

brian steinberger · Nov 2, 2009

I just developed my first rolls through my new Hassy this evening and of course, things can't be simple. About half the frames on the two rolls were ruined by what seems to me to be a light leak in my A12 back. And the rest all have a "halo" of fog extending around each frame. I have attached scans of two examples. The streaks are on the left sides of the frames (emulsion down). I'm assuming it's coming from the dark slide slot. The shots taken in the shade out of the sun were fine for the most part (besides the fogging). I have also read about the film loaded above the metal clip causing problems. I made sure to load the film correctly. Could the film still come from underneath the clip? Also, spacing of the frames are very very close!

I bought this film holder in EX condition from KEH. What should I do? Shouldn't an EX condition film holder be light tight? First I'd like to make sure it's not something stupid I'm doing wrong. Thanks.

Anscojohn · Nov 3, 2009

Hi Brian,
I think your surmize about light coming in from the dark slide side is probably correct. Did the KEH ad say anything about new light seal in the mag?
BTW, where in Pennsylvania? Go Phillies!

Q.G. · Nov 3, 2009

Those are the typical signs of a worn dark slide slot seal indeed.

I would indeed expect that an "excellent" grade back would have a good seal inside.
Yet, if the back itself is in "excellent" condition it's worth considering keeping it, and changing the seal yourself. (It is something you will have to do regularly, i.e. every two or three years, at least).
Though even then i would ask KEH for a new foam.

bdial · Nov 3, 2009

Yeah, an EX back should be light tight. I'm sure that KEH has at least one other EX back they could send you in exchange, which they are probably more likely to do than send you a seal.

AshenLight · Nov 3, 2009

I've purchased and used these seals on a couple of A12 backs.

http://shop.ebay.com/?_from=R40&_trksid=p3907.m38.l1313&_nkw=hasselblad+light+seals&_sacat=See-All-Categories

Ash

bill schwab · Nov 3, 2009

Q.G. said:
Those are the typical signs of a worn dark slide slot seal indeed.

This leak is not from the darkslide. If so, it would be on the other side of the frame. Darkslide is on the left. With the image inverted as it is, this is coming from the right side and top. It is also inconsistent leading me to believe that the back is fitting loose or not clipping at the top correctly. Look to see if the L shaped brackets on the body that hold the back on that side are bent down slightly. This is sometimes the reason although many will think darkslide. This looks to me as if the back isn't seating correctly. Good luck!

bill schwab · Nov 3, 2009

PS. Does the back "wiggle" some when on the camera? It shouldn't. If so, I think the problem is with the brackets as I mentioned or with wear in the reciving slots on the back. If this was a camera I had just purchased, I would return it along with the sample frames you showed here.

Andrew Moxom · Nov 3, 2009

Brian, as a light trap test, load the film in the dark or subdued light, remove the darkslide and cover the slot with a couple of strips of gaffa tape. Take some pictures in sunny conditions with the sun facing the darkslide slot. Then develop as normal. If the problem goes away, you know the source of the problem. I know it will take one more roll of film, but then you know for certain if the back is the culprit or not. then you can decide whether KEH should fix it, or if you want to do it on your own.

Q.G. · Nov 3, 2009

billschwab said:
This leak is not from the darkslide. If so, it would be on the other side of the frame. Darkslide is on the left. With the image inverted as it is, this is coming from the right side and top.

Teach me what is a dark slide slot seal leak and what is not ...

It definitely is a dark slide slot seal leak.

I understand your reasoning: the light enters on the left (the image's right), thus the leak should be on the left (the image's right).

But what you haven't considered is a step: the film is lying behind the plane of the dark slide slot.
That step means the film cannot be reached directly by light coming in.
Instead, light starts to reach the film halfway across, and eventually bounces off the opposite edge of the film gate and (as here) the lower edge of the film gate too, with the side where the slot is unaffected, shaded by the step.

The criss-crossing is due to the light entering the slot at different occassions from different directions. The camera held one way first, another way later.

What we see here is archetypical for a Hasselblad dark slide slot seal leak. A text book example.

bill schwab · Nov 3, 2009

Q.G. said:
Teach me what is a dark slide slot seal leak and what is not ...

Neither one is from the dark slide.

FWIW - Leaks from the dark slide do not come on the top and bottom of the frames as is shown here. IMO you should save yourself the trouble of one more roll and send this one back. You didn't pay for a leaking camera.

Q.G. · Nov 3, 2009

AshenLight said:
I've purchased and used these seals on a couple of A12 backs.

They'll work.

When buying and replacing seals, remember that only the foam needs replacing.
The folded foil bit only (!) if it is torn or damaged in any way.

Not buying and using new foils when not needed can safe a buck or two.

I cut my own seal foam pads from a piece of black, dense closed cell foam, available int crafts and hobby shops. A sheet bought for a couple (literally) of dollars will yield many, many replacement foam pads.
They are so cheap in fact, that i now probably change seals far too often.

Q.G. · Nov 3, 2009

billschwab said:
Neither one is from the dark slide.

FWIW - Leaks from the dark slide do not come on the top and bottom of the frames as is shown here. IMO you should save yourself the trouble of one more roll and send this one back. You didn't pay for a leaking camera.

As said before, the light seen at the edges of the frame is light reaching those edges from the opposite side. Trace the longer rays back from the edge, and you'll end up at the position of the dark slide slot. The shorter rays (or rather the haloes at the edges) are the reflections of the longer ones, reflected at the film gate edge.

So yes, leaks from a dark slide slot do reach all the bits we see them reach here.

So though i hate to say this, you are wrong. 100%. Trust me, you are.

bill schwab · Nov 3, 2009

Q.G. said:
So though i hate to say this, you are wrong. 100%. Trust me, you are.

I have no reason to try and correct you further.

The bottom line is the OP bought a camera that leaks. Send it back.

Q.G. · Nov 3, 2009

billschwab said:
I have no reason to try and correct you further.

The bottom line is the OP bought a camera that leaks. Send it back.

I must continue to protest, simply because you are urging the OP to do things based on a false assumption.

And mind you: that is not just a guess, or an opinion. You really are wrong about this light leak.
The images show absolutely nothing that would be wrong with the camera. Its' a text book example of what a deteriorated foam will do.

Which you too will see if only you take a bit of time and think about it.

bill schwab · Nov 3, 2009

Q.G. said:
... you are urging the OP to do things based on a false assumption.

And you are asking someone that paid good money for a back that was listed in excellent condition to accept it and perform repairs at their own expense? Look... if you feel the need to be right, then fine. There's no need to be stupid though. There are hundreds of good backs out there that work. To suffer another minute and even more money on one that doesn't is just ridiculous if you've only just purchased it.

Q.G. · Nov 3, 2009

I am not saying that the OP bought a wonky camera that he should return. That, i have left to you.

And i am not asking the OP to ignore the bad dark slide slot seal and have his camera looked at (without any indication that there's something wrong with it), instead of doing something about the back he just bought (which, as is demonstrated, does have a problem).
That too is something best left to you, i think.

About what i think he should do with the magazine, i have given my thoughts quite a few posts ago.

Sirius Glass · Nov 3, 2009

Just FYI, "How to change light seals in Hasselblad film magazines"

http://www.hasselbladhistorical.eu/HT/HTSeal.aspx

Steve

bdial · Nov 3, 2009

No foam required between the magazine and the body, the ridges and groove in the back form the light seal. That the magazine can move slightly is normal.

brian steinberger · Nov 4, 2009

Ok, I feel like an idiot now for a silly assumption.. Either way, I'm going to call KEH tomorrow and ask for an exchange. But it is nice to know about seal replacement in the future since I'm sure it will be required at some point.

Andrew Moxom · Nov 4, 2009

Also Brian, stay away from the generic seals when you do learn to change them yourself.... They work great for regular film, but suck for IR film... Tell me how I know this I used a cheaper than OEM brand off of EBay and it just has a mylar piece and foam. The OEM seal has a mylar piece, and foam that is backed with foil. It worked much better at keeping IR fogging to a minimum. If you are changing them every two years, the gumming problem of the OEM foam will not be a problem.

John R. · Nov 4, 2009

If you are unhappy with the back KEH will exchange or repair it as you may request. They are very good about that.

I believe you are looking at a classic seal leak when I compare your image defects with seal failures I have had, but they don't look exactly alike, kind of similar, yes. I definitely am not a repair specialist on the backs but I do replace the seals periodically and I purchase new seals direct from Hasselblad. FWIW, I always store my empty backs with the slides removed and have found seal replacement is less frequently needed when the backs are stored in that fashion.

PVia · Nov 4, 2009

Well...quite a thread here.

I had some back leak problems when I bought my 500cm on craigslist a few months ago, but the leaks didn't look anything like the OPs. After replacing the seal, I had two frames on a roll that looked like they had leaks, but may have been flare. So, I'm no expert in these matters as it is still a learning experience for me.

However, as Lance Armstrong says, "It's not about the back."

;-)

Sirius Glass · Nov 4, 2009

John R. said:
FWIW, I always store my empty backs with the slides removed and have found seal replacement is less frequently needed when the backs are stored in that fashion.

Of course the film gets fogged this way, but what the hay!

Steve

Q.G. · Nov 5, 2009

Sirius Glass said:
Of course the film gets fogged this way, but what the hay!

Film, in "empty" backs?

brian steinberger · Nov 7, 2009

I called KEH yesterday and told them about the back. They were very apologetic and are going to exchange. I'm also going to send then a strip of negatives from the test roll. They are very easy to work with.

Hasselblad A12 back, light leak?

brian steinberger

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