Follow-Up to "Removal of a Lindahl darkslide holder"

[Ira Rush]

This is actually a follow-up to a posting I made about two months ago, regarding the “removal of a Lindahl darkslide holder”.

In summary, I had bought a used A16 back with the Lindahl holder attached and found I had to jump through hoops to mount the back onto one of my 500 C/M bodies when I had the PM90 prism mounted. I originally thought that the previous owner had mounted the darkslide holder to high on the magazine back, because the top of the holder was hitting the bottom of the prism. Mounting the magazine was a major hassel (pun intended!)

So here it is just about two months later; …bottom line…never removed the darkslide holder for fear of tearing the leatherette covering.

Now get this…it finally dawns on me to test the magazine with my other bodies.

I find with my other two bodies (another 500 C/M and my ELM) using the PM90 NO problem mounting the magazine… nada…zip… mounts easy, as it should (which really surprises me especially with the ELM as the motor housing slightly obscures the support catches on the camera body!).

So hears the question now, … albeit a new revised question… what is causing the problem of mounting this magazine, with for lack of a better term “500 C/M body - A”. If it were the lower support catches, that were the problem. If they were bent let’s say, I would think that other magazines (A12, A24 etc) would be affected too, (not so much hard to mount as they do not have the slide holder) but more likely light leaks since if the catches were a problem they would not bring the magazine close to the body as they should.

In using an A16, you really have to use a PM90 (90-degree prism), and by its very design it does extend far beyond the back of the camera body. I know for a fact that if I were to use my waist level finder or my PM5 (45 degree) finder using this A16, (which of course I wouldn’t!) there would be no problem due to those finders basic design.

So, one final thought and the question… could there be a problem with the “guiding grooves” on “500 C/M – body A”, that it is not really griping the PM90 finder properly?

Since the only common factor is the PM90 and that A16, I really do wonder if the body is not mounting the finder properly.

Yet while I use other finders (PM5, waist level, etc.) with this body, I do not use that A16. So I don't notice any problems with the finder mounting, I don’t have any problems with any other magazines, nor any other finders. I also do not notice any stray light coming in (lens removed, looking into camera body). So if it were the body/prism guiding grooves that are causing the problem it must be a minor gap, but still a problem with the finder.

So any thoughts… what's causing this problem with this one particular combination?

Thanks in advance!

 

[Q.G.]

Remove one of the two common factors: the 90 degree finder.

If the A16, and other magazines too, mount with less ease on that one 500 C/M body, not on others, the thing is clear: it's that body. The hooks on that body are bent. Or the inner chassis is sticking out a tiny bit too much.

If only the A16 mounts with greater difficulty on that one 500 C/M, and on other bodies too, it's also clear: it's the magazine.

If only it would be as simple as that, right?
You can have both body and magazine issues at the same time, of course, making this a bit harder to figure out.

And you mention the seating of the prism, and there indeed is more to compound this problem finding exercise right there.

The grooves the finder slides in should not be a problem, unless there is something in there obstructing the finder, so that it will not slide in fully.
Check the 90 degree prism on all of your bodies, and check whether the rear edge of the finder's bottom plate completely disappears over the top of the body, or sticks out ever so sightly. It shouldn't do the latter, of course.

 

[Ira Rush]

Q.G.

Thanks for replying, I knew I could count on you

On that one 500 C/M body in question... all other magazines mount easy, no problem... all finders mount easy, no problem. It is only with that one combination the PM90 and the A16 with the slide holder. Using that PM90 and any other magazine no problem! Using any other finder and any other magazine (including that A16) no problem.

On the other 500 C/M and my ELM No problems with that combination, or any other combination for that matter. The PM90 mounts fine, the A16(with the slide holder) mounts fine, no muss, no fuss.

The focusing screen latches are fine, the screen rests where it should, no dust/dirt/grit within the guide grooves...

Strange but true.... the combination from Hell

 

[Sirius Glass]

Ira,

First see how Q.G.'s advise works, then if really necessary, you can remove the Lindahl darkslide holder by carefully prying it off the magazine. I have done this several times and it is not a lot of fun to do it and not damage the magazine covering.

OT, the Lindahl darkslide holders have a tendency to drop off the outer layer when a darkslide is inserted. To stop this from happening, place a drop at each plastic pin [four of them], place the part on and make sure the darkslide can be inserted an removed without force or binding up.

Stev

 

[Q.G.]

Strange, yes.

I'd first have a look at the PM90 on that one troublesome 500 C/M.
Does it slide forward far enough to have the rear edge of the bottom plate clear the back?

And then at the black rear plate of the camera: how far does it stick out (if at all)? And is it more than the back plates on your other cameras stick out (if at all)?
As you will know, Hasselblads have the moving bits mounted on an internal chassis, that sits in an outer shell.
The upper magazine hooks are attached to the chassis, the lower hooks however to the shell. If the chassis isn't pushed into the shell far enough, there will be problems attaching magazines.
(The chassis comes out when a camera is serviced. And when adventurous pre-owners like to have a rummage inside a Hasselblad. Who knows, maybe it wasn't put together again properly?)

These problems can be made more complex by the magazine itself.
The top hooks are caught by a catch (a slider) somewhat inside the shell of the magazine. The bottom hooks however hook behind the face plate of the magazine.
That face plate too is something that very likely has come off and was put on again a fair number of times (you do that everytime you change a light trap seal, which should be rather often).
Now if the top of the face plate isn't mounted properly (i.e. not 'deep' enough) the top hooks will have trouble reaching behind the slider.
Behind the bottom of the face plate, where the lower hooks grip the thing, flat spacers are inserted to ensure a good fit. Though the fit would sooner be too loose than too tight, there might be a problem there too.

The fact that only one camera body gives problems with only one magazine, and any other combination is fine, will be a matter of tolerances acting against each other.
And points towards a compound problem, with not just one single thing causing it.

But here's a thought: since there is such a pesky slide holder on that magazine anyway, instead of trying to find a way to take that slide holder off and fix the 'fit problem', why not dump that A16 and get another one? A16s are cheap. And chances are good that there will be no problem then.

 

[Ira Rush]

Strange, yes. ...........

But here's a thought: since there is such a pesky slide holder on that magazine anyway, instead of trying to find a way to take that slide holder off and fix the 'fit problem', why not dump that A16 and get another one? A16s are cheap. And chances are good that there will be no problem then.

I once said of you "the voice of reason"... how true, how true...

I guess it's time to stop banging my head against the wall... and get another A16....

Now why didn't I think of that!

Once again, thanks Q.G... you are indeed the "voice of reason"