Nikon F, prism doesn't attach securely
I have a Nikon F with two standard prisms, and I have problems getting them to attach securely.
Prism one is not perfect, has some kind of separation and lots of other marks of use. It goes all the way in, but it can move up and down so it's not staying tightly.
Prism two, which is the one I am using, is nearly perfect optically and mechanically and I believe there is nothing wrong with it, snaps in tightly from the rear, but the front keeps raising up. It can be pressed down, but when I release my finger, it rises back up again about 2 millimeters (didn't measure, but noticeably.)
I have tried tightening all the screws in the body and the prism but that didn't help. Then I started looking at the front and rear latches in the body, the ones that move sideways when you press the finder release button. I think the problem is that the front latch is slightly bent upwards unlike the rear one, which is totally straight.
Now if this is causing my problem, can you suggest an easy way to "bend it back into shape" ? Seems like it can't be removed from the camera unless I take the top of the camera apart.. also I am pretty clumsy when it comes to fixing mechanical things but would like to try anyway. Unless you can suggest someone in Berlin who will fix a simple thing like this for a reasonable price.
1 - the prism from the rear, you can see how the front is raised slightly
2 - the camera body rear latch
3 - the camera body front latch, curved upwards slightly
I dusted off my F and had a look: the front latch piece on it is bent exactly like yours.
I only have a Photomic prism, but when the front outside catches are released, it also has a c. 2mm play in the front (the Photomic attaches to the front latch as well as having the outside catches).
Perhaps that amount of play is normal?
M6, SL, SL2, R5, P6x7, SL3003, SL35-E, F, F2, FM, FE-2, Varex IIa
Just pulled my two F's out of hibernation- they both have perfectly flat front catches. I have about 0.5mm of play on my finder front sides, but the spring pushes them upwards so they stay stable.
It looks like you would need to remove quite a bit of hardware to get that latch out of the camera to properly re-bend. I would try to press it back into shape while still in the camera first. Make a square of wood or plastic the exact size of the ground glass and put it into the camera- juuust in case you slip when pressing down on the latch. And find a nice flat screwdriver that matches the latch flat part well. Since the bottom of the latch opening is never touched by any part of the camera, it should not matter if you scratch it up a little. And the front of the finder housing is all ready scratched up from the finder- so give it some nice, steady pressure and see if you can bend it back.
After all, someone bent it upward by (presumably) trying to remove the finder incorrectly- so you should be able to bend it back downward.
That front piece that you show is bent. On both of my F's - and F2 as they are the same fit, these are perfectly straight and both my prism and Photomic finders are very tight. Who ever had that camera would've had to have exerted quite a bit of force to bend it like that.
BTW, the F bodies without prisms are cheap on KEH as it's the plain prisms that are much sought after. This may be another way to "fix" the problem.
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I glanced at my two Fs; both are straight. The tally: 6 straight, two bent. It would take some mighty force to bend the retainer upward.
I just checked 2 of my F cameras with plain prisms, and in both the front retainer bar is straight. There is a SLIGHT up and down play when the prism is pushed into the body and then released, due to compressing the rubber gasket and play or clearance with the hardware. In my cameras, the play is less than 0.2mm, but that may vary because of the age of the gasket.
I don't have an F, but on my F2, there are two little leaf springs on either side of the prism that push upwards. Mine seemed kind of smushed, so I got some new ones and they are much less flat.
I think I am going to try fabricating some kind of pushing-down tool to correct the bend at first. Going the "just get another F body" route is not a bad idea either, especially since I'm now having heretic thoughts, that maybe the black body looks better after all ..
Strange, I was just trying to research this problem for my primary camera, my black Nikon F. I've learned that the part is officially called the "prism Frame Holder Lever". It's actually not a front and a back, but one whole piece. CLICK HERE for photos of the two different types that were made. I am having the same trouble with my prism. I find that the prism locks into place when I press down on the prism and slide it to the drivers-side left of the camera but then it disengages when force is applied to the right. THe problem is more pronounced when I try to use the sports action finder, due to the increased weight pulling the finder to the right.
I just noticed..when I remove the ground glass the problem vanishes and the prism locks down very securely and cannot become disengaged. Try it out. I am curious if you find the same results. I check further and find that when the ground glass is inserted fully, the prism frame holder lever actually slides slightly to the left, just enough to prevent the prism from locking down securely. Toninikkanen, do you find the same with your camera?
PS. BLACK IS BEAUTIFUL!