Pentax KX - dented prism

[filmamigo]

I've got a Pentax KX with a dented prism, but am concerned because the plastic strip onto which the prism sits is also cracked.

Mechanicals on the camera seem fine, and I am putting a roll of film through it to test.

But will the cracked plastic strip on the prism housing cause light leak troubles? Is it worth it, or even reasonably straightforward, to remove the top plate and replace the plastic?

This was a bargain-bin junker, so no real investment so far. I would like this camera to be a user, but KX's aren't common around here, and often sell for quite a bit....

 

[frank]

I don't think there'll be a light leak, but why not put a roll of film through it to see for yourself?

 

[summicron1]

no. The tunnel through the body of the camera from the lens to the film is light-tight when the mirror is up during the exposure, and the pentaprism is on the outside of that tunnel, so there should be no light leak. Your test roll should confirm this. Be sure to take the camera outside and expose it to bright sunlight, just to make sure of everything.

 

[Pioneer]

The prism cover is under the top cover. It could be possible that there was damage but not very likely.

Removing the top cover is relatively simple. This video of a K1000 top cover removal will help.

https://www.youtube.com/watch?v=y6ehEPbOiRc

 

[Steve Roberts]

It'll be fine. I have a KM which had half of that strip missing with no problems. At the time of exposure, the mirror is up and sealing off the prism housing. Taking it to extremes, cameras with removable pentaprisms used at waist level work fine! The top comes off the KX easily enough and whilst it's off you should be able to push the dent out carefully whilst fitting a new plastic trim piece. I used one from a dead K1000 on the KM and as far as I know that would fit the KX as well.
Best wishes,

Steve

 

[filmamigo]

Excellent info, thank you all!

 

[filmamigo]

I don't think there'll be a light leak, but why not put a roll of film through it to see for yourself?

Yep, I'm in the middle of the roll now

 

[Pioneer]

It'll be fine. I have a KM which had half of that strip missing with no problems. At the time of exposure, the mirror is up and sealing off the prism housing. Taking it to extremes, cameras with removable pentaprisms used at waist level work fine! The top comes off the KX easily enough and whilst it's off you should be able to push the dent out carefully whilst fitting a new plastic trim piece. I used one from a dead K1000 on the KM and as far as I know that would fit the KX as well.
Best wishes,

Steve

I didn't even think this was possible.

 

[PentaxBronica]

Probably a bit late, but I've not been into this section for ages and only just noticed. Hope the film test went well, the only thing I do differently is to try one frame with my 50mm f1.4 (I'd use an f1.2 if I had one) wide open, to check that the camera is focussing accurately. I do this if there's a dent in the prism housing as the camera has clearly had a knock, and it's the easiest way to check that it hasn't upset the mirror, focusing screen, or lens mount.

The K1000 is basically a KX/KM with the nifty bits taken off, in fact if you look at early Japan-made K1000s and KMs you can see a raised circle near the rewind crank. The KX has the battery test button there. I wouldn't be surprised to see a blanking plate under the leatherette on the K1000 where the higher spec bodies have their self timer and depth of field preview controls.