Spot of oil on focus screen, Pentax MX

Too old to care · Jul 7, 2012

After quite a bit of search I located a virtually new looking Pentax MX, what a sweet camera. I tested all the functions and it seems perfect, I will run a roll of film through it soon. However, there is a very small drop of oil on the focus screen, in the bottom right of the screen. It is so tiny you can hardly see it when looking in from the lens, but seems much bigger in the finder.

My research says to never touch the screen. I know how to remove that screen and have a kit on order for my K5 that will give me the proper tool, but I am worried about trying to remove this drop. Who knows how long it has been there, although I can see that it acts like a small magnifying glass so it must still be in a liquid state. I am afraid with use that it may spread.

Any suggestions? If it cannot be removed safely I think I will just try to find a new focus screen.

Thanks, Wayne

Roger Cole · Jul 8, 2012

Glad you found one. At worst you can replace the screen. They're superb cameras, aren't they? You'll love shooting with it. I don't say it too loudly so my LX doesn't get jealous but I think mine is my favorite 35mm (at least if I'm not shooting flash - the off the film plane flash metering of the LX is really nice.)

Anyway, I've cleaned focusing screens before with a q-tip and lens cleaning fluid. I don't think they're all that delicate. But if it's liquid that could just smear it around. This will bump your post too, so maybe someone will have more experience.

Newt_on_Swings · Jul 8, 2012

I would try to absorb it with a bit of soft but thick paper. or you can try using compressed air and blowing it off. To clean any residual, any solvent that evaporates cleanly will do. such as good lens cleaning solution (eclipse, metol based) or with xylene. you can apply it, let it loosen whatever oil is residual, and blow it all off. and repeat. I would not wipe the screen as it may scratch it.

250swb · Jul 8, 2012

I would say wipe it off with a Q-tip just dampened with lens cleaning fluid. It isn't recommened that you touch the screen because of possible damage to the fresnel surface, but common sense should say that if the oil doesn't come off with gentle application of the Q-Tip, then stop. The problem with blowing it is that it doesn't remove the oil (or dust), it just sends it somewhere else.

Steve

hugopoon · Jul 8, 2012

There's paper that people use to absorb skin oil and you can buy it in packs...try using that if you can find it.

I've used a Q-tip and rubbing alcohol on my FM's screen before with no visible consequences.

benjiboy · Jul 8, 2012

This Residual Oil Remover stuff is magic http://www.ror.net/, and made in the U.S.A.

Too old to care · Jul 8, 2012

Thanks everyone for the replies. Looks like I am off to the camera store to get some lens cleaning solution and use a Q-tip on the screen. I checked on-line trying to find another focus screen, none could be found for the MX, although some from the LX will work and I found a source for those in Europe. But, they sure do like those screens, some of them are close to what I paid for the camera alone. I can live with the spot, but I am worrying it may migrate. I have a feeling that it is left over from a recent cleaning. Today, I am going to run a roll of B&W through it to make sure that all is well, but from the looks of this thing, I am sure it will be.

Thanks again,

Wayne

Les Sarile · Jul 8, 2012

Easy enough to pop it out and clean it as recommended.

For being the smallest fully mechanical SLR it has the largest viewfinder! BTW, did you get the chrome or all black model?

Too old to care · Jul 8, 2012

It is chrome. I cannot describe how nice i is, ebay sale for "bye it now" for $125. Even the small plastic insert in the on/off switch is there, on most chrome ones I saw it was missing. The MX will replace my K1000 because I can no longer focus that camera, the split image on the MX makes things much better. Hate getting old, eyes are not the first to go, but near the top.

I need to replace the light seals, found them on-line for about $11. The bumper on the mirror looks new, maybe that is why the oil is there, someone already replaced it. I used my flash and checked the shutter speeds, compared it to my K1000 and the slits matches up at all shutter speeds up to 1/500 of a second. Since both have 1/60 synch, I can assume that the curtains travel the same speed, thus the slits at each speed should match. At 1/1000 the MX is a bit wider (thus slower), but since I shoot mostly B&W, this will not be a problem.

i am partially through one of my last rolls of Plus X that I will finish off tomorrow and develop to make sure that it does not scratch the negatives. I think it will be ok, because there are no wear marks on the pressure plate either.

Thanks again everyone.

Wayne

Too old to care · Jul 9, 2012

It must be me, my bad luck. After fully testing the MX with no film, I loaded a roll of Plus X and went to the park to shoot it. After 5 exposures the film advance locked up. I removed the film and check the inside for some film locking the sprocket and could not see anything. The rewind worked perfectly with the rewind button pressed in. Even with no film, the camera is locked up. The shutter lock makes no difference either.

I am returning it to the seller (already made arrangements) for a refund. This is my third attempt to get a nice MX. The first seller told me that she has a nice one coming in too, so I may just wait for that. Or, I may just keep using my old K1000, at least it still works, just wish I could get a split image finder. I keep looking at KEH too, may go that route if nothing turns up better. This camera was in much better condition than the ones KEH has had listed over the past few months.

Wayne

Roger Cole · Jul 9, 2012

Wow, sorry to hear that Wayne.

Are you SURE it's nicer than KEH? It's hard to tell with KEH. My MX was listed as BGN and anyone on the 'bay would have almost certainly listed it as excellent. In fact I can't find anything wrong with it at all. OTOH I did get a BGN zoom lens that really is BGN. It's fine, but it's cosmetically bargain and the zoom is a tad loose.

Too old to care · Jul 9, 2012

Hi Roger,

The ones I have seen on KEH, BTW with an outstanding warranty, say average or more than average wear. That said, you should see my old Mamiya C3 that I gave to a friend of mine. It looks really beat, but keeps on working. It put me through college and help buy our first house, and I got it used too. So, physical beauty is not everything.

KEH stands behind their products and I will probably go that route. Since MX's come and go, I will jump on the first one that says near excellent from them if my first source (with a 90 day warranty) does not come through.

Thanks,

Wayne

PentaxBronica · Jul 11, 2012

Bear in mind that the LX and MX screens are not entirely interchangeable...

The LX screens in an MX will produce a slight exposure error, I think it's about 1/3 of a stop?

The other way around is fine as the LX meters off the film, so the screen doesn't change things.

I have three MXs (two chrome, one black), main problem I've hit so far is wobbly metering on one of them (it tends to overexpose by half a stop or so). It's probably dirt in the film speed mechanism as I have a KM and K1000 with the same fault.

lxdude · Jul 11, 2012

PentaxBronica said:
Bear in mind that the LX and MX screens are not entirely interchangeable...

To clarify, they are all physically interchangeable. The LX screens are brighter.

The LX screens in an MX will produce a slight exposure error, I think it's about 1/3 of a stop?

Something like that.

lxdude · Jul 11, 2012

BTW, note that KEH has a couple of nice K1000 SE bodies. Those have a split-image screen (maybe split/microprism, I don't remember).

Too old to care · Jul 11, 2012

LXdude, thanks for the info on the K1000SE. I did not know about the split image. My K1000 is apparently not the SE version, since it doe snot have split image. I will check that out, my main use for the camera is something not too expensive that I can carry on my motorcycle to replace the K1000. It still works perfectly, but I don't.

Wayne

Felinik · Jul 11, 2012

benjiboy said:
This Residual Oil Remover stuff is magic http://www.ror.net/, and made in the U.S.A.

I have been using RoR for years for my telescopes and eyepieces, great stuff. Use with q-tip, or with disposable cleaning tissues like these: http://www.lumicon.com/dealers/thumbnail/LA3025.jpg

Good Luck!

lxdude · Jul 12, 2012

Too old to care said:
LXdude, thanks for the info on the K1000SE.

Wayne

Forgot to mention, some came with brown leatherette, some with black. I think the earlier ones had the brown.

Spot of oil on focus screen, Pentax MX

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