My pentax p30t is focusing beyond infinity... what can i do?

[diogo_paradinha]

hello! i've aquired a pentax p30t recently, body only! mechanically

seems well functioning but when i've inserted a lens (smc-a 1.7

50mm), immediately i noticed it is focusing beyond infinity... what

can i do?

will it focus correctly at other distances, i mean, what i see

through the lens is exactly what will show in the photo (i haven't

done yet a film to test it)!

by the way, the problem is not on the lens, because on another pentax

it focuses correctly...

thanks,

diogo

 

p.s. if i'm not asking that much, why does sometimes the split image

gets darkened, like a water stain (because it moves if move my eye),

and if i reattach the lens that does not happen?

[Jochen_S]

There are 2 options: The good one would be The camera is quite fine but somehow the lensmount is too close to the film. Then yuor pictures would be in focus and you could maybe fix it by putting some thin paper under the lensmount (I myself wouldn't dare to losen a KA mount, but I'm a coward)

 

Bad one: The levers holding the mirror could be misaligned, your photos won't be in focus.

 

One roll should tell the truth.

[stemked]

Diogo,

 

Try first a new lens and see if the problem is with the lens or body.

 

If the mount isn't flush with the body you might have this problem (as previously noted).

[stemked]

Another thought poped in my head. Check the pressure plate (back of the camera) and see if it seems to be 'ok', not bent, dented or something similar.

[david j.lee]

some pentax lenses are designed to focus past infinity. that is what they

brochure says. don`t worry, just try it and see.

[gordon_ian_stalker]

Ok, first check the mirror. A dark stain that moves as you move your eye, but disapears sounds like a mark or stain on the mirror.

 

The fact that it disapears with a lens fitted has to do with the lenses tendency to contrain the light entering the camera into a fairly well directed beam. The effect is the same as a partial obstruction just behind the lens. (Which is the the same thing really!)

 

That suggests that the mirror may have been disturbed, or even inexperty replaced. Check that it is properly mounted, is the right way around (ie silvered on the front!) and not actually damaged.

 

Next check the focusing screen is properly seated. The screen itself is kept in position with a set of small springs, and it is just possible to jar the screen out of place, or it could be the result of someone poking at it with a finger. If it is stuck in an odd position it won't focus correctly.

 

Use only a clean cotton bud to gently probe the screen at the corners if it does not seem to fit square on the top of the mirror cage.

 

The next thing to check is the lens standard/mount. The whole thing is mounted on a plate screwed to the front of the body. If the lens mount is mis-aligned badly enough you may notice an uneven gap between the back edge of the standard, and the front of the mirror cage.

 

The ony way to access these screws is to peel off the fake leather covering, but don't try this unless you feel confident that you can take the camera apart.

 

Check out www.mypentax.com where you can get an idea of what to do. There isn't actually a P30 there, but there will be one day. (It's my website, but I havent't got around to preparing the P30 page yet!) To give you a start, the first thing you need to do is remove the cover on the film winding lever. (Look at the underside of the lever.)

 

However, if the standard is evenly maladjusted then there isn't neccesarily a problem. As long as the mirror-screen distance is the same as the film-screen distance, whatever you see on the screen will be what goes on the film. (With the exception of any muck on the mirror & screen of course!)

 

As to looking at the film-plane and pressure plate etc, I don't think that has any bearing on the problem. That wouldn't show-up in the viewfinder.

 

What you might want to check is that the focal plane is flat, so that the top, bottom, left, and right edges are all in focus at the same time. This is fairly easy to check, all you need is a big flat surface with something to focus on, like a brick wall. You have to make sure that the camera is dead square on to the wall, (which is the trickiest part of the whole operation) then you can check that the focus at opposite corners and edges is the same.

 

(You might find that with some lenses that the edges and the centre are not exactly in focus at the same time. That's not uncommon. A lot of lenses sacrifice a flat field in order to improve performance in other areas. Unless you spend a lot of time taking pictures of brick walls at f1.4 it's not something you are going to notice!)

 

Gordon

[amy_de_taranto]

Your camera is focusing to infinity and beyond? Surely the answer is obvious - sell it to Buzz Lightyear!

 

Amy

 

ps. This is not intended as a serious answer, but I just couldn't resist!