K-7 attracts dust behind focusing screen too fast?

*LeDave* · 11-06-2009, 01:38 AM

Anybody else realize this? I think it's 'cuz there's a bigger gap from where the screen is to cover the pentaprism.

My older K2000 had a really tight screen with small gaps so dust never gets behind there. With my K-7, it seems like dust gets in there everytime I swap lenses no matter what. I have a piece of dust stuck inside my pentaprism now that I can't remove with rocket blower also.

wlachan · 11-06-2009, 01:41 AM

The dust is probably trapped between the focus screen & the prism. Just pop off the screen & blow it off. Takes less than a min.

*LeDave* · 11-06-2009, 01:43 AM

Originally Posted by wlachan

The dust is probably trapped between the focus screen & the prism. Just pop off the screen & blow it off. Takes less than a min.

I pop out my screen all the time and blow it off because dust always get in every time I do a lens swap, unlike my K2000 which never gets dust through the screen. The one dust is stuck inside my pentaprism and rocket blower can't even remove it and it's not on the screen because if it was, it'd be gone when I look through the viewfinder by now.

wlachan · 11-06-2009, 01:52 AM

If it is visible when you have looked "through" the viewfinder, the dust must be on either side of the focus screens, or the lower side of the prism. If it is visible only when you look "at" the viewfinder, it is between the eyepiece and the prism (nothing you can do except to remove the entire top). Dusty camera bag often causes the issue you have. Time to dust it if that's the case.

knoxploration · 11-06-2009, 01:53 AM

I've not yet tried to remove my focusing screen, but do have one visible bit of dust behind it. Not sure if it was there from the factory or appeared later - I didn't notice it until I'd had the camera for a week or two.

I'm a little hesitant to try and remove the focusing screen without the appropriate tool though, so I'm just living with the dust speck for now. It isn't hugely distracting, and doesn't affect my photos obviously.

*imtheguy* · 11-06-2009, 08:34 AM

Originally Posted by knoxploration

I've not yet tried to remove my focusing screen, but do have one visible bit of dust behind it.

If you only have ONE spec of dust and you remove the screen to clean it, I am will to bet you have more than ONE spec when you put the screen back unless you have access to a "clean room" and use 100% lint free cleaning system.

stormcloud · 11-06-2009, 05:24 PM

you all must be changing lenses in some dusty places - dont have any dust in mine but i am careful about when and where i will change lenses

*Wheatfield* · 11-07-2009, 12:13 AM

Originally Posted by stormcloud

you all must be changing lenses in some dusty places - dont have any dust in mine but i am careful about when and where i will change lenses

Same here, though i am not really careful at all about changing lenses. I do wonder though if perhaps because of the weather sealing if Pentax got a little lazy about dust sealing inside the mirror box.

Pentaxor · 11-07-2009, 02:40 PM

eversince I blew my mirror (mirror down) and sensor (mirror-up) clean months ago, I never experienced any dust particles. it was annoying then since I always get some stubborn dusts before. but now it's 100% clean all of the time. also a factor is the way you switch lenses. definitely removing the lenses in an upward position would attract more dusts as opposed to removing your lenses downwards. dusts just don't come up unless you blow them.

eva2000 · 11-07-2009, 11:31 PM

weird stuff you're experiencing... no dust here as well with K200D and K-7..

*SPB* · 11-08-2009, 12:21 AM

I have a K10 presently and experienced exactly this problem after 1 week of ownership. It obviously does not affect my images, but every time I look through the viewfinder and see the speck of dust inside it annoys me. In my view this is a design fault.

*Wheatfield* · 11-08-2009, 09:09 AM

Originally Posted by SPB

I have a K10 presently and experienced exactly this problem after 1 week of ownership. It obviously does not affect my images, but every time I look through the viewfinder and see the speck of dust inside it annoys me. In my view this is a design fault.

They can't make cameras 100% dust proof. If you are using a zoom lens, you are probably pumping air around inside the mirror box every time you zoom. Every time you take the lens off the camera you are potentially getting dust inside.

Calling reality a design failure isn't realistic. Dust happens, dust has always happened, and photographers just have to learn how to deal with it.
Find something else to be annoyed about before you make yourself mental.

*SPB* · 11-08-2009, 09:15 AM

No zooms used. Point taken.... usually I forget it, sometimes it niggles.

ManuH · 11-09-2009, 10:32 AM

Originally Posted by LeDave

Anybody else realize this? I think it's 'cuz there's a bigger gap from where the screen is to cover the pentaprism.

My older K2000 had a really tight screen with small gaps so dust never gets behind there. With my K-7, it seems like dust gets in there everytime I swap lenses no matter what. I have a piece of dust stuck inside my pentaprism now that I can't remove with rocket blower also.

Same issues for me. The K-m/K2000 never gets any dust on the VF, but my K-7 seems to attract it. Hopefully, the sensor never got any dust in 11000 pictures! I'd like to find a way to clean it myself but I'm not very confident and I don't have the tools to remove the screen to clean it. If anyone has an idea, it's welcome...

Glen · 11-11-2009, 06:26 PM

My K20 has the same problem. I've used the Arctic Butterfly to clean the sensor which worked great. There are no dust marks on my photo's but there is dust all over the viewfinder. It is always in the same spot so it must really have stuck hard when it got in. I would sure like to be able to clean it but how?