Dust spots and bug

Hi just joined

When looking through the view finder I can see a little bug and when I took a photo of the sky to check I can see dust spots and one of the bugs legs i think

Now to my question how can I tell where it is on my Pentax k20d

It could be on the sensor on the mirror or up in the top bit where the brackets are there is a glass screen that you can release down think it’s called focus screen

Tried the on board shake clean several times

Thanks

Hi Astraman and welcome to the site.

I think this could be potentially two issues (although please read on to the end), if something is visible while you optically look through the viewfinder, the bug (or particle) could be between the pentaprism and focus screen, laid on the focus screen or on the surface of the mirror.

If it's in any of the above places, it wouldn't be visible on the photos, since the mirror lifts to allow the light from the lens to project onto the sensor.

So your blue sky photo is probably highlighting dust on the sensor.

The final thing to check and potentially could be visible on both, is something on the rear element of the lens, but not 100% sure how visible this would be optically or on the sensor and images.

Def not the lense as I took this off at one stage to check and could still see it through the view finder think I’m going to drop the focus screen down to check there if I can’t see it there I will prob take it to be cleaned professionally as I haven’t tried before and don’t want to damage my camera

Thanks for your input

If you can see dust spots and a bugs leg on an image you have taken then these are not what you are seeing through the viewfinder. You may well have something on the focus screen or in the viewfinder or on the mirror (as Rick has suggested) but the bugs leg is more than likely a hair on the sensor, and sounds like some dust on there too!

I'm not familiar with sensor cleaning on the K20D but it may well be worth having a professional clean unless you are confident with the technique recommended in the documentation.

If you do attempt this, just a few words of caution, it's hinged at the back, with the release clip at the front, the likelihood is when you release it the focus-screen will dislodge itself from the frame and the frame will lower onto the mirror, so be prepared.

Ideally you could do with some tweezers to hand, since the focus-screen has a little tab on it to use. Whatever you do, don't touch the screen with anything, they're so easily marked. Only use a camera dust bulb/blower on it to blow off any debris, even this can take several attempts (of refitting it and checking) to ensure there's no fine fibers on there.

Thanks for the info

Being put off more and more

Think I’ll take it in to the professionals I’m not gonna mess with it

Thanks again all

You can check what dust (if any) is on the sensor by using the Dust Alert function. It's described in the user manual, section 'Cleaning the CMOS Sensor' starting page 252. It's easy to do and will show where dust is on the sensor.

Removing dust with a blower is also described and is also easy to do - had to do it fairly often with my K20D. After blowing, use Dust Alert again to check whether any dust remains. A second blow may be necessary. Just need to be careful of 2 things (a) use a fully charged battery, you really don't want to find out what happens if the battery runs out half way through; (b) don't touch the sensor with the blower, or indeed anything else.

If there is still dust on the sensor after blowing a couple of times, it must be sticky dust so sensor cleaning methods that involve contact with the sensor must be used. There are kits and devices for doing that (a Pentax kit is advertised in the Accessories section of the manual so it is definitely a 'user maintenance' thing). They do work and it isn't difficult. However, if you have any doubts about your ability to follow instructions to the letter and do delicate operations with you hands it's best to leave touching the sensor to the professionals.

Steve

Thanks for the info

Being put off more and more

Think I’ll take it in to the professionals I’m not gonna mess with it

Thanks again all

Thanks for the info had another look today and found the dust alert

Was one spec which the shaker removed so had another good look inside and I think I can see it under the focus glass in the top so I’ve ordered some plastic tweezers and a rocket blower shall wait for them to arrive and I’m gonna have a go with some of the useful tips I’ve been given

Shall update in a few days when stuff arrives

One bit of advice..... take out the focus screen by all means and blow it with a rocket blower.

But do not try and wash, clean, or wipe it in any way

Ok thank you

Ok thank you

Just an update stuffs been delivered and upon taking out the focus screen I could see the bug above where the screen goes what would be into the view finder managed to blow it out

Put it all back together jiggly bit of dust/fiber but going to charge the battery up and give it a good blow out with the rocket blower

Good to hear you've located the bug and removed it, yep it might take a few attempts to ensure there's no fibers on the focus screen, but you'll get there.

I once bought a M 40mm/2.8 that had a dead spider inside.