K-7 : help with dust

Hi, i am having trouble with a fairly large piece of something appearing on my pictures.

I am using a k-7 and have run a couple of sensor cleaning protocols which cleared up some particles registering on the sensor test. However the original piece of dust is still visible in photographs. The dust does not seem to be present with other lenses, is it possible this is in the lens?

[IMG]http://img715.imageshack.us/img715/9978/imgp3293.jpg[/IMG]

Any help is much appreciated,

thanks

Fraser

Easy way to tell whether the lens is the culprit is try another lens and see if it's still appearing on the pictures.

Take the lens off and shine a torch through it - that should highlight where any dust lies. A spot as big as that should be fairly obvious.

Close down the aperture (say f/16 or smaller) and take some longish exposure shots of plain uniform light surface.
Do that with a few lenses and see it's in all your images or just one that you can associate with a particular lens.

Edir: Or do what hefty suggests first

ok, have decided its the sensor. Gave it a quick blow and now the big bit is gone, and im left with several smaller ones...... its progress

On another note why are parts of the menu sometimes not available? the dust mapping option is no longer accessible to me for some reason?

thanks

Fraser

I have noticed that the dust alert menu function is greyed-out if the camera is set to manual focus or the mode dial is set to video.

Glyn

get yourself an arctic butterfly, works great and it's easy to carry around.

I have always been advised against using brush type sensor cleaners by my local Camera shop as they can shed bristles which can get lodged within the Camera. I have used the Pentax Sensor Cleaning kit successfully for 3 years now and have used it on my K7 several times. Available from SRS.

Regards - Pete.

Hi, the kit seems pretty overpriced for what it contains.

will be using the camera tomorrow night at a fashion show and expect to be keeping to the larger apertures so should be fine.

Thanks for all the help as usual.

Fraser

I have been using an Arctic Butterfly for at least three years now, and have never had a bristle drop from it. If you buy a good quality product it just won't happen. Don't believe everything your local camera shop tells you, they want to sell you stuff remember.

I use the Pentax cleaning Kit as well and can recommend it - it might seem expensive but it lasts a long time

Actually the Camera shop did not stock the Pentax Cleaning Kit or the identical Nikon one.They actually cleaned my sensor for free using some relatively cheap swabs (£17.50 for 10) and a cleaner that smelled like Methylated spirit. Brushes do lose bristles! I am a painter so i know only too well! Even the best made ones are going to shed them at some point! Either through breakage, Wear or through disintegration of the vulcanised rubber or whatever they use to hold the bristles in the ferrule. so i agree with the shop! Yes the Pentax cleaning kit is expensive for what it contains but compared to the alternatives it is incredibly cheap! The Pad of sticky papers have lasted well and i have used them on other people`s sensors as well as my old K10D and my K7 and still i have loads left.

Regards - Pete

I'm another Arctic butterfly man!,,,,unbeatable piece of kit!.......

I had an episode with dust not long ago. It had got suddenly much worse, so much so that I was avoiding taking pictures.

I got an Arctic Butterfly, and it was completely ineffective.

Then I got some fluid and swabs from CameraClean.co.uk, and the results were quite good.

You can see some before and after pics here; the crap on the sensor has been made more obvious by cranking up the contrast, but it was unusable for all intents and purposes.

Note that when I managed to introduce a large lump of dust that wasn't too stuck, the Arctic Butterfly worked fine, so it may be the best thing for the OP.

But for anything sticky, especially if it's been on there for a while, a wet clean is probably going to be the only way.

I do mine before it gets as bad as that!....I could have loaned you a shovel to get rid of most of that!....I do mine usually every 2 weeks or so,a 2 minute job with the "Fly!".....