Dangermouse wrote:
It comes down to a simple calculation - how much did the lens cost, how much will it be worth when cleaned, and how much does professional cleaning cost?

Algernon wrote:
Sunlight won't clear haze (unless it's moisture), it will only clear yellowing, but takes ages, so don't bother with it.

The picture you posted shows dust, not fungus and not nicotine which would be very unlikely anyway.

womble wrote:
One other thing... I have found that AWB on older glass gives a different reading to that on newer glass. I found when comparing my K 135mm f/2.5 with my DA* 50-135mm that initially the results, colour wise, were disappointing until I set the white balance on the K images to the same value as for the DA*. Although I still leave the camera on AWB I do see what impact changing the setting to "daylight" in Lightroom does.

I have a K24 too and the images it gives are excellent. See my "The Loch" images.

Cheers, Kris.

Dangermouse wrote:
As the links should show, generally you unscrew the finishing ring/nameplate after which you can unscrew the front element group. The dust is usually between the front and rear element groups as this space isn't airtight - the aperture operating lever goes into it.

Do not disturb the focusing helix or the infinity stop as otherwise you'll have to re-set this, which is annoying. Assuming the 24mm is basically the same design as the 50mm then you shouldn't need to. I've dealt with a couple of lenses of late (K 28-50mm with fungus and a Tokina 28mm with a dislocated focusing ring) where there was no way to avoid disturbing these parts and I really wouldn't care to open either up again!

You might want a lens spanner like this, it makes it much easier to unscrew the notched rings used to hold some lens parts in without risking slipping and damaging the glass.

I wish I could find a 24mm for £45, with or without dust! I saw one go for £60 a while ago with a declared fungus problem, I was very close to buying it but felt the price a bit daft for a lens with a fault.

Dangermouse wrote:
I'm not sure about the K 24mm but I've opened a few 50mm and a 55mm lens before now to blast dust out, it wasn't too hard. You will never get it completely dust-free unless you have a clean room, mask, hairnet, white coat, etc. I have never had a 24mm in my hands so I've no idea how it comes apart - hopefully someone else will turn up who has done so! I find a can of compressed air (air duster) very effective for this. I even managed to blast most of the dust out of a zoom without opening it up, just by putting the air duster nozzle into suitable gaps and giving it a few good squirts.

The K lenses usually produce cooler tones than the more recent glass, I always put it down to the SMC coating recipe having changed over the years.

Algernon wrote:

Bjørn the Exif data is showing 35mm for shake reduction, which won't be helping. Try a shot also with no shake reduction, also try to get 1/250th sec. exposure. It's been reported here and elsewhere that the K-7 suffers from shake at around 1/125th. The K20D doesn't but just to be safe 1/250th with SR OFF would be safer.

For any lens tests you need to take the shot at least 4 times and then pick the sharpest of the 4.