Strange dust problem

I was testing a new lens today when I noticed a small spot, only visible at F13 and above. I thought it was dust on the lens. But then I noticed the same spot is visible on my other lenses too. So I thought it must be dust on the sensor. I ran a sensor check, which showed nothing. Did a visual inspection (and air blow) of the sensor, which again showed nothing.

So what is it?

100% crop:

Try sweeping the sensor with an Arctic butterfly brush.

Yes my friend you have dust on your sensor!....."The butterfly" will fix it

You might also be able to clear it using the "sensor clean" function assuming your camera has one. This vibrates the sensor to shake dust off and usually works pretty well.

Thanks will try that.

If that doesn't work try a Giottos "Rocket Blower" and then if all else fails the Arctic Butterfly. The Butterfly is apparently superb but at the price they charge it really should be!

The dust alert function on my K200D used to show a few spots of dust. I must admit to getting a bit anal about cleaning the sensor and spent quite some time using the sensor clean function and a Giottos Rocket Blower in an attempt to banish dust forever. I then naively assumed, at least until recently, that because the dust alert function on my K200D showed no dust, there was probably no dust on the sensor.

One day recently, I took a few a few shots at f16 that included quite a bit of blue sky and lo, I do have dust!! To check just how much dust, I took a photo of a white sheet of paper, at f16 and then enhanced it a tad in PSE8 by upping the contrast a bit. I can count *about* 19 distinct round and quite obvious spots of dust. Maybe my dust is the wrong kind of dust, because the dust alert will still not admit of its existence. Ho hum ....

I've read about the Arctic Butterfly and know that they are popular with many forum contributors - but they are also a bit on the expensive side and do get mixed reviews in some places . Anyway, I've ordered some (much cheaper) sensor swabs after a troll through Ebay. I quite like the idea of them being manufactured in a clean room and pre-impregnated - saves the cost of buying cleaning fuid separately and less for me to screw up.

Here's hoping ....

Andrew

Swabs and liquid aren't cheap ...the last time I cleaned with them I used all 6!....that was £28.00 worth!.....A shop clean will cost you at least £35.....£50 if you have to post it!...My butterfly was £44 ,3 years ago,it is used every week for a good clean,and it's still going strong on the first battery!.....work it out for yourself!

ps. I see the btterfly is only £44.99 from SRS!...A BARGIN IN MY OPINION!

I thought trolling was somewhat deprecated these days.
Indeed.

I had a bit of a hoover the first time I wiped a wet, tissue-coated ice-cream spoon across my sensor. So I guess you could call it a clean room.

People, you may think it's a big deal, but it really isn't. Even one as cack-handed as myself has failed to trash a sensor with a wet swab, and (wait for it) I actually dripped the fluid on it myself.

And, with both hands, reversed it and gave a second wipe.

Seriously folks, less of the wimpishness, please. We do more sophisticated wiping in another clean room every day.

Fortunately (or otherwise), I am old enough to remember and sometimes use words in their pre-internet sense - as in this "wandering about" session on ebay. I do, however, usually have the sense to avoid challenging the most politically sensitive distortions of modern english usage

I managed to replace the focussing screen on my K200D without mishap a while back, so I suppose I shouldn't really be trembling at the notion of applying a "known clean" swab to the "sensor". I will attempt to banish both dust and wimpishness, as soon as the swabs arrive in the post.

I usually manage to avoid having to do the "washing up" - my condolences.

Andrew

Did you not mean 'trawling'? As in, let the net out, and see what it catches?

Yes, we drive cars, empty dishwashers, operate electical equipment of various kinds. We drill, saw, press buttons on remotes, carve cooked chickens...

... but clean a sensor... whoa Dobbin. Scary stuff.

I had a thoroughly odd moment with dust alert a while ago. On my 28-80mm and 35-70mm zooms it showed loads of the stuff around the corners (which wasn't there when I tried the white sheet of paper at f16 trick), swapping back to the kit lens saw a clean result again!

No, I did mean it in one of its original english senses - to wander about or ramble.

In a way, cleaning a sensor is scary stuff. Film cameras are much more forgiving if you trash some sensor material - you just get another roll out of the fridge, problem solved. For a DSLR, you have visions of having to buy a whole replacement camera.

Hang on a mo, I've had an idea ............

Andrew