What is this on my sensor?

[Bandit4000]

Hello All
I wonder if anyone can help identify what is on my 30D sensor. I have tried cleaning it without success, I have not used this camera in a while and was thinking it might be fungus.
Thanks
Mark
Brisbane

[Tannin]

I am seeing three or four dust bunnies and some compression artifacts in a rainbow shape. The former can be cleaned off with a standard wet cleaning process (at least I have never yet many that could not be), the latter is nothing to do with the sensor or indeed the camera, it's causes by some software somewhere along the chain trying to compress a gradual range of colours into (in this case) just three uniform shades.

[Bandit4000]

Thanks for your reply, i'll get myself a cleaning kit and give it a go
Mark

[Tannin]

can be cleaned off with a standard wet cleaning process (at least I have never yet many that could not be)

I meant to say "at least I have never yet seen any that could not be". Proofreading error - it's an error not to do any!

[Geoff79]

Aside from the obvious marks, that washed out effect looks familiar to what I had recently when I tried to self-clean my sensor with a (supposedly proper) wet cleaning tool. Never again. I took it into 'my chap' and he said how lucky I was to escape with the sensor still unscratched. That's just me being too inexperienced to clean it on my own, but I'll definitely take it in to the professional for anything I can't get rid of with those blower devices.

[arthurking83]

G'day Geoff.
I'm not sure about this washed out look you're referring too, but the strange block and limited colour graduation in the OP's image is simply due to overcompression of the image.
He's compressed a 1000pixel wide image, into a 19kb file size, and in doing so, is obviously going to get serious degradation in the image.(even if the image is a single solid colour).

I'm curious to know about this washed out effect you got tho.
If you used a quality product to clean your sensor with, you should have had no problems with the process.
But in saying this, I did once(long time ago) have an issue myself, and it was partly my fault and partly Eclipse's fault.
On one occasion, I cleaned the D300's sensor, and got the dust specs off, but didn't initially notice the 'streaky' effect that I subsequently saw in a few images later.
Initial thoughts went along the lines of OMG! .. I've stuffed the sensor, scratched it, or whatever.. the usual stuff that an inexperienced person would automagiaclly assume.

Whilst looking at the sensor directly(with magnifying glass too), I saw the streaky effect on the sensor's surface, and it looked 'wet'. It wasn't wet of course as the Eclipse fluid dries almost instantaneously, but it had this water wet streaky look to it!


It then struck. I hadn't used the fluid for a while, and it's obvious now that there is just enough water in the Eclipse fluid to allow part of it to separate and leave this kind of residue/streaky effect.
The fix was as simple as .. shake bottle of Eclipse vigorously before use, and clean it all again .... and violá! Streaks gone.
Now I know better, even tho Eclipse don't state this in the directions of use .. I always shake the bottle before I use it.
(the only issue with this, now natural, tendency too shake the bottle before use, is that I sometimes do it to the can'o'air, I use before I attack the camera with the cleaning routine. It's just a habit, and if I do shake the can'o'air by mistake, I have to either allow it to settle for a while, or alternatively .... spray out any possible excess of propellant in the nozzle system out into thin air, and wait for it to clear, before I can spray the camera.

In the OP's image above there are two effects to see: dust speckles which are easily cleaned off with a wet clean product, and massive compression artefacts which have caused posterisation in the image.
I suspect an 80kb sized image will look a lot nicer in the way the colour graduations are displayed.

One last thing about cleaning too. There is/are products that don't use this wet cleaning process, and use a sticky pad method, where you peel off a protective film off a sticky pad which is at the end of a long stick, and you press the sticky pad onto the sensor.
The idea is that the sticky nature of the pad is also going to have a sticky effect onto the dust particles on the sensor.
The theory is that when you lift the pad off the sensor, you are also lifting the dust off the sensor as well, as long as the pad's sticky force is stringer on the dust than sensor used to have.
I've been wanting to try this product out now for a while, and know I can get a pack from the local photographic shop(Vanbar), but I found the price per clean to be excessive compared to the wet clean method.

To the OP: as Tannin said, you need a sensor clean. And also is the effect as obvious at a more common working aperture range, where more common is equal too an aperture value you generally tend to use.
f/25 is quite small, and not a value you would tend to use on a day to day basis. Try it at f/11 too and see how badly the sensor is still affected by dust.
FWIW: I think the largest dust particle in this image is still going to be evident tho.