Dark Cancerous spot

[marcotrov]

Hi Guys
Would really appreciate some feedback. I have this dark oblongish spot which appears at varying intensities from time to time. Seen here in the drummers lower left trouser pants and again in his left sleve. It also appears on the shoulder of the dark haired belly dancer seemingly like a light bruise in her upper right arm. I thouoght it might be dust on the ccd despite its irregularity. The drummer are taken with my new 80-400VR (thanks to birddog) and the ladies with my 80-200 F2.8. Any ideas and suggestions how to get rid of it besides photoshop.
http://www.pixspot.com/thumbnails.php?album=594
Thanks in advance
marco

[Sheetshooter]

Marco,

What aperture were you shooting at? Which way did you rotate the camera for the vertical? (Shutter release at top or at bottom?) Do you regularly change lenses or did you take the lens off the camera sometime soon before the shots?

I suspect one of two possibilities before your answers are posted. One is a fluff ball hanging by a thread from the mirror or some other thing it could catch on and the second is that there is an insect inside the mirror box.

Since the mark is never sharply defined it is not on the actual surface of the chip but is either on or in front of the low-pass filter. The variation in sharpness would indicate to me that its position is not only happening laterally as you can see from the position on each frame, but also towards and away from the chip. The aperture would need to change more or less from wide open (dancers shot) to closed to f16 or something for the sharper of the blobs on the drummer. (Oh, that beat!! I hope there was plenty of kibbe and shish on offer!)

[marcotrov]

Sounds a possibility mate. I rotated the cameraleft to right and yes despite the slight crop for the 2 dancers the spot is always in the same spot only darker or fainter and yes I do change lenses but i'm always very careful where and how i do it. Obviously not careful enough. Any ideas how to locate and remove? I suppose good magnifying glass and blower brush?
My wife always tells me that belly dancing is sensual not sexual but i keep telling her part of me doesn't always agree with that view.
cheers
marco

[Sheetshooter]

Marco,

If you saw my 150kg belly you would think it was neither. It does, however, make for a very effective verandah over the toy shop!

Cheers,

[sirhc55]

Marco - a silly question but have you cleaned the sensor at all

[marcotrov]

Never Chris. I stay right away from that stuff. Too risky. All I just did was have a looksy and held it facing down and gave it a blow out with my squeeze blower. Can't seem to see anything though.
marco

[sirhc55]

Marco - most of the dust bunnies on a sensor are not really visible to the naked eye I would suggest you have a rogue bunny that is chasing around the sensor and you really should take the plunge and give it a clean

[marcotrov]

Thanks Chris. IAfter giving it the blow out I mentioned I took some test shots with the 18-70 and 60-200 on one of my white/cream walls and the spot seemed to be gone. I'll just see how this goes because the rest of my frame is pretty spotless I'd hate to make it worse as you often read is the case when people start to tamper with cleaning the ccd. Actually it could have been as Sheets shooter mentioned something hanging just in front because normally the dirt marks on the ccd would present more defined and constant in appearance. I'll see how it goes if it reappears I may have to consider it.
thanks guys
marco