I had dust on my Nikon D600 after less than 1000 shots and before I ever even changed the lens. Something is up with Nikon and dust. Either a shutter design or something else. I even had 2 hot pixels and ended up returning. I'll probably end up re-buying but i'm worried about these issues. Even the reviews are pointing them out:
http://learningcameras.com/reviews/4-dslrs/75-nikon-d600-full-review

i tried the '' clean sensor of the menu'' and i had more black spots ! i contacted nikon and they confirmed that the sensor needs to be cleaned, so i took the camera today to the service centre kingston ,london .the service was just great and they have done it while i was waiting .
the whole process done within 4o min.
thank ou msmoto for your reply .

@ sary

Shoot an exposure of a plain white sheet of paper, camera focus at infinity, paper at about two feet. In post processing, increase contrast to full and then post image. This should show the problem more clearly than a 10 second exposure.

here is the link to see the mark

thank you for the reply msmoto , how can i post a pic as attachment ?

Now that we are in the correct thread...just a little note. Unless I am in an extremely dirty venue, I do not clean lenses. Some have never been cleaned in several years except to possibly blow dust off. And the rear element is never touched unless some unfortunate event occurs and a piece of dirt or smudge gets on the glass.

The pro Nikon bodies do seem to have a tendency to accumulate oil spots. After about 10,000 clicks I cleaned my D4 sensor which had over 70 oil spots, by count, and I have not had another in the past 7,000 clicks.

And, Sary, welcome to NRF. Maybe you could post a photo showing the spot..... or what a while and see if more accumulate.

sary said:
hi guys i've just noticed a mark (same size and location) in some of my pictures taken with my d800 , i've tried differents lenses but still same thing .i do clean my lenses before and after use .has someone experienced same issue please ? is something to do with the sensor .it happens on 3/4 out of 20 pictures !
thank you

I had the same problem when new. Cleaned the sensor after about 1800 shots and it's been fine from then on. I have to blow off a dust spot every now and then but the self clean normally does the job.

Nikon should clean it under warranty. I just did it myself.

I cant say I noticed any, though admit I have not looked for them.

What's a good method ? Shoot a white sheet and overexpose so nothing is there, then look for spots ?

nope, where have You changed Your lens - what conditions?

Hi everyone.

I found problem of oil spots or dust issue at my D800 make Oct. 2012, only 1100 cut.

I took the dust or oil spots photos at my camera and adjust more clearly show it. used lightroom.

this is detail 100% crop

I will check in NIKON as center in Korea tomorrow. If i have something more news from AS center, i`ll more report.

However, nobody expriance about this ?