- At 2000 shots I noticed spots at f/8. I thought they were oil spots. I had mine professionally cleaned. All the shop did was use a blower, which got rid of the spots (although a few small spots could be visible at very narrow apertures). Related blogpost here.
- At 4500 shots I didn't see spots but checked the sensor. I could not see spots on the sensor but when I took a shot at f/32 and maximized the contrast, I could see small spots (again, those spots don't show up in my normal shots). I used a blower to clean the sensor. Related blogpost here. Here is what the frame looked like at f/32 (desaturated to make it easier to compare):
- At 5700+ shots, I checked for spots. I have been changing lenses often (at least once every time I shoot, and often more than that). Other than the blower I used at 4500 shots, I haven't cleaned the sensor. I still don't see spots in my typical shots (usually f/5.6 or wider). I took a test shot just now at f/11 I noticed *one* speck. It was not round. It looked like a small piece of fabric on the upper left corner of the frame. I believe I can blow it away. I also took a test shot at f/29 and noticed many small spots (similar to those I saw at f/32 with 4500 shots). I did not clean the sensor (not even with a blower).
- At 6300+ shots, I still don't see spots in my normal shots. Anyway, I checked for spots again. That one speck I saw at 5700 shots is still there. Here is what my frame looked like at f/29:
Some of the spots in the 4500 shot are still there (such as the biggest spot in the lower right hand of the frame). But other than that one "thread" in the upper left hand of the frame, there is no noticeable increase in spots. (If anything, it looks like there are less spots, though I don't understand why because I didn't clean the sensor between the previous shot at 4500 and this shot at 6300.)
Anyway, I used a lighted sensor loupe to inspect the sensor. I could see a few very tiny specks but they weren't showing up in the shot. Conversely, I could not find the "thread" in any of the corners.
I nonetheless tried to use the blower several times. The few very tiny specks were moving around (but not getting removed). The "thread" on the other hand remained there. After 4 attempts of blowing and checking, I gave up on trying to remove the thread. Here is what the frame looked like (at f/29, with contrast and clarity maximized).
I compared the shots before and after cleaning and it appears that virtually all of the spots were not removed by the blower. Argh. The good news is that these tiny spots don't show up in my shots. Here is what the frame looks like at f/11, f/16, f/22 and f/29, all before cleaning. These are at the usual 1600 pix size that I most often use.
Meanwhile, I am wary of using the sensor swab on the D600 sensor to try to remove the 'thread' and the tiny spots. If ever the spots begin to bother me, I am considering a Firefly blower, which is designed to blow both positive and negative ions to discharge the static electricity that's causing some of the dust spots to cling to the sensor.
Nikon D600 Resource Page (see under "Dust Spots")
Firefly DSC-2000 Review