I took some pics the other night of light poles that I thought were interesting in a "War of the Worlds" sort of way. OK, so the the idea really didn't pan out, but I discovered strange spots on the images, all in the same location. The lens was completely clean and dry, frankly I'm stumped. Can anyone help me figure out what these may be? They were taken as NEF raw files, corrected for exposure, color temp and vignetting (full correction-I can see why the 24-85 f/2.8-4.0 is not highly rated in that area), long exposure noise reduction was on, saved as jpegs, and resized for the web. The spots appeared on all images in the same place, from original raw to the jpeg's. Help!!!
If you see it on all image files then it's on your camera's sensor. Looks like some kind of stain. Could any moisture have gotten inside during a lens change? Regardless, you'll learn that spots or dust on the sensor is a common issue with DLSRs, inevitable in fact. Some send it into Nikon for cleaning. Many, myself included, clean the sensor ourselves periodically. Most times, a Giottos Rocket Blower is enough to do the job. Occasionally, a wet clean is necessary. I suspect a mark like the one you have here will require a wet cleaning. There are several products out there and I suggest you do a search on the topic.
There has been only one lens on the camera, I installed it the day I got the camera and it has not been off since. I've had them less than a month. I'm thinking sensor also, since its in the same place every time. I hate to send the thing to Nikon and be without it after just getting it! Hell, I returned the first body to a dealer due to a dead pixel, and now this!! Anyone know the turn around time on fixing something like this? Never had any problem with all the Canon DSLRs (5) I've owned. Not a happy camper.
Since you have never taken the lens off, check it first as there may be a spot on the rear or front element. Also run your cleaning mode on the camera, though I don't expect that it would remove a dried spot it is worth a try. IF none of that works you can clean the sensor yourself, just buy a cleaning kit. This kind of thing will show up on every DSLR eventually. Also if you have Capture NX2 you have the option of making in image of the spots (see your manual) and then NX2 will automatically remove them in the image.
Thanks for the input Bob. The lens is perfectly clean front and back, I have the camera set up to clean on both the start-up and shut-down. I talked to Nikon and they want me to reset everything to the default settings and send an unedited (origial metadata showing) raw image with the problem showing so they can diagnose the problem. I'll have to take some new pics to do that as I no longer have what they want.
The cleaning kit is a good idea and I will get one, but with it being so new I think I'll just send it back to Nikon, there's really no good reason for there to be any kind of defect in a camera this new.
Why not just clean the sensor yourself? The kit is like $20 USD and it takes about 2 minutes to do. I went to my local camera store and he showed me how to do a wet cleaning, very easy. Not worth sending it out and waiting for it to come back. All cameras get dirty sensors even new ones!
Shoot some other examples, I see two almost exactly the same pictures - and both of them are very wrong example to make any conclusion.
Dirt on sensor or back lens element look different, and cannot be seen on open aperture, only at very closed one (f/8+). Is it really so difficult to try to reproduce it in other situations, daylight for example?
Shoot empty sky at f/22 and check it then, or shoot blank Microsoft Word page from close distance (or other bright white screen on PC) with ISO200, f/22, and move camera close and away while the exposure takes place (it will be around 1 second).
To me this shows like lens flare. Have a careful look at the second image: There is a similar, but less visible - structure on the top left also, just barely visible. Given the fact that this scenery does have almost infinite contrast, and there are bright highlights in the frame, I guess any kind of lens / camera combination would produce some flare; at least there is the risk of doing so. And the colour also supports that: green and smaller violet round structures, the typical reflections of coated glass.
Thanks to everyone who responded, I really appreciate all the help and input. I have been unable to reproduce these spots and as such, I'm going with lens flare as the culprit. Actually, all things considered, that's the best case scenario, this means I don't have to mess with the sensor, which I was really not wanting to do.