Dust on the camera sensor is a nuisance that most DSLR photographers have to come around to dealing with at some point or another. The above photos show the same image; one image has the dust specks and spots removed, while they remain in the other. (You’ll probably need to click on them for the full-sized images to see the difference.) I simply used the “healing tool” in GIMP – which essentially covers them up using another spot as a reference – to remove them. It’s a simple but tedious procedure. Below you can see another image in which I also did a before and after the dust removal. It is a besmirchment and chore I’d rather avoid.
When I was in Florida in early spring, much to my dismay, I finally realized just how dirty my sensor was. It showed up prominently on a particular series of shots, and I had the epiphany: my sensor was filthy. Now I feel a little silly for not having noticed it earlier, especially knowing how I tended to change lenses in the field often, leaving my camera susceptible to invasion from dust and the like, but this is a case of living and learning by skinning your knees. Or you camera sensor.
So it was long overdue for a cleaning, something I had been apprehensive about; I thought of it like cutting open the body: you want to avoid surgery if at all possible. (Plus I’m a surgeon with shaky hands!) As always there were monetary considerations, and though you can pay someone else to do this, from what I read, that was a more expensive option for likely not much better results if better at all. I ended up using the Visible Dust EZ Sensor Cleaning Kit, that I picked up from B&H’s online store. For the most part it worked well; there were a couple small specks near the periphery of the sensor that were not removed, but I decided I would just save a $5 dollar Q-tip for the next cleaning which undoubtedly will need to be done sooner than I’d care for.
One problem, I had initially in diagnosing my problem, was that I thought my lens might have been the culprit because of the dust that had entered inside of it (which I’m sure is partly a vagary of reverse lens photography). I had read that it would have to be pretty copious and/or large particles for dust inside the lens to do it, but I took some test shots;changed lenses and took some more test shots; and didn’t see the same dust, so I thought, “It’s the lens!” Well, wrong. I didn’t do a useful test, otherwise I would have realized what my initial suspicion told me. Nasim at Photographylife.com has a nice article about how to determine what is befouling your photos. I used his test and found the little prominent specks showing up consistently. As you can see by the crops below of the two images above, the specks appear in exactly the same configuration as they rest on the sensor which is a dead give away.
And there you have it. Good luck cleaning your sensors and may your cleanings be few and far between!