One of our readers sent me an image with the following question as a Case Study:
I have no idea what this streak is on my pictures could you give me an idea? I bought a new lens, because there was a small scratch on my old one. However, the same streak appears in the exact same place. It is a line about 1 inch on the top right of my pics. Usually seen when shooting skylines, clouds. etc.
So, what are those spots and streaks that are clearly visible in the above image? First, the good news – the above spots and streaks have nothing to do with the lens. In fact, lens problems and even major scratches on the front lens element rarely ever show up in images. Unless the rear lens element is damaged/scratched, you should not see any lens defects show up in your images. Those of you who have seen my articles on cleaning DSLR sensors probably already know what these are. They are dust spots, along with a piece of hair that is sitting right in the middle of the camera sensor (the long dark line streak). Now the bad news – whenever you see something like this consistently show up in your images when shooting at small apertures, you will have to either clean the camera sensor yourself or send your camera for cleaning in order to get rid of all this dirt on the sensor. The latter is a safer method, but will cost you a lot of money to continue sending your camera every time you need it cleaned; plus, you won’t be able to take pictures while it is in service. The cheapest method is to clean your camera sensor yourself. As I have shown in the my cleaning DSLR sensor article, you can clean a sensor very quickly without any hassles, as long as you have the proper tools. Is it risky? Unless you do something stupid, the procedure is very safe (obviously, I take no responsibility for any potential damage to your camera). Just watch the video and then watch the more detailed videos on how to clean DSLR sensor and keep your camera gear clean for more info.
Let me know if you have any questions!