Lieberman Posted October 3, 2013 Share #1 Posted October 3, 2013 Advertisement (gone after registration) How can you tell the difference between dust which can be indicated by the menu "dust detection" represented by "black pixels" and real dead pixels which are not dealt with in the manual? The difference is important because you would not try to get rid of dead pixels by additional efforts of cleaning. Link to post Share on other sites More sharing options...
Advertisement Posted October 3, 2013 Posted October 3, 2013 Hi Lieberman, Take a look here Dust. I'm sure you'll find what you were looking for!
paulsydaus Posted October 3, 2013 Share #2 Posted October 3, 2013 Take two pictures of a clear sky. One with the aperture at f/16, and the other at f/5.6. Sensor dust will show only on the picture at f/16 as dark blobs (but not completely dark) and covering an area much larger than 1 pixel. A stuck/broken pixel will appear in both images as a single pixel that is either black or white, or some other crazy colour. Cheers, Paul Link to post Share on other sites More sharing options...
Lieberman Posted October 3, 2013 Author Share #3 Posted October 3, 2013 Take two pictures of a clear sky. One with the aperture at f/16, and the other at f/5.6.Sensor dust will show only on the picture at f/16 as dark blobs (but not completely dark) and covering an area much larger than 1 pixel. A stuck/broken pixel will appear in both images as a single pixel that is either black or white, or some other crazy colour. Cheers, Paul This is great help, many thanks the sky in Munich showed me that it is dust! But how come that this is not visible on the f/5.6 picture? Link to post Share on other sites More sharing options...
paulsydaus Posted October 3, 2013 Share #4 Posted October 3, 2013 This is great help, many thanks the sky in Munich showed me that it is dust! But how come that this is not visible on the f/5.6 picture? Because the light rays at f/5.6 are more angled from different directions and hence the dust particle cannot impede them. At f/16 the light rays are basically all perpendicular and hence the dust particle casts a much stronger shadow back onto the pixel/s underneath. It's magic huh? But before you clean the sensor, check and clean the rear element of your lens. You don't want to be cleaning the sensor unnecessarily... Link to post Share on other sites More sharing options...
Lieberman Posted October 3, 2013 Author Share #5 Posted October 3, 2013 Great explanation. It is not the rear lens which I just cleaned and the dust (3 spots) do not come off by using the blower, so what is the best to remove it or just leave it and try to not use small apertures? Link to post Share on other sites More sharing options...
paulsydaus Posted October 3, 2013 Share #6 Posted October 3, 2013 Great explanation. It is not the rear lens which I just cleaned and the dust (3 spots) do not come off by using the blower, so what is the best to remove it or just leave it and try to not use small apertures? Well as long as you stick to Apertures <= f/11 it shouldn't be a problem. I tend not to use these apertures but if you do, you might want to consider a sensor clean. With the 1/4000s on the M, you shouldn't ever need to use f/16...? Link to post Share on other sites More sharing options...
Lieberman Posted October 3, 2013 Author Share #7 Posted October 3, 2013 Advertisement (gone after registration) Thank you so much. do you have a reccomendation for cleaning? Link to post Share on other sites More sharing options...
Philinflash Posted October 3, 2013 Share #8 Posted October 3, 2013 My guess without seeing the equipment would be that the dust is on the sensor, not on the rear element of the lens. Do a search for "sensor cleaning" on this forum and you will be exposed to many choices and views thereof. Link to post Share on other sites More sharing options...
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