Kenboy Posted June 20, 2020 Share Posted June 20, 2020 Hello, I've just bought a 2nd hand Canon 550d + 50mm F1.8 lens On taking a long exposure picture with the lens lid on - i notice widespread and multiple small red and blue dots, some even white dots I've also noticed some of these fixed dots on live view finder when I'm following a star on 10x zoom Are these just hot pixels? and are they normal to have? haven't taken any astropics yet - but would'nt this affect all my pics (especially when I add on a refractor scope later on) thanks! Link to comment Share on other sites More sharing options...
wxsatuser Posted June 21, 2020 Share Posted June 21, 2020 (edited) You will find lots of hot, dead and stuck pixels, imo normal. You should be able to fix most by doing a manual sensor clean. Make sure the camera has reached ambient temperature and switch to manual or bulb mode. Find menu item sensor clean do clean now. This will update the bad pixel map and should remove these pixels, remember to only shoot RAW as jpegs will not be updated. When you add a telescope you will no doubt stack multiple images, this will normally get rid of bad pixels during the stacking process. Edited June 21, 2020 by wxsatuser 1 Link to comment Share on other sites More sharing options...
Kenboy Posted June 21, 2020 Author Share Posted June 21, 2020 awesome thanks Link to comment Share on other sites More sharing options...
richard ashbee Posted June 21, 2020 Share Posted June 21, 2020 this might explain what has happened https://photographylife.com/dead-vs-stuck-vs-hot-pixels 1 Link to comment Share on other sites More sharing options...
CloudMagnet Posted June 22, 2020 Share Posted June 22, 2020 Yep, completely normal for any camera. When you come to process astro photos, you should also take "dark" frames. These are pictures taken with the lens cap on at the same exposure length and ISO setting as your normal pictures. Stacking software will use these to help subtract hot pixels from your final image. Link to comment Share on other sites More sharing options...
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