brrttpaul Posted July 5, 2015 Share Posted July 5, 2015 where this is? I thought I typed in M52 (could have made a mistake) last night but i am not sure it is with the swirl of nebulosity bottom right. I also seem to have got myself three dark spots on the lens of the scope and I have no idea how to remove them. any suggestions much appreciated Link to comment Share on other sites More sharing options...
wxsatuser Posted July 5, 2015 Share Posted July 5, 2015 Thats M52 and the beginnings of the Bubble Nebula.https://www.google.co.uk/search?q=messier+52&tbm=isch&imgil=tdyiPilagNu_YM%253A%253BNaaQeAjRr2wDYM%253Bhttps%25253A%25252F%25252Fen.wikipedia.org%25252Fwiki%25252FMessier_52&source=iu&pf=m&fir=tdyiPilagNu_YM%253A%252CNaaQeAjRr2wDYM%252C_&biw=1366&bih=671&usg=__8YhTjwtR5Opgs6z3ehrddgM8VcM%3D&ved=0CDMQyjc&ei=mPWYVYCUIqnU7Aadp6T4Ag#imgrc=OAiV_fYjFw1N2M%3A&usg=__8YhTjwtR5Opgs6z3ehrddgM8VcM%3D Link to comment Share on other sites More sharing options...
brrttpaul Posted July 5, 2015 Author Share Posted July 5, 2015 Thx very much, I must have been off slightly and picked it up, glad I got it considering the moon was out but annoying me those liquid spots Link to comment Share on other sites More sharing options...
Tinker1947 Posted July 5, 2015 Share Posted July 5, 2015 The dark spots are likely to be dust on the camera sensor, a dust blower should get the off, just don't touch the sensor with anything.........M52 being the cluster to the top left on the image... Link to comment Share on other sites More sharing options...
reddoss Posted July 5, 2015 Share Posted July 5, 2015 A good idea is to take flat frames (http://www.astro-imaging.com/Tutorial/Frames.html). They will help reduce the problems of dust or light gradients. Like dark frames, they are another calibration used during pre-processing. Link to comment Share on other sites More sharing options...
Pete Presland Posted July 5, 2015 Share Posted July 5, 2015 Other than the obvious issues with the image, that can be address in the future with calibration frames it is a nice start. M52 is showing very nicely while retaining some very pleasing star colour. The Bubble Nebula with some nebulosity around it is coming through as well. An excellent start! Link to comment Share on other sites More sharing options...
brrttpaul Posted July 5, 2015 Author Share Posted July 5, 2015 Looking on the DSS help it says flat frames should be taken with the same ISO, focus etc but it says let the camera decide the exposure time through AV mode. So I presume these will be very short exposure times then? Link to comment Share on other sites More sharing options...
reddoss Posted July 5, 2015 Share Posted July 5, 2015 Looking on the DSS help it says flat frames should be taken with the same ISO, focus etc but it says let the camera decide the exposure time through AV mode. So I presume these will be very short exposure times then? Yes, they are usually much shorter than your 'Light sub frames' - it depends on a number of factors, but around about 200 Milliseconds or so is a rough representative exposure time for a flat frame. Link to comment Share on other sites More sharing options...
brrttpaul Posted July 5, 2015 Author Share Posted July 5, 2015 thx very much for that so just et the camera to 1/200 or should i just stick the camera into auto and let it decide Link to comment Share on other sites More sharing options...
michael8554 Posted July 6, 2015 Share Posted July 6, 2015 Exposure will depend on brightness and your telescope F number, reddos was suggesting a ballpark speed that exposing in AV mode would produce.So try AV mode.Michael Link to comment Share on other sites More sharing options...
brrttpaul Posted July 6, 2015 Author Share Posted July 6, 2015 Well wont Av mode change the ISO settings as its auto? Link to comment Share on other sites More sharing options...
Tinker1947 Posted July 6, 2015 Share Posted July 6, 2015 There is a Auto ISO setting but on my DSLR's its turned Off.....so the 600D is 800 ISO all the time... Link to comment Share on other sites More sharing options...
ollypenrice Posted July 6, 2015 Share Posted July 6, 2015 Exposure for flats should ideally have the histogram peak about 1/3 of the way from left to right. This can usually be displayed on the camera immediately.Flats must be calibrated with darks for flats. However, bias frames will be effectively the same as darks for flats so just put your bias frames into the darks for flats section and the software will use them for that purpose.Olly Link to comment Share on other sites More sharing options...
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