tornado33
11-03-2006, 10:23 PM
Hi again
Some more images taken a few nights ago but only processed today.
I imaged galaxy M83 in the wee hours starting at aroud 2:50 am, after the moon had set. M83 was nearly directly overhead, in fact I had to stop imaging when the bottom of the scope tube was about to hit the mount leg. Some patches of high cloud were present but mercifully seemed to steer clear of the patch of sky I was pointing at straight up :)
Its 4x10 mins (40 mins total imaging time). ISO 200 Modded 350D, darks flats and bias done in IRIS, then finished off in Photoshop. No filters used. Coma Corrector was used. As Photoncollector has pointed out ISO 200 is the best to use when using astro software like IRIS or others that use Linear extraction, as we get the full dynamic range of the image sensor. I now find using higher ISO's seems to introduce more noise, on these warm nights.
I didnt expect to get the Humunclous Nebula. Earlier, Id been imaging Eta Carina with the H Alpha filter (posted the image of it earlier) As I canot see anything through the Ha filter visually, I was taking short test pics to verify I was on targed and correctly focused. I noted the actual Eta Carina star wouldnt focus, rather had this blob round it. I thought it may be the Humunclus so took 7 pics of it at only 4 or so seconds each. When I stacked them in Iris and used Gamma adjustment to bring out the background detail it just lept out. I upsampled the image by 2x with PS CS and applied some unsharp mask and the result is what you see. Gee these modded cameras are sensitive to the deep red and the Humunclus must be a very strong emitter of red and IR light.
Scott
Some more images taken a few nights ago but only processed today.
I imaged galaxy M83 in the wee hours starting at aroud 2:50 am, after the moon had set. M83 was nearly directly overhead, in fact I had to stop imaging when the bottom of the scope tube was about to hit the mount leg. Some patches of high cloud were present but mercifully seemed to steer clear of the patch of sky I was pointing at straight up :)
Its 4x10 mins (40 mins total imaging time). ISO 200 Modded 350D, darks flats and bias done in IRIS, then finished off in Photoshop. No filters used. Coma Corrector was used. As Photoncollector has pointed out ISO 200 is the best to use when using astro software like IRIS or others that use Linear extraction, as we get the full dynamic range of the image sensor. I now find using higher ISO's seems to introduce more noise, on these warm nights.
I didnt expect to get the Humunclous Nebula. Earlier, Id been imaging Eta Carina with the H Alpha filter (posted the image of it earlier) As I canot see anything through the Ha filter visually, I was taking short test pics to verify I was on targed and correctly focused. I noted the actual Eta Carina star wouldnt focus, rather had this blob round it. I thought it may be the Humunclus so took 7 pics of it at only 4 or so seconds each. When I stacked them in Iris and used Gamma adjustment to bring out the background detail it just lept out. I upsampled the image by 2x with PS CS and applied some unsharp mask and the result is what you see. Gee these modded cameras are sensitive to the deep red and the Humunclus must be a very strong emitter of red and IR light.
Scott