Dear All
Hagar kindly sent me the fit file to play with from his eta image above as an example from his QHY6 camera. There is very little dark noise with very few slightly hot pixels. The offset is about 700.
I am not anything like an expert in processing images and I have had lots of trouble getting a colour balance that is vaguely correct.
I have attached some attempts that I have had. I have found that to get close to white stars (using another image of eta that I have to pick which stars are reasonably white) I end up with a very green nebula. I tried playing with curves in Gimp and achieved the second image. It is better but still not anywhere near correct. Any suggestions?
If Hagar likes I can post the individual r, g, b, channels as binned and compressed files here. 4x binned (480k each) they end up the size of the second image but still useable for colour balance etc.
Dear All
Hagar kindly sent me the fit file to play with from his eta image above as an example from his QHY6 camera. There is very little dark noise with very few slightly hot pixels. The offset is about 700.
I am not anything like an expert in processing images and I have had lots of trouble getting a colour balance that is vaguely correct.
I have attached some attempts that I have had. I have found that to get close to white stars (using another image of eta that I have to pick which stars are reasonably white) I end up with a very green nebula. I tried playing with curves in Gimp and achieved the second image. It is better but still not anywhere near correct. Any suggestions?
If Hagar likes I can post the individual r, g, b, channels as binned and compressed files here. 4x binned (480k each) they end up the size of the second image but still useable for colour balance etc.
Getting color balance really depends on which software you use. I have always hated Maxim for its Debayer tools, where as Astro Art does a better job. I remember having loads of issues with Maxim Debayer and my Canon 20D. In the end i downloaded a plugin to debayer color better.
Also i thnk you meant QHY-8 camera and QHY-6 in your comments.'
Getting color balance really depends on which software you use. I have always hated Maxim for its Debayer tools, where as Astro Art does a better job. I remember having loads of issues with Maxim Debayer and my Canon 20D. In the end i downloaded a plugin to debayer color better.
Also i thnk you meant QHY-8 camera and QHY-6 in your comments.'
Theo
Sorry, Typo. Yes the QHY8. I used Iris to debayer and played with the colour balance in Iris, Gimp and PS elements. (I don't own PS)
Getting color balance really depends on which software you use. I have always hated Maxim for its Debayer tools, where as Astro Art does a better job. I remember having loads of issues with Maxim Debayer and my Canon 20D. In the end i downloaded a plugin to debayer color better.
Also i thnk you meant QHY-8 camera and QHY-6 in your comments.'
Theo
I am realy glad someone else is seeing green. It seems to be the only really good colour I get. Using Maxim, Images plus and nebulosity. My monitor is colour corrected using spyder Pro calibration. I have been puting it down to reflection of moonglo on the local smoke in the sky but really question this assumption. I have had some advise re settings from other QHY owners but at this stage I am considering a paint brush and canvas. My DSLR is far easier and delivers better results.
It is a shame the camera doesn't come with some instructions and good software with instructions then perhaps some standards could be maintained or at least set.
Had a quick play with hue in Photoshop. I'm no expert but I figured that hue re-assigns color channels and may re-arrange any de-bayering errors. It's still not the right colour, but the green is gone.
Just a thought. Is there a mismatch between the QHY8 driver encoding and the post-processing software decoding, eg is there an bayer encoding option which isn't set the same in both applications?
...We need some advice from an experienced QHY8 user... Anyone?
Problem is the debayer method used by Maxim, regardless. As i said, i dont use Maxim to debayer, it used to make my 20D images look all green too. I had to do a color balance to fix it. So i used a plugin for debayer on the 20D and also any other camera that has the same encoding.
Processing takes many hours of work. This does not get supplied by the camera manufacturers. Instructions to create images as they look from others took me a long time as others would agree. Just to show how much work can go into it, here http://www.southern-astro.com.au/php...ng-ngc2070.php is a link that i recommend users look at that want to know how much work it takes to create an image. Its not just point and shoot, happy viewing.
Had a quick play with hue in Photoshop. I'm no expert but I figured that hue re-assigns color channels and may re-arrange any de-bayering errors. It's still not the right colour, but the green is gone.
Just a thought. Is there a mismatch between the QHY8 driver encoding and the post-processing software decoding, eg is there an bayer encoding option which isn't set the same in both applications?
...We need some advice from an experienced QHY8 user... Anyone?
I think this was the problem. I debayered in Iris using the 40D settings. It is suppose to have the same arrangement of colour. This is obviously not correct. I have debayered it in Deep Sky stacker which has a channel for the QHY8. This gave much better colours- red nebula without red stars. Then a "asinh" stretch in Iris and some noise reduction resulted with the attached image. Much better and amazing for a single 5 min exposure with no dark or flat.
Stunning, smooth result, particularly for a single 5-minute sub. Deep Sky Stacker did the trick, and it's free!
We're looking forward to some great results from you now, Hagar...
I think I need a QHY8... (I think I need to find some $$$)
Terry is right, you cant just use the same settings from one camera to another. Even between same cameras (20D, 30D, 350 etc.). You need to play with the settings to suit. But as Terry found out, there is simpler ways that do it better.
Remember that you dont have to just work on one image.. If you split the image into RGB you can then play with each color and get some really good results.
The image that Doug made is pretty good, and in light of it taked during a full moon is even better.
Nebulousity has drivers for the QHY8. But can you advise if the program works to debayer the QHY8 raw images correctly?
It has a setting for Canon DSLR's but I haven't had any luck with my 400D - colours seem off. So I'm worried if I get a QHY8, what program should I use to convert from RAW?
Hi Graig,
I have another user that uses Nebulosity, and claims it does very good with the QHY-8. Iris also does it, but from memory some one said that you needed to flip the image horizontally because of the way Iris reads the file.
Theo.
Quote:
Originally Posted by Craig_L
Hey Theo,
Nebulousity has drivers for the QHY8. But can you advise if the program works to debayer the QHY8 raw images correctly?
It has a setting for Canon DSLR's but I haven't had any luck with my 400D - colours seem off. So I'm worried if I get a QHY8, what program should I use to convert from RAW?
