Hi.
had some really nice seeing last night and got some good Ha data on NGC6302. This is the first processing attempt, stretched enough to show some faint extensions of the nebulosity (and also the spider diffraction from the very bright core - never had a diffraction pattern from a nebula before!). This is going to take a lot of time to do right, since it has a huge dynamic range. Was so pleased with the data though, that I just had to post it in this early form - very little patience I guess . Thanks for looking. Regards Ray
Yep, lookin good Ray, being so bright most of the outer features of this neb show up in rather short exposures but the solid amount of exposure time here has helped to reveal the few very faint features like the perpendicular ray emanating form the core and when the seeing cooperates it is always a bonus too. You seem to be getting lucky with the seeing lately
Ray, you mention you're using 2, 3 and 5 minute sub-exposures. Is this to preserve dynamic range (I'm just thinking about your other thread, with regards to getting a specific ADU for your camera)?
Yep, lookin good Ray, being so bright most of the outer features of this neb show up in rather short exposures but the solid amount of exposure time here has helped to reveal the few very faint features like the perpendicular ray emanating form the core and when the seeing cooperates it is always a bonus too. You seem to be getting lucky with the seeing lately
Mike
Hi Mike. Yep, have had a two good seeing sessions - in amongst 4 arc sec nights of course.. Am finding that Skippy Sky does a pretty good job of predicting seeing.
Quote:
Originally Posted by Octane
This is going to be amazing!
Ray, you mention you're using 2, 3 and 5 minute sub-exposures. Is this to preserve dynamic range (I'm just thinking about your other thread, with regards to getting a specific ADU for your camera)?
H
Hi H. Yes, this thing is very bright, so the core saturates at anything longer than about 2 minutes on my system. I should have used much longer subs to get the dimmer bits, but the seeing was coming in patches with wobbly bits going across a few times an hour and messing up the subs. I was able to use most of the 5 minute subs, but would have had to discard much more of the data if I had used longer subs - better to put up with some extra read noise.
You confirmed my suspicions, thanks! I'm looking forward to this weekend where I will set up my old STL-11000M with the FSQ-106N and see how long it takes to get the appropriate ADU. How short should the short dark frame be to get the bias read out? Looking forward to where you go with this image. H
You confirmed my suspicions, thanks! I'm looking forward to this weekend where I will set up my old STL-11000M with the FSQ-106N and see how long it takes to get the appropriate ADU. How short should the short dark frame be to get the bias read out? Looking forward to where you go with this image. H
I don't think it is critical for working out sub exposure - maybe a second or so - or whatever the shortest practical exposure is.
. Thanks for looking. Regards Ray
How short should the short dark frame be to get the bias read out? Looking forward to where you go with this image. H
