I am currently collecting data on this image and am now have some data to present the Ha part of the image. I intend to take something like 12-15 hours of Ha data and at this stage the image contains 5.5 hours. Sub length is 30 minutes.
Of note is that the halos I had with the Astronomiks filters are not present with the new Astrodon filters. The Astrodon filter I am using at present is 5nm latest generation.
I will present several version of this object as I collect the data for each filter. I am interested to see what a bicolour image looks like, a complete narrow band and of course the traditional HaLRGB with the new filters.
Looking good Paul (needs more exposure huh? more exposure ya canna get enough exposure ) actually, I squeezed in 6X5min subs on this just this morning as dawn was breaking...some steady air at that time but oh man, you would have been impressed with the noise in the dark areas
Looking good Paul (needs more exposure huh? more exposure ya canna get enough exposure ) actually, I squeezed in 6X5min subs on this just this morning as dawn was breaking...some steady air at that time but oh man, you would have been impressed with the noise in the dark areas
Mike
Yep lots more exposure. No noise wanted. Why not do 15 minute subs? What NM filters do you have? I have found with the 5NM Astrodon filters I need to do 30 minute subs. At the conference I spoke to Don at length about this very issue. He stated that long subs is the way to go. Jay had the same opinion. I asked if diameter of the objective mattered and each said even if you're using a FSQ106 long subs are the way to go. I know from experience you can use shorter subs because of the diameter but surely 5 minutes is too short.
Quote:
Originally Posted by multiweb
Awesome vista already. Great image scale. Is that the RC12?
No Marc, this is with the TSA and QSI. The RC12 would have a much smaller field of view. No imaging has started with that rig yet. Another couple of months yet. Dome has just gone up and I don't have the adapter for the Atlas to STXL yet. Ordered that on the weekend, it should be here in 3 weeks or so I imagine. In the mean time I have to get the pier made up and the electrics installed to automate the dome. Then of course commissioning. I am hoping by new year to have the system up and running.
Looking very promising, Paul. The inverted-Y composition is growing on me... something a little different to normal.
Btw, it might be worth looking at your stacking settings. In the large image, I can see that hot/cold pixels aren't being properly rejected, and I think the bright areas will be smoother too with better noise rejection. When I use PixInSight, I've found that SNR can vary by huge amounts just by experimenting with different settings - I imagine that CCDStack would be similar.
Why not do 15 minute subs? What NM filters do you have? I have found with the 5NM Astrodon filters I need to do 30 minute subs. At the conference I spoke to Don at length about this very issue. He stated that long subs is the way to go. Jay had the same opinion. I asked if diameter of the objective mattered and each said even if you're using a FSQ106 long subs are the way to go. I know from experience you can use shorter subs because of the diameter but surely 5 minutes is too short
Mike is just showing off because he has low read noise (probably about 5e- vs 8e- for the QSI-683) with his fancy-pants Sony sensor
Read noise is the reason why longer subs give you better SNR. It is incurred once for each sub, so you need to overwhelm it by collecting enough signal that the read noise is insignificant. I suspect that 5 minutes is still a bit short for narrowband imaging with Mike's setup but I haven't done the calculations...
Looking very promising, Paul. The inverted-Y composition is growing on me... something a little different to normal.
Btw, it might be worth looking at your stacking settings. In the large image, I can see that hot/cold pixels aren't being properly rejected, and I think the bright areas will be smoother too with better noise rejection. When I use PixInSight, I've found that SNR can vary by huge amounts just by experimenting with different settings - I imagine that CCDStack would be similar.
Yeah notices those too. Some hot pixels but lots of cosmic ray strikes that were not rejected properly. The normal setting is now working it seems. Time to revise that.
) actually, I squeezed in 6X5min subs on this just this morning as dawn was breaking...some steady air at that time but oh man, you would have been impressed with the noise in the dark areas 
