Back into imaging at last - M16 in Ha

[Craig_L]

Originally Posted by multiweb

Sounds good. I wasn't aware they had Ha filters for DSLR. Looking forward to your shots too.

No they don't, it's just a 2 inch filter that screws into the front of the Canon adaptor. Craig

[richardo (Rich)]

Hi Mark,
looks like things are coming together with the newt! (go the newts!)
What flocking material did you use?
Good to see you up and running again.
Can be hard this time of the year with the weather.

This is not the easiest object to pull out the data on. Generally I've had to really concentrate on what areas I'm happy with after the first initial stretch, then find myself selectively masking these areas off in PS and concentrating on the out laying areas as there's quite a bit of nice subtle nebulosity to be found.

I brought your image into PS cs3 and did a quick shadow/highlight as a quick check, and while it did bring out a lot more to the surrounding areas, the lack of total exposure time is the main setback to this approach.

I think you could possible bring a bit more out, ( as Jase mentioned) by selectively masking certain areas and applying perhaps curves to other areas but the noise will be the limiting factor with this image, unless you get some more data. I know hard when you have your sights on something else.

All in all, you've picked up some nice details to the main object.
I do see some coma radiating out to the corners.... what corrector are you using and have you checked the spacing from it to the CCD/ window?

Any ways, good you're back in the saddle and look forward to your M8 image.

All the best for now
Rich

[multiweb (Marc)]

Originally Posted by richardo

I think you could possible bring a bit more out, ( as Jase mentioned) by selectively masking certain areas and applying perhaps curves to other areas but the noise will be the limiting factor with this image, unless you get some more data. I know hard when you have your sights on something else.

All in all, you've picked up some nice details to the main object.
I do see some coma radiating out to the corners.... what corrector are you using and have you checked the spacing from it to the CCD/ window?

Thanks Rich. Yeah I need definitely more data on this one. Coma's a bugger. I have a MPCC but no real way to modify the spacing. I've always had this problem and I'm not sure how to resolve it. The spacer doesn't allow to shift back and forth even a couple of mills. It's one solid piece of aluminum I was thinking at one stage to make a spacer that I could shorten like a helicoidal focuser but I haven't found anything anywhere ressembling it.

[Bassnut (Fred)]

Excellent work Marc, even zoomed in at 400%, detail in the core is very good. Ive seen some strange star distortions in some of your other images that maybe guiding related, but not with this one (apart from possible coma or whatever Rich points out, not that bad really)

[multiweb (Marc)]

Originally Posted by Bassnut

Excellent work Marc, even zoomed in at 400%, detail in the core is very good. Ive seen some strange star distortions in some of your other images that maybe guiding related, but not with this one (apart from possible coma or whatever Rich points out, not that bad really)

Thanks Fred. Previously on axis I had some nasty astigmatism. Crossed stars. My diagonal plane was tilted and my primary also rotated on its axis. I've fixed those two things since then so on axis is as good as the scope resolution will be. The outside of the field... well, it's a different story. I need to find a way to accurately space my coma corrector. At the moment it's really bugging me coz I have to play with star masks and deconvolution and it's a lot of stuffing around to "hide" things.