.....and yet another Eta Carina

[Imme]

I've been having issues with my rig for a while but finally got out last night under the stars.

This is around 90 minutes of 60 second exposures with the QHY 8. Bias and darks applied.

There are plenty of issues, especially with star shape at the edges.....I think I need to check the distances on the coma corrector because it seems it isn't doing it's job!

It was good to finally produce something again

[RickS]

Yes, some issues in the corners but nice detail overall.

[Anth10]

Great that you got things together to have a go out there Imme! Put some good time into this by the looks, nice work.
As for the stars it seems as though coma is evident as you say around the edges but it appears as though the stars around the middle areas may be ever so slightly elongated too which points to tracking not being 100%. It's always hard if you're not guiding and 60sec subs will definitely show up any drift.

What scope are you using and I'd be interested also in the coma corrector you have. I'm getting mine today and I'm ready for the usual issues I hear about spacing etc to get it right. I'm using a DSLR so setup will be different to yours.
Have you followed the prescribed offsets for your camera?

Anth

[Imme]

Hey anth, I've got a GSO corrector (same as the bintel one I believe) which from memory requires a 80mm spacing....however I'm at around the 76mm mark due to not having the appropriate spacers. It made a noticeable difference to the pics overall. I don't think you'll be disappointed with putting one in. I guess my only advice is try and use as few spacers as possible to make up the required distance......less spacers = less opportunity for those minor errors that cause us issues.

Scope - this is from a GSO 200mm F4....not bad for something I picked up cheap off here.

As for this pic of mine....I didn't go through the 90 odd subs as it was a very quick stack before work this morning. Maybe I do have a dodgy sub or two in there. However....I was guiding last night and have been getting less than 1 pixel variation on PHD....I actually did a few 10 minute subs the other nighty on another target with minimal issue. I'll have another look through them tonight and see if I can track down the issue/s.

You and Mickoid should make some plans to come up......I can now set you up inside the obs rather than on those slabs outside....saves wind deflection!

[Anth10]

Cheers Imme,

I'm getting a Baader MPCC III corrector delivered today - this doesn't need such a large spacer distance I believe, Should work Ok,

That's excellent that you are guiding, Like to see how this works sometime

Thanks for your invite look forward to it, hope you have a heater hooked up , damn freezing last time we visited brrrrr.....(nothing that a few wines wont fix hehhehe)


Anth

[xelasnave]

Great work.
You can never have too many Etas.
I hope to do yet another tonight.
Alex

[Mickoid]

Nice to see you actually imaging again Jon, it's been a while. You'll sort out your star shape soon enough, I'm sure. Carina is in the best part of the sky at the moment and along with Centaurs, there's plenty to photograph before the moon waxes this week, so don't stop now, keep on imaging if we get clear skies. You have good detail in the Keyhole so your focus must be good. I think you could tease out more nebulosity in post processing with 90 mins of data. Look forward to coming up and seeing your set up.

[Mickoid]

I agree Alex, I have peanut butter in my sandwiches nearly every day!

[Imme]

Welcome anytime Mickoid.

.....I'm still playing with the Gain on this camera to get to a point where I pull enough signal.....but don't saturate it.

[xelasnave]

I found some yet to be downloaded from my old canon which I havent found a driver for...but a surprise because I think they were thru my 12 inch set up for astrophotos....ten years plus ago.

I just hope to be taking some 30 seconds shots when it blows.
alex

[Imme]

I'm now 100% convinced my issue is imaging train tilt.

I normally focus on a star near the centre of the image and find top right ends up in streaks after a session. It's always been the case with this scope not matter where I'm pointed or what rotation I do with the camera. (meaning it's not sag or a camera sensor issue IMHO)
Last night I focused on a star in the bottom left of the image and then realized after my imaging session the top right stars were shockingly out of focus.

Tilt adapter ordered....hopefully that will fix the issue.

[Mickoid]

Good one Jon, nice problem solving. I hope you bought some flowers before you ordered the tilt adapter. ;)

[N5SE]

:thumbsup: