M106 - a tough nut to crack

[Sparrow]

Following on from a thread on here, I decided to change my set up so that instead of using the Startravel scope for guiding, I'm now using the doublet (astrotech). There's no doubt that it gives much tighter stars but it did take me time last night to find the optimum setup in PHD for it. Once found, the guiding far exceeded previous performance using the Startravel.

So, as I was messing with guiding last night I thought I'd aim at M106 which was next on my list anyway, but was keeping the subs down to 3 minutes as All I wanted really was to see how tight the stars were in the image. As a result, this image is lacking the fainter detail and I had to process it really hard to get this. That has left me with a very noisy and patchy background and seemed to lose me some of the galaxy detail in the spirals. It really deserves 5 or 6 minute subs, so I will be returning to it at the earliest opportunity.

I also realised that if I'd framed it differently, I'd have got NGC4217 in the shot which would have added interest, so I'll do that next time.

2hrs 11 minutes of mostly 3 minute subs at ISO800 through the 8" newt. Darks and flats used (really need a new set of flats!!!!).

[MikeD]

Looks pretty god to me, you have some great Ha regions showing through.

Mike.

[ollypenrice]

I'm surprized that the change of guidescope had any effect. I've guided with small apos and ST80s and settled on the ST80s.

Anyway, you have a really good core there. I think that if you added some longer subs you'd get the outer disk as well. Looks great.

Olly

[Sparrow]

Thanks Mike - yes I was quite surprised to capture those, but processing lost the definition in them unfortnately. Just wish the sky was clear - I'd be straight back out there tonight with longer subs.

[peter shah]

thts really very good for 3mins subs on a DSLR, its quite tricky to pull out those outer arms

[Sparrow]

Thanks Peter, Thanks Olly.

Re the guiding Olly - the ST80 is a doublet isn't it? The Startravel I was previously using is not a doublet and doesn't have the clarity of the Astrotech. It was clear from the view in PHD last night that the stars were far more pin point with the Astrotech which has got to help. Although the Astrotech is slightly slower at F6.3 compared to the Startravel at F.5, the better optics make up for that.

Having said all this, I need to get some decent data now. Really struggled to get much imaging done this year so far thanks to the weather. Last night was a necessary sacrifice and well worth it, but I could really do with a good run of clear skies now.

[Anweniel]

It still looks really good to me, almost as if the dust is falling of the right edge. Look forward to seeing what you produce with the longer subs

[ollypenrice]

The ST80's a doublet. At least mine are! The stellar image is awful but the centroid calculation is, according to some, made easier by being out of focus. The quality of stellar image through an OAG is truly dire and yet for high precisin guiding at long FLs they are essential. Anyway, no matter. You have a system that works so don't even think about changing it!!

Olly

[Sparrow]

Hi Olly. Only time will really tell guiding wise, but early results are promising. The Startravel is on standby just in case for the moment. That's interesting what you say about having it slightly out of focus. I always value your opinion and find myself agreeing with you alot, so I'll take good notice of what you say

Furious that I couldn't get out last night - lovely clear sky and I was stuck inside helping my offspring with his CV - needs must.

[Zul]

Nice!

[RobH]

[quote name=ollypenrice;2184096the centroid calculation is' date=' according to some, made easier by being out of focus.

Olly

I'd second Olly's words....I actually slightly defocus my stars when using PHD. The centroid calculation is more accurate and they are less prone to atmospheric effects too.

Rob

[sanmatt]

Lovely!

And I dont really know what to look for, but theres more than one DSO there? Am I right in that I can see 3 ?