M83? + m8

[Cosmic]

Just a few question please :D

After searching high and low left and right, I was unable to find M83. Mind you my goto's on my neq6 are not the best, but Im still able to get ok polar alignment? Any help there I would be very thankful.

Last question after failed attempts of finding M83, I decided to get shoot a quick and dirty on M8. I hate walking away from a session empty handed :lol: My stars are somewhat of a funny shape, im guessing coma but its really bad with the bright stars not even close to the edge.

Thanks again,
Dan

[renormalised]

Good attempt there, Dan:)

Actually, it's pretty good:)

What you have there is eggy stars, probably caused by a combination of your image train not being aligned exactly with the optic axis of your scope and some field curvature. What you need to do is play around with your camera and extension tubes/spacers a bit to get them square on with your focuser. That, and to invest in a field flattener (a Baader MPCC would be the go). They're not overly eggy and for what you describe as "OK" polar alignment, it's a good piccie:)

As for not finding M83...make sure you get a good polar alignment, spend a little time on it doing a good drift aligning routine. Then, train your goto...do a 3 star alignment and make sure you centre the target stars in your eyepiece then enter each alignment. That way, you'll make sure that the goto will work properly. It's then just a matter of dialing your co-ords for M83 and it should take you there:)

[cybereye]

Dan,

This is what I use to get an exact location for dso's...

www.saratogaskies.com/articles/cookbook/Precise-GoTo.xls

Cheers,
Mario

[Cosmic]

Thanks Carl, I did try best I could. I guess until I do flats, darks get a guildscope and MPCC it feels like im only 1/4 of the way there. I wonder how the image will be then :)

Perfect that solves that I knew it wasnt all coma. When I tighten up the focuser it moves quite considerably, maybe I should back it of a tad till it moves a mm or 2. Truth be known im most likely over tightening the lock in screw of the focuser. Im hunting around now for a MPCC as next piece of kit for the TS.

As for the polar alignment 3 star hmm I hate to admit it but I didn't do any star alignment just drift, never had. So that would fix that problem to im guessing.(dear me!) Thanks for terrific advise Carl.




Thanks Mario I need all the help I can get haha without the experience im going through some good learning curves atm.

[renormalised]

You can pickup a MPCC at Bintel:)

Also, check out their guidescopes and cameras as well.

[Cosmic]

Thanks, yeah I have been looking at Bintel a far bit lately.

Dan

[multiweb]

Great shot. Gorgeous colours. Before you get a MPCC I'd check the camera tilt and also micro guiding errors. I'm not convinced you have significant coma yet.

[renormalised]

The camera tilt is most likely the majority of the cause. I don't think he is guiding....doesn't have a guider, apparently.

[Cosmic]

Hi Marc and thanks you, im more than happy with the results all things considered. Its was taken with a canon 550d with a newton 8 @ f/5 mounted neq6 pro. No guiding...just manual movements with live view on the pc from time to time, to recenter.

I have been shining a light in the viewfinder of the canon to see the sensor and there is a heap of movement there on the primary. So im thinking that the standard Bintel Crayford Focuser 10:1 maybe not so good nor meant for imaging in the first place...I maybe wrong. But there is alot of slop when tightening the locking screw.



Correct ;)

[multiweb]

The focuser's probably alright. Just needs a bit of tweaking.

1_ Get a drill and make an extra two threaded holes at 60 degrees apart around your focuser ring so you get a good even tight hold of your camera on three points with two additional thumb screws.

2_ As fars at the draw tube goes, there will always be a bit of slop but if you tighten the focuser a bit harder and use extension tubes rather than racking it out it'll make a world of difference.

Try that first and see how it improves your imaging train. :thumbsup:

[DavidU]

What a great effort Daniel. A couple of small problems to solve and you are on your way. Fab effort !:thumbsup: