Tracked Star Adventurer - happy days (nights)

[thomasv]

Finally quite happy with my portable tracked SA setup, been testing it last night. These were 14 x 6 mins subs, polemaster earned its price, tracking looked good (ok the phd screengrab was for the best ever, but RMS error was generally max 1.3"). At 100% star shapes are not great in the corners, wonder if I have some tilt, will try to use CCD inspector.

 

[Rob]

Very Nice indeed!. Setup & image that is. I'm thinking about grabbing one of these mounts. Rob

[mikeyj1]

that's really good, I have to say i am struggling with 2 min exposures at 360mm with the WO61mm and DSLR, although i don't have either polemaster or guiding going on.  in fact I thought i was overloading the rig, but having seen everything you have hanging off it, I think that's not the issue ?

Any other tips to share?

Mike

[thomasv]

I would say that based on my experience 360mm untracked is really trying to push it beyond its capabilities, even for 2mins. Longest usable focal length untracked for me was 200mm, even then had to discard some of the frames. I assume you do use a counterbalance kit? Don't know the exact weight of my kit, but as it's well balanced, it seems to cope with it well.

If you happy to have a laptop with your setup, then I can recommend guiding, as it also gives you instant feedback how well things are going. I've been hesitating for a while whether to  invest in a polemaster, but no regrets, it makes PA so much easier and more accurate.

 

[mikeyj1]

thanks Thomas, yes i have the counterbalance kit and get the RA balanced well, although DEC is what ever it is.   noticed last night that the PA was critical, and that leveling the scope more precisely helped alot.  I guide with the main scope, (AZEQ6 250pds) but i also have a Synguider which i have never used, maybe i should press that into service.  i try to avoid the laptop with the SA setup, as i use it primarily for portable back pack type astrophotography.  30 sec exposures are fine, and DSLR with even the 200mm lens works well...but those longer exposures elude me.

Mike

[geordie85]

4 hours ago, mikeyj1 said:

that's really good, I have to say i am struggling with 2 min exposures at 360mm with the WO61mm and DSLR, although i don't have either polemaster or guiding going on.  in fact I thought i was overloading the rig, but having seen everything you have hanging off it, I think that's not the issue ?

Any other tips to share?

Mike

Polar alignment is critical. I've used my WO star 71 (350mm focal length) and dslr using 2 min subs unguided perfectly fine. I polar align, get my target in the FOV of my scope then double check polar alignment again to make sure it's as close as I can get it. I do this without the use of a polemaster. 

[JimothyC]

Nice setup. Using the guidescope to counter balance the main scope is a great idea. How did you get hold of another dec mount to go on the bar? 

I'm having to add additional counterweights to balance my DSLR, Scope and Guidescope. If I moved the guidescope to the other side, I could maybe get rid of the extra weight. 

[thomasv]

I just bought another L-bar with the dec mount to make a dual mount bar. The guidescope is not that heavy of course, but the vixen clamp and dec mount has some weight which serves as counter balance. Still need the counterbalance kit though, which then prevents setting some dec angles for the guider, but that's not a big issue.

 

[Jkulin]

Hi, Maybe I am being a bit dopey, but I thought the SA can only track via ST4 and on the RA not DEC, but your PHD graph seems to show it guiding on both?

When I have used my SA you are absolutely correct PA is so very important so I use my Polemaster as well and have got up to 450 secs unguided with a 14mm f2.8 Samyang on my D800.

Thanks for your input.

[thomasv]

Hi, I did set None as DEC algorithm, and the guide log shows RA guiding pulses only, so I think it guides in RA only, and just displays the drift in DEC.