Starlight Xpress Active Optics and PHD, minus Lodestar/Lodestar2

[Eden (Brett)]

Hi all,

I have purchased an Starlight Xpress AO-LF and I understand that it can be operated via PHD 2.x without a Lodestar/Lodestar2 camera.

Is there anyone here running an SXV-AO in this configuration and if so, which camera are you using in lieu of a Lodestar and what sort of results are you getting?

I realize the choices of alternate guiding camera are limited because of the way the SXV-AO is designed but I have a QHY5L-II here which I am hoping will do the job.

Cheers!

[gregbradley]

I am interested in how you find this unit as I am planning to get one soon.

I am not an expert in AO units but I did have the idea they operate best at maxmimum hertz (cycles per second) and that requires a bright guide star and a sensitive guide camera.

As such I think it could be limiting the effectiveness of the unit if you used a less sensitive guide camera.

I would consider the Lodestar X2 for that job. Perhaps an SBI STi.

Greg.

[Eden (Brett)]

G'day Greg,

I am interested in how you find this unit as I am planning to get one soon.

As soon as the weather permits I'll be putting together a thorough review and will post it here. In the meantime, you might be interested to check out some images taken by this gentleman over at Astrobin:

http://www.astrobin.com/32169/

Most of his work was done with the SXV-AO, a fairly modest camera (QHY9 Mono) and Meade LX200 12". From my limited imaging experience they look pretty good to me and should give you some sort of an idea what to expect. I think a with AO/without AO comparison is in order though.

I am not an expert in AO units but I did have the idea they operate best at maxmimum hertz (cycles per second) and that requires a bright guide star and a sensitive guide camera.

That is how I understand it to be. I'm particularly interested to see how much difference it makes on nights when seeing is less than ideal.

After spending $900 on an Atik Titan Mono not that long ago, I wanted to use it with the SXV-AO because it has a similar quantum profile to the Lodestar, has active cooling and does around 15fps. Unfortunately it's too big to mate with the OAG on the SXV-AO and doesn't have a C-Ring thread, so it looks like Lodestar2 or bust.

PHD does allows you to operate the AO from a camera connected to a guidescope instead of the SXV-AO OAG but there are obvious disadvantages in doing that.

[PRejto (Peter)]

I guess if you want an expensive solution to use the Atik Titan you could consider using an ONAG. It has t-threads going to the guide camera.

I'm looking forward to your review! I wouldn't mind adding an SX-AO-LF but using my ST-i though I'm not too excited about using PHD with a Paramount mount...

Peter R

[multiweb (Marc)]

Originally Posted by Eden

Hi all,

I have purchased an Starlight Xpress AO-LF and I understand that it can be operated via PHD 2.x without a Lodestar/Lodestar2 camera.

Is there anyone here running an SXV-AO in this configuration and if so, which camera are you using in lieu of a Lodestar and what sort of results are you getting?

I realize the choices of alternate guiding camera are limited because of the way the SXV-AO is designed but I have a QHY5L-II here which I am hoping will do the job.

Cheers!

The bottleneck might be your guider frame rate and sensitivity, not the software used. The lodestar will pick a guide star at a reasonable rate so you can guide at 0.2Hz. I had a QHY mono and it didn't. It wasn't a newer model though.

[Eden (Brett)]

Hi Peter,

I guess if you want an expensive solution to use the Atik Titan you could consider using an ONAG. It has t-threads going to the guide camera.

Thanks for suggesting ONAG. Up until you mentioned it I had only heard of it in passing. I checked out the ONAG offerings at Innovations Foresight and considering what they're capable of, they're actually really good value -- more guide stars vs an OAG, Near-Infrared guiding (which in itself is a brilliant concept and is something worth getting excited about) and real-time auto-focus adjustment.

Looking at the theory behind Near-IR guiding, this is where the Lodestar2 (and other cameras using the ICX429AL) stand out -- their much higher sensitivity to light at that end of the spectrum. The Atik Titan doesn't even come close and would cripple an ONAG system in that respect.

Since I only have a low-end refractor I can't expect too much out of these technologies but I'm sold on ONAG, it's definitely going to be my next purchase.

[PRejto (Peter)]

Don't want to hijack this thread to a big discussion re ONAG! Do a bit of a search on this forum and there are some long threads. My own experience is mostly very positive, but "might" not be too great with a smallish refractor due to less IR light through the ONAG. That is, my TEC140 managed, but the TEC180 is clearly better. I'm going to try out the auto focusing soon but the software driving this technology is a bit limited at the moment forcing one to give up something to get something. I will post details once I try this.

Peter

[Eden (Brett)]

Hi Peter,

Thanks for your suggestions, much appreciated. I have read a couple of older threads on here regarding ONAG and one over at CloudyNights. I think a new thread with ONAG discussion in mind is warranted, I will start one later.

With respect to the original topic here, for the moment it looks like the Lodestar2 is the only sensible option for the SXV-AO since most of the other cameras I have seen which are mechanically compatible with the SXV-AO are not as sensitive, the QHY5L-II included.

[PRejto (Peter)]

Did you miss this one? Pretty recent!

http://www.iceinspace.com.au/forum/s...highlight=onag