Autoguiding

[JohnG]

Hi all

I would like some comments on an autoguiding solution. I already have an ST-4 but find that it is very cumbersome to use, the head is heavy and the cable is thick and relatively inflexable, it also adds a fair bit of weight to the imaging system. What I am looking to is use a more user friendly system, along the lines of, say, Meade LPI or Celestron Neximage or similar using GuideDog with Shoestring adapter or similar software.

Could someone out there give me some advice/pitfalls etc of going in this direction or should I stick with the ST-4. It will be used with a Losmandy G-11/ Gemini and a Canon 350D.

Thanks in advance

JohnG

[[1ponders]]

Hi John.

I don't have the Gemini, just the standard Losmandy Digital Drive, but I have been using the ToUcam up until now with few problems. I'm about to start experimenting with the DSI and LPI, once the clouds clear. The ToUcam and DSI will be operated through K3CCDTools V3 (and the LPI if K3 will let it) or through Guidedog if it will take the DSI. Don't know that one yet. As an interface I've been using Robby's Starmate instead of the Shoestring adapter.

However with the Gemini I don't see any problems running through the autoguiding port on the Gemini as long as K3 or GD talk to gemini

[JohnG]

Autoguiding with the Gemini is not a problem providing you place the Gemini in All Speeds or Photo mode. In that respect it is identical to the standard digital drive.

JohnG

[[1ponders]]

One thing about the ToUcam though. I find that on nights of poor to average seeing the autoguider wants to chase the seeing all over the place. The problem I'm finding is even when I set the exposure to its lowest setting, the frame rate to the lowest setting and set the interval time to 1.5 sec or more (this is using K3) I still get chasing. I'm hoping that with the LPI and DSI I will be able to genuine longer exposures to help mitigate that jumping around. Sure I will end up with a larger star but the movement will hopefully be averaged out over a couple of seconds. That's the theory anyway

[JohnG]

Thats an interesting observation, I live right on the coast and turbulance is a fact of life down here, the joys of having the mountains close by. Maybe some other people out there have had experience using an LPI or Nextimage and could comment on the exposure situation. The ST-4 is erratic in this respect, but thereagain that could also be user error, the use of a guidestar on the screen is what appeals to me.

JohnG

[[1ponders]]

Well you certainly get that with K3 and guidedog

[seeker372011]

unfortunately, Guidedog does not yet support the DSI. It only supports the LPI in real time ie not in long exposure mode. Its a bummer. Steve Barkes is supposedly working on this but a quick visit to the Guidedog forum suggests that there has been little progress for quite some time. Yes I know :(

[[1ponders]]

Hopefully the next fine night out I get I'm going to play with all of the above with K3 v3 and see how they go and compare to autoguiding with Meade autoguiding software. So far my experience with that has been yuck. Can't get it to happen for some reason.

[JohnG]

I will wait and see what you have to say about your tests, the new G-11 wont be arriving until the end of the month/early March so I have plenty of time to do some research.

JohnG

[Robby]

I have not had much luck with the DSI in K3v3, so have gone back to the ToUCam. It seems the Meade Driver API that K3 has been given is very buggy & probably very undocumented, and probably in French! It seems Meade like to keep there little secrets secret!
And as such I'm still getting steady enquiries for my star-mate lx200 emulator which allow DSI users to autoguide non-meade mounts with the meade Envisage auto-guide software...
Pity I have no stock atm and am not likely to have any for at least another month! Bludy electronics industry!
Cheers

[[1ponders]]

I had some sort of prob with the Envisage Robby using the DSI. The Star-mate didn't seem to want to "recognise"?? any commands sent by Envisage. The software seemed to be applying the corrections but Star-mate didn't seem respond to them. I'll try again soon and see if I can put together a better description. It was a while ago.

Sorry to hijack John.

[JohnG]

Not a problem, I am personally more interested in using either the LPI or NexImage, using a DSI seems to be an overkill to me ( my opinion only). I have been led to believe that the DSI software was problematic to say the least anyway and I wanted to steer away from that. All that I am after is a nice clean interface with the minimum of problems, I really don't envisage using autoguide for extremely long periods anyway given my camera.

JohnG

[[1ponders]]

Robby, Do you know if the K3 v3 will take the LPI. I haven't checked yet.

John, if nice and easy then the Shoestring adapter with either guidedog or K3, or Star-mate with guidedog or K3. Striker is using Shoestring and guidedog and ToUcam with his G11 and Gemini. I'm using Star-mate, K3 or guidedog and ToUcam atm. Though as I said before I'm really looking to get longer exposures than the ToUcam will allow. And Robby is using the same setup as me but just with the K3.

[JohnG]

Looks like that is the way to go, I will still be interested in how your tests go. I will have to do some research on the pro's and con's of the LPI vs NexImage.

JohnG

[[1ponders]]

If you're looking for info on the neximage, then it's basically the same camera as the ToUcam, in which case you might find this review from CN interesting http://www.cloudynights.com/documents/meadelpi2.pdf . This review is from an imaging basis though and not aimed at autoguiding. Also I've seen imagers here do a much better job using the LPI than is showcased in the review.

[Striker]

I am trialing both the toucam, LPI and soon to arrive SAC4 which looks to be at the post office awaiting my pick at 4:30pm today.

I want to see which is the best to guide with...I dont get good results with the toucam here in brisbane and found the LPI to be better in my situation so far...as Paul said I am using guidedog with the shoestring adapter...I use the same system for my travel set up as well.

I have used the LPI in guidedog as a test up to 15 second exposures.

I like the idea of taking 2 second exposures corrected every 3-5 seconds in guidedog.

[JohnG]

That is exactly what I am after, minimum of fuss, I have gone ahead and ordered the parts I need from Shoestring Astronomy and downloaded Guidedog. I want to be able to use this setup on the GM-8 as well as this will be my grab and go mount. It all looks promising now.

JohnG

[JohnH]

You could also try de-focussing your guidestar a bit - can make tracking smoother.

[[1ponders]]

Thanks John. Yeah I have tried that and on a good star it does help. My biggest problem is when I'm in an area where there are few stars bright enough to do that. When I defocus I loose the star at times. Hence the desire for longer exposure times.

I'm trying not to point my guide scope too far from the direction of my imaging scope. If my polar alignment is spot on it doesn't seem to matter much, but if I rush the alignment and I'm out a bit I've found it can make a difference come final alignment of images and having occasional arcing stars near the outer edge.