Losmandy Star Lapse v Vixen Polarie

[firstlight (Tony)]

I suppose I might wade in on this thread. I got Anne-Louise a Starlapse this year after looking at what we wanted to get out of a setup. The AstroTrac was to be our first choice but as has been pointed out it is limited to 90 minutes if I recall. The Starlapse has the advantage of turning into a timelapse panning head, which was a key attraction for Anne-Louise. Weight was also a consideration and we decided only a few days before the transit to use the Starlapse with my WO 110 and Cano 50D. We were not well polar aligned, but I think that Anne-Louise only reset the viewing on the Sun 5 or 6 time over the 6 1/2 hours, and was pretty steady considering we had over 1000 kids and teachers tramping accros the basketball court where we were set up. At this stage I think it is great value for money. Can't wait until we can use it in anger .

For a portable and compact setup and transport, I think the AstroTrac has it over most of the competition, it is very clever, but again I get a bit disappointed to have to rewind every hour and a half.

[Poita (Peter)]

On the Astrotrac I had, the tracking time was actually very close to 2 hours, then press one button and it rewound in just over a minute, so that wasn't really an issue for me, but I can see how it could be for some uses. Getting a full night's use out of a set of AA batteries is nice too.
The surprising thing for me was that it happily held my 4" scope and DSLR and tracked nicely.
There is an option for RA autoguiding now too.

[firstlight (Tony)]

As I said it is a nice and clever unit, as well as good weight capacity, however I may be pendantic: if you wanted to do some animation of the images, after the 2 hour run, rewind recentre the target or jump to another scene. Not my cup of tea, really.

This shouldn't be a Holden v Ford thing though. We all know that EVERYTHING in this hobby is compromise and personal preference. The Starlapse won our vote due to the longer exposure times possible ie. longer tracking on the same object/area of sky, and the versitility of using it as a paning head. The AstroTrac is a very attractive product and 20+ 5 min subs widefield should yeild some nice imagery. I only wish we could afford both.

Can't really talk about the other devices that have been discussed here. No experience with them and from memory there was not the versitility or the cleverness of the other two.

[originaltrilogy (Petr)]

But did you have to reset the starlapse 5 or 6 times for some reason on your exposure?
The astrotrac only needing two rewinds for transit, yes?

[firstlight (Tony)]

Yes. We had never set up the Starlapse and aligned it, we adjusted the elevation pretty close and the azimuth was pretty as well, but it certainly wasn't right. In the configuration we had it in, and if we were polar aligned, there wouldn't be any need to adjust it at all, I expected to have to do EQ flip but it wasn't necessary.

Better planning, such as having the rig set up at least 1 or 2 nights before hand and drift aligning (although it does have a polar scope), I expect that we would have been able to image all day without a problem.

[JB80 (Jarrod)]

Originally Posted by Poita

How are you finding the polar alignment for longer exposures with the Polarie, is it fussy?

In my experience it's not very fussy at all.

http://www.iceinspace.com.au/forum/a...e.php?a=117167
This was a 3 minute and 5 second exposure at 28mm with an ISO of 1600. I haven't done any processing of the pic apart from a resize.

It was done without the polar scope, very easy to do a simple rough alignment.
Maybe more fussy though for those using Octans but from Mikes thread that I have just seen results were impressive too with rough alignment.

There is also a new Polar meter being released which is basically a more accurate compass and latitude finder for daylight use and when you can't visually see your alignment stars.
I have yet to see it tested but I imagine it'd produce similar results as using the sight hole as opposed to a polar scope.

http://www.vixenoptics.com/mounts/35511.html
http://www.vixenoptics.co.uk/PDFs/Us...User_Guide.pdf

[gregbradley]

Originally Posted by iceman

Problem with the Pentax though is that you're stuck with a Pentax

Mike,

Pentax K5 is regarded as the worlds best APS sized DSLR per DPReviews.

So you might be surprised. I was when I read about that.

Pentax also make high end Medium format digital cameras that start at about $10K.

Greg.

[Bassnut (Fred)]

Originally Posted by iceman

Problem with the Pentax though is that you're stuck with a Pentax

Yeah, that would suck big time. Almost as much as a Nikon