AstroTrac: How many would buy one?

[Star Hunter]

If this product was available in Oz, I wonder how many would sell?

[MrB]

Not sure I understand?
Quite a few Aussies already have them, myself included.

[Star Hunter]

I'm asking because a bloke I know, is thinking of becoming a dealer for them in Oz. Maybe he might be flogging a dead horse?

[MrB]

Ah ok. Well it's a limited market here, and they're not exactly a hot item.
Also, typically, locally stocked product costs more than purchasing direct, which could be offputting for potential future buyers, but I suppose if the local price is reasonable then it might work for him.

[skysurfer]

No, too heavy and expensive.

A better alternative is the iOptron Sky tracker for $469 (http://www.teleskop-express.de/shop/product_info.php/language/en/info/p5940_iOptron-SkyTracker---Star-Tracker-Nachfuehreinheit-fuer-Astrofotografie.html): only 1kg heavy, has a pole finder, fits on a photo tripod and can carry 3kg and runs on just 4 penlites (5V).

[MrB]

For who?

Same

Same

Same

15kg

only 4 more(12V)

True, the other trackers are cheaper but they are also less accurate (AT claims 5 arcseconds peak to peak over 5 mins), they don't have Autoguiding capability, and they can't take a load much greater than a camera body and medium sized lens.

Being able to take 5 to 10 min unguided subs with longer focal lengths on a system that fits in a backpack means, for me, the AT is the better alternative.

Being able to mount two scopes side by side and a guide cam, while still remaining very portable means, for me, the AT is the better alternative.

Different needs, different gear.
Apples and Oranges.

[skysurfer]

You're right.

I read a recent test in the UK where it was priced UKP 800 and far more than 1kg.
But TS supplies the Astrotrac for $493 and 1kg, hardly more expensive but much better than the Skytracker.

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p2425_AstroTrac-320XAG-verbesserte-Version-mit-ST4-Anschluss---Montierung-fuer-Astrofotog.html

But 12V is 10 penlites, not 8.

[MrB]

Actually, it is 8.
1.5V per AA cell.

[skysurfer]

That is with alkalines.
Currently many people use NiMH of 1.25V per cell.
With devices such as trackers I don't use discardable batteries but rechargables which are all 1.25V.
Unless the Astrotrac runs on 10V 8 penlites are enough.

[MrB]

Ah ok yeah, AA rechargables are not my preferred due to their crappy self discharge.
I use a lipo battery and solar when away from home and keep alkaline AA's as backup, just in case.

[CJ]

Isn't it 493 Euros plus another 122Euros for the pole finder + P&P?

[Camelopardalis]

I've seen the AstroTrac in action, it's a great piece of kit, well designed and engineered. You are paying for "western world" design, manufacturing and support.

[Peter Ward]

Really? :rofl: That would give it a heavier payload rating than a Losmandy G-8

I've toyed with them at numerous trade shows....nice piece of kit, but no way would I agree they can carry that sort of payload without flexing all over the shop.

[Star Hunter]

So the iOptron may be better buy than a AstroTrac? I was thinking of getting one myself but now I'm beginning to wonder if it would be a waste of time?

I see the new AT's have an Autoguider port http://www.astrotrac.com/Default.aspx?p=tt320x-ag but if it can't move in Dec how the hell can it autoguide??

So what are the Pros and Cons of the AstroTrac and iOptron tracker mounts?

Thanks,

Jim

[Peter Ward]

Some interesting questions. The Astrotrack only guides in RA, hence can only be autoguided on that axis.. Any Dec drift and you can expect eggy stars.

I had a look at the Astrotack website...they indeed claim a 15Kg payload....which sorry, really is laughable. I found it struggled with flexure with just a short focus 80mm refractor (3 kg)

Most camera tackers are just that: camera trackers. They are pretty similar in performance....just don't try and place too much camera+ lens on them and you'll get great results.

If you want a portable tracker+integrated tripod, sure the Astrotrack is a good solution..... but if you want a dual axis portable EQ mount, "none of the above" is the answer.

[MrB]

Haha. Yes they wouldn't be the first mount manufacturer to exaggerate their load rating


For now ;)


I often use it with a Stellarvue SV70ED and an Orion ST80 (which is very light) + QHY5 in side-by-side configuration, works well.
Obviously not as solid as the mounts you're used to tho :D


True.
There is also the iOptron SmartEQ (http://www.ioptron.com/index.cfm?select=productdetails&phid=03c86716-b870-417b-8beb-0c0ba49ddf1d) which isn't quite as portable as the others, but is dual axis and is goto for ~$360.
The Pro version (http://www.ioptron.com/index.cfm?select=productdetails&phid=6650b0b6-9767-494d-b9e6-9e82c223c1a6) has guiding for ~$500.
I was almost ready to pop on the Pro when the Astrotrac came up for a good price.

[rcheshire]

I don't think the Astrotrac can be compared to a Polarie or iOptron tracker, as far as intended use, capability and price is concerned. Despite its tangent arm design and the required accessories, the Astrotrac is better compared to some of the smaller EQ mounts, and for unguided AP, periodic error, portability, complexity, stability, capacity - if unguided light weight AP is your thing?



More comparable...

[Joshua Bunn]

How does that work...? the Ioptron Sky Tracker (http://www.ioptron.com/index.cfm?select=productdetails&phid=febb7d36-d904-4ccd-8020-41a6103fae86) is $558 with a lighter payload etc. (im not questioning you, its on their website)

[jenchris]

Cor you guys are wimpy.
I just bung my NEQ6 in my back pack with a couple of counterweights and a deep cycle battery - then carry my OTas under my arms withthe tripod.
It's the laptop I have a problem with.

[MrB]

Probably quality. The SmartEQ's seem to be a bit hit and miss in that regard, and some reviews I've read say they need some work and fine tuning to get them working their best, which I was quite happy to do.
The tripod that comes with them, and with the Sky Tracker package in your link, is apparently only good for filling your rubbish bin.
There are a few informative threads on CN and SGL if you're needing more info.

[Joshua Bunn]

I see, I will be picking up my Sky Tracker tomorrow, so ill see how it goes. I do have my own tripod for it. :)

thanks

[skysurfer]

Well after some looking at reviews it looks attractive.

I read the user manual :
http://www.astrotrac.com/media/AstroTrac%20TT320X%20Instruction%20 Manual%20v1.0%20-%20Web.pdf

My SP mount weighs 4kg and this mount only 1kg (plus about 0.5kg of the Manfrotto tripod head I already have, which saves 2.5 kg in my air travel luggage. But how should I mount the Televue Genesis on the Astrotrac ??

And isn't the $220 polar scope a Requirement ?
I see some sketches of the sky in the user manual with the surroundings of both poles (resp Crux+Achernar and Ursa Major+Cassiopeia). Is there a reticle supplied ?

The 20 years old SP mount with polar finder is very accurate: point the +7 star BQ Oct (not Sigma Oct !) in the center of the polar scope and voilà ready to track at least 5 minutes per frame with the Genesis.
So only the 2.5kg luggage gain is a reason to buy it.

[mbaddah]

I don't have experience with other trackers, but I can assure you the Astrotrac is an absolute gem. For months I hadn't realised I had the tangent arm the wrong way around (I blame the manual!) and even then I was able to get several minutes of sharp stars using wide focal lengths. After correctly setting up and polar aligning the astrotrac I've been able to achieve 5 minutes of perfect tracking using a Canon 200mm lens. I probably could have pushed it even further but didn't try as I was happy with that.

I'm a member of the Astrotrac yahoo forums and have seen people do some crazy things with their astrotracs.. like mounting a C5 SCT on it, 4" refractors, and even a 152mm Takahashi refractor!!! (http://cosmicbug.files.wordpress.com/2008/11/tak-fs-152-tt320-glee1.jpg).

Personally I think the Canon 400mm f5.6 is perfect for the astrotrac. Decent focal length for dso imaging and with good polar alignment you don't need to autoguide. My 2c.

[MrB]

As you have found, fitting a ball head is easy. Mounting a scope is not.
The trackers are designed for camera's, hence the easy attachment of a ball head.
Astrotrac though has accessories available for mounting scopes, ofcourse they increase the overall cost and add weight.
First you would need the Declination head: http://www.astrotrac.com/Default.aspx?p=head
Onto which you can mount dovetail plate adaptor.
An example is this one: http://www.firstlightoptics.com/astrotrac/vixen-type-saddle-for-astrotrac-th3010-head-.html

I'm not using a dovetail. I have a solid 20mm thick by 50mm wide by 200mm(or 250mm?) long aluminium bar bolted to the head which has various sized holes(some are threaded) that allow me to attach tube rings and ball heads and whatever else I want. I think this is much more rigid than any dovetail.


For short focal lengths, not really. You can get it close enough by eye and a bit of fiddling.
For longer lengths(scope), yes, you will need it.
However, Roger Groom (rogerg) has an attachment that holds a laser pointer and he uses this to align. This should work out to be a much cheaper alternative.


What you see in the polar scope is as per the manual.
I have never used the constellations and stars as etched on the screen, I just set the centre (cross point of lines) as close to the correct offset from Sigma as possible. This is usually good enough for 5 to 10 min subs for me.

[Peter Ward]

There are other solutions....I've carted my rig (pictured) from central Australia, to Tennant creek, to Iceland.

All that airline travel really makes you appreciate the lack of counterweights :). The relatively recent addition of a carbon fibre tripod also helped.

[MrB]

Not biased at all Peter? ;)
Actually, I had looked at the Starlapse system when I was scouting around for a system. Once I factored in the additional expense for the declination axis though, it blew my budget.
Truth be told, the full-kit Astrotrac system I bought blew my budget too, by ~50%, but I got a pier with it too.
The Starlapse was going to blow my budget by more than 100% and I would still need to spend on a very solid tripod or pier.
I will admit it is an impressive system, I just couldn't afford it.

[Peter Ward]

:question: Yes.... I probably am biased :).

But my needs were more for an eclipse travel rig...hence lightweight/no counterweights and rigidity were top of my "luggability" list.

As a camera-only tracker there are more affordable solutions that clearly will do the job. :thumbsup: