Hi there,
I have recently booked a holiday in Rarotonga for later in the year and I'm thinking about investing in a light weight tracker to mount on my tripod (Manfrotto 055XPROB) and get some astro shots of the Pacific night sky.
It seems both the Polarie and Astrotrac are valid options. Has anyone used them in the field?
I will probably take my Olympus OM-D with an assortment of M4/3 lenses (25mm f1.4, 45mm f1.8, 40-150 f4-5.6 + a very good 1.5x tele and a decent .5 wide convertor). The Olympus has a x2 crop factor. It won't shoot tethered (I miss backyard EOS), but I have a remote that lets you set times, frames etc.
I'm not travelling until May and would greatly appreciate any suggestions.
This a difficult question as both are very good for what they are intended to do.
The Astrotrac is more expensive. You probably also need the wedge to align it without driving yourself crazy. Has a much heavier payload and you can go deeper if properly aligned.
There are guys on the Astrotrac yahoo group who say they have taken 5 and 10 minute exposures with camera lenses
The Polarie on the other hand really requires only the tripod and a ball head
I have used it with the same tripod you plan on taking for the solar eclipse and for widefields with a 50 or 55 mm lens
I have both. I use the Astrotrac with a short tube small telescope if I am driving. Astrotrac also sells a pier and other kit. I found I had to use a beefier tripod than the 055XProB for my set up with an Astrotrac. So all in all s little more gear compared to the Polarie. But heck if I am driving I will take both the Astrotrac and the Polarie
If I am travelling by plane I'll take the Polarie in my camera backpack it's that small and lightweight
5 minute tracking with my Olympus OM-D and 8 & 12.5 minute tracking with 35mm Sony RX1 full frame camera.
I had 15 minute examples where the stars are still perfectly round. I'm thinking that I could, at this FOV, even get half an hour. That's very, very impressive.
Photo 1) Sony RX1 - single frame, 518 secs (8.63 mins) at f/4 ISO800, NR off. Straight from camera.
Photo 2) Sony RX1 - single frame, 733 secs (12.22 mins) at f/4 ISO800, NR off. Straight from camera.
Photo 3) Olympus OM-D - stack of six 300-second images at f/5.6 ISO400, NR off. 12-50mm kit lens at 12mm.
The Polarie, weighted reasonably (650 grams in the RX1's case and 1,150 grams in the OM-D's) is a very good performer and will track from horizon to horizon without any reset. I've had it loaded to 2.8kg at 600mm and still get decently round stars after 5 minutes.
With your OM-D - use LiveTime and watch your image magically build in real time. What a feature.
Just to add to your woes , I see Ioptron have just relesed a Vixen Polarie clone , called 'Ioptron Sky Tracker' $349usd .
Google it as it looks similar to Vixens except this comes with a built in polar scope .
Brian.
After the precision I'm getting with the Vixen polar scope, the iOptron's looks a little primitive in the way it's inserted. It's probably OK though. The Vixen is machined to fit precisely via a series of machined conical surfaces, and is drawn in to position by magnets. It's really exceptional quality. I guess that the old adage survives, you get what you pay for. I'd be interested how accurate the iOptron's tracking performance was in comparison to the Polarie.
Yes we will see , primitive ???? .
Seen one yet ?
Brian.
Quote:
Originally Posted by Omaroo
After the precision I'm getting with the Vixen polar scope, the iOptron's looks a little primitive in the way it's inserted. It's probably OK though. The Vixen is machined to fit precisely via a series of machined conical surfaces, and is drawn in to position by magnets. It's really exceptional quality. I guess that the old adage survives, you get what you pay for. I'd be interested how accurate the iOptron's tracking performance was in comparison to the Polarie.
The way they've engineered the polar scope insertion, yes, it looks comparatively primitive in the images I've seen. Compare the basic push-fit and thumb screw with the beautiful self-centering system Vixen have come up with.
At the end of the day, it's probably not really important as far as its ultimate performance goes. We're not talking about a PME here. It'd probably perform every bit as well as the Polarie in its intended use.
having a few of these toys now i can say that for ease of use the astrotrac and the polarie are equal. As for fitting the purpose that you want - the polarie doesnt take up much room but you cant use a lens like a 135 - 200 etc but for the smaller wide fields - its perfect. the astrotrac will handle the larger lens and the smaller ones - but your limited to a 1h45 window. not so with the polarie. the next step up for payload capacity is the starlapse - but that means you need a better tripod. for simplicity get the polarie. and for what it is worth you do get the quality you pay for - been there several times on cheaper items. but there are some rough diamonds out there
I would love to play with one my self , they look the bees knees for travelling .
Brian .
QUOTE=h0ughy;935837]having a few of these toys now i can say that for ease of use the astrotrac and the polarie are equal. As for fitting the purpose that you want - the polarie doesnt take up much room but you cant use a lens like a 135 - 200 etc but for the smaller wide fields - its perfect. the astrotrac will handle the larger lens and the smaller ones - but your limited to a 1h45 window. not so with the polarie. the next step up for payload capacity is the starlapse - but that means you need a better tripod. for simplicity get the polarie. and for what it is worth you do get the quality you pay for - been there several times on cheaper items. but there are some rough diamonds out there [/QUOTE]
With the camera and lenses you intend to use, I would recommend the Polarie too.
There is nothing wrong with the Astrotrac (quite the opposite, it can handle small scopes with ease, I have used my Stellavue70ED @ 420mm without issue) just that for what you will be doing the Polarie is the less expensive option.
If you think you may be tempted to use longer lenses or a short scope in the near future, then maybe look at the Astrotrac.
Thank you for all the excellent replies.
I'm leaning towards the little Polarie at the mo. So compact! I imagine the additional polar scope is necessary?
Will definitely check out the new ioptron one.
For wedge equivalent, I thought to use my Manfrotto 460MG as it is still fairy light (also have a 410 which is very solid but also heavier). Then i'd pop the ball head (496RC2) on the tracker.
I have yet to try the liveview exposure on the OM-D, but it does sound neat to watch the exposure take place.
Looks like the ioptron one is limited to two speeds, I think the Polarie has had a great deal more thought put into it and looks like it would last longer also.
This is a really nice device but the price ($415) is rather hefty, so for me the Super Polaris + homemade aluminum tripod including a pole finder North and South (all together 10kg) remains my travel setup. And it can carry 5kg (e.g. Televue Genesis + EOS 7 body).
But for people who can bring only limited capacity on a trip it is a good option.
Even a Canon EOS 5 or 7 body + a tank class lens like a 70-300 f/5.6L or 70-200 f/2.8L fits on it (2kg).
I'd get the astrotrac, I think it is a better long term investment, and if you don't like it the resale value is excellent.
It will take any lens/camera combination you throw at it, and even one of your smaller scopes, which is great for grab and go at home after the holiday is over.
Just gave livetime a little try on the OM-D, wow what a cool feature. Basically like bulb mode except you see the picture exposing before your eyes.
Pretty neat. Reminds me of watching a Polaroid instant print develop, though in this case you see the exposure taking effect over time. Thanks for the tip Chris!
I guess it's a little bit like Live View Exposure Simulation on the Canon systems, in that the LVES shows you what your exposure will look like for a given aperture, shutter and ISO value, which takes the guess work out of obtaining an exposure (especially when light is changing quickly). With the Olympus one, you tell it when you've exposed enough/are happy with the exposure as you see it build.
Just to add to your woes , I see Ioptron have just relesed a Vixen Polarie clone , called 'Ioptron Sky Tracker' $349usd . 
Me to jjjnettie , thats why I mentioned it .
