Tag Archives: Polarie

Astrophotography Equipment Follow Up

Andromeda

New Equipment vs Old

In the years since I began writing about astrophotography techniques and equipment (including review of the Polarie, pointing tips, and processing techniques) things have obviously changed for me.  For one, I’m not working at astrophotography as hardcore as I expected.  The reality of managing an informative website (this one!), creating publishing and supporting tools, conducting fairly frequent expeditions and workshops, writing and improving content for webinars *AND* having a day job means I have to temper my enthusiasm. Or to say it more plainly, have my enthusiasm tempered by reality.

However a student asked me this question and I felt it was a good topic. The question:

I read your review suggesting the Orion Astroview EQ mount with optional dual axis motors. I’ve been looking for a cheap way to do decent tracking and have considered making a homemade Barn-door mechanical tracker to something more reliable (motor driven).

On Orion’s website, I find their Astroview EQ mount (#09822) and the dual axis motors for the Astroview (07828).

Soooo, my question is this: Since you wrote that article, is that still the most bang for your buck, or have you found something better/bigger/cheaper?
— Bruce L.

As I noted in my article, there are definitely bigger and better and significantly more expensive things … though nothing cheaper that I’d recommend. The Polarie is in the same price league.  After I made my recommendation my Astroview suffered a series of blows to the declination drive that rendered the drive useless.  The first blow was that the locking nut fell off in the dark and was lost. Once I replaced the lost piece (at about $35) the next blow was quite literal and it bent the drive axis rendering the motor useless. The truth, however, is I really didn’t need the second axis at all and I’d have saved a few bucks by only buying the single drive motor to begin with.  The Astroview is just beefy enough to carry the weight of my Orion 80ED refractor and a camera.  And to be quite honest since it is lighter and not a “GoTo” mount it’s actually easier to set up and take down than it’s bigger cousin, the Sirius mount. But the Astroview is nowhere nearly as well made.  So yes, I’d still recommend an Astroview as a minimum viable solution… provided you stick with a camera and telephoto / normal lens to do imaging.  Most telescopes worth mounting on the Astroview will cross the boundary of what the Astroview is designed to carry and will be too heavy for good operation.

Automating Focus – Two Steps Forward, One Step Back

I had upgraded the focuser on my 80ED to one sold by ScopeStuff (#RNFR) – a $320 motorized focuser. That focuser proved easier to use and more versatile, but I later found it coming apart and it required some heavy tinkering and investigation to get it working again.  I also realized that the system was not that well thought out – it was designed to have the motor base mounted to the focus TENSIONING screw rather than attached to a fixed screw on the focuser.  That’s probably in part why when I got it, the tube would not travel all the way through the almost 4 inches of focus. I’ve restored it to operation but it still won’t travel in the final 3/4 of an inch… that’s fine, however as I have never needed that much in-focus – I’m usually working with the focus tube nearly fully extended.

In focus - moving the camera inward, toward the front element of the telescope, thus shortening the overall length.
Out focus (aka back focus) - moving the camera outward from the front element lengthening the apparatus.

Is A Barn Door Tracker A Good Solution?

Let me address the question about a Barn Door Tracker.  There are no places that I have found to buy barn door trackers, it’s strictly a home-built type of thing. As I explain in the Astrophotography 101 webinar, a barn door tracker is a form of an equatorial mount that has been simplified to drive only one axis (the right ascension) and with a limited tracking time.  Various designs like the double arm version improve tracking accuracy while complicating assembly. My personal bias is that even though I’m pretty handy with tools I’d rather spend $400 on a fully built system than $80 on parts and 10-20 hours of my own labor building and perfecting the system.  I suppose if someone handed me a robust kit for $100 and told me I could assemble a motor driven barn-door tracker in an hour or less, I’d give it a try.  But at much more cost in time or money the barn door tracker starts bumping into fully built solutions like the Orion Astroview and the Vixen Polarie or the iOptron SkyTracker.

One of the principle impediments with all things astrophography – and part of the reason I created the Astrophotography 101 course is that there is a LOT of language used that is foreign to most people. And, there are legion of difficult choices to make. For example, I recently bought a William Optics Telescope. It is a well built, heavier than expected, refracting telescope that features a power focuser. Perhaps as a surprise to the uninitiated the “power focuser” is not actually powered (motor driven), it is an improved version of the manual Dual speed Crayford focuser and the term “power” implies it’s ability to hold focus without slop or creep – even if the other end of the focus mechanism is a pretty substantial camera.

I had hoped my existing finder scope and guide scopes would easily attach to the new William Optics telescope, but they won’t. The fittings are all different. For the most part astronomy and astrophotography equipment is a wild west of non-compatible, non-interchangeable components.  Much like you see if you try to use a Nikon lens on a Canon camera.  Or an intervalometer built for a Sony on a Lumix camera.  The difference, at least to my way of thinking, is that the compatibility of components is much better spelled out in the camera world than the astronomy world.

What about the Polarie?

The Polarie will work well with normal lenses. When I mounted my 70-200 with a 1.4x and the Canon 5D Mark II (or 40D) on the Polarie, tracking accuracy was pretty bad – but not directly because of the Polarie. The problem is that the systems is not balanced and there are three different points around which the apparatus gets sloppy: at the connection between the ring-collar of the lens and the head mounted on the Polarie. At the point where the head is attached to the Polarie screw, and where the “collet” with it’s two thumb screws attaches to the Polarie.  Invariably one of those would become loose enough that it would slip.  I found that putting a counter weight at the end of the lens reduced slipping and improved the tracking – but it’s a hassle and highly dependent on where you aim.  A true equatorial mount is easier to balance. The Polarie system works better when there isn’t a lot of torque around those attachment points.

In summary, I like and use the Polarie because it’s compact, light, not bulky and easy to take with me literally anywhere I go. But I would not use it to take serious astro images.  The Polarie best fits Landscape astrophotography.  For example, below is a 63 second exposure using a Canon 40D at 1000 ISO, f/2.8 at 16mm.  Using the 500 rule, star streaking would become apparent at about 12 seconds.  In this small size there is nothing at all visible, but do notice how the foreground head frame at Bodie State Historical Park is blurred – that’s because the Polarie was tracking the sky at 1/2 sidereal (star) rate. The photo has been exposure enhanced (brightened) to see details, and noise reduced a bit.

B_180-002309_sm

 


Here is an exposure that is a bit more germane. Two exposures, actually. One focused for the hand-lit tree, the other focused on the stars and both were combined in Photoshop.

Heaven Bound [C_075698+701]

Astrophotography – The Polarie

Published: November 1, 2012
Last Revised: December 16, 2018

We have a once-in-a-while webinar on beginning Astrophotography. The purpose of the webinar is to get people acquainted with the tools and techniques required to delve into this interesting genre of night photography.  As we teach in that webinar the single most important piece of equipment you can buy is an Equatorial Mount.  An Equatorial mount is an apparatus that counteracts the rotation of the earth so that your camera can peer at the same place in the sky for long enough to capture an image without streaks. There are many equatorial mounts that range in price from almost nothing (and not even worth nothing) to more expensive than logic would dictate.  For more background please see our survey of Astrophotography Gear.

One of the newer pieces of equipment in the arsenal is a less-than three pound piece of gear called a Polarie.  Here is what it looks like with a ball head attached to its face.

Polarie – Close Up

What Polarie Can Do

As noted earlier, the primary purpose of Polarie is to counteract the effect of the earth’s rotation so that objects in the night sky can be exposed longer without getting streaking. Below are examples of 42 second exposures using an effective focal length of 215 mm. The image at the left is with the Polarie turned on in normal mode, the middle image is the same length exposure but in 1/2 speed mode, and the right is what you get if you use no tracking at all.

Polarie Test - Telephoto

Tracking is less critical when shooting with wider angle lenses. I ran a test with a 200mm telephoto lens because it is a more difficult scenario. For example when shooting the Milky Way, an effective focal length of 10 to 50mm makes more sense.

A Critical Look At Polarie

I purchased only the Polarie unit (about $400 USD) not any of the accessories. The unit is deceptively heavy at almost 3 pounds but at that weight it is still – and by far – the lightest equatorial mount you can find. The only other device in its weight class at present is the Astrotrac with a starting price about twice as much. The Astrotrac does come with a better tripod mount, however at a total cost of around $1300 USD.  I paired up the Polarie with my Canon 50D and the 70-200 f/4 lens.  The addition of a Giottos ball head brings the total weight of the equipment attached to Polarie to about 6 pounds.

The Positives

  • Inexpensive
  • Good instruction manual
  • Mostly easy to set up and to use
  • Suitable for a beginner
  • Good power for the price.
  • Can be powered with mini USB (or two AA batteries). Claimed life is 4 hours on AA batteries but mine lasted at least 6 hours using rechargeable batteries.
  • Compact and MUCH lighter than almost everything else.
  • Can be used in Northern or Southern latitudes.
  • Tracks at star, solar or lunar rates (and yes, they are all different) as well as a 1/2 speed rate which should be good for Landscape Astrophotography.

The Negatives

  • The back plate can be unscrewed to peer through the axis of the motor and also houses a built-in magnetic compass but the plate is almost flush to the Polarie body and it is quite hard to grip.
  • The inclinometer (angle measurement device on the side) seems like a good idea except that the markings are so small and coarse that to my eyes it is illegible.  The lighted inclinometer *might* help if the North Star is obscured by trees or such.
  • The front plate has a 1/4″ retractable bolt and attaches awkwardly to the motor plate with two thumbscrews that are hard to reach once a head is on the motor plate. I would have preferred that Polarie supply a 1/4 to 3/8″ adapter since most good heads attach via 3/8″ bolts.
  • The battery compartment door is a nail buster to open.
  • Since Polarie will certainly be used with a DSLR camera, Vixen really missed an opportunity to add a remote release cord – I see no jack for one.
  • Not sure what the point of the flash shoe is. I do see the Vixen has another (much larger) inclinometer that can be attached there, but you may be able to do better using an application on your smart phone.
  • The optional polar alignment scope is expensive, and bulky. It’s also complicated to operate because you must remove the ball head and camera from the device. BUT the weight of the camera and ball head is likely to create enough “sag” that the careful measurements will be wasted.  We like the SkyTracker much better in this regard.

There is a sight hole to line up Polaris – the North star. I used only that method to align Polarie and got fair results. To get really long exposures one of two methods will need to be undertaken to increase the alignment accuracy: either invest in a Polarie polar alignment scope at almost double the cost or do drift alignment. Drift alignment is not simple and probably would frustrate the aspiring astrophotographer. The Polarie can be purchased with an optional ratcheting tripod base which might be a good idea, however the stated load capacity of the bundled tripod seems too low to use with a heavy camera.

Noteworthy

Remember that you will need at least two heads and you’ll want them both to be ball heads for optimum configurability. The head on the tripod should be sturdy – see below for why.  Below I refer to tripod head – the apparatus that joins the tripod to the Polarie, and to the Polarie head – which is the hardware used to attach a camera to the Polarie.

Problem Areas

In addition to the negatives listed above, there are several other sources of problems including every point where one element attaches to another. For example: the Polarie base if not attached securely to the tripod head can rotate.  If using quick release plates the attachment point creates another source of rotation. If the camera is not securely attached to the Polarie head rotation can occur there, too. All the pieces together may severely tax a cheap tripod head making it difficult to hold up or adjust the load.  In my configuration I found I had to allow some slouching – meaning I had to adjust the camera so it was pointing slightly above my target and then tighten the head so that it would settle to the right place.

What Can You Do With A Polarie?

Maybe we should have put this section first! Some of these things can only be done with a Polarie are highlighted in RED.

  • Point the Polarie straight up and use it as an automatic panning motor for a time-lapse.
  • Align Polarie and take a series of shots of the night sky – the sky will stay in the same place in every shot – and any minor movement can be compensated for using Astrophotography procedures.
  • Outfit your lens with a solar filter and track the sun (e.g. for photographing eclipses or solar activity)
  • Track the moon e.g. to catch the space station flying across its face, the slow creep of the terminator, or just to get a time-lapse as the moon sets or rises.
  • Double your exposure on a landscape astrophotography shot by using 1/2 speed mode.

For more hints tips and examples on how to use Polarie, stay tuned to this channel!

My first test of the Polarie was to track the radiant point of the Orionid Meteor shower. My attempt was mostly a bust due to clouds, however note how stable the time-lapse is – and remember this spans almost 14 minutes of real-time.

Brilliant Meteor Leaves a Trail

Here are two more ways I’ve used the Polarie – as a horizontal panning device
Star Flight and Moonset

As a sky tracking device
Soaring 1920x1080

Meteor Hunting

I thought the evening was a disaster. I got to bed at 10 pm. Set the alarm for midnight. Got up and saw that the clouds were impenetrable at my home near Los Gatos, California. With a sigh I finished packing up my equipment and set out toward the place I had picked days before.  It was a private home with an open lot and a great view of the Diablo Mountain Range.  The owners had agreed to let me arrive at midnight and remain until about 5 am. BUT when I arrived I couldn’t see the stars or the mountains. Darn.

I know that sometimes the mountains east of the San Francisco Bay Area block the low clouds from advancing inland, so I continued on. Sure enough I noticed from the freeway that I could actually see a huge hole in the sky. Astronomers call them “sucker holes” because they sucker you in to thinking its worth setting up equipment.  I had to find a way to turn around on the freeway and find an off-freeway road with a decent view.  Finding such a place took about 20 minutes, and by the time I arrived, thick clouds had enveloped the eastern sky, but at least I could sometimes make out stars to the north, including the all important Polaris.

I set up and aligned my Polarie, and started the automatic timer to take continuous 44 second exposures (2000 ISO) starting at 1:28 AM. I figured, the clouds were sometimes thin enough that I might capture a meteor through them – after all, once in a while I could make out where the bright planet Jupiter was.  Time passed and I huddled in my car with what seemed like 20 layers of clothes. I had forgotten my pillow and my sleeping bag and didn’t have my customary thermos of hot chai. The night was cold, breezy and a little damp so the shelter of the car was essential.  I slept fitfully. Each time I awoke I saw thick clouds. From 2:16 to 2:23 the clouds seemed like they were going to disappear but they were just teasing me! I slept and shivered some more. I finally found my emergency coat – a tattered old garment I keep in the car which my wife would never willingly let me be seen in public with,  and a towel to use as a blanket on my legs. By 3:56 AM the Polarie had tracked Orion high into the sky so little of the foreground was left in the shot. But now the sky was dramatically clearer! Thick clouds threatened in the west but my view of the sky was much better.

I moved the camera and reoriented it vertically so I could keep the slope of the hillside in the shot for at least a while. I watched for a bit hearing the familiar sounds of the shutter closing, pausing, opening…  A brilliant meteor appeared – it was definitely in my field of view! I was almost ecstatic until I noticed the sound of the shutter opening again and realized the bright one had appeared and left while the camera was between shots. It got away! I later discovered that I did catch one little meteor in the vertical mode (see above).

From 4:16 to 4:55 I let the rig continue running in the vertical alignment and retreated again to my car for warmth. But now Orion was heading farther and farther south where the fierce light pollution from Fremont and San José was daunting. I aborted the vertical shot and framed up a lovely spreading oak tree that caught my eye. I spent a solid 15 minutes on that oak tree with Orion hanging above it.

It was now 5:03 in the morning and I was colder than ever.  So I decided I’d reframe the sky shot to avoid the glow of the cities and retreat to the car out of the wind. It was then that I finally really slept and I woke when my alarm went off: 6:02 AM.  I was leading a group of hikers to scrub graffiti off the summit of Mission Peak and some were going to meet for breakfast at 6:30 AM.  The sky was mostly cloudy again, but I spent a few more minutes framing up my friend the oak, collected my equipment and headed for Denny’s.  I spent the rest of the morning and afternoon with a wire brush and paint remover.

After my graffiti scrubbing expedition I was exhausted and slept until early Saturday evening. I copied and started looking through my images. I found a very peculiar one almost right away.  I wondered what the “squiggle” was.

Looking at the frame before the squiggle was still there, though the shape was different.  I kept going backward until I found a brilliant flash. BINGO! It seems the meteor appeared at almost exactly the time that my alarm went off. I never saw it with my tired eyes.

I hastily grabbed the frames from just before the meteor until the floating squiggle ceased to be visible and assembled them into a timelapse:

And there you have it. Almost 5 hours of clouds, a very few meteors and one of the most fascinating phenomenon I’ve ever captured.

By the way, I now have literally thousands of shots to sort through from the following night which was much clearer. So far no brilliant streaks. 🙁

If you’re wondering what settings and tricks to use to capture a meteor, please see my article.

Resources for Astrophotography

Original Publication: Oct 12, 2011
Last Revised: Nov 9, 2017

Local Stores (San Francisco Bay Area)

Orion Telescope Center

10555 S De Anza Blvd
Ste 105; Cupertino, CA 95014
(408) 255-8770

Mon-Sat 10 am – 5:30 pm
Sun 12 pm – 5 pm

Equipment Recommendations

There is a lot of gear out there and a lot of thought about what is good / better / best.  For the purpose of my recommendations I’m assuming your interest is primarily Astrophotography and primarily based around using a telephoto lens or a small/lightweight telescope attached to a DSLR. Of course you might succumb to a small telescope. Most of my recommendations are based on personal experience. Some are based on observations of people much wiser than me.  If you decide to get a mount, here are representative alternatives.

OrionMountsCompared

Before we dive into conventional mounts, however, lets take a look a well featured, light-weight solutions.

Approach A: Good, Light and Portable

Astrotrac

AstroTrac TT320X-AG – photo from AstroTrac site.

Since, portable, inexpensive and stable do not all fit into the same category the best solution is the AstroTrac. It is light, well made and moderately priced (from $546 to $1,959 depending on the package – not including shipping). You will be limited to using the AstroTrac with a telephoto lens on a camera unless you buy some dubious additions to turn the AstroTrac into a big scale solution – but since you’re reading this that is probably what you intended anyway. Be sure to get the Polar Scope as it is difficult to align without it! This mount will track at Lunar, Sidereal or Solar rate!  While $546 might sound expensive, for the light weight versatility it’s hard to beat. For a video and more information, see the manufacturer’s page.

Pros: Total schlep weight (tripod, heads, polar scope, battery, AstroTrac) is about 12 pounds (less if you have a lighter tripod); setup is pretty easy; accurate tracking;  maximum load is 33 pound; stops automatically to prevent damage.

Cons: Limited weight; repointing at a different object may compromise the alignment;  2 hours tracking before reset; single drive solution.

Orion Astrophotography Bundle

A possible solution – much cheaper at $180 but also with very significant limitations is the Orion Astrophotography Bundle.  It is a light weight, low load mount with a single axis drive and no alignment scope. At 14 pounds assembled and a load of up to 7 pounds it’s not bad for very wide field astrophotography – but it will never take more than a single camera load. I DO NOT recommend it. For why, please see my review.

Polarie

Another product that has caught my eye is the Polarie device.  Imagine a device about the size of  a DVD slip case only about 3 times as thick.

Polarie Device with Polar scope (image from Amazon) – requires TWO heads and a tripod.

The Polarie device costs about $400 USD, but that doesn’t include the possibly unnecessary polar scope – which is an extra $250 – or a tripod rig to set it all on.  Like the Astrotrac, Polarie is light and portable and runs on conventional batteries.  A competitor is the iOptron Skytracker. Very similar features to the Polarie with a few advantages and disadvantages. The Polarie is a miss, mostly in that the scope is expensive, and requires removing the whole face. Once you put camera gear on it, the distribution of weight changes enough that the alignment via the scope is useless.  It didn’t do a good job managing my Canon 50d with a 70-200 mm lens.

iOptron Sky Tracker

iOptronSkyTracker (requires head, tripod)

Of the Polarie and the $400 Sky Tracker, I prefer the Sky Tracker. It’s better thought out.  The down side is you’ll need to remove the head from your tripod and put this in it’s place then put the head from the tripod on the face of the Sky Tracker.

The faceplate only “locks down” via that single screw. I found it sometimes slips. Also there is a little slop in the gearing. The good news is that unlike the Polarie with its expensive polar scope, you can actually mount your camera ON the face and make sure there is room to also use the scope to accurately position things.

There is a newer Sky Tracker Pro available which is more like a “real mount”. Haven’t investigated that much.

The advantage of the SkyTracker over most solutions is that it is light and easily portable.

A Canon 50d with a 70-200mm lens was more than it could manage well.

 

iOptron Sky Tracker Pro

We have no experience with this unit, however one of our workshop participants managed to make it work well. iOptron Sky Tracker Pro (no experience)

 

Astro

There is even a new contender rising in the KickStarter arena… it’s called Astro: Time-Lapse Motion Control.  It’s not clear if it will be accurate enough to track at sidereal rate, but I am hopeful.

It’s not designed for astrophotography, but if the rate can be set precisely enough, and a simple alignment done it may work quite well.  It does have a built-in intervalometer, though and as you can see it’s quite compact.

NOTE: I purchased one and found it disappointing.

 

Approach B: Good, Economical

The next bump up in capability is the Orion AstroView Equatorial mount ($250) to which you must add the single or dual drive ($140, recommended) motors for a total outlay of about $390. It’s carry weight is around 31 pounds including batteries but it can handle 12 pounds of payload and you may not need to use all 12 pounds of counterweight. Orion does have mounts in between, but I say skip ’em.  The disadvantage here is that it really can’t take a telescope, there is no autoguider port, and no “GoTo”. But it does come with a polar alignment scope. Tracking accuracy at sidereal rate is pretty good. I haven’t pushed the mount beyond 450 mm so I can’t make final conclusions. One advantage over a normal “tripod” is that the extra weight makes this solution much more stable than a conventional tripod. The latitudes range for use is 18-63 degrees. With some finagling I was able to physically get the angle down to 0 degrees – but you can’t track the RA axis at that angle. Two more drawbacks are that the tripod is lightweight aluminum square tubing with a plastic clamp – it’s begging to fail from overtightening, and the drive motor connectors stick out like sacrificial lambs begging to be broken off when placed down on a hard surface incorrectly.

Approach C: Serious Astrophotographer

Once you move up the value chain you will want to get a “GoTo” scope. This moves you from the $400 neighborhood to the $1400 address which gets an Orion Atlas EQ-G that can support 40 pounds of payload, and costs about 80 pounds in back buckling schlepping to move it around (22 pounds are counterweights).  The good news is a modestly sized telescope can go on this thing – you could even give your toddler a ride. The bad news is there is still plenty you’ll want to buy: an autoguider… and perhaps even a telescope. If that’s where you want to go, perhaps the best bet is the even stronger solution, the Orion Sirius EON 120mm EQ-G GoTo APO at $2800.  None of the above  include an autoguider, or the few miscellaneous parts you’ll need to attach your camera.   If you want a slightly less expensive, lighter system the Sirius mount isn’t a bad deal.

If you KNOW you’re going to put a immodestly sized scope on your mount, you might find yourself in the $4,000 district where a forklift or weightlifting team can help you move the apparatus around. Trust me, $4,000 still isn’t the penthouse suite!

Approach D: Insanely Serious Astrophotographer

Actually I can’t recommend anything in this category because it enters a realm where I’m not willing to go financially. For a down payment on a house you can get a large refractor (or reflector), massively accurate GoTo mount with autoguider, a high-end imaging camera, and a wheelbarrow full of accessories. Names like Losmandy, Takahashi, AstroPhysics and others rule this realm.

Polar Alignment

  • http://www.astronomy-pictures.com/Imaging-Tips.htm#zero
  • http://www.petesastrophotography.com/polaralignment.html
  • http://www.astronomy-pictures.com/Zeroing%20it%20in.%20Using%20a%20DSLR%20or%20CCD%20to%20Align%20Your%20Scope.pdf

Imaging