Sky tracking mount

[chuck]

I am looking for a sky tracking mount to allow me to use a 500mm f/5.6 lens to photograph deep sky objects. Does anyone have

recommendations?

[john_harper9]

<p>For that focal length and deep sky (i.e. dim) objects, a very stable platform, accurate tracking, and polar alignment are essential. I don't think the "sky tracker" genre of mounts will suffice. Look into telescope mounts and search astrophotography sites for success stories and lessons learned on equipment, techniques, and software.</p>

[AzDavid]

<p>Chuck:</p>

<p>You might check out a device from Ioptron called the Skytracker. (See links below.) It's been out for a few years and currently retails for about $299. It can be polar-aligned and is built to track the Earth's rotation. It is supposed to support up to 7.7 pounds, so you'd want to figure the total weight of your camera setup before purchasing this device. You also would need a very sturdy tripod and proper hardware to mount the Skytracker to the tripod.</p>

<p>I have not used the Skytracker because I already have a telescope and mount that can carry my camera when I'm photographing the night sky. But the Skytracker seems to get glowing reviews in places like Amazon and some of the astronomy online communities and publications. </p>

<p>You would need to evaluate Skytracker's effectiveness for what you plan to do. It's a relatively low-cost way to start shooting the night sky. If this is a serious, long-term desire, you might explore purchasing a proper telescope and mount. You can always take photographs through the telescope, itself. And then there're CCD cameras that connect to telescopes and are built specifically for astrophotography. </p>

<p>http://www.skynews.ca/review-ioptrons-skytracker-ultraportable-camera-mount/<br>

https://www.amazon.com/iOptron-3302B-SkyTracker-Camera-Mount/dp/B00EFRN1GE</p>

 

[photo_galleries]

<p>First of all, I assume you already have an incredibly stable tripod--braced if possible. If so, you need to be able to drift align with miniscule periodic error -- doubtful that the azimuth or altazimuth type of mounts will do the job. I would personally opt for a higher-end equatorial mount. There are low-end cheap equatorial mount, but note that they are cheap for a reason. A good "reasonably-priced" equatorial mount is probably in the $1k-$2k range. Check out the Losmandy mounts.</p>

<p> </p>

[Ed_Ingold]

<p>You are better off with a 4" refractor or 6" (or larger) reflector telescope designed for astronomy than a telephoto designed for land photography. For deep space objects the diameter is more important than the f/stop, and a simple achromatic lens will suffice. The more elements in a lens, the more parasitic reflections you will encounter, which will be amplified in long exposures. It goes without saying you need a solid tripod and tracking equatorial mount. I see star trails in a 10 second exposure with a 25 mm lens, much less a 500 mm.</p>

<p>Deep space photography requires very specialized knowledge and techniques. You need to do a bit of research before you start pouring money into it.</p>

[AzDavid]

<p>It's not really clear what level of astrophotography interests Chuck. While I agree with others here that most serious astrophotography is done with telescopes, equitorial mounts and other complex (and expensive) equipment, I think a great deal can be accomplished - including deep-sky photography - with simpler tools. Just visit flickr.com and search out images and/or groups with keywords "ioptron skytracker." Again, I don't own the device and have no stake in its success. But the fact is that ... yes ... you can take good deep-sky images with a camera and a telephoto lens. </p>

[Ed_Ingold]

<p>The Ioptron Skytracker is a light to medium duty device which is too small to handle more than a DSLR or possibly an Hasselblad. It is mainly designed to shoot wide areas of sky without creating start tracks, like Milky Way images or constellations. It is an equatorial tracking mount with an optional telescope to align its axis with the North Star, Polaris. Polaris is actually 2 degrees from the celestial pole, consequently is not exactly a precise target. Boötes is a typical constellation, containing a former North Star, Arcturus. It fits comfortably in the FOV of a 25 mm lens. The star trails are easily seen below. Arcturus is the orange star in the lower right of the pentagon.</p>

<p>A7Rii + Batis 25/2, 20 seconds @ f/2, ISO 400<br>

<img src="http://d6d2h4gfvy8t8.cloudfront.net/18273638-lg.jpg" alt="" /></p>

<p>Even the best equatorial mount is not going to perform well for long, deep sky exposures without supplementary tracking. This is done by keeping a particular star in the crosshairs of a finder, manually or with an automatic fine tracking device.</p>

<p>You can't see stars in the viewfinder with any degree of certainty, nor can you focus. I trusted the OLED display on the Batis lens to set the focus at infinity, and pointed by guess and by darn in the direction of Arcturus (North Star in the reign of Cheops II).</p>

[john_harper9]

<p>While I don't have a sky tracker, I have built a number of mounts - German, Dobsonian, and barn door. The barn door type is closest to the sky tracker use case and based on my experience, the balance of the camera and lens quickly becomes an issue once you go up in lens focal length. The relative ease of obtaining wide field sky shots does not translate into successful long telephoto images. The biggest problem I see with a 500mm is keeping the combined camera and lens, ball head, and sky tracking mount weight centered over the (hopefully rigid) tripod head. Once the rig is out of balance, there is a significant moment arm that allows for sag and vibrations. </p>

<p>The German style mount includes counterweights so the weight is centered over the tripod head and is probably the best choice for serious long focal length astrophotography. That being said, my heavy German mount stays in the attic. I enjoy wide field sky shots using a barn door tracker which is portable and is always with me when camping in dark sky locations. I think the sky tracker is great solution for wide angle to short telephoto lenses. I would buy one if I didn't have home-built mounts. If the weight and balance challenge is accommodated, a sky tracker just *may* be successful for a light 500mm lens.</p>

<p>Of course, technique in gear setup, image capture, and post processing is critical to producing good deep sky images. A significant learning curve is ahead for a neophyte getting into deep sky astrophotography.</p>

[chuck]

Thanks for everyone's responses.

 

I think I should clarify how I intend to use the tracking mount. I like to take one or two solo, 1-2 week long

camping/hiking/photography trips a year. These always involve flying to a region and driving to a several locations,

camping a couple of days at each location. So there is a limited amount of equipment I can bring. A astro-telescope with

its own tripod is somewhat out of the question. A carry-on suitcase sized camera bag and a tripod in a duffle is about all

that can be accommodated.

 

I have a D810. It nominally go up to ISO 51200. Long exposures at above ISO 12800 is too grainy for normal

photography but that may not matter too much with deep sky objects. I've had reasonable luck shooting andromeda

Galaxy using ISO 12800, 200mm f/2.8 and around 4 second exposure with no tracking. So I was thinking with basic

tracking, I might extend the exposure with a 500mm lens to several minutes. I am not thinking of 20-30 minute

exposures.

 

Is a basic tracking unit that mounts on a normal tripod sufficient for this?

[Ed_Ingold]

<p>https://www.bhphotovideo.com/c/product/979344-REG/ioptron_3302b_skytracker_camera_mount_with.html</p>

<p>The Ioptron Skytracker is the most likely to meet your general needs. The weight limit of 7.7 # includes a ball head, and is probably optimistic. It is relatively small and light and battery operated. It attaches to an ordinary tripod with a 3/8" stud. Here is a review from "Sky and Telescope" magazine.</p>

<p>http://www.skyandtelescope.com/wp-content/uploads/documents/SKYTRACKER.pdf</p>

<p>In order to compensate for noise, distortion, vignetting and other issues, you might consider taking multiple exposures rather than one long one, and combining the results using one of several software packages designed for this purpose. It is one way to incorporate foreground objects with star fields, minimizing both star trails and blurring.</p>

[Andrew Garrard]

<p>Sorry this is late, but if anyone checks back, Skywatcher have recently launched a thing called a "star adventurer" that seems to be a bit more robust than the competing portable mounts and is appreciably cheaper, though it's a bit more bulky (but only 1kg) - Sky at Night reviewed it <a href="http://www.skyatnightmagazine.com/review/mounts/sky-watcher-star-adventurer-dslr-mount">here</a> (which I should have remembered to read beforehand) and gave it 4/5, though they've not quite said what they don't like. I took one with me on my holiday around the US (vouching for its size), but I didn't have the chance to use it, partly due to the limited time I had in any given place and partly due to lots of places being on fire (so the sky wasn't very clear). I'm reasonably confident it'll hold a 70-200 f/2.8 or a 300 f/4; I might give it a go with the 200-500 f/5.6, but I'd be pleasantly surprised if it does miracles - it's not a substitute for a dedicated telescope driven mount. Like most portable options, it won't track stars of itself (it's just a motor on a timer), although it does have a connector for a single-axis auto-guider. I bought the basic version, which is cheaper, because I already have a geared mount and a solid ball head which I can combine with the tracker. My only concern with the design so far is that there's no retaining screw for the upper tripod head, so nothing's stopping it coming unscrewed under load except friction (or gravity if you're the right way round). I may try to report back when I've had the chance to try it, although at UK latitude I'm going to have to wait until later in autumn before I have a hope of dark skies.<br />

<br />

Actually, worse than that, because I'm near London and the default sky is orange. I've also recently picked up a 77mm LPR filter and - it being the largest I could find - a 52mm IDAS LPS-V3 (nebula filter), so I'm hoping one of them will give me a step up on the light pollution. The 300mm f/4, 70-200 f/2.8, 24-120 f/4 and Sigma 50mm f/1.4 Art all have 77mm filters, fortunately; to test a 200-500 I'm going to have to go to a dark sky site. With the LPS-V3, I'm mostly looking at my 50mm f/1.8 AF-D, 135mm f/2.8 AI and my (acquired just for this) 200mm f/4 AI. Just thought I'd report that to save anyone else replicating my research!<br />

<br />

Incidentally, I'm sure I remember a relatively solid driven mount that was essentially two arms being driven by a long screw thread; my google-fu fails me and all I can find now is DIY versions, but you may have more luck. There's also the Fornax LightTrack II, which is rated up to 5kg, but it's a lot more expensive than the other options discussed here. I can't yet provide any personal experience, I'm afraid. In any case, stacking lots of shots is the way forward (it also means you can remove light pollution because you can avoid saturating the sensor), but a driven mount ought to reduce the definition of "lots". I'm relying on being able to do this to get some shots, at some point, with relatively small glass - I also have a 10" Dobsonian for visual astronomy, but it's not hugely worth the cost and effort to make that track.</p>