The wife and I will be taking an overseas trip to the Northern Hemisphere in about 18 months, and I'd like to take a star tracker with me. There's a lot of conflicting reviews about what's out there, so I'm looking for advice.
I should say that I was one of those people who purchased one of the early Skywatcher Star Adventurers that turned out to be a dud. Not interested in one of those and it would be too big to carry in any event.
So I'm looking for something that...
- Would fit on a mid-weight camera tripod;
- Would be able to be packed into a bag for air transport without breaking any weight allowances;
- Would be taking a weight of only a DSLR and lens (either a modded Canon 60D or 6D, lenses include Samyang 14mm f2.8 & Canon 135mm f2, maybe a Redcat 51 MkII at most);
- And would preferably have it's own power source / battery inbuilt or replaceable, as I probably won't get the chance to use external power.
So if anyone has thoughts, experiences, or inside knowledge, I'm all ears.
The wife and I will be taking an overseas trip to the Northern Hemisphere in about 18 months, and I'd like to take a star tracker with me. There's a lot of conflicting reviews about what's out there, so I'm looking for advice.
I should say that I was one of those people who purchased one of the early Skywatcher Star Adventurers that turned out to be a dud. Not interested in one of those and it would be too big to carry in any event.
So I'm looking for something that...
- Would fit on a mid-weight camera tripod;
- Would be able to be packed into a bag for air transport without breaking any weight allowances;
- Would be taking a weight of only a DSLR and lens (either a modded Canon 60D or 6D, lenses include Samyang 14mm f2.8 & Canon 135mm f2, maybe a Redcat 51 MkII at most);
- And would preferably have it's own power source / battery inbuilt or replaceable, as I probably won't get the chance to use external power.
So if anyone has thoughts, experiences, or inside knowledge, I'm all ears.
Vixen Polarie without doubt.
If you want a bit more payload, Losmandy Starlapse (sadly discontinued, but occasionally pop up on Astromart).
Neither are inexpensive....but quality always carries a premium.
Hadn't considered the Vixen at all, it doesn't seem to get a lot of press. Thanks indeed for the heads-up, I'll dig around and have a bit more of a look at that one.
If you want small and light, there's also the 'Move-Shoot-Move' tracker.
I was looking at one (many years ago) but went with the Star Adventurer 2i instead, for various reasons (payload and easier polar alignment being the two big ones).
There are several trackers on the market and I have had a few over the years.
There is also a good You Tuber reviewer who reviews the 3 main contenders.
He rates the iOptron unit highly.
Going overseas means you need something small and light and easy to use.
My first unit was a Vixen Polarie. I have taken it overseas as it is small and light and takes internal batteries (AA). It has fairly high periodic error around the +/- 20-24 arc seconds level. It will also do time lapses. I agree with Peter this is one of the better choices. There is a newer model which is more expensive but has extra features.
20 arc secs is about the limit of error you want. But taking widefield images using say a 14mm F2.8 lens like a Samyang periodic error is not much of a concern as the widefield is very forgiving. If you want to do 30 or 50mm then that is a different story. Vixen's polar scope is also quite good.
Fornax makes a Lightrack 11 mount. Not sure if it takes internal batteries, best to check their site. I always use a power brick to power mine.
It has very low periodic error - around 3 arc secs or perhaps less.
It has a swing arm that has to be turned back to the start after 2 hours. Not really an issue if you are doing a night scape of say 8 exposures x 30 seconds ISO3200.
Also longer heavier lenses can make the motor skip as it uses a friction drive. Balance is more important. A gimbal mount being recommended (about $50 on ebay).
It's larger and heavier. Also you need to calibrate a polar scope before you can use it which is a pain.
iOptron Star tracker I haven't used but it rates well, is small, light and I think it takes internal batteries - check their site.
Unitec Swat - a premium Japanese tracker. I have the Swat 330. I was out using it the other day. It will take a load of up to 15kg!. Periodic error is conservatively listed as 14 arc seconds. . It's very solid and a bit heavy but not large. There are a large number of high end accessories for it. As good as it is I don't think I would take it overseas as it's too heavy (about 1.5kgs or so). It's also the most expensive on this list at around AUD$2400. I have to translate the manual to use it. I stumbled/bumbled my way through it the other night.
Move Shoot Move have a couple of very small and light trackers.
Haven't used them.
It depends also on what focal length you intend to shoot at. I find it's more about how accurate your polar alignment is than the periodic error.
It's should be way easier in the northern hemisphere as you merely line up Polaris.
A decent tripod is needed. A carbon fibre one makes sense to keep the weight down.
If you plan on longer focal lengths than about 24mm then expect a big jump in perfection of polar alignment to be required.
I often read that such and such mount can do 300mm and laugh. The longest I have been able to achieve is about 55mm!!.
300mm would require counterweights.
To achieve a decent polar alignment I use an ASIAIR + wifi unit which has a polar alignment feature. I would practice using the unit with your phone before you venture out in the dark and wonder why the camera is not connecting to the ASIAIR. It's a bit fiddly but once setup and you have drilled how to use it then it becomes my go-to method for polar aligning a tracker unit. But in the northern hemisphere a lot of this difficulty is not there.
I also have a Skywatcher GTi unit. It's larger and heavier so taking it overseas would be out of the question unless you buy one over there.
What type of nightscape are you thinking of? What focal length?
If you are using 14mm lenses then you don't really need a tracker. Simply take 15 second exposures and up the ISO to 6400. Most modern mirrorless cameras have really low noise sensors so you can do that. Simply take double the normal number of exposures.
Greg.
Last edited by gregbradley; 15-04-2024 at 06:40 PM.
Just reading the translated Japanese manual for the SWAT330.
It is saying 14 arc second error is good enough for up to 135mm lenses (assuming a good polar alignment).
This matches my experience. So keep in mind a Polarie with it's 20-24 arc second accuracy will be really only able to handle 75mm lenses tops.
There is a SWAT 350 with ultra precision of 2.8 arc second errors which probably makes it the most accurate tracker out there. But it's around AUD$3,000.
Again, that matches my experience.
Greg.
Last edited by gregbradley; 15-04-2024 at 06:37 PM.
Firstly, my sincere thanks for the replies and overall information. I am not worthy...
We'll be in the UK / Iceland area, and I'm looking to capture some of the northern sky with a view to making a relatively large (about A2 sized) print or two for the wall on our return. Hence the star tracker. If I'm going to be printing an image that size, I want things to be as sharp as possible.
I have a selection of tripods, aluminium, carbon fibre, and steel. Very conscious of the fact that the more stability the better, but I'm also going to have to carry it hither and yon. And while I still have a reasonable level of fitness, my best days are behind me, so I want to keep it all light.
Hadn't heard of the MoveShoot Move either, will be looking at those as well.
It'll be carrying a load of a Canon 6D with lenses including a Samyang 14mm f2.8, a Canon 35mm f1.4, and possibly a Canon 135mm f2.
Firstly, my sincere thanks for the replies and overall information. I am not worthy...
We'll be in the UK / Iceland area, and I'm looking to capture some of the northern sky with a view to making a relatively large (about A2 sized) print or two for the wall on our return. Hence the star tracker. If I'm going to be printing an image that size, I want things to be as sharp as possible.
I have a selection of tripods, aluminium, carbon fibre, and steel. Very conscious of the fact that the more stability the better, but I'm also going to have to carry it hither and yon. And while I still have a reasonable level of fitness, my best days are behind me, so I want to keep it all light.
Hadn't heard of the MoveShoot Move either, will be looking at those as well.
It'll be carrying a load of a Canon 6D with lenses including a Samyang 14mm f2.8, a Canon 35mm f1.4, and possibly a Canon 135mm f2.
Cheers for all the advice folks!
I'd go the carbon fibre tripod.
The 14 2.8 should be easy to use. Is it a good copy? The 135 will require an excellent polar alignment (much easier in the northern hemi). I tried imaging with a 135 with my polar alignment done with an ASIAIR (so reasonably close) and it was so so. That would be tough in the field without practice of nailing polar alignment. Is that lens also heavy?
I reckon the new Polarie would be good. I liked my original Polarie and got a lot of use out of it. Mostly 14mm to 24mm.
Try searching on yout tube for the guy that reviews a lot of these trackers. He didn't review the Polarie though. Keep your setup simple. Some of these trackers have a peephole to align Polaris with and that's good enough for round stars at smaller focal lengths.
Sharp 14mm images are better than trailed 135mm images. But you can up the ISO and lower the exposure time as a strategy.
...
So I'm looking for something that...
- Would fit on a mid-weight camera tripod;
- Would be able to be packed into a bag for air transport without breaking any weight allowances;
- Would be taking a weight of only a DSLR and lens (either a modded Canon 60D or 6D, lenses include Samyang 14mm f2.8 & Canon 135mm f2, maybe a Redcat 51 MkII at most);
- And would preferably have it's own power source / battery inbuilt or replaceable, as I probably won't get the chance to use external power.
So if anyone has thoughts, experiences, or inside knowledge, I'm all ears.
Hi Warren,
I know you said you didn't have such a great experience with one of the Skywatcher star adventurer mounts, you didn't say which one, but seem to recall it might have been the Skywatcher Star Adventurer GTI from past threads (??? backlash), anyway I used their earlier AZ mount, the Skywatcher AZ GTI and got a good result , albeit with 10 second exposure at 135mm focal length on full frame.
And I think that's the key..... Use a moderate Tracked Exposure duration which considers focal length. Sort of like the untracked 500 or 600 second rule, but applied to tracked exposures on mini mounts with moderate periodic error. In my case above @135mm focal length & 10 seconds, there was no star trailing evident with reasonably nice clean stars into the corners.
Having looked at many images on trackers even including Pentax's very clever, although somewhat limited, Astrotracer, which moves the sensor to track the stars, I would say that for a tracked exposure on one of these mini mounts, one should look at using something around a 2000 to 3000 rule (product of exposure duration in seconds and focal length in mm). You could reduce that guide somewhat, depending on how critical you are of perfection and the distance you are from the celestial pole.
In the case of my image, an exposure duration of 10 seconds and Focal length of 135 made it 10x135 = 1350
Final Image is 49 x 10second images at f/2.8 ISO 100, Nikon D750, Sigma 135mm f/1.8 & tracked with SW AZ GTi. Polar alignment was by compass and inclinometer.
Based on the results i'd suggest that 20-30 seconds would also possibly be OK, but I'd push the sensitivity first, since the above image was taken at ISO 100, maybe even open the lens to f/2 as a trial.
BTW Canon & Nikon, if you're listening ..... ADD AN ASTROTACK FUNCTION
I know you said you didn't have such a great experience with one of the Skywatcher star adventurer mounts, you didn't say which one, but seem to recall it might have been the Skywatcher Star Adventurer GTI from past threads (??? backlash).
Best
JA
Correct. To the point that when I purchased another mount, I went with iOptron (although the HEQ5 still functions fine). And thanks indeed for the info, much appreciated.
Sean - Nice work. The bottle adapter for weight is a novel idea. Cheers.
Hi Greg,
Yes indeed it was true south, using an app called Dioptra (as I recall) on my previous phone. I couldn't find it on the app store last time I looked to load it . I onto my new phone. I must research it again, it was excellent. It could overlay the compass azimuth on to what the camera was seeing as well as the elevation, although I used a inclinometer for that.
I use a Skywatcher Star Adventurer 2i and I quite like it. It would seem to fit your requirements well. Just be careful to pack it without batteries (AA) as the power switch easily turns on inside a bag and will flatten your batteries.
I use a Skywatcher Star Adventurer 2i and I quite like it. It would seem to fit your requirements well. Just be careful to pack it without batteries (AA) as the power switch easily turns on inside a bag and will flatten your batteries.
Looking at a few of the reviews for that one, it's a point that comes up quite frequently. Nice to get some real-world confirmation. Cheers.
Hi Greg,
Yes indeed it was true south, using an app called Dioptra (as I recall) on my previous phone. I couldn't find it on the app store last time I looked to load it . I onto my new phone. I must research it again, it was excellent. It could overlay the compass azimuth on to what the camera was seeing as well as the elevation, although I used a inclinometer for that.
Best
JA
I just downloaded it off the app store. It's a gps stamp app. How did you use it to get true south?
Hi Greg, if it's the same one I had, on my previous phone, then within the settings for the app there is either a control to use the local declination setting or for you to input an offset. I don't recall which and it won't play ball on my Google pixel 6 pro ... Grrrr. Also I recall in the settings, needing to TURN ON the option to show the bearings/elevation etc...
If it's the one I used one could see the real landscape through the phone's camera with the azimuth grid shown overlaid as well as the elevation on the right side and the phone yaw angle on the left hand side. Does that sound like the one you have?
I might have to dig out my old phone and see if it's still going.
