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07-08-2018, 01:10 PM   #1
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Best Equatorial mount for under 600$

Iím very interested in AP but the Astrotracer hasnít lived up to my expectations. Anything longer than 10 seconds I get egging. Donít matter if Iím using the 15 mm lens or 70 to 200mm.
I decided that a motorized EQ mount would be a good solution. Just canít seem to find a good one that has excellent reviews in that price point. Any advise?

07-08-2018, 01:40 PM   #2
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Hmm, you can try calibrating the GPS module better, it definitely works for me. With UWA lenses I can have up to 1min exposures with pinpoint stars. With longer lenses shorter, but even then people tell me it's all down to calibration.

Although I was looking at mounts also, ioptron one seems like a good value, but not sure if it'll work with my rather heavy k-1 and 15-30 setup
07-08-2018, 01:51 PM   #3
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So what you're saying is I have to calibrate gps+ astrotracer. Ive only been calibrating astrotracer
07-08-2018, 03:06 PM   #4
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Yes. The GPS system needs to know where you are in the world and where the camera is pointing to allow the Astrotracer to work to its best ability.

Regards

Chris

07-08-2018, 03:15 PM   #5
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Thank you sir
07-08-2018, 04:39 PM - 2 Likes   #6
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QuoteOriginally posted by AI8877 Quote
So what you're saying is I have to calibrate gps+ astrotracer. Ive only been calibrating astrotracer
Since you are only doing 10 second exposures and not getting pin point stars, I doubt that the astrotracer is calibrated and engaged.

It's a multi step process. You need to turn on GPS, then enable astrotracer, and then calibrate the astrotracer.
  • Yes, you need to turn on GPS with the button marked GPS next to the mode dial. Note that you get an orange led lit up indicating that's its on. Then on the rear monitor you should get a satellite icon that comes up red, and then as the camera starts to acquire the satellite signals, the color turn to yellow. When the GPS receiver in the camera locks on a location, then the satellite icon will turn green.
  • You need to go into the "B"ulb mode.
  • Then you need to enable the astrotracer - Go to the menu, then go to the [camera icon] menu 3, arrow down to the ASTROTRACER item, left arrow to then choose [on]. This enables the ASTROTRACER, however you still need to calibrate it so that it understands both where it (the camera) is located and where the camera is pointing (direction and pointing elevation angle).
  • On the same menu item as the ASTROTRACER function, directly underneath it is the Precise Calibration item. Down arrow and select this this with the right arrow, and you get the percise calibration function, where you need to physically rotate the camera around each of the axis X, Y, and Z individually and one at a time until you get the indication that the unit has been calibrated and hit [OK] to exit.
Now, you are ready to point the camera where you want to take an image and setup the amount of time for an exposure. Then enable the shutter to start capturing the image while tracking the stars.

I have had good luck with my K1 and K5. I, myself don't want to haul around the additional weight, batteries and cables for a physical tracker, set it up and then do the polar alignment with the unit. So for with the astrotracer, this has done everything I really want. I've found that 60 seconds of tracked exposures provides an excellent image.
____________________

On the topic of a physical tracking mount, the best folks to ask are the ones down in the Astrophotography group.

Last edited by interested_observer; 07-08-2018 at 05:00 PM.
07-08-2018, 06:59 PM   #7
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I'll let others diagnose the astrotracer issue and go to the question of equatorial mounts. For modest focal lengths, certainly 100mm and less, and likely even to 300mm, I'm aware of these options under $600 USD. based on your location I'll let you track down Can$ pricing.

iOptron SmartEQ Pro: A traditional German Equatorial Mount with go-to capability.

iOptron SkyGuider Pro: A more compact camera mount. Can be used without counterweight for light loads and wide angles. Accessories available such as a better head for polar aligning, counterweights to balance heavier loads. If you plan to use the 70-200 lens look for the full kit with most accessories included. No go-to.

Sky-Watcher Star Adventurer: Similar to the SkyGuider Pro above; it's a Different product not just a rebadge but all my comments apply.

If I was shopping I'd pick the SkyGuider Pro. I know enough about astronomy to not care about go-to for typical 200mm targets. iOptron support in USA is very good. On the other hand I know people with the Sky-Watcher and they have gotten decent results with it.
07-08-2018, 07:54 PM   #8
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A few days ago, I ran across this on another astro site. It's about the SkyWatcher Star Adventurer tracker. I think that the basics should apply to most of them since they use very similar approaches to the problem. It's also on the list on the post above ^^.


Well over 20 years ago, I was involved in designing a little telescope out in the hinterlands of Texas. I designed the star tracking system for the little scope. HET

I've not used any of the tracking mounts - Just the Pentax astro tracker.



07-08-2018, 08:20 PM   #9
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QuoteOriginally posted by interested_observer Quote
Since you are only doing 10 second exposures and not getting pin point stars, I doubt that the astrotracer is calibrated and engaged.

It's a multi step process. You need to turn on GPS, then enable astrotracer, and then calibrate the astrotracer.
  • Yes, you need to turn on GPS with the button marked GPS next to the mode dial. Note that you get an orange led lit up indicating that's its on. Then on the rear monitor you should get a satellite icon that comes up red, and then as the camera starts to acquire the satellite signals, the color turn to yellow. When the GPS receiver in the camera locks on a location, then the satellite icon will turn green.
  • You need to go into the "B"ulb mode.
  • Then you need to enable the astrotracer - Go to the menu, then go to the [camera icon] menu 3, arrow down to the ASTROTRACER item, left arrow to then choose [on]. This enables the ASTROTRACER, however you still need to calibrate it so that it understands both where it (the camera) is located and where the camera is pointing (direction and pointing elevation angle).
  • On the same menu item as the ASTROTRACER function, directly underneath it is the Precise Calibration item. Down arrow and select this this with the right arrow, and you get the percise calibration function, where you need to physically rotate the camera around each of the axis X, Y, and Z individually and one at a time until you get the indication that the unit has been calibrated and hit [OK] to exit.
Now, you are ready to point the camera where you want to take an image and setup the amount of time for an exposure. Then enable the shutter to start capturing the image while tracking the stars.

I have had good luck with my K1 and K5. I, myself don't want to haul around the additional weight, batteries and cables for a physical tracker, set it up and then do the polar alignment with the unit. So for with the astrotracer, this has done everything I really want. I've found that 60 seconds of tracked exposures provides an excellent image.
____________________

On the topic of a physical tracking mount, the best folks to ask are the ones down in the Astrophotography group.
Thank you for the clear info. I’m actually on the way to Elk water here in Alberta to try the Astrotracer one more time after following the advise. If I don’t get the desired results I’ll look into an EQ mount
07-08-2018, 09:00 PM   #10
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QuoteOriginally posted by AI8877 Quote
Thank you for the clear info. Iím actually on the way to Elk water here in Alberta to try the Astrotracer one more time after following the advise. If I donít get the desired results Iíll look into an EQ mount
I hope it works for you.....

07-09-2018, 09:33 AM   #11
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A couple from last night
Attached Images
View Picture EXIF
PENTAX K-1 Mark II  Photo 
View Picture EXIF
PENTAX K-1 Mark II  Photo 
07-09-2018, 02:26 PM - 2 Likes   #12
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Those look like about what I'd expect. Pretty good at 90 secs. 260 is too long for the astrotracer. At that length you will really need a tracking mount.
The iOptron and Star Adventurer are definitely the most popular choices.
07-09-2018, 02:38 PM - 1 Like   #13
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QuoteOriginally posted by AI8877 Quote
Iím very interested in AP but the Astrotracer hasnít lived up to my expectations. Anything longer than 10 seconds I get egging. Donít matter if Iím using the 15 mm lens or 70 to 200mm.
I decided that a motorized EQ mount would be a good solution. Just canít seem to find a good one that has excellent reviews in that price point. Any advise?
Cloudynights.com has a great deal of helpful info. Skywatcher and Ioptron brands are big sellers and work great! Many of these small kits backpack and fit medium tripods nicely. They usually deliver excellent results fir timed exposures. Also check Sky & Telescope and Astronomy magazines. First, before investing several hundred dollars more, calibrate and test your GPS & astrotracer.
07-09-2018, 10:46 PM - 1 Like   #14
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I picked up a star adventurer, I see you live in Alberta it might be worth you time to chat with
All-Star Telescope - Telescope and Astronomy Sales for Calgary, Edmonton, and Central Alberta they are in the Didsbury area and are very friendly.

I like the star adventurer for tracking up to 10min with very little drifted, here is 2 images overlaid without any photoshop auto aligning with a total of 10min worth of tracking just to see how much drifting I could expect. Crop of the lower left of the frame.




I would recommend downloading an app for your cell that will aid in polar alignment that gives you realtime and location corrections for polar alignment.

Also to speed up setup I found if you have a way of aligning your tracker vertical so that you can level the crosshairs in the polar alignment reticular with a level it is rather quick to setup in the field

I just use a level attached to the main plate. once level its very easy to sight for polar alignment



https://3.img-dpreview.com/files/p/E~forums/60366564/0cd54d1d3e5643b18948f71a568fdac4

One nice feature I also like is the half speed tracking, with this you can track at half of the speed needed and this allows you shoot landscape in the scene and what essentially does is allows you to place half of the stars movement into the landscape and half of the movement in the stars. This way you can shoot with a shutter speed of twice as long as you would use normally without a tracker.

You will also find the tracker useful for time lapse where you want to pan during the video that can also be setup to trip the camera's shutter with a lot of customizable options

Last edited by Ian Stuart Forsyth; 07-09-2018 at 11:00 PM.
07-10-2018, 11:40 AM - 1 Like   #15
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my $0.02
Both pictures you provided look fairly reasonable. As astrotracer doesn't do rotation longer exposures will show trails as you move out from the center. Also at 260 seconds you really are really close to the upper limit of what astrotracer supports. Instead I would have probably shot that scene as 6 to 8 60 second exposures at ISO1600 and stacked the individual images using Deep Sky Stacker. Between each shot I would have recomposed the image to keep the center as close as possible to the original image. My general rule is to try and keep astrotracer exposures to under 1/4 of the suggested maximum as it seems like the errors really do start adding up.

Your first image looks like it isn't fully in focus, I would suggest getting or making a bahtinov mask so that you can nail the focus. I would also suggest going to f/4 to see if that helps.

I have had pretty good luck using the O-GPS1 on my K-3. I have been chasing some deep sky objects and as I am not all that good at finding them I end up with star field pictures. I started without any form of tracking and would just crank up the ISO so that I could avoid trails. The biggest improvements I had were when I did the following:
1. Getting a heavier tripod
2. Using the 2 second mirror up delay with shutter release cable
3. getting bahtinov mask for focusing
Astrotracer helped but that is only because it allowed longer single frame exposures. That can be made up for with a bunch more short exposures at a higher ISO. Try to eliminate other sources of error before throwing more expensive gear at the problem. Also astrotracer goes sideways fast if not calibrated correctly. It went sideways on me Saturday night and I got one frame that had the whirlpool galaxy (M51) in it where the galaxy was just above the noise floor of the image and the in rest something went wrong and I ended up with star trails going in all sorts of directions. The good one was the first one where I was checking that the settings were producing something sane and that the calibration was correct so things went wrong after that. I think it is because the battery may be dying in the O-GPS1 as it is the one I first put in it.
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