The entirely re-engineered all metal polar scope snaps firmly into the AstroTrac Swing the right ascension drive through degrees and use the polar scope adjusters to ensure the polar scope is perfectly collimated for precise polar alignment. Forget quirky handpads and software installation. Control your AstroTrac from your familiar browser environment out of the box.
Modular patent pending. Don't weight. Go German Equatorial Mount. Single Arm Mount. Camera Tracker. Instrument Mounting. Tracking and pointing. Ultimate accuracy. If any of the pins appear bent, request a RMA to send the unit back to our UK factory for assessment and repair.
The black knob is known as the "latitude locking lever" and correct use is described on page 5 of the manual at the end of the section "Setting your latitude" - it just needs to be tightened gently after setting latitude.
To attach through the base, it's necessary to remove the circular camera mounting plate from the head of the TTX-AG by removing the three small hex screws.
You then need to carefully remove the base of the TH Head from the body by loosening the RA friction lever watch out you don't loose the small round brass friction disc which may drop out!
Please see the downloadable product manuals in the support section for more detail. Mount the TTX-AG so that the polar scope cross hairs are centered on a distant point or preferably a star.
Without moving the polar scope arm, rotate the polar scope through degrees and check to see if the cross hairs remain centered on the point. Unscrew the polar scope illuminator from the polar scope barrel. Looking into the threaded illuminator hole in the polar scope barrel you should be able to see the edge of the reticle cell and a small slot for the LED light to shine.
You need to make sure the slot stays roughly in position as you complete the following procedure as it is possible for the reticle cell to rotate during centering so the led and slot no longer line up. This will prevent the reticle illuminating properly. There are three small set screws in the polar scope barrel spaced at degrees.
To avoid rotation of the reticle cell, make sure you make adjustments in small steps. Decide which way you need to move the reticle and loosen the set screws which you want to move the reticle towards by half a turn and tighten the set screws on the opposite side by the same amount. Repeat steps 3 — 6 until the reticle is centered. Be careful not to overtighten the set screws or you may damage the reticle cell or reticle glass. Next, loosen the single set screw in the front of the polar scope body which grips the long plastic objective lens tube.
You can then screw the long plastic objective lens tube until the star is in focus. Gently tighten the single set screw once focused. If the scope is a few years old, try replacing the batteries 1.
If it's a recent purchase, try cleaning threads in the illuminator. This may happen if you try to unscrew the tube without first removing the set screw. You can try to wrap the tube with PTFE plumber's tape found in your local hardware shop. In some cases, this damage may not be repairable. We don't recommend additional lubrication in the form of oil, grease or synthetics as it attracts dust and dirt which can jam the screw.
Avoid extremes of temperature and humidity if possible. The screw thread is lightly greased and very fine so it can attract these objects which can affect the tracking speed or stop tracking altogether. For widefield shots, you can simply mount the AstroTrac on your tripod and your camera on a ballhead on top of the AstroTrac.
It does not automatically rewind, so you have to be an active user of this mount. It tracked for 1 hour, 49 minutes, and 15 seconds. I tested the mount time duration for the southern hemisphere, and again for the northern hemisphere. Same results So, my mount does not track for 2 hours, but I do not find that much of a big deal The mount has a button to control the loudness of the beeping, and the brightness of the LEDs.
I have both of mine set at max. The skies finally cleared out for me to get a night out with the new mount. I went to my regular observing site and set up the mount. It went together easily and quickly. I put the polar scope in the holder to do a polar alignment. I had to hold the flange of the polar scope against the polar scope holder while I rotated the scope to line up the stars for the polar alignment.
Then I would lock the scope in place while I made adjustments to the mount. Then I would be back to the polar scope, unlocking the scope to made adjustments and then locking it in place to readjust the mount. I am not sure if I was missing a piece, or if it is the way the polar scope is designed, but it sure would help if there was some kind of ring on the polar scope that would allow me to turn the polar scope without having to manually hold it in the polar scope arm.
The polar scope is well designed for quick and accurate polar alignment, with the Big Dipper Ursa Major and the Big W Cassiopeia printed for the northern hemisphere, and Crux printed for the southern hemisphere. For the northern hemisphere, you turn the polar scope to roughly align Ursa Major and Cassiopeia in the scope. Then you place Polaris in a open area, marked for Polaris, and then you align a dimmer second star in the opening marked, next to the circle for Alpha Eridani, and you are polar aligned.
It is a very easy polar scope to use. The AstroTrac TT positions the head that will be carrying the camera or telescope over the pivot point of the mount. This design gives the TT an advantage over other mounts that require balancing of the axis arm. It also allows the use of more sturdy Ball Heads to handle heavier equipment. I proceeded to shoot images over a series of evenings, trying to find weaknesses in the mount.
I shot with a variety of lenses on my modded D, my 30D, 20D, and 10D's. I shot with my mm f2. I shot with Olympus wide angle lenses. The TT took it all in stride. I shot short exposures of 2 minutes.
I shot long exposures of 10 and 15 minutes. Although some showed some trailing, it was mainly due to polar alignment issues on my part. When I took the time to properly polar align the mount, it work as advertised. As you could probably guess, if you are going to use a longer focal length, your polar alignment must be more accurate.
However, even if you are shooting wides, an accurate polar alignment is something that will pay you back many times over, given the accuracy of this mount. I have over 30 hours of imaging already with this mount, and every time I use it, it gets better. I am pretty sure that it is the fact that I am getting used to the mount, and getting better at polar aligning it.
Regardless, I keep getting better images, and that is what it is all about. In one of my last tests before writing this review, I used a Canon mm lens, set to 17mm, on my Canon 30D for a series of photos.
I chose the Cygnus area for this test. I would shoot a series of 5 minute exposures over most of the travel of the mount. They would be in a series of three 5 minute exposures, with a few minutes of break time in between each series.
I wanted to check for drift over the full range of the mount arms travel. I ended up taking fifteen 5 minute images, for a total of 75 minutes of data, over a period of one hour and thirty five minutes. When I imported the images into Images Plus for processing, the stars barely moved in the frames over that entire period.
The only other mount that I own that will do that for me is my Mountain Instruments MI, and it costs many thousands of dollars more than the TT Of course, the MI will also carry five times the capacity of the TT
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