Hi all - Finally had a couple clear nights where the final testing on the new CEM40 EC mount could be completed.
SUMMARY:
1) The iPolar (Polar alignment system) works well and has produced Polar Alignment errors less than 1 arc min. After the first use (where a one-time calibration is required that takes about 5 minutes or less) Polar Alignment takes a minute or less.
2) The guiding has been sub arc second which is keeping my stars nice an round. No more thrown out frames because of guiding issues.
3) I really like this mount!
iPolar SYSTEM
Before using ithe Polar system you will need to download the iPolar software. Clicking on the link below will download the iPolar software to your laptop.
http://www.ioptron.com/v/firmware/3339_ ... iPolar.exe
The instruction manual for the iPolar system can be opened from the link below.
http://www.ioptron.com/v/manuals/3339_i ... Manual.pdf
Using the iPolar system
1) Connect the iPolar usb connector (located on the rear of the
2) Open the iPolar program (downloaded at link provided above). The opening screen will appear as shown below.
- a) Click on Connect to connect the iPolar system to the laptop.
- b) Where the Connect button was located you will see a message telling you a Dark Frame is required.
- c) Click on Settings and then, in the window that opens, click on Take Dark Frame and follow the instructions.
- d) Check the box Auto-Load Last Dark Frame and you won't need to take a Dark Frame next time. Close popup window.
- e) The iPolar system will now start taking images and Plate-solving them. It requires at least 4 stars. When a plate solve is successful it will show a round red dot indicating where the North (or South) Celestial Pole is located (see image below). If this is the first time you have used iPolar the red "+" symbol will not be present. In that case you will need to "Calibrate" the mount as described in step (3) below. If the red "+" is present skip step (3) and go straight to step (4).
3) CALIBRATION (Only required for first use)
- Rotate
RA axis clockwise until telescope and counterweight are approximately parallel to ground, then, click on the Confirm Position 1 button.
- Rotate
RA axis counterclockwise approx 180 degrees until telescope is on other side of mount and telescope and counterweight are again approximately parallel to ground. Click on the Confirm Position 2 button.
- Rotate
RA axis until telescope is approximately back to zero position. Click on the Confirm Position 3 button.
- Calibration is complete. You should now see the red "+" near the center of the screen.
4) Polar Alignment. Using the mount Alt/Az knobs, move the red dot until it covers the red "+". When the dot and + are close the screen automatically magnifies to ensure accurate alignment (see image below).
Once the red dot covers the red + you are Polar Aligned. All that remains is to do a 1-star alignment to correct any
NOTE: The next time you turn on iPolar to Polar align, the previous Dark Frame will automatically be loaded, and, you will see a screen similar to the one below. All you have to do is use your mount Alt/Az knobs to align the red dot and red "+" and you are Polar Aligned. Couldn't be easier! However, remember to finish with a 1-star alignment to correct any
GUIDING/TRACKING PERFORMANCE
I setup the mount, performed the Polar alignment + 1-star alignment, did focussing, then slewed to the target for the night (M13). I use PHD2 to perform the guiding (along with BackyardEOS) and did the normal PHD2 calibration. Following that I ran the Guiding Assistant) which turns off the guiding and watches the
Guide assistant showed a Polar Alignment error of >0.4 arc-min which is very encouraging.
Next the guiding was started and 3 min exposures were the longest I could take with the
This guiding produces perfectly round stars which are a pleasure to see.
As a final test I ran 3 min UNGUIDED exposures to see how well the encoders work. The mages below compare two image taken just 4 min apart. The one on the left was guided and the one on the right is unguided.
Visually they are almost identical. An analysis showed the
CONCLUSIONS
1) The cable management capabilities for this mount are excellent. They make balancing a breeze.
2) The GPS works easily and well.
3) The iPolar system for Polar Alignment took a bit of learning to get used to. However, once learned, the alignment is extremely easy/fast to do (takes only about a minute to do complete polar alignment) and my alignment errors appear to be sub arc-min. The recovery after Dithering is very fast (only a matter of several seconds).
4) The rms guiding performance has been sub arc-sec so far with no bad frames.
5) This mount is providing, by far, the best and most reliable guiding I've ever had.
Overall I am really enjoying this mount and would recommend it without any reservations. How much of the good performance depends upon having the encoders I really can't say. Clearly it will help for the Unguided performance.
Hope this review proves useful for you.
All the best,
Steve King