Hi folks,
To add to this thread, I'd like to share my recent experience since my initial expectations of the iPolar were somewhat askew.
I had a chance to use the iPolar last night for the first time. First with the iPolar software, and then with SharpCap. The reason I switched back to using SharpCap was because after polar aligning with the iPolar software, the polar positioning target in iPolar drifted off center when rotating 90-deg back to the Zero Position. So I wanted to double check the results with SharpCap.
According to the manual, drivers for iPolar are embedded drivers that install when the device is first plugged into your computer. As Robin pointed out, the camera appears in SharpCap as a DirectShow camera. But as such, it looks like the only available color space is YUY2, and exposure time can only be extended up to 500ms. Is this right?
At first, I was also disappointed by how noisy the sensor was, but was quite impressed by how much the image improved after using the Capture Dark Frame routine. Which has the option to automatically save and apply the darks in the Preprocessing panel. Super easy, and yields excellent results.
In comparison with my WO UniGuide 32/120mm guide scope with P1 Mars-M (IMX290), the iPolar was noticeably more difficult to work with when using the Polar Alignment routine. The values fluctuated wildly when using the iPolar scope, with a range of roughly +/-30" compared to the +/-5" that I'm used to with the guide scope. But this is basically in line with the expected accuracy of the scope as listed by iOptron. Which I understand to be attributed to the difference in pixel scale. The guide scope has a pixel scale of 4.98"/px, while the iPolar has a pixel scale of 31.1"/px (
source). I knew this ahead of time, but was still surprised by the result. I think my expectations were askew. I was still hoping for better from the little polar scope.
The guide scope may have a higher resolving power than the iPolar, but I'm not sure that it's necessarily more accurate. Like Robin
has pointed out, while the iPolar is mounted in the axis of the RA, the guide scope still rides on top of the main scope. Which makes it subject to flexure from the mount and everything in between. How accurate the Polar Alignment routine is with the guide scope depends on how solid your mounting game is.
It's probably a coin toss as to which is more accurate. The iPolar is a little wonky to work with in SharpCap, but it does work and may work just as well if not better.
Hope this helps provide some insight to others who might be considering use of a digital polar scope like the iPolar with SharpCap.
Clear skies,
Nikko