One of the terrible things about having so many choices is that it paralyzes one from making decisions, at least for me. For example, if I go to the grocery store I don't mind risking a few dollars on something new, but when it comes to a new telescope I can easily drop thousands of dollars on a new setup, only to discover that it did not meet my expectations. Part of the problem is the horrible job that manufacturers and retailers do to market their products. It is hyperbole without much substance. So, my response is to stick with the same set up I have had for the past 45 years: a Unitron Model 142.

I only have a motor drive on the RA axis: a stepper motor driven by a Raspberry Pi and Adafruit MotorHAT with my own Python code. I just added a routine to do Periodic Error Correction. I am very pleased with the results. Without PEC I was limited to 30 second exposures max. With PEC I am limited now by my uncooled camera but still I can image galaxies. So with PEC I was able to reduce PE from 50 arc-sec p-p to 10 arc-sec. I know that sounds awful compared to the sub-arc-sec guiding that you achieve, but for me it is a quantum leap forward.

The next step is auto-guiding. My RA stepper motor has a resolution of 0.43 degrees per step. I am confident that it can do the job. One of the problems is that I do not have a DEC motor -- I don't even have the gearing for it. Actually I work very hard at getting an accurate polar alignment. Over a 5 minute exposure I get very little DEC drift.

My questions are:
1. Can I use Ekos Guiding with a driver that only gives it control in RA? (Someone told me that PHD2 will do that.)
2. Can I use Ekos with a driver that does not have slew-ability? In other words, can I continue to use my setting circles?
3. With my set up can I use Ekos Polar Align?

Thanks to all for your help!

Read More...