Re: Mach1GTO - Crazy calibration with PHD2

Michael Fulbright <mike.fulbright@...>

Honestly if your DEC gear mesh is reasonably set then I doubt it matters much what you use for DEC.  I've always used the default in PHD2 - I think it is 'Auto' where it works it out.

If you had a mount with considerable DEC backlash it then would make a big difference.  In that case you purposely polar misalign slightly so there is a definite drift in one direction for DEC and PHD2 would work it out (using Resist Switch) and only guide in one direction in DEC.

Easiest way I've found to figure out guiding parameters is first set the DEC aggressiveness to 0 and watch the behavior of the mount.  Then slowly ramp up aggressiveness and watch the guide graph (enable showing corrections as well) and see how well the guiding corrects for DEC drift.  Keep incrementing aggressiveness until you converge on consistent good corrections.

Michael Fulbright

On 4/26/2017 2:36 PM, chris1011@... [ap-gto] wrote:

I'm not very familiar with PHD, so I suggest going on their user group. Lots of knowledge there.


-----Original Message-----
From: Leonid Shatz leonid.shatz@... [ap-gto]
To: ap-gto
Sent: Wed, Apr 26, 2017 1:18 pm
Subject: Re: [ap-gto] Re: Mach1GTO - Crazy calibration with PHD2

Thanks, Rolando.

This makes sense now. While speaking about PHD2 guiding, is there a short summary of PHD2 starting settings recommended for this mount ? My friend had suggested that I probably should use hysteresis guiding algorithm for DEC axis instead of the default resist-switch, also use lower aggressiveness of RA hysteresis algorithm of 60 instead of 70.



On Wed, Apr 26, 2017, 20:22 chris1011@... [ap-gto] <ap-gto@...> wrote:
Orienting the camera with respect to RA/DEC is not absolutely necessary. It does make calibration somewhat easier to understand and eliminates one more variable when trying to solve a problem.


-----Original Message-----
From: samara_c@... [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Wed, Apr 26, 2017 11:40 am
Subject: [ap-gto] Re: Mach1GTO - Crazy calibration with PHD2


Thank you. I will check the guiding camera for orientation. It is good to know that the mount works best at 1 x guide rate, it's not what I have been using but in this case I actually tried both, 0.5 x and 1 x. I will definitely change it permanently to 1 x. The problem happened out of nowhere, last time I imaged everything worked fine and than I spent several weeks without imaging because of the weather and then last night this happened.

I didn't know the orientation of the guide camera mattered, I will definitely double check. 

Thanks again!

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