Optimising PHD Guiding Performance

[Oscar in Bin (John)]

I have just started using PHD for guiding and interested in people's views about the best way to optimise your settings. Apart from visually checking your images - very time consuming, you can check some parameters from the graphs. So two questions.
1. Is using parameters such as RMS a good way to fine tune your settings?
2. If so, what are good target numbers for these parameters?

[multiweb (Marc)]

Originally Posted by Oscar in Bin

I have just started using PHD for guiding and interested in people's views about the best way to optimise your settings. Apart from visually checking your images - very time consuming, you can check some parameters from the graphs. So two questions.
1. Is using parameters such as RMS a good way to fine tune your settings?
2. If so, what are good target numbers for these parameters?

I think 0.3 RMS is about right. Anything over 0.5 or close to 0 is over or under correcting due to balance, wind, stiction, ect... At the end of the day don't worry about it too much. What's important is to quantify the seesaw graph in relation to your pixel size on your picture. If you zigzag up and down but still stay within a pixel on the camera then you're good to go so don't stress about it. It's all relative. Good enough is just that.

[DJT (David)]

Hi Mark
I just started using Backyard Eos which integrates with PHD and they have a feature called dither which at the end of each frame will send a signal to PHD to randomly and slightly readjust the lock. This makes the noise generated on the image be in a different location on every image. When you stack it is then much more efficient at removing noise. Without this then "you are stacking the noise itself and dark subtraction can only do so much." This is quoted from the user guide and whilst not improving the performance of the guiding, does ultimately make darks subtraction more effective.

I also found that changing the setting to a frame every 2 seconds in PHD rather than the default 1 worked better as well