Dithering Settings BYEOS

[martindowd61]

I have tried the default settings in BYEOS with PHD2 guiding and my guiding takes a long time to recover from a dither anywhere from 1 to 2 minutes and sometimes it  never recovers back to the guiding prior to the dither

Should I increase Dither settle value from 0.25 to 0.3 or 0.35 ?? My dither Aggressiveness is 2 which is low and calm down 20 seconds which is an arbitrary value considering the time for guiding recovery

My guiding total rms is usually around 0.85 to 1.50 on most nights of average seeing which allows me to take up to 3 to 5 minute subs before stars start to elongate 

I’ve looked at various old posts of CN forum and they suggest to increase dither settle to allow PHD2 to recover in a timely manner

Please explain in plain English what Dither settle is and does ?

Appreciate any advice on the above 

Many thanks

Martin Dowd 

Sydney Australia

 

 

 

 

 

[astroman133]

Martin,

You can't consider the Dither aggressiveness as "low" unless you also consider the Dither Scale value which is set in PHD. The two work together.

Increasing the "Settle dither at" should allow the dither to finish more quickly.

Have you read this thread ?

It talks about how to back calculate the dithering settings based on how many pixels you want to a dither to move. You also need to take into account the focal length of the guiding train vs. the focal length of the imaging train when deciding on the appropriate settings.

[martindowd61]

Thanks astroman 133

My Dither scale is set to 1 in PHD2 and Dither is set to random , I have tried Spiral as well with no improvement in guiding recovery 

I will try an increased Dither settle of 0.35 and see if my guiding recovers a bit sooner

thankyou 

[martindowd61]

Yes I had read debunking dithering a while ago

thanks

[s3igell]

The time a specific Mount is going to take to successfully Settle is going to be more a function of the characteristics of the Mount itself than any of the settings exposed in BYE.  Backlash and Stiction, and the PHD Settings to control those issues; RA-Only as well as Random vs Spiral Dither Settings; and the Physical Environmental elements such as Balance and Seeing

Depending on the general Guiding Performance of your Mount, the lower Settle values may be more than you can expect from your Mount.

Remember:  BYE/BYN only tells PHD When to Dither, How Aggressive to Dither, and How Patient to be about Post-Dither Settling.  Dithering, like Guiding, is configured and controlled by PHD and you will find much greater support over on the OpenPHD.org forums.