Dither and premium mounts

With mounts such as 10Micron, the usual recommendation is to use long guide frames (about 10s) to avoid “chasing the seeing”. However, when you do that and dither every frame, this could imply waiting more than 20s to settle. Is there an option when using Voyager with PHD2 to apply shorter guide frames during dithering and revert to normal once the mount has settled and star acquired ? The alternative is to no dither which may make sense with more modern CMOS such as ASI 6200.

Hi Frederic,

so many users have your mount running but usually doesn’t guide at all.
If you need to guide I suggest to lower the time 20s is too much. There is no way to do actually what you asked also because for doing this Voyager need to stop guiding and restart loosing a lot of information.

All the best

I agree with Fredd. I think this would be a good feature to add. I have both a 10micron and Planewave L-350 with ONAGs on my scopes. Both track really well but still need guiding on long narrowband exposures. IR guiding with an ONAG needs longer guide exposures. I often have to use 12 seconds or more for good S/N. Dither settles can take 2+ minutes. Maybe you can consider adding this feature?


I explained that this mean to stop guiding and you will lost more than the time you want to save.
I will check if is possible only to change timing in PHD2 without stop guide (other guiding system for sure need to stop it), in this case answer will be yes.

All the best

Hmmm…I think you have a point. The shorter guide exposures might lose the guide star. With an ONAG on a large obstruction CDK or SCT, the star profile would suffer (dark center from obstruction). There are probably better ways to handle this. Thanks for the quick reply.


With TheSkyX guiding and Voyager you can fastening the corrections during dithering … not sure this is possible in PHD2

Thanks. I realise the easiest may be to do LRGB with no guiding and narrowband with guiding in which case the dither time may be less important. In dragscript, I assume i could have one sequence with LRGB and guiding followed by another sequence with narrowband and guiding.

yes … sure … you can create sequence with different settings dithering included or dithering with less frequency.

All the best

I am using this feature and it speeds up dithering tremendously when guiding at a frequency of 10s.



I’m sorry, which feature? Sequence with LRGB and no guiding (and dither) and narrowband with guiding (and dither) or some other feature ?

Fredd, If you use SKYX for guiding, there is an option to “override aggressiveness” on the guiding tab under setup. Setting aggressiveness higher than the guiding parameter should speed up settling. I haven’t tried it yet. Sounds like a good solution if you use SKYX.

This only seems to work with SKYX guiding. There isn’t an option for PHD2.

I plan on trying that with my Planewave and 10micron setups. Both my mounts track really well and I also use long exposures to guide. I agree that this helps average out the seeing to limit any unnecessary guide corrections.



I have an MX+ and only guide narrowband. I get acceptable wait times (in dragscript) by stopping guiding, doing an unguided dither, re-aquiring with RoboGuide and PHD2. I used to use TSX to guide but I prefer PHD2’s multistar guiding

Seems quite complicated having to stop dither and restart. I assume this was deemed the quickest solution ?

Sorry I haven’t replied earlier. Dragscript is a bit of a learning curve but once mastered stoping guiding, unguideed dither, restart guiding is only 3 lines of code. I timed it and it was quicker.

You can do the same things in sequence if the profile haven’t guide configured. Non necessary to use Dragscript. Voyager will use unguided dithering.

Thank you, Leonardo. You are, of course, 100% correct. The thread is about guided dithering especially where users have to use long exposures in their guide cameras (e.g. IR guiding).

You said on 15 June “I explained that this mean to stop guiding and you will lost more than the time you want to save.” I would like to respectfully point out that this is not true for me (I have mentioned this before). Robostar is so efficient at picking guide stars that I find “bump dithering” (i.e. using dragscript to turn off guiding, dither, reacquire guide star, start guiding) so much more efficient. It is quicker for me and more reliable.


Ian, in this way you are not using sequence and all the watchdogs inside… I must tell this to you.

About your statements that is more quick … the sum of time of each operations outside of the Sequence I’m not sure is more quick than waiting the dithering or use a dithering with high speeds correction dedicated to TSX (you must use TSX for guiding). But its up to you …

Thank you Leonardo. I appreciate I am operating without the protection of watchdogs, but as ‘bump dithering’ is not incorporated into sequences, I don’t have a choice.

I have an MX+ which I have worked hard to fine tune. I believe in collecting high quality data at the expense of quantity. So, for narrowband I get better quality data if I guide. When I guide (because I have a mount which performs well) I like to follow Dr Gaston Baudat’s recommendations Introduction to Optimal Autoguiding: How to Get the Most From Your Setup - YouTube i.e. low / no minimum movement, low aggression and relatively long exposures.

Just like those who use IR guiding we need relatively long guiding exposures which means dithering takes a relatively long time.

It may, of course, be peculiar to my setup but speed is not an opinion it is a fact. I have measured it and (for me) ‘bump dithering’ is significantly faster than guided dithering.

I hope that explanation helps.