We're gonna need a bigger dither


#1

I have been imaging recently with a 200 mm lens and STT 8300. It is being done unguided with “dither by mount” and it has run very smoothly.

The problem is that even with “extreme dither” selected, the dither is very small. It would be even worse for the commonly used 135 mm lenses.

Can I suggest one of two things to provide a bigger dither?

Either:

  1. A scale factor that would multiply the dither by a user selected amount (say a range of 1-5 - probably both + and minus).

Or:

  1. Just one more larger dither, at least 2-3 times more than the present maximum. Since “extreme dither” is already used, maybe you could call it “ludicrous dither”. :wink:

#2

Increase the dither scale. Worked for me.


#3

That will not work in the case. That is a PhD setting and, as I mentioned, this is “dither by mount” for unguided imaging.

PhD is not even running nor needed and, in fact, would make things much more complicated than they need to be since at 200 mm with pro-track I can take up to 30 minute unguided with perfect stars.


#4

I would also like more control of direct mount dithering when using camera lenses for wide field work. With an ASI1600 + 16mm lens, my image scale is 43.9"/pixel, so I would need dither pulses of around 15 seconds at x1 sidereal rate. I don’t know if my EQ6 mount or EQMOD accepts pulses that long, so perhaps they could be broken down into a sequence of shorter pulses.


#5

Another alternative for very large dithers would be for SGP to simulate a manual nudge to a random direction by the user (as if the user pressed the telescope control direction buttons momentarily).

That would be preferable to waiting for a 15 second guide pulse to complete at x1 sidereal.


www.mainsequencesoftware.com