Dithering

[Ronclarke]

To Dither or not, that is the question??

[Ags]

Don't dither, dither!

[Budgie1]

Try it without dithering, if it results in walking noise then dither. Simples! .

[ONIKKINEN]

I dither once every 20 minutes at the moment with an IMX571 OSC camera which is very clean to begin with so there is little need for dithering. Calibration with a bad pixel map and a matching dark takes all the hot pixels out and so far seems to work well. Used to dither more often, but it just takes too much time off imaging with how long my mount usually takes to settle down afterwards so have tried to reduce it.

If the camera used is not so clean, like DSLRs and some other older models with some fixed pattern noise then i think one should dither more often (dont know about the 183 if its the case). Also if there is significant cone error or polar alignment error (resulting in field rotation) then dithering might be a good idea to break the pattern that can emerge from that. Try dithering say once every 10 minutes and go towards either direction from there if there are issues with walking noise or some other pattern noise emerging.

[ollypenrice]

We don't dither using a CMOS OSC on either of our rigs and I didn't dither with the CCD rigs either. They were dual rigs so it would have been complicated. Looking at your kit list, I'd only regard it as essential with the DSLR and there it really is essential.

Olly

[WolfieGlos]

I dither every 10 minutes (or near to that depending on sub length). I did suffer from walking noise last year on 6 minute subs dithered every 3...changed it to every 2, and it disappeared.

But I am a DSLR user, and I find 45s to settle is plenty with my rig.

[Ronclarke]

OK, next session without dithering and check for walking noise, thanks everyone...:-)

 

[Scott Badger]

Depending on your sampling, drizzle integration can improve resolution but requires dithering to work.

Cheers,

Scott