Dithering????

[MarkS]

Hi All,

 

Are you using dithering when imaging? And what amount?

 

I believe it is important to do this if undersampling, but what about in general?

 

I am assuming that Sequence works OK in this mode, but I'm interested to know peoples' experience with it.

 

Mark

 

 

[lukepower]

Hi Mark,

 

I am always using it, but usually with ACP's ditherig, it is a random value in a random direction = works well for me.

With Sequence, I have the feeling it moves for the amount you tell (like 3 px) every picture it takes and always in the same direction, costing me at the end quite a few pixels of the image...

[MarkS]

Thanks Luke.

 

Are you guiding? Do you know if Sequence dithering works unguided?

 

Mark

[lukepower]

Hi Mark,

 

dithering works definitively unguided. But only in the beta version

And for guiding, I actually am thinking going back to guide again I struggle way too much to get a precise pointing model, and MLPT only works from within Sequence and not from ACP...

[dalelieb]

I use dithering for both unguided (<=300s) and guided from ACP.

Random but typically a few pixels

 

Dale

[john32712]

Hi Mark,

 

I did not see anyone comment regarding Maxim Dl, so here goes. I use dithering through Maxim Dl. If you go to the "Camera Control" window, under "Autosave" (the feature to create a sequence run) you can select dithering via guider or mount. I use "Via Mount" with "2" (pixels).

 

It works perfectly every time.

 

Best regards,

 

John Nemcik

[MarkS]

Hi John,

 

Does this work when you are using Sequence?

 

Mark

[john32712]

Hey Mark,

 

I have never tried it while utilizing sequence. Only when shooting images which will require stacking. Why would you need dithering when shooting successive non-related images?

 

Best regards,

 

John

[lukepower]

Mark,

 

I am quite sure that the dithering setting in MaximDl would not work when shooting with Sequence, as it's using the scriptable interface...

[john32712]

Lukas,

 

Am I missing something here? I have a feeling that I will be learning something...

 

Why would one dither on a non-repeatable image series(one that you will stack). In sequence you are moving from position to another position take single shots. You dither, to remove hot pixels during the stacking process.

 

Is there some other purpose that I am unaware of?

 

John

[lukepower]

John,

 

I guess we are talking about the Beta version of Sequence

In the beta version, there is a function to take images of objects (a bit like in CCD AutoPilot): You say, for example, take images of M51, 8 each in L,R,G,B with 600 seconds each, and dither it

[john32712]

Ok Lukas, now it makes sense!

 

Thanks,

 

John

[MarkS]

Hi all,

 

Just to close the loop on this one - I am now routinely using dithering in Sequence and I am assured by Philipp that it is random. This appears to be so from my experience so far.

 

Mark