Dithering

[twitterme]

What are the units of Dithering aggressiveness? For instance, pixels. Also. what are the units of Settle dither at?  I would like to see units for all entries where it isn't obvious.

Cheers,

Denny Morse

 

[astroman133]

Denny,

Did you read this thread in the How To Forum?

 

[twitterme]

I know exactly what dithering is. I am asking for units clearly shown on all parameter entries. For instance, pixels verses arc-seconds. For time entires, seconds verses milliseconds, etc.

Cheers,

Denny

 

[astroman133]

From the How To article:

Dither aggressiveness: The dither sent will be a random number of pixels in X and Y, scaled by the level you set here.  In the lowest level, the random numbers will vary from -0.5 to 0.5 pixels and in the highest they will vary from -1.5 to 1.5 pixels in the guide frame.  Since people typically guide at shorter focal lengths than they image at, this will usually have a much larger effect in your main images.

Settle dither at: This parameter specifies how far off the star can be from the lock position before Dithering is considered a success.  Typical value is between 0.10 and 0.30.

The dither aggressiveness value is unitless, but relates to units of pixels. I would assume that the relationship is linear and so would be something like this

1: +/- 0.50 pixels
2: +/- 0.75 pixels
3: +/- 1.00 pixels
4: +/- 1.25 pixels
5: +/- 1.50 pixels

From the context of the article It seems pretty obvious that Settle dither at is in units of pixels.

Hopefully you can get what you want from that.