u mnie oba "via" dzialaja przez eqmod.
via mount uzywam bez guidingu.
maxim manual
"Dither
Camera sensors are not perfect. A common problem is "hot pixels" that have much higher dark current than the surrounding pixels. Hot pixels also have significantly more noise, as the random noise goes up as the square root of the number of electrons. Even after dark subtraction and stacking these hot pixels will still show up because of their higher noise.
There is a simple technique to eliminate the hot pixel problem. If you move the telescope slightly for each exposure, the hot pixel will fall on a different position in the sky. When the images are realigned for stacking, the hot pixel will appear in a slightly different place in each frame. Now during stacking you can use a technique such a Sigma Clip or SD Mask to almost completely eliminate the influence of the hot pixel, as those algorithms will recognize the "out of place" hot pixel and remove it. For more information on these algorithms please see the Stack command.
There are three modes for dithering; two are configured here. If you are autoguiding, select Dither Via Guider; the autoguider guide point will be repositioned slightly between each exposure. This will move the image slightly across the main sensor.
If you are not autoguiding but have a telescope connected to the Observatory Control Window, select Dither Via Mount. This will command a small GO TO operation between each exposure.
Dither will move the telescope only a small distance each time, and on average does not move it at all, since it dithers around the initial position. The amount of movement is controlled by Max Deviation (pixels).
If you are using an AO device, dither is configured through the AO control window. Please refer to SBIG AO Control or Starlight Xpress AO Control as appropriate."