Dithering

[Matzi]

So I'm not familiar with the term 'dithering', but what does it mean, and how do you do it?

I downloaded a dithering program for phd2, and I am following someone who uses the phrase "dithering aggressive every frame"?

[AngryDonkey]

If you google 'astro dithering' there many sites explaining what it is and how it is done with the various different cameras and software packages. You can also put dithering in the search box here on the SGL site and there will be many threads on this. Here is a good description of the basic concept:

https://www.skyandtelescope.com/astronomy-blogs/astrophotography-jerry-lodriguss/why-how-dither-astro-images

Normally dithering is controlled by the image acquisition program e.g. (SGP, APT, BackyardEOS etc.) so if you use one that can do it you won't need a stand alone program. If you tell us what camera and software (if any) you use we can be more specific.

"dithering aggressive every frame" just means that a large dither (move) command will be issued to the guiding program (or the mount if not guiding).

[Matzi]

52 minutes ago, AngryDonkey said:

If you google 'astro dithering' there many sites explaining what it is and how it is done with the various different cameras and software packages. You can also put dithering in the search box here on the SGL site and there will be many threads on this. Here is a good description of the basic concept:

https://www.skyandtelescope.com/astronomy-blogs/astrophotography-jerry-lodriguss/why-how-dither-astro-images

Normally dithering is controlled by the image acquisition program e.g. (SGP, APT, BackyardEOS etc.) so if you use one that can do it you won't need a stand alone program. If you tell us what camera and software (if any) you use we can be more specific.

"dithering aggressive every frame" just means that a large dither (move) command will be issued to the guiding program (or the mount if not guiding).

I'm using Zwo Asi 120mm mini guide cam and Nikon D5300 as main, using SGP

[AngryDonkey]

SGP already has dithering built in so there is no need to use an additional dithering program. Most of the information you need is in the SGP manual. The sections on dithering is covered here:

http://mainsequencesoftware.com/Content/SGPHelp/SequenceGeneratorPro.html?AutoGuiders.html

There is also a good tutorial about using SGP with an OSC or DSLR camera here (which also covers dithering):

http://mainsequencesoftware.com/Content/SGPHelp/SequenceGeneratorPro.html?OneShotColorOSCandDSLRCameras.html

[ollypenrice]

1 hour ago, Matzi said:

I'm using Zwo Asi 120mm mini guide cam and Nikon D5300 as main, using SGP

You'd probably be best off trying a large dither, around 12 pixels, with a DSLR to combat irregular colour in the background sky.

Olly

[Matzi]

3 hours ago, AngryDonkey said:

If you google 'astro dithering' there many sites explaining what it is and how it is done with the various different cameras and software packages. You can also put dithering in the search box here on the SGL site and there will be many threads on this. Here is a good description of the basic concept:

https://www.skyandtelescope.com/astronomy-blogs/astrophotography-jerry-lodriguss/why-how-dither-astro-images

Normally dithering is controlled by the image acquisition program e.g. (SGP, APT, BackyardEOS etc.) so if you use one that can do it you won't need a stand alone program. If you tell us what camera and software (if any) you use we can be more specific.

"dithering aggressive every frame" just means that a large dither (move) command will be issued to the guiding program (or the mount if not guiding).

I'm using Zwo Asi 120mm mini guide cam and Nikon D5300 as main, using SGP

[Matzi]

Thanks for your help guys.

Now I do get confused when how to slew to my target. Do you use a program such as Stellarium, or when polar aligned, can you use SGP? And what about star alignment, I heard you don't need to do that anymore with SGP?

[Davey-T]

You can use various programs like CDC or Stellarium to slew to your target or simply the handset and then plate solve in SGP and centre it.

You only really need star alignment for GoTo accuracy if you're planning on changing target continuously, after PA I generally just do a sync on a star near the target and go from there.

Dave