Downloading image effects guiding?

[TiffsAndAstro]

Hear me out I know this sounds odd.

I've been staring at my guiding graphs during recent sessions and I *think* I can see my guiding go wild, briefly around the same time a sub completes and downloads to Nina.

Task manager doesn't blip. 

If this is happening it's power related, but would be shocked lol, but could be my usb bandwidth is filled with image, so auto guiding commands don't get through?

Is there a way to prioritise mount usb traffic over camera download speed?

This all goes through a probably usb2 hub. Images download fast, like 1/4sec ish.

...Or... just not touch anything considering I'm getting best numbers ever wrt focus and guiding?

[ONIKKINEN]

Are you dithering after every sub? That would explain the erratic guiding, if your mount is having trouble settling after a dither.

I find it difficult to believe that USB traffic would hamper guiding, although with USB everything goes. You should look at your guide logs with PHD2 log viewer and see if there is anything funny going on. If there is, it will be in the log - guaranteed. By something funny i mean things like star mass or SNR changing for no apparent reason, which would have to coincide with a repeating period equal to your sub length.

[Budgie1]

It does sound like it's being caused by dithering. If you open PHD2 and watch the graph, it will say "Dithering" every time it dithers. 

To test this theory you can set PHD2 to dither after every second or third image. If you change this setting and then you should see the guiding alter after that number of images. With your RisingCam IMX571, dithering every 2 or 3 images should be sufficient.