Dithering

[padraigh]

How about a post-processing Dithering tool?

General idea: The tool could load a sequence of images, and create a new sequence where each image has had random offsets applied based on a scale selected by the user.

This wouldn't destroy the originals, and would allow the user to play with various offset scales.

It could be run during the day where SharpCap would be started and the image sequence loaded.

It certainly would be appreciated by those of us who are not using autoguiders and ties in with SharpCap's overall philosophy.



Regards,

PH

[cuivenion]

Unfortunately it won't work. Even though the stars would appear to move frame to frame the light would still have fallen on the same collection of pixels on the sensor. Dithering spreads the position of the captured image across different positions on the sensor to average out pixel to pixel differences. I had a similar thought and got answers here:

https://stargazerslounge.com/topic/3294 ... s-is-daft/

Also to be fair such a tool wouldn't suit Sharpcap, it's not post processing software.

[lkrustev]

Dear developer, I just love Sharpcap and the only reason I am looking some paid software is the dithering. It works, but it is missing many of the subs - about 1/3 in my case. So I have a question/suggestion - is it possible so the next exposure is delayed until the dithering is settled. This would be just great. At the current state I am loosing too many subs of 3-5 min length. I even paid for SGP only for this reason, but it is so frustrating and I am back to Sharpcap. Just taken two days ago with Sharpcap:

https://www.astrobin.com/v923b1/B/?nc=user

[BlackWikkett]

Hi
Can't remember witch revision of SharpCap 3.2 this was added in but Robin added a temporary work around for loosing long exposures during dither. Update to latest version to make sure you have the feature. Keep in mind Dither only works in Live Stacking with PHD. In the Live Stacking Guiding tab make sure you select Reduce Exposure While Dithering. When PHD is dithering SC will change exposure time of the camera to 1 second until it receives the settle signal from PHD. The one second exposures will not stack and will generate a warning that frames a dropping but your only dropping a few seconds instead of minutes as it was before. See image below for details. You'll want to adjust your settle settings for your rig the ones in the image are just defaults.

-Chris

SC-dither.png (27.46 KiB) Viewed 1677 times

[lkrustev]

Thank you very much! If this works I will be very happy, because Sharpcap is everything I need. I didn't noticed the "reduce exposure ... " check-mark somehow.

[admin]

I was going to post exactly the same screenshot that Chris did, but he beat me to it. Don't forget that you can also adjust the settling parameters if you find that you are still having problems because their main imaging frames restart too soon.

Cheers, Robin