Jupiter with GRS at -4C (30/11/23)

[geoflewis]

6 hours ago, IDM said:

It’s interesting that you are going as slow as 100fps, I have always tried to go as fast  as possible, that is clearly not required as judged by your image quality!!

There is a trade off between capture speed and signal. I've had discussion about this with a few different folks, a couple of who are top planetary imagers in Australia, Anthony Wesley and Niall MacNeill, both of whom prefer signal over speed, though their seeing conditions are usually better than we experience in the UK. You only need enough speed to 'freeze' the seeing. Take a look at the discussion thread on this image of mine in Astrobin, where Niall shares the analysis that he did and observations about Anthony Wesley's (nickname Bird) methodology.....

https://www.astrobin.com/0znu04/

That said, as @Kon mentioned, after experimenting with 5ms, 8ms, 10ms and 13ms, I too have settled on 10ms as my goto standard for Jupiter and Saturn. I also shoot for a fairly high histogram of 85%, which seems to help render a better colour balance in post processing.

Edited December 3, 2023 by geoflewis

[Pete Presland]

A fine end result, a very good looking image. Interesting to read about your thoughts regarding speed 10ms and having histogram up at 85%.

[Kon]

42 minutes ago, Pete Presland said:

A fine end result, a very good looking image. Interesting to read about your thoughts regarding speed 10ms and having histogram up at 85%.

Regarding the 10ms, I am not hard fixed on it, but between 9-11 seems to give more signal and less noise (mostly thanks to the nice comparison from @geoflewis). I tried it and it worked. Same for histogram, the more signal you get on the sensor the better the final result. With my mono I am all the way up to 95%. Anecdotally, my last few Jupiter images hardly needed any denoise and I think it is the combination of the two. Typically, a histogram of 50-60, is quite grainy during capture, and I think that's noise, but with the higher gain it's a lot cleaner. Would 5ms at high gain also work, I will have to try but this inconsistent seeing makes experimenting difficult.

[Pete Presland]

i have been using a similar time of around 9-10ms, but a histogram of 70%, i will definitely try a higher one next time out.

[geoflewis]

2 minutes ago, Kon said:

Would 5ms at high gain also work, I will have to try but this inconsistent seeing makes experimenting difficult.

For me a big downside of very fast capture speeds is the much larger SER files that creates. The only time I've felt that super fast speeds worked was with Mars last year in poor seeing and even then I'd say the jury was still out. With the much smaller ROI on Mars, it wasn't the issue that I get the huge file sizes from the much bigger Jupiter.

[orion25]

Another brilliant image, Kostas. I see that feature you mentioned; could it be some kind of message??

The things we do for astronomy, eh? Don't get hypothermia, my friend!

Reggie