Saturn, Jupiter, Mars, Uranus, Neptune 30 August

[Cosmic Geoff]

Despite feeling poorly the previous day I decided to take advantage of the clear night of 29/30 Aug and get the CPC800 out.  4am BST was really a little late for Saturn, but the other planets were well placed.  

Camera ASI462MC, IR/UV cut filter,  videos mostly 5000 frames, processed with Autostakkert and Registax.  For the first time, I varied the camera gain for each target in an effort to equalise the exposure times.

I was pleased to get some surface detail on the very small Mars, but have not located a 2024 timed surface map for it yet.

[Kon]

Good images and quite a bit of effort to get all of them in one session.

23 minutes ago, Cosmic Geoff said:

For the first time, I varied the camera gain for each target in an effort to equalise the exposure times.

Is there a reason/benefit behind it?

[Nik271]

Nice collection of planets! I was looking at Mars and Jupiter this morning 30 Aug at 4:30am and I'm happy to see some of the visual detail in your images, eg the dark band on Mars and the brightening of the north polar region. For real time map of Mars try this: 

nik

 

 

 

[Cosmic Geoff]

5 hours ago, Kon said:

Is there a reason/benefit behind it?

Upping the gain to reduce exposure time for the dimmer more distant planets is definitely a benefit.  As for reducing it for the bright ones, I could not see any ultimate effect - I had wondered why nobody else was quoting the very short exposures (under 1 ms for Mars) that I was using last year.

[Kon]

13 minutes ago, Cosmic Geoff said:

Upping the gain to reduce exposure time for the dimmer more distant planets is definitely a benefit.  As for reducing it for the bright ones, I could not see any ultimate effect - I had wondered why nobody else was quoting the very short exposures (under 1 ms for Mars) that I was using last year.

Interesting. For Uranus I used 20-50ms last year when I was trying to capture the polar hood. I was aiming for a histogram of 70-90 % with IR pass and it worked really well. I have seen longer exposures too trying to get it's rings. Same as Neptune it benefits from the longer exposures.

I used to do short exposures too but @geoflewis and @neil phillipsdid some interesting comparisons at higher exposure and there was benefit. A 'consensus' seems to be 10-13ms and I have seen it from other top imagers too. Too fast sometimes introduces more noise as the snr is low despite stacking several images. 

[orion25]

Nice presentation, Geoff! You had quite a planetary night

Reggie

[bosun21]

Nice work Geoff. A very productive nights planetary imaging.

[Cosmic Geoff]

On 30/08/2024 at 22:30, Kon said:

Interesting. For Uranus I used 20-50ms last year when I was trying to capture the polar hood. I was aiming for a histogram of 70-90 % with IR pass and it worked really well. I have seen longer exposures too trying to get it's rings. Same as Neptune it benefits from the longer exposures.

FYI my logged exposures were:  Jupiter 2.9ms, Mars 4.45ms, Neptune 50.5ms, Saturn 9.8ms, Uranus 13.2ms 

[Planetary Observer]

Nice set 😎