Jupiter and Saturn 18/09/2022

[Adam1234]

My first ones of Jupiter and Saturn this year, also the first using my Ritchey Chretien 8" f/8.  Taken with ZWO ASI120mc-s, 2x barlow, ZWO ADC, EQ6-R Pro. I've since discovered that RC's are a less than optimal instrument for planetary imaging. 

Jupiter: 31 x 45s videos, av.95fps, exposure 5.9ms, gain 100%. Total frames stacked 27329 out of 130840.

Saturn: 4 x 120s videos, av.30fps, exposure 30ms, gain 100%. Total frames 920 stacked out of 14122. Saturn could have been better but I had to discard a load of bad quality videos because of cloud. 

Each video stacked, sharpened, derotated and further sharpened. Firecapture, PIPP, AS3, Winjupos.

One thing I struggled with during capture was getting a decent histogram, especially with Saturn. I could barely get it above 30% even with gain at 100%, so had to cope with 30ms and less than optimal fps. I guess probably because the 8" is smaller than my 10" dob, plus the large central obstruction on the RC.

 

 

Edited September 26, 2022 by Adam1234

[CraigT82]

Nice shots! Jupiter looks good with some nice sharp detail but the Saturn might be a touch out of focus? It’s tough to get focus when they’re low down in the murk. Might just be fuzziness due to the relatively long exposures.  Don’t worry too much about the histogram it can be really quite low and dim raw frame and still result in a nice bright final image after processing. Faster exposures are more important and that will also lead to faster frame rates.
 

 

[Adam1234]

5 hours ago, CraigT82 said:

Nice shots! Jupiter looks good with some nice sharp detail but the Saturn might be a touch out of focus? It’s tough to get focus when they’re low down in the murk. Might just be fuzziness due to the relatively long exposures.  Don’t worry too much about the histogram it can be really quite low and dim raw frame and still result in a nice bright final image after processing. Faster exposures are more important and that will also lead to faster frame rates.
 

 

Thanks! Yeah Saturn I definitely think was slightly out of focus, it was tough without an autofocuser (can anyone recommend an motorised focuser for Stella Lyra scopes?), I was going backward and forward manually for ages and just settled on what looked OK since I couldn't see much detail

[CraigT82]

I think the standard skywatcher motor focuser unit will probably go on there, might require a bit of bodging to get it to fit but will be worth it, motor focusing is great.