Jupiter & Saturn - 1st attempt at planetary Feedback welcome!

[brettd (Brett)]

Hi All,

I upgraded my telescope in Jan (previously a non goto 6" newt), and have finally succeeded in a 'somewhat serious' attempt at planetary imaging.

These were taken in Melb near midnight on 16th July 2020.
I have no idea if the seeing was poor / average or excellent (just not enough experience)

I know I did some things wrong, but would love to know from those with more experience if I am on the right track, and how much more I should expect from my current equipment.

• Scope : 8" SCT (Celestron Edge HD)
• Mount : Celestron Evolution
• Camera: Celestron Neximage 5
• Barlow: Televue 2x Powermate (don't know if this helped or hindered???)
• Cap sw: iCap (came with the camera)

I just used the default settings (which I now know unfortunantly compressed the video) and made several 20sec captures (640x480 @ 6 FPS)

Subsequent reading suggests I should shoot longer videos (2-3 mins) to get more data, and use a non compressed codec.

I chose 2 videos within a few minutes of each other for each planet, and:

• Combined them in PIPP.
• Stacked with Autostakkert 2
• Sharpened with Registax6
• Combined the 2 images and tweaked in Gimp.

Was surprised how damn hard it was to locate the planets, keep them in the view and focus on them!!!

I'm actually pretty pleased with the results, but would love to know what improvement is realistic, and what other changes are recommended.

Brett

[xa-coupe (Jeff)]

I'm pretty impressed.
The advice I have received, and am trying, is the same as what you say (2-3 mins) but I was going for 10 minute videos. The ones I have processed certainly don't show any less detail than my monster videos. I haven't been out for a while to continue refining my technique.
I've spent a lot of time in Registax playing with the wavelets, it's been quite interesting and given my results a boost.

[foc (Ross)]

Great start! Saturn particularly nice. Jupiter focuses much more easily when GRS is in view. I also have a C8 on a EVO and so can relate to your experience. Seeing can be everything in determining the quality of the images, so hard to judge a single instance but I suspect there is considerable (blue) noise from processing a small number of frames and pushing for detail and brightness. If so the following may help. There are also tutorials online including for your camera.

Your frames per second sounds very low for a planetary camera, these are very different to DSLRs. Adjust exposure to try and get enough frames to have in the order of multi thousand frames in your AS!2 quality stack). Yes for Jupiter use either a 3 minute run with your histogram (if your capture software has one, I use firecapture and a (ZWO224mc) at 40-60% or 2 minutes is imaging its moons and perhaps using Winjupos. Use longer captures for Saturn say 5-6 minutes, its further away, captures not so affected by its rotation and not as bright so you will catch less frames.

[morls (Stephen)]

Nice pics!

[brettd (Brett)]

Thank you all for your input and comments (greatly appreciated)

Originally Posted by foc

... so hard to judge a single instance but I suspect there is considerable (blue) noise from processing a small number of frames and pushing for detail and brightness.

Your frames per second sounds very low for a planetary camera, these are very different to DSLRs. Adjust exposure to try and get enough frames to have in the order of multi thousand frames in your AS!2 quality stack

I think you are bang on there foc (Ross), regarding the noise and pushing to try and extract some detail. Very nice Jupiter image as well ... gives me something to aim for. (was that with a barlow?)

Regarding the FPS... Thanks for the pick-up ... I guess I just left it on the default slow setting from the high res mode (for locating) I just played around with it and I can choose up to 50FPS once the res is down to 640 x 480.

Any opinions on if the 2x powermate is worth leaving in with a neximage 5 (2.2 micron square pixel size) on an 8" sct?

Regards,

Brett

[LostInSp_ce]

As Ross says keep the exposures short. Take lots of them at the highest frame rate available and practice anticipating the focus sweet spot. The rest comes down to a little experience and a lot of luck. You've got a good scope for the job and combined with the 2 x Powermate it'll be perfect for nights of exceptional seeing as you will be able to image at f20+, but for nights of average seeing I wouldn't use it. You're definitely on the right track and with a little more practice together with the right conditions you should start to see some big improvements. Well done!

[etill (Elliot)]

A number of the guides on planetary imaging suggest shooting at a focal ratio of 5 to 7 times the pixel size depending on conditions. The Edge HD at f/10 is probably a good place to start.

With Jupiter at 30fps I think you can safely collect 4 to 5,000 frames without issues from rotation. At 50fps you could collect quite a bit more, but uncompressed (my camera is 1080 native res) that will be a very large file, I filled up my laptop first time around without noticing how much data was being collected.

[foc (Ross)]

I have been using a 2.5x powermate but once my camera is fitted the f ratio is smaller than 25. You can either use the barlow and get a nice resolution of detail with good image scale but (in most locations) to achieve this, have to fish frequently for occasional and sometimes small periods of good seeing, or to meet more typical seeing you can use a smaller image scale without a barlow at f10, or even adding a reducer below f10 and go for a wider angle shot of a tiny sized planet and its moons. Catching the planet with its moons make a nice pic in itself.

Another option is to use the barlow all the time but reduce the size of the final processed image when seeing is poorer.