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Over the last year, I have started to take up the hobby of astrophotography. At the moment I have been focused on planetary astrophotography. Up until now I have been using a Celestron 5SE telescope (125mm aperture, 1250mm focal length) and a Sony Alpha 6000 DSLR camera I borrowed from a friend. Using this setup I have had some decent success with imaging Jupiter and Saturn (see below).

jupiter saturn

I think I am ready to take my photography to the next level with higher quality images. I believe my images are as they are because of the limited aperture of my telescope (though I could be wrong). I was wondering if the community had any advice for me in regards to my next steps. Should I buy a bigger telescope like a 8" or 10" SCT/Dobsonian for more light gathering power and higher magnification or should I instead invest in a better camera like the Sony A7R III camera with its full-frame 40MP sensor. Or is there another thing that I have not yet considered as a next step?

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    $\begingroup$ Have you tried stacking the images? Is this a single photo, or is this already stacked? Maybe this is a next step you haven't yet considered. $\endgroup$
    – User123
    Sep 17, 2021 at 5:46
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    $\begingroup$ Those images are already stacked. I've been using the camera's time lapse app to take 60ish pictures 1s apart. I then run the resulting video through PIPP to remove the extra dark space, then AutoStakkert to actually perform the stacking. $\endgroup$
    – Hals
    Sep 17, 2021 at 14:55
  • $\begingroup$ You could maybe continue with 100 or 1000 images. The quality would be somehow better. $\endgroup$
    – User123
    Sep 17, 2021 at 14:56

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Planets are very small objects. Getting a camera with a bigger sensor won't help you here. The 23MP of the Sony a6000 is already more than enough.

Make sure you're capturing them when they're at their highest point and when the seeing is at its best. I like to check meteoblue. When the "arc sec" value is low, below 1.0, then you should get great pictures. If it's above 1.5 then probably don't bother trying.
The lowest I've had was 0.60 and that night I was able to see details on Jupiter which I'd never been able to see before.

More aperture will get you better resolution, but first you might want to try a Barlow lens. A 5x Powermate will give a noticeable improvement. If that's too expensive then even a relatively cheap Orion Tri-mag 3x Barlow, for example, will help.

Another thing you can try is to get an astrocamera with a high framerate. With many astrocameras a reduced resolution (a mode known as "Region of interest") can help achieve a higher framerate. You'd be looking for something with USB3 here: the higher data rate is needed to record high framerate video.
The key with this is to try and capture those fractions of a second of clear seeing - the technique is known as "lucky imaging".

Also an atmospheric dispersion corrector can help reduce the fringes of colour on either side of the planets.

Finally ensure that your focusing is as good as it can be. An electronic focuser can help here, though they're not cheap.

Here are a couple of images I have lying around on this computer that I did two years ago. They're not great, being my first attempts at planetary imaging, but they're all that I have to hand:
Jupiter Saturn
These were taken through a 10" Dobsonian with an Altair 385C. Neither of those are the right tools for the job!
I recorded video, then used PIPP to extract the frames and centre and crop each one, then I used Registax's wavelet post-processing on Jupiter. It's over-processed. I was playing around to see if I could sharpen it up and I went too far.
With the Saturn image I just stacked it and didn't post-process. I was experimenting with different software at the time.

So to conclude, before getting a new telescope, try:

  • a Barlow or Powermate (if you get a new telescope in future you can continue to use this)
  • an astrocamera with high framerate and low resolution (if you do deep sky astrophotography in future you can use this as a guide camera)
  • optionally, an atmospheric dispersion corrector
  • possibly an electronic focuser
  • and finally work on your post-processing skills: I use PIPP to centre and crop, AutoStakkert to stack, and Registax's linked wavelets to sharpen.

I'm not an expert by any means. Have a look at Cloudy Nights planetary imaging forum for more information from actual experts.

Good luck!

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    $\begingroup$ Thanks for the great information. I have already been using a 2x barlow lens for my photography (one came with a lens kit I bought with my telescope) which is why I was considering a bigger telescope. I have never heard of an atmospheric dispersion corrector before, I'll look into it as those colour fringes would be nice to correct. I'll look at astrocameras too; I have had bad luck with "cheap digital eyepieces" in the past (not being able to find my target, not being able to achieve focus, colour balance issues etc) which is why I have been hesitant to buy expensive astrocameras. $\endgroup$
    – Hals
    Sep 17, 2021 at 18:23
  • $\begingroup$ @Hals my pleasure! I hope it proves useful. I was thinking: before buying an astrocamera, try recording video with your a6000: it can do 60fps, which should get you more useful frames than using the time-lapse function. The only issue would be that it won't record raw video, but if you use the digital zoom feature while recording video then it should produce better results than if you cropped the frames afterwards. Try that first, in combination with your 2x Barlow, on a night with good seeing, and your results will probably improve without having to buy anything new. $\endgroup$
    – Aaron F
    Sep 20, 2021 at 15:40
  • $\begingroup$ @Hals and another thing - if you increase the distance between the Barlow lens and the sensor then it'll increase the magnification (at the expense of distortion around the edges - but the planet will be centred so will be unaffected). If you have an extension tube then you can get some additional 'free' magnification without having to buy a higher-powered Barlow or Powermate. Oh, and once you've discovered what works for you, then maybe come back here and write an answer to your own question, with some new pictures attached! :-D $\endgroup$
    – Aaron F
    Sep 20, 2021 at 15:45

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