Switched to Sony...

jrista

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Dec 3, 2011
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jonrista.com
I have not tried taking any pictures through my telescope since I used slide film over 15 years ago. I imagine that the old Canon mount for the telescope might work with my current digital bodies, but I haven't tried. Light pollution around here is too great to photograph much of anything. Even back then, I don't think the clock mechanism was that accurate. I got some decent shots of Jupiter, but didn't try Saturn, though it was relatively close at the time and looked good through the telescope. An exposure long enough was too likely to be a blur, so not worth wasting film on. Also eyeballing the angle to Polaris with my equipment that is rather primitive by modern standards would have given even more of a tracking error.

So I would be interested to know what you come up with in method, equipment, subject matter, even though I'm not gung ho enough to travel to dark places and try my hand.
These days, you want a German equatorial tracking mount, or GEM. You can pick a lower end one up for around $1500...I started with an Orion Atlas myself, but I used my Canon 600mm f/4 L II lens which is relatively large. An Orion Sirius is cheaper, just under a grand, and could handle smaller scopes easily. You can start with camera lenses and a DSLR if you want.

If you use a short enough lens, such as a Samyang 135mm f/2 (an excellent lens for wide field AP), you could also use a tracker on a tripod, rather than a full GEM. I also use the Star Adventurer, which is a small GEM mount head that can be put on any standard photography tripod. It works great with DSLRs and smaller lenses. The 135mm is about as long as you can use on a tracker like this, and you need to get a better polar alignment (although that is not too difficult with something like the Star Adventurer). You can easily use shorter focal lengths, 85mm, 24mm, or 14mm (again, you can get all of these from Rokinon/Samyang and their corner star performance is, well, stellar! Better than just about any other camera lens, from Canon, Sigma, Zeiss, etc.) A 135mm focal length, though, can get you some great views.

Now, if you cannot get out to a dark site, then my recommendation is to try to get a monochrome camera and use narrow band filters. The image I shared above was done with a mono camera and three 3nm narrow band filters: Ha, OIII and SII. Narrow band filters block out the vast majority of light pollution, and pass only the key emissions from emission nebula. Narrow band is not all that great for galaxies, nor is it good for dark dust nebula, reflection nebula, or star clusters...but you can image a LOT of emission nebula that are in our galaxy.

There are two good mono options on the market now. The Panasonic M sensor and the Sony IMX183 sensor have been used in cooled, CMOS astro cameras from QHY and ZWO for a few years now. I jumped on this bandwagon when it first started in April 2016, and have been having a blast with both cameras. The IMX183 cameras cost a little under a grand, the Panasonic M cameras (slightly larger sensor) cost around $1200. You will need filters, but...you can just start with a single Ha filter and do monochrome imaging to start if you need to stay on a budget. (Eventually you will want to add at least an OIII filter and a filter wheel, along with some control software, to get the most out of the system.) You can pair either of these cameras with a Samyang 135mm lens...the ZWOs are a better option here as their backfocus is just 6.5mm, which makes it easier to fit both a filter wheel and an EF adapter in the mere 44mm from the lens mount to the sensor.

As a quick side note...I mentioned I use 3nm filters. With very wide angles like with the 135mm or wider (or even at 200mm), you are probably better off with wider bandpass narrow band filters. Something in the 6-8.5nm range, which are available (and also cheaper) will ensure that the whole sensor gets good, even illumination (there are specific reasons why this is necessary, but it is more technical and a discussion for those who get farther along in the hobby.)
 
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Berowne

... they sparkle still the right Promethean fire.
Jun 7, 2014
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Great AP, Jon! Thanks for showing.
Greetings Andy