First Step in Planetary Imaging

[Maru (Alessandro)]

Hi everybody,

I've been doing visual astronomy for a bit more than 2 years now and I would like to take my first step into astro-photography. I have a 12" collapsible Dobson and I wanted to start with planetary imaging. What woulod it be the best camera to start? Sorry if this question has already been posted and thanks for your help!!

Cheers
Alessandro

[sil (Steve)]

Not sure about Dobs, but you can start with what you have and shoot through the eyepiece.Or a smartphone mount that holds onto your eyepiece making mobile photography much easier. Then there are the T converters etc that let you attach your camera to the focuser just like an eyepiece. But you may get flexing from the weight that throws off the image and you may find your focuser doesnt have enough travel "inwards" I think to achieve focus with your camera. If outwards travel is limiting focus you can get extension rings. These are all for taking a nice single "photo" when you click.

Beyond this you are looking at recording video, striping out the still frames and aligning and stacking and processing these into a single final photo. I'd suggest a zwo asi camera, maybe the 120mm (mono, uncooled). If its not a goto dob you can say line up with the planet at the edge of screen, start recording video and letting the planet drift across the frame. If you can track then you should be fine for a couple of minutes capture. but not much more, remember the planets or not only moving but spinning too so you only can really use data from a couple of minutes window to keep surface detail.

From there there's no limit but the zwo are versatile cameras, just pop in like an eyepiece attach via usb to a computer (laptop usually), firecapture or sharpcap are free capture apps for astro imagers and a great starting point. What you are looking for here is fast frame rates not pixels. Colour would be good for planetary but mono might be best considering all the limitations of dob imaging. I'm sure someone else with donsonian imaging will give you bit more accurate advice.

Perhaps if you can start with what dob you have, tracking features if any. Its not ideal but also far from impossible and plenty here have used dobs successfully for imaging. I dont know if faint fuzzies can be captured well or not.

[LostInSp_ce]

Maru, Dob's aren't really designed for imaging so I wouldn't recommend them anyone who wants to image. However since you already own one then I suggest getting a colour planetary camera as they will be much easier to work with. If you're looking for more control over colour and detail then getting a mono with filters will better (most of the time I can't tell the difference). As for brand there are plenty of choices but QHY and ZWO seem to be the favourites. To reiterate what Sil has already suggested the ZWO ASI120 is quite popular. I've been playing around with one lately and although it's not considered the best, it sure is good enough.

Planetary imaging with the Dob may not be the easiest or the best way to go about it, but it can yield interesting results and will save you from having to buy another scope.

[sil (Steve)]

Originally Posted by LostInSp_ce

Planetary imaging with the Dob may not be the easiest or the best way to go about it, but it can yield interesting results and will save you from having to buy another scope.

Or encourage you to buy more scopes I should have mentioned the asi120 is probably the best cheap imaging cam out there, but its not a piece of garbage and will get stunning results. Its strong for lunar/solar/planetary but imagine isnt like using a regular camera and pressing a button *click* you have a photo. This world is about capturing hundred/thousands of photos in the form of video frames and stacking /processing them to eventually have a single photo to show for it. Tools like PIPP can process a video and recenter the planet (align/register it) in each frame making it easier if you dont have a tracking mount. The centered frames you can give to registax or autostakkert to process easier. AS!2 does its own wavelets/sharpening and registax gives you wavelets controls to reveal features. Your video will probably start with the planet as a bright blob swimming in water but you can get amazingly detailed images after the processing step from it.

ZWO are pretty strong in astroimagers and the 120 (colour or mono) are their entry level cams and as I said, they are very good. I dont see any point looking at orion/celestron offerings, ultimately it seems most brands are using the same sensors and sometimes you get stuck with dodgy custom drivers/capture software. the zwo cams just work and typically perform better then competitors using the same sensor. I'd recommend mono for you though, the colour would be nice but you only have three practical colour targets to image anyway (Mars/Jup/Saturn) (dob imagers please correct me if i'm wrong here, I dont know how well a dob can image neptune), everything else is probably going to require tracking and longer exposure times which may not be possible with your dob). So probably best going for mono for best quality imaging, will be awesome for lunar and maybe solar if you have a filter. Plus if you get put off by the process you haven't lost much and a 120 should be an easy second hand sell.

ZWO have a range of offerings too if you want to go up the tree with imaging. Including manual filter wheels and models with /without cooling. The zwo cams make good guide cameras too so again if you upgrade a 120 its going to be useful for guiding for someone. Damn it, i'm convincing myself my 120mc was a mistake, should have been the 120mm oh well next buy I've got picked out is a zwo mono with cooling.


All the software I've mentioned btw is free. The zwo drivers are stable and from what I've seen all zwo cams can be used for planetary (fast fps) and at least brighter deep sky (longer exposure times per frame). I prefer FireCapture (its not firewire only capture, its usb too), seems to support most/all astroimager brands and I like its features. Either way you'll bee spending time fiddling with settings. Getting a good exposure on screen I find a waste of time with planetary as stacking and wavelets tends to bring up the exposure without overexposing. So I drop exposure a few ms to gain a little fps, likewise I capture at a cropped resolution often somewhere near 640x480 or under instead of the full resolution of the cam just to gain fps. The more fps the more subs you end up with so ultimately the more (hopefully) good subs will be there to work with.

[Maru (Alessandro)]

Thanks guys!! I'll let you know what I end up buying and I might bother you again with my questions...
Cheers!

[Camelopardalis (Dunk)]

Echoing the above, it's easier if you have a tracking mount.

But I'd spend the extra few $s on the ASI224 instead - it's substantially more sensitive than the 120 and combined with lower noise can give better results.