Visual observing with a digital screen - Video Astronomy
Quote:
Originally Posted by mental4astro
Video Astronomy - is it for me?
A common city slicker problem:
I have a nice scope, one that I am happy with and a nice mount. I'd love to go bush, but for whatever reason I'm stuck at home (no car, work the next day, too far, don't want to drive, etc, etc). Light pollution kills everything I would chase down. I could do astrophotography, but I don't have the funds, or maybe the time, or maybe the patience for it. It's a clear night, AND I WANT TO SEE SOMETHING!
Then video astronomy could be for you.
Video Astronomy (VA) involves using a video camera to capture a live video feed through a telescope, and display the image on a computer screen or other monitor (such as a portable DVD player). No many hours of exposure times, no post-processing, minimal fuss with setting up, minimal learning curve, and an instant deep sky image. Even under light polluted skies.
VA is also a powerful outreach tool. With an ever dirtier light polluted sky in urban centres, those very objects that we crave to see are becoming just about impossible to see with much detail, and galaxies are all but invisible to novice eyes. Yet VA provides an electronic 'boost' to an outreach evening, where participants can both get a visual experience through a telescope, and a VA image can compliment that experience and help people understand the real problem that light pollution is. It is disturbing to hear that there are some cities in the world were no stars are visible at all due to light pollution.
This is just a little introduction to what Video Astronomy is and can offer following on from the recent 'sticky status' bestowed on this thread.
The idea of this thread is to now provide an Australian information source on VA, how it works, where to get gear, and how-to info.
Believe it or not, Australia is at the forefront of VA, with some of the most high profile practitioners of VA in the world being Aussies, and one astro retailer being a producer of Video Astronomy hardware AND software (the GSTAR range from myastroshop.com.au {G'day Steve! }).
VA is not overly expensive. It can be as simple as converting a webcam to a astro video camera (there is an article here in IIS on how to do this!), or splashing out on some quite sophisticated equipment to produce outstanding images of deep sky objects. And like all aspects of astronomy, VA also benefits from a dark sky situation, but can handle light polluted skies very well - I've seen the Horse Head nebula from my home in Sydney's east through a humble 8" SCT this way .
I am in no way a guru on the topic. Far from it. But I am a big fan of VA, and I can only share my limited experience and help out how I can and point out people and resources that best serve.
I hope that the VA community will find this IIS thread a comfortable place to share their knowledge and photos. It can only work with everyone's participation.
Mental.
I only do visual observing however I would like/LOVE to be able to see more detail and possibly more colour in nightsky objects, especially dso's. I like what can be seen with video astronomy.
What digital imaging device with a built-in screen can I attach to the telescope that will let me do visual observing and not have to have extra equipment (same as video astronomy but without seperate monitor/laptop and no real need to record).
I am considering a DLSR camera because it has a built-in screen.
With the DSLR:
Will I have a live image?
Will it have more detail than visual observing through the eyepiece?
Will the be colour?
Will the image be larger scale/size than what the eye sees through the eyepiece?
Will a Canon 350D be suitable?
Would a mobile phone be more suitable?
I realise that camera, or phone, will need an adapter to attach to the telescope.
I have a cg5 GoTo mount with Celestron 200mm sct, refractor 120mm & Saxon 150mm mak. I will be trialing these 3 scopes for which are most suitable for this "digital observing".
Thanks
Last edited by RB; 13-11-2015 at 07:34 AM.
Reason: Requested by Craig and Alex
First off if you haven't already connected the 350D to the telescope you will need an adapter that replaces the 350D Lens.
This adapter then slides into your focuser, however with the CCD chip embedded deep inside the camera body achieving focus may be difficult and a modification to the telescope may be warranted.
Secondly I believe the 350D does not have Live View, I thought the 450D was the first with Live View.
Assuming it does have Live View, only bright objects, Moon, Jupiter, Saturn and M42 will be possible in video mode. Anything dimmer will need longer exposure times (welcome to Astro-Photography) to build up a decent picture.
Detail and colour again is dependent on exposure time. Image Scale is dependent on the size of the CCD chip, but should be equivalent to the FOV of your lowest magnification eyepiece.
If you are interested in Video Astronomy, Stargazers Lounge have a dedicated forum for this, check it out may give you more information of what can be achieved.
Hi Craig, with live view you will only see the brightest stars. I don't think that you will find a stand alone viewer a web cam type camera will still need a screen ie a laptop.
To see colour or more detail you need to take a short exposure at high iso and with a fast f ratio scope.
Here is a pic of the orion nebula 15sec at iso 6400 (canon 1100d) 120mm f5 achro refractor.
Craig, I started off with a Pentax KD100 which didn't have Live View, however I did see the Moon and Jupiter with someone else's setup with Canon Live View.
He only used Live View for focusing before taking an image, but I was impressed with the Moon video, Jupiter was a bit small and you couldn't see much detail like you would with a high power eyepiece.
Remember at prime focus you are at the scopes lowest magnification, unless you connect the camera behind an eyepiece (which has its own set of issues).
As an alternative to trying to use a DSLR in LiveView, what about a low-cost high-sensitivity colour star-cam (like a ZWO MC or Orion StarShoot or similar) and a cheap 8" - 10" Windows tablet computer (which you can pick up for a couple of hundred dollars). You can set the camera for "moderately long" exposures of 10 - 30 seconds say, and get a refresh on screen for every frame. It's almost the same thing as true 'live" viewing, but will give you much greater sensitivity and ease of use than trying to use a DSLR for visual amplification. An 8" - 10" Windows tablet can give a pretty good image when you view the camera preview window in full-screen mode.
(Just make sure the camera is capable of long time exposures for DSOs, not just a short-exposure planetary video webcam camera.)
Thanks for pointing out why a dslr will be unsuitable. That is what I needed to know.
The video camera with tablet seems a good idea. Thanks Julian. Video astronomy is actually what got me thinking about live views with digital (or analogue) equipment. And using a tablet sounds great.
So it needs to be windows. Not that that's a problem.
So more thinking and I'll have to visit some video astronomy sites. Plenty of time - actually I still need to decide on which 2 telescopes to keep.
In the meantime I will probably try some mobile phone adapters. They are cheap enough for experimenting with.
So it needs to be windows. Not that that's a problem.
A Windows tablet will be easier than any other alternative that I can think of, because iPads and Android tablets etc generally won't interface with standard USB cameras.
I use a ZWO ASI120MC camera connected to an 8" Toshiba Encore tablet that I bought about a year or so ago (it was originally running Windows 8.1, but is now running Windows 10 very happily). My total outlay for the camera and tablet was about $550, but prices might have gone up a bit with the falling Aussie dollar.
I think if you truly want to do "video astronomy" you need to get a CCD video camera which integrates exposures up to about 2.56 sec like the G star ex or 10sec like the Samsung 4000. These are very sensitive cameras and gare the nearest thing your get to live view of deep sky objects. The g star is a mono camera and the Samsung colour . If you have the money Atik have recently released a video camera for the purpose you described. I'd imagine it would be very good. I spent several years using the G star and Samsung to capture photos and know they are capable of doing what you want. The ZWO cameras are excellent but are really solar system cameras and need much longer exposures to give similar results.
Regards philip
The ZWO cameras are excellent but are really solar system cameras and need much longer exposures to give similar results.
Regards philip
Not really 100% correct - they might be primarily intended as solar system cameras, but the ASI120MC for example can do exposures of up to 1,000 seconds, so can definitely do DSO work as well.
I think you misunderstood my line of thought , I was talking about near real time video observing of DSOs. A matter of a couple of seconds lapse between taking and observing a video stream.
Regards philip
I enjoy video astronomy, and find it a fantastic tool with outreach nights under light polluted skies. For outreach, I take two scopes, one for visual use, and another with the camera and a small portable DVD player as the monitor.
I started with the GSTAR EX CLR colour video camera from myastroshop. It is a dedicated astro video camera that is easy to use. Being colour, its resolution is not as good as a monochrome camera. But is you want an all in one colour camera, it is a good place to start. It has a built in UV/IR filter over the chip that cannot be removed. It comes with a 1.25" adapter.
I now use another camera, a 'cheapie' from aliexpress. It is more sensitive than the GSTAR, but because it is not a dedicated astro video camera, it is a more involved to do what we want. It also has more TV lines than the GSTAR, and shows a wider true field of view. This camera can be ordered either with or without a built in UV/IR filter. Using the camera under light polluted skies, you really do need a UV/IR filter, which can be a 1.25" one put into the 1.25" adapter. Like the GSTAR, it has the camera controls on the back of the unit. It is much less expensive than the GSTAR, but it IS more tricky to use to achieve the astro results we want. You will need to purchase a separate c-mount to 1.25" adapter, coax-video cables and power source (12V). All up it is comes in at about half the cost of the GSTAR.
If you want a camera that just works with minimal buggerizing to switch between planets/Moon & DSO's, I'd recommend the GSTAR.
If you don't mind the extra work that the 'cheapie' camera involves in order to get more grunt, you might enjoy using the cheapie. Make no mistake, it really is more involved as the instructions are poor, and you will need to do all the ground work to determine the appropriate settings - no free lunch here...
I've also used a ZWO colour CMOS camera, and found it similar to the GSTAR in terms of sensitivity, but probably better resolution, but not as sensitive as the 'cheapie'. In terms of ease of use, it is as easy to use as the GSTAR, with very similar imaging capabilites (software wise).
I checked on some video astronomy forums and found some good info. A USA store is selling a package that fits the bill.
Orange County Telescopes (USA) is selling a complete package for live viewing including small 7" flat monitor - the Revolution Imager. They have modified an existing video camera and packaged it with monitor, battery, cables & carry case. Aimed at beginners to video astronomy or those who are not sure how to put such a kit together.
Ken(BallaratDragons) was sent the Revolution Imager and has made a youtube video review of the it.
This similar to your idea, Julian: Camera + tablet. I want to not have a lot of cables. Equipment size is also imortant, small is good. The tablet or monitor can probably be mounted on the scope somehow.
The Revolution kit seems to fit what I want except the monitor could be higher resolution - although some screen shots look good of dso's. However for the price shipped to Oz I could maybe get better imaging quality buying piecemeal. Will have to research what I need.
I now use another camera, a 'cheapie' from aliexpress. It is more sensitive than the GSTAR, but because it is not a dedicated astro video camera, it is a more involved to do what we want. It also has more TV lines than the GSTAR, and shows a wider true field of view. This camera can be ordered either with or without a built in UV/IR filter. Using the camera under light polluted skies, you really do need a UV/IR filter, which can be a 1.25" one put into the 1.25" adapter. Like the GSTAR, it has the camera controls on the back of the unit. It is much less expensive than the GSTAR, but it IS more tricky to use to achieve the astro results we want. You will need to purchase a separate c-mount to 1.25" adapter, coax-video cables and power source (12V). All up it is comes in at about half the cost of the GSTAR.
Could you supply some details of the camera you bought on aliexpress
Regards philip
On cloudy nights forum there are some threads on the same camera. They mention PAL version is better for astro than NTSC.
So with the camera + power & power cable + camera to monitor cable + 7" lcd monitor + nosepiece + focal reducer, I will be able to do live viewing in 8“ sct?
I don't need to mod the camera?
Alex, what is the "extra work" to get an image with this cheapie camera than with Gstar or similar?
ooooo that Revolution Imager kit is looking very interesting. The setup guide video they even used a telescope I have . Just need a tracking mount. The Advanced VX mount in the video looked pretty good too!