Video astronomy kit

[Ben Ritchie]

Prompted by this thread

http://stargazerslounge.com/observing-discussion/153007-imaging-bad-your-health-2.html#post1925319

i've been thinking about video astronomy, but despite browsing Bernard's ModernAstronomy pages i'm still not clear about what I need or what the equipment can do.

As mentioned in the link, my goal is very much simplicity - I want something that can plug in, focus and be up and running in a couple of minutes, with no guiding, processing or anything else, and view on a basic netbook (single-core Atom 1.6GHz, XP). Budget would be around a couple of hundred quid, so that appears to be something like the Mintron 12V6HC-EX. The Watec sounds nice, but is too expensive.

So, I guess questions are:

- is video astronomy as simple as it seems? Really plug in, focus, and go?

- how suitable is my 5" f/8? the focal length is relatively long, and with quite small CCDs I guess the FOV is quite small? So do I need to budget for a focal reducer too?

- what's image quality and sensitivity like for these things? Do they automatically 'stack and add' for S/N, if so, how does this cope with unguided tracking - i.e. does the image start to smear if the tracking is poor?

- in that note, 2.5s integrations with the Mintron 12V6HC-EX seem pretty short, the 22S85HC-EX can do 5s (still short?) but lacks other features and is more expensive. So these don't seem that exciting? With the EQ6 i'd expect to do 10s unguided with no trouble, or longer if I guided via a SPC900 on the piggybacked achromat.

- do I need anything else? I expect a reducer of some sort, but filters etc.? adapters?

- what's used availability like? I can't remember seeing many on UKAB&S and the like, but I don't know if this is because it's very much a niche or if happy users don't part with their kit...

So the general idea looks quite interesting to me, but I wonder if it would be any cheaper or more capable than picking up a sensitive cheap monochrome CCD (e.g. DSI II mono, Atik 16-ic etc.) and just running that with 15s integrations in preview mode?

Any feedback very welcome. I've thought about getting this kit several times in the past, and almost always stall on these questions.

[Psychobilly]

Hi Ben,

Take a look at this Earlier thread "Disappointed with DSO views...."

http://stargazerslounge.com/astro-lounge/147700-disappointed-dso-views-i-have-answer.html

Thats the one that sparked my interest.

The first cam I bought was a Samnsung SCB-2000 (£90-100) it 1/3" format Colour (and B&W) camera that can integrate up to 512 video frames (at 50fps) . To connect it to a scope you would need an C - 1.25" adaptor (around £10) and your basically off to go (might need an extension if your using a frac with the diagonal removed and cant reach focus)

The camera outputs composite video so can be plugged into most TV's and some monitors directly .. to get the video into a "computer" the chances are you will need a USB video grabber dongle - I bought one in Maplins for about £30 which I am using with Sharpcap rather than the software that came with it...

I bought an rechargeable battery powered 7" LCD TV Monitor which has video in - again form Maplin for £99.

I have modded my "2000" - I have removed the internal IR filter so that I can do IR pass work with the camera and also added a remote keypad so I don't have to touch the camera to change its settings when its on the scope.

The IR filters in these cameras , unlike those in DSLR's already allow through the "crucial" astro wavelengths as they are meant to be used with NIR floodlights for improved nighttime use.

The more expensive SCB-4000 has automatic switching of filters for day (colour) and Night (B&W) use - you can override the camera auto colour/B&W selection to take Colour images in low light. Its day filter has a lower IR cut-off so that camera benefits from filter removal.

There are a number of videos on Youtube showing whats achievable.

Peter...

[West End Wendy]

is video astronomy as simple as it seems? Really plug in, focus, and go?

In theory yes - I'm only interested in live viewing not capturing frames, so I dispensed with the computer and got an LCD screen. If you want to capture you'll need a USB device and a computer but it's no big deal. You'll also need a nosepiece (from Bern again), and the Samsungs need their infra-red filter removed (a little fiddly but not difficult)

- how suitable is my 5" f/8? the focal length is relatively long, and with quite small CCDs I guess the FOV is quite small? So do I need to budget for a focal reducer too?

I mainly use a 4" f9 refractor with one of Bern's focal reducers (about £25 I think). I find with the half inch chip that's just about perfect for most DSOs (globulars, galaxies, smaller nebulas). The larger DSOs (Andromeda, The Veil , North American Nebula) behefit from a shorter tube.

- what's image quality and sensitivity like for these things?

They get grainy at high gains and resolution is low, but that's why they're so sensitive (larger pixels). I see noise as the acceptable price you pay for the instant hit of live viewing. On brighter DSOs (M51, M13) the noise can be kept pretty low.

The Samsungs suffer from amp glow. The Watec doesn't.

Do they automatically 'stack and add' for S/N, if so, how does this cope with unguided tracking - i.e. does the image start to smear if the tracking is poor?

The Samsungs do a stacking-type noise reduction, but my experience is that you need guiding to avoid smearing and artefacting. The noise reduction should work superbly with guiding, but I prefer to keep my setup simple so I don't use the noise reduction.

- in that note, 2.5s integrations with the Mintron 12V6HC-EX seem pretty short, the 22S85HC-EX can do 5s (still short?) but lacks other features and is more expensive. So these don't seem that exciting? With the EQ6 i'd expect to do 10s unguided with no trouble, or longer if I guided via a SPC900 on the piggybacked achromat.

I think you need a camera that does 10 secs integration, but the Samsung SCB2000 does this and is a brilliant introduction to video astronomy at a very low price (check on ebay). 10 secs is no problem for an unguided mount. Sometimes I don't even bother to accurately polar align (if I'm feeling lazy).

- do I need anything else? I expect a reducer of some sort, but filters etc.? adapters?

Yes, a reducer, a nosepiece (the longer the nosepiece the greater the focal recuction - check with Bern). You may also need an extender to reach focus, but the old cheapo Barlow with element removed trick is fine for that. An infra-red filter shouldn't be necessary if you have a reflector but some sort of light pollution filter can help alot (I use a Baader neodymium). I've also had good results with th Astronomik UHC-E. Bear in mind I live in light polluted London.

- what's used availability like? I can't remember seeing many on UKAB&S and the like, but I don't know if this is because it's very much a niche or if happy users don't part with their kit...

A bit of both I think - but the beauty of the Samsungs is that they're mass-produced security cameras, not specialist astronomy gear, so often come up on ebay

Hope that helps,

Tim

[Ben Ritchie]

Terrific, thanks guys, that's very useful. I'd only want to view too, not capture/process in any way, but it's probably cheaper to view via a USB frame grabber than buy a dedicated LCD TV. Although the 'scope is observatory-mounted, i'd really prefer to avoid guiding etc. so I think 10s integrations unguided would be ideal.

The Samsung does look interesting, does Bern do them? Or if he just does the Minitron/Watec, any recommendations for where to get a Samsung? After reading about the Watec it looks a really nice option, but a big stretch for the available budget at the moment and i'm running out of things to sell. I might be able to make it, but does it offer significant advantages over the Samsung?

I have a piggybacked 80mm SD achromat that could be used for the widest-field objects, so swapping between 'scopes shouldn't be a problem.

[PeterW]

You will need good tracking and as short a focal ratio as you can get. 8" sct or the newer short newtonians seem to be commonly used. Focal reduce, focal reduce, focal reduce! Good polar alignment or autoguiding is needed to avoid smearing as mentioned. Maurice Gavin has shown what a starlight lodestar,*WPO - Meade LX200+ETX-70+SX Lodestar-C

straight onto your computer, any exposure you like. The video cameras have auto accumulation and noise reduction, but limit the total exposure time you can take. Meade dsi2 and dsi3 using the envisage software appears to offer the auto averaging. there appears to be a gap in the software Market allowing acquisition of images and video, auto aligning and simple processing, allowing as "live" a view as you want.

I am going to recommend one of the samsungs to a colleague as a cheap way to imaging.

We are in-between imaging and pure visual, but there is plenty of opportunity for heated disagreement as to whether short ccd exposures or stacked video gives the most "live" experience.

Grab images, show your friends and get more people out there and able to see things they'd be unable to see visually.*

All the best

PEterW

[Ben Ritchie]

We are in-between imaging and pure visual

Yeah, and it seems that it offers many of the advantages of imaging with little of the faffing around - as an ex-imager turned observer I love the simplicity of visual, but there are certainly things the eye can't readily do under semi-suburban UK sky.

[West End Wendy]

The Watec will actually do unlimited integration times (obviously dependent on tracking accuracy), but above 10 secs it is simply a single exposure, not a constantly updated live image. As Peter points out above, the line between "live-viewing" and "looking at a picture" is ambiguous.

I did a comparison of the Watec with the Samsung here:-

http://stargazerslounge.com/showthread.php?p=1899442

Tim

[West End Wendy]

there appears to be a gap in the software Market allowing acquisition of images and video, auto aligning and simple processing, allowing as "live" a view as you want.

Try this:

http://www.coaa.co.uk/astrovideo.htm

Works really well, but I felt I was getting dangerously close to imaging. 

[Ben Ritchie]

I did a comparison of the Watec with the Samsung here:-

Samsung 2000P v Watec - Stargazers Lounge

Tim

Thanks, Tim - that comparison is really helpful too.

[Ben Ritchie]

Thinking about requirements, what i'd be most interested in are the fainter objects off the beaten track of Messier objects, all the Messiers are in fairly easy reach of the 14" Dob from my back garden and I can star-hop well enough to quickly find the majority of them. As I head towards the fainter NGCs then my semi-suburban conditions become more problematic, and I think this is where video could really make a difference.

So I think the Minitrons have shorter exposures that would really be ideal for this?

[PeterW]

.... There is software like that you pointed out that will do auto stacking on video images, but it it also did the same for single frames acquired automaticlly from a low end ccd camera then we'd properly be in business. Deepskystacker live will auto accumulate images saved in one folder, I have yet to give it a try, but I would like it all in one simple package..... Keep acquiring and stacking till I have a good enough image, tweak with simple controls, save and move on to the next one. I have the kit, but as I can't easily polar align I have yet to get auto guiding working in order for me to start going with my lodestar/dsi3 combo.

Cheers

Peterw

[Electron]

Hi All,

I also have been thinking about an video "live" view option, so thanks for starting this thread Ben.

I am considering either the Samsung SCB-4000P from Buythis - Electronics, CCTV and Security Products or the Mintron 72S85HP-EX from Modern Astronomy.

About the same price but for me the issue would be the availability of the remote control, as I would use it with hyperstar.

I noticed that Psychobilly has added a keypad to his camera, so would like to know if this home made addition or are they available as an accessory ?

The mintron remote mod has been done on older cameras but I expect that it would be the same for any of the "four keys" control type keypads.

This mod can be seen at Homepage DD1US under "astro downloads"

Another source of info is x-bit-astro-imaging: Developing a real-time deep-sky colour frame-integrating Mintron video camera

Sorry if this info is already well known.

Cheers,

Denis

[Psychobilly]

The Keypads are home made.. the 4000 is a lot easier to mod than the 2000 as the 4000 conenctions are made to the pins on a "joyswitch" module where as with the 2000 its to tiny surface mount pads on surface mount switches...

The Switches I use are from Rapid...

http://www.rapidonline.com/Electronic-Components/Low-profile-push-switches-30972

as is the case...

http://www.rapidonline.com/Tools-Equipment/CASE-ABS-66-X-66-X-28-GREY-30-3800

Peter....

[Ben Ritchie]

Hi Denis, there's more discussion on the Video Astronomy social group here too, where Peter et al. have been helping me understand just what I need.

I am considering either the Samsung SCB-4000P from Buythis - Electronics, CCTV and Security Products or the Mintron 72S85HP-EX from Modern Astronomy.

About the same price but for me the issue would be the availability of the remote control, as I would use it with hyperstar.

Would be interested to know your thoughts on the two, as i'm still slightly torn between the Samsung and Minitron options. Think i'm heading for the Samsung as the longer exposures seem good, but not totally decided yet.

[Electron]

Hi Ben,

First thanks to Peter for the "remote" info, they look ideal.

I was originally 99% going to go for the mintron, mainly because of the info/examples on Steve Wainwright's blog spot

(link in earlier post), and because it already has the IR filter removed, has documented a remote mod.

It seemed the only option for price/colour camera. Then I read about the Samsungs here, and on cloudy nights

and on QCUIAG WEBSITE about the Samsung SDC-435.

I also think that the info for Samsung is more readily available than for the Mintron.

I asked Bernard about specs for the 72S85HP-EX and either he hasn't got them or missed that part of my email.

Anyway at least you can get the manuals for Samsung very easily and I think removing the IR filter will not be a big issue.

After Peter's post about the remote I feel more that the Samsung is the one to go for.

I have already knocked up a very crude adapter to mount a "C" mount camera or webcam onto the hyperstar

(canon rear lens cap) just to check I could actually get it to focus.

So I think that the "C" mount to Canon EOS will do the job ok, or with slight modding to it's length,

as I also want to use the camera for low light wildlife also, mainly local Owls.

I guess really there is not much to choose between them apart from price so I think I'll be going for the Samsung,

at about £50 less, which will pay for the EOS lens adapter.

[Ben Ritchie]

Well i've just ordered a SDC-2000P, thanks all for the comments.

[Psychobilly]

For nature use .. on the 2000 remove the Internal filter, and use IR lighting... the 4000 is a "True Day/Night" camera with a moveable filter in night mode the filter swaps over and allows more IR into the camera but gives a B&W image...

[Electron]

Well I finally decided and bought the Mintron (72S85) at the last minute !

A Talk with Bernard, at MA, and the deed was done.

I suppose in the end it is the one I first wanted and is a lot smaller than the Samsung.

Now just the wait, having it delivered to relatives in UK and so coming over in 9 days, and counting, to get it... Ooops visit them of course.

[FishInPercolator]

^{How is this compared to the Mallincam?}

[Paul81]

.... There is software like that you pointed out that will do auto stacking on video images, but it it also did the same for single frames acquired automaticlly from a low end ccd camera then we'd properly be in business. Deepskystacker live will auto accumulate images saved in one folder, I have yet to give it a try, but I would like it all in one simple package..... Keep acquiring and stacking till I have a good enough image, tweak with simple controls, save and move on to the next one. I have the kit, but as I can't easily polar align I have yet to get auto guiding working in order for me to start going with my lodestar/dsi3 combo.

Cheers

Peterw

Funny you mention this but I am currently working on an application to do pretty much what you describe. I am primarily a visual observer, but as others have stated, sometimes you just want to go deeper or the fainter NGC objects etc are just out of reach, thus video style astronomy seems ideal - keeps things fairly simple and instant but dips the toes into the imaging side of things.

Work so far is early days, but I am basing the app around the SX Lodestar (its pretty cheap, sensitive and is simply powered by a computer). I figure using a computer (laptop) for live view is no more hassle than a portable monitor (well I guess I am a software engineer by profession so I would say that). The concept is pretty much what you describe, you can set the exposure time (the idea is between 10-120 secs say - the limit will depend on the camera, conditions and your mount), and it keeps a live stack on display, and the image should (hopefully) get better the longer you keep watching. I am adding dark frame calibration, a focus assist option, and some simple controls to tweak the output. It will also save the raw files (if desired) so if you wish you can stack via a more sophisticated offline means and play with the images (like the long exposure folks).

The idea is to keep it simple, I like the simplicity of visual observing, and to some extent do not want to lose that connection with the sky you gain from visual observing but at the same time would like to enhance my view sometimes.

My ambition is to get a first cut done by the end of the summer when observing time gets more realistic. If this is something that attracts genuine interest I can put it online when it is at a suitable point. As always the main delays are the weather (lack of test data) and work schedule!

[DoctorD]

Hi Paul

I've been looking at the BS Mammut camera for this same purpose - I'd like a little more control than my SDC435 video camera but am primarily interested in electronically assisted viewing.

Keep us posted - perhaps start a new thread in the Video Astronomy section (it's under science for some reason)

Clear skies

Paul

[Ben Ritchie]

Wow, as this is an old thread of mine that's come back from the dead, I thought i'd add

is video astronomy as simple as it seems? Really plug in, focus, and go?

Yes!

Almost two years on and one of my best astronomy purchases IMO. These days I quite often start an evening visual, and then swap to video for some of the fainter targets that are out of reach of the eyeball in my skies. I have a 17" monitor on a swivel arm on the wall of my observatory, and just plug in the camera and go

The Watec sounds nice, but is too expensive.

Well I ended up with a Watec in the end. It is nice

[Ben Ritchie]

The concept is pretty much what you describe, you can set the exposure time (the idea is between 10-120 secs say - the limit will depend on the camera, conditions and your mount), and it keeps a live stack on display, and the image should (hopefully) get better the longer you keep watching. I am adding dark frame calibration, a focus assist option, and some simple controls to tweak the output.

The idea is to keep it simple, I like the simplicity of visual observing, and to some extent do not want to lose that connection with the sky you gain from visual observing but at the same time would like to enhance my view sometimes.

My ambition is to get a first cut done by the end of the summer when observing time gets more realistic. If this is something that attracts genuine interest I can put it online when it is at a suitable point. As always the main delays are the weather (lack of test data) and work schedule!

I would certainly be interested! It sounds like just the sort of thing I enjoy, with the benefits of imaging but with simplicity and immediacy

[Paul81]

I will have to look into the BS Mammut. I wonder what the OSX / Linux support is like (my laptop is Mac). SX publish their USB protocol spec, so I can easily write code for their cameras, this was one of the main factors in favour of the SX Lodestar.

When I have something more to show I will start a thread in Video Astronomy / Software discussion. I have mainly been playing around with some of the algorithmic concepts in the limited time so far. My next job is to buy the camera, and then write the USB control code for OSX (I am using popular open source user space USB and user interface libraries, so should be easily portable to WIndows / Linux). That should keep me occupied for a while! I'll be happy to post the program online when it is a suitable point to share!

I think the main hurdle will be the next purchase... The eagle eye'd might have noticed I have a dob, so I have been looking at EQ mounts for this endeavour.. Got to 'sneek' that purchase pass the boss.. Maybe a pair of shoes or a nice bunch of flowers..??