GStar EX/2

Grimmeister (Anthony) · #1 06-12-2011, 04:27 PM

Hi All,

I am looking to purchase the GStar EX/2 camera as I often perform open nights in Brisbane for our Astronomy club up on Mt Cootha and from what I have read this camera would make an ideal public display tool.

However before I take the plunge into purchasing one I would like to see one in action to better understand how it works/how well it works. (I normally understand technology quite quickly and easily but the way this product works/is explained has me baffled).

The camera details are here: http://astroshop.com.au/guides/gstar/gstar-ex2.htm and what I would like to ask is if there is anyone in the Brisbane area that has one I could borrow for a few days to see it in action.

If any one can comment on their performance or better yet lend me one/show me one in action I would be most grateful.

If you can? please PM me for my full contact details.

Many Thanks

Anthony

Poita (Peter) · #2 06-12-2011, 04:40 PM

See if you can get to see a mallincam extreme as well.

Grimmeister (Anthony) · #3 06-12-2011, 04:46 PM

Thanks Poita, will check it out.

Poita (Peter) · #4 06-12-2011, 04:48 PM

This review might be helpful to explain how these style of cameras work.
http://www.cloudynights.com/item.php?item_id=2590

graham.hobart (Graham stevens) · #5 06-12-2011, 07:58 PM

gday!, I have the mono version and it was recently quite a hit at our local astro open day -it does tend to get saturated quite easily because it is so sensitive so filters help. It's basically a CCTV camera which accumulates frames in camera then delivers the accumulated frame. It is excellent for visual and show and tell though I haven't been that succesful with imaging with it though I haven't really pushed it really hard as I am more into DSLR imaging. If you can't find one nearby I can lend you mine for the cost of postage as I hardly use it.
You need a video converter to take the signal into your laptop, or use an old TV type screen with the video outputs.
I have heard of people using it for a finder scope. It is great fun and the software bundled with it /available on the web site is easy to use.
I showed some friends 47 Tuc with it on a cloudy night and it was open mouthed wonder!
You can adjust the frame accumulation rate from I seem to call zero to 128 and there are adjustments for zoom focus and electronic shutter.
Hope this helps
Graz

Poita (Peter) · #6 08-12-2011, 06:00 PM

To me most of the interest is seeing colour, so I'd be less inclined to go with b&w.

You can also use one of those portable/car DVD player things, they often have a screen with video input as the display.

tonybarry (Tony) · #7 08-12-2011, 07:09 PM

I have a GStar-EX which has been my mainstay camera for over two years now. I use it for occultation work, and also at the local University Observatory on their open nights, where the club has a standing invite to help out with extra telescopes for the eager masses to view with.

I have used it with a Meade LX90-8" SCT on a Knight Owl 0.5 focal reducer. FOV is around 20 arc minutes.

The GStar-EX is greyscale, and very sensitive. For showing a number of people something in the field-of-view as the scope slews, it cannot be beat.

M83 (Souther Pinwheel Galaxy) can be seen in realtime, the spiral arms and the curious lumpy central region are quite see-able on the screen (whether laptop or TV monitor).

M104 (Sombrero Galaxy) is also visible in realtime, with the dust lane down the centre being quite easily seen.

M8 is quite spectacular and easily seen. M42 is awesome, and in fact requires some reduction in the settings because it is so bright.

I have also used a Watec 120N+ borrowed from Dave Gault, and it performs similarly to the GStar, although it is able to integrate to 256x instead of 128x as is the GStar-EX.

The new GStar-EX2 can apparently go to 256x as well, so this makes it a moot point as to which is better (GStar or Watec).

The Watec's handbox is a compelling advantage for an observer at the telescope; the GStar's serial control is a compelling advantage for an observer who wants remote control and titling ability.

The Mallincam is a colour camera and has both a stellar price and a stellar reputation. Since I don't have one and have not seen one in use, I can't say much more than this.

But in general, the viewing public are quite tolerant of greyscale as long as they can see structure. Fuzzy blobs do not excite them much at all. Your best bet is a camera which is easy to set up and does not require a computer to operate - and the GStar, Watec, and Mallincam all fit the bill.

Hope this helps,
Regards,
Tony Barry

dannat (Daniel) · #8 08-12-2011, 08:27 PM

In regards to seeing stuff in color, I don't know you'll see a great deal, I've seen a colour gstar produce next to no colour on orion neb, the malincam might show more colour, though you don't see much colour at the eyepiece, it takes exposures of 5 mins to show good colour, these cameras are still using short enposures.
Hopefully ken will chime in, he's the video astro moderator on CN

tonybarry (Tony) · #9 08-12-2011, 08:46 PM

Colour video cameras require Big Glass (12" or better) to produce useful results on dim objects. Mallincams will integrate to around 56 seconds (i.e. your scope must track the object passably well for a minute or the integration will smear). This is not really real-time, but the Mallincam people seem to think it is OK.

Regards,
Tony Barry

Grimmeister (Anthony) · #10 08-12-2011, 09:30 PM

Hi All,

Thanks soo much for the feedback on this/these tytpes of cameras, I think I get it a bit better now in that the cameras do onboard stacking of an image then output the video stream to the PC allowing for fainter objects to be viewed in great detail, and I think bhy the responses of those that own one, the advertising is not just hype but a real representation of the cameras ability

For me a B&W model would be fine as I think it more important in public viewing nights for people to see structure rather than colour and as mentioned colour is really a long exposure item.

A special thanks to Graham for the offer to lend me his, still waiting to see if there is a local Brisbane person that may be able to loan/demonstrate theirs for me.

Also thanks to Tony for his input and the range of items he has seen with the camera, Tony sounds like he uses his for the same sort of purpose as I would be looking to.

Now all we need is some clear skys to see one in action

Cheers

Anthony

keni (Ken) · #11 08-12-2011, 09:36 PM

Hi Anthony,
I'm sure Astrojunk (Jonathon) uses one as well.
He's a local lad heavily involved in the AAQ.
It might pay to PM him about it in case he misses this post.

Ken.

Grimmeister (Anthony) · #12 08-12-2011, 09:39 PM

Thanks Ken I will do just that

Cheers

AstroJunk (Jonathan) · #13 08-12-2011, 10:13 PM

Thanks for the nudge!

Firstly, to not see colour in Orion with a Gstar colour is either a duff camera, a duff cable, a duff user or a b/w monitor!!!

As usual in astronomy, there is no correct answer. A high sensitivity B/W camera is a must in everyones kit bag as they are just a whole heap of fun. The Gstar range are the most flexible is terms of settings, but the watec 120 N+ is most user friendly. My personnal experience says the the public do like to see a bit of colour in planetary views though, so the answer is get one of each!

Colour Malincams are superb BTW - they are modified Mintron (like the gstar) cameras with some wizard electronics for taking long expsures. The best part though is the thermoeletric cooling which makes a massive difference during the warmer months.

ballaratdragons (Ken) · #14 08-12-2011, 10:55 PM

Quote:

Originally Posted by dannat

In regards to seeing stuff in color, I don't know you'll see a great deal, I've seen a colour gstar produce next to no colour on orion neb, the malincam might show more colour, though you don't see much colour at the eyepiece, it takes exposures of 5 mins to show good colour, these cameras are still using short enposures.
Hopefully ken will chime in, he's the video astro moderator on CN

Thanks Daniel,

The Gstar-Ex Colour camera does show colour and quite nicely. Obviously it isn't as spectacular as a $1200 Mallincam but that is the same with any Astro gear.
If you want top results, you have to pay more.
And yes, the Mallincam shows lots more colour. I am currently using the Mallincam Xtreme and I am still blown away by the lovely colours it shows on objects.
Trifid is beautiful pink and blue, Lagoon a nice red/pink, NGC 253 Galaxy had a fantastic yellow core with light blue arms, etc etc.

The Mallincam Xtreme takes far more than 5 min integrations. It goes up to 99 hours! Not that anyone will ever go that far

Quote:

Originally Posted by tonybarry

Colour video cameras require Big Glass (12" or better) to produce useful results on dim objects.

Absolutely wrong.
A popular myth.

I do some of my best AstroVideo and Astrocasting (internet Astro broadcasting) through an ED80 and often blow away the guys using big SCT's and Reflectors.
Many others also use ED80's, WO 110's, 4" reflectors, and many other small scopes.
It comes more down to focal length with Video, not so much aperture.

Quote:

Originally Posted by tonybarry

Mallincams will integrate to around 56 seconds (i.e. your scope must track the object passably well for a minute or the integration will smear). This is not really real-time, but the Mallincam people seem to think it is OK.

Regards,
Tony Barry

Again, Mallincams integrate up to 99 hours.

Gstar-Ex, Mintrons, Watec's etc around 5 seconds. Some only do 2.5 seconds.
NO AstroVideo camera gives exact real-time video. It is always the amount if integration behind.
The so called 'Mallincam People'

and others know this, and explain it during 'live' broadcasts so more people aren't misled.

I set my Xtreme usually around the 4 to 7 second mark because of my dark sky. That shows most DSO's.

But a really good tool to start out in AstroVideo, especially to get the WOW factor on public nights, is with the little Gstar-Ex Colour camera. It is quite good. Same price as the Mallincam Junior and gives the same results.
http://www.myastroshop.com.au/guides...star-exclr.htm

* I am amazed at the amount of mis-information circling lately about Video astronomy and the products.
It really helps to Google for the real results and tests, or get replies from people who own and use the equipment.
I am just one of the few in Australia trying to advance AstroVideo and get more people interested in being involved in this rapidly growing area of Astronomy, and yet I keep reading so many replies with wrong information in threads.
It makes it hard to get people interested in a branch of Astronomy when the answers given are so wrong.

Anthony, feel safe getting a Gstar-Ex Colour camera. Coloured 'almost' live images right there on a PC monitor or TV screen for $479

ballaratdragons (Ken) · #15 09-12-2011, 12:30 AM

Quote:

Originally Posted by AstroJunk

Colour Malincams are superb BTW - they are modified Mintron (like the gstar) cameras with some wizard electronics for taking long expsures. The best part though is the thermoeletric cooling which makes a massive difference during the warmer months.

See, another example of totally incorrect information!

As popularly believed, Mallincams are NOT modified Mintrons.

They are wholly designed by Rock Mallin, and the cases and some parts are made for him to his specifications by Wakayama in Taiwan.
Some parts are manufactured for him in USA. The rest of the circuitry and other parts he makes himself in his own company workshop in Canada.
You can get a Class 1 or even a Class 0 sensor (None of the other video camera suppliers offer this).
Other brands usually use Class 2 ,3 or even worse.

Every single camera is hand made one at a time by order, and tested on the night sky by Rock Mallin. When he is happy with it he then sends it to the dealer in USA who re-checks it's operation before sending it out to you.
Currently, Rock is able to make and test up to 60 cameras per month.

Interestingly, with the TEC cooling in a Mallincam, they cool slowly and at the end of the nights use they warm slowly.
This is to prevent Thermal shock to the sensor, a feature also found in some SBIG CCD imagers.

To help clarify the difference I shall link you to the information that has already been supplied in here and I quote Rock Mallin in his own words: http://www.iceinspace.com.au/forum/s...70&postcount=4

Don't mistake me for a Mallincam Zealot though.
I also like the results from Gstar-Ex's, and I also still enjoy using my Modified Samsung SCC-A2333 AstroVideo camera.
I just don't like seeing wrong information given about a product.

To see how much colour can be seen by these cameras, watch my You Tube video where I show my modified Samsung in use with a 120mm refractor, and then remember that the Mallincam gives even far better results than the camera I use in this video: http://www.youtube.com/watch?v=JHiCNmYdkaE

AstroJunk (Jonathan) · #16 09-12-2011, 01:38 AM

Quote:

Originally Posted by ballaratdragons

See, another example of totally incorrect information!

Gosh I stand corrected.

I'm astounded how these two completely indpendent companies came to exacly the same interface specification, firmware and dies for their casings. Smarther than me, that's for sure.

Poita (Peter) · #17 09-12-2011, 09:47 AM

Quote:

Originally Posted by tonybarry

Colour video cameras require Big Glass (12" or better) to produce useful results on dim objects. Mallincams will integrate to around 56 seconds (i.e. your scope must track the object passably well for a minute or the integration will smear). This is not really real-time, but the Mallincam people seem to think it is OK.

Regards,
Tony Barry

Not true, a mallincam works just fine on an ED80 in full colour, often with just a few seconds integration time, smear free.

It is about the speed of the scope, not the size of the glass. The mallincam is relatively low resolution anyway (720x576 or something like that) so you don't need the extra resolution that big glass brings. You do need speed though, F6.3 or better is the way to go, using a reducer to get you down under F5 makes integration times really fast, that is why they are also popular with hyperstar setups as you get down to F1.9

But on a bog standard ED80, you get full colour, check out the Night Skies Network to see the results.

tonybarry (Tony) · #18 09-12-2011, 12:29 PM

As with Jonathan, I stand corrected.

My understanding of Mallincam integration length was based on older information (about two years ago); and my understanding of the aperture required to obtain useful colour was based on the images presented on Rock Mallin's website.

If persons who have the camera are able to correct these misunderstandings then I am grateful.

I would however caution the unsuspecting user than a telescope which can track any celestial object for more than 12 hours must reside near either the north or south pole. At those latitudes, thermoelectric cooling is not required.

Integration times in excess of a few seconds require very good tracking or guiding ... i.e. a good mount. Times in excess of a few minutes also require some method of avoiding field rotation (i.e. equatorial mounting or a field rotator).

Regards,
Tony Barry

Poita (Peter) · #19 09-12-2011, 01:54 PM

I agree the Mallincam site doesn't do them any favours. I think the whole area of Video Astronomy is misunderstood.

I'd love it if Ken would write an article we could put here, and maybe on the Mallincam site as well!

ballaratdragons (Ken) · #20 09-12-2011, 08:14 PM

Quote:

Originally Posted by AstroJunk

Gosh I stand corrected.

I'm astounded how these two completely indpendent companies came to exacly the same interface specification, firmware and dies for their casings. Smarther than me, that's for sure.

It's OK Jonathan. It's no magic worth being astounded about. And I'm not trying to prove people wrong. Just trying to supply correct information.

Wakayama (the Parent Company) used to own Mintron. Same plans, same dies, same machines. That is why the parts are the same.
But the 2 companies had a split and are now in competition with each other.

Gosh