Gstar versus StellaCam2

[Poli_74]

I was told by someone in my club that the stellacam2 video camera is superior to the Gstar video camera? I dispute this. Is this true?
it might be better for visual work but for photography I am not sure about it.

Emmanuel.

[iceman]

I don't have any practical experience in either camera, but I've seen some great results from the g-star. The stellacam2, I haven't seen much of lately.

What telescope and mount will you be using it on?

Are you using it to view live feeds, or for astrophotography?

[peter_4059]

Emmanuel,

From what I understand the G-Star has the Sony ICX429ALL CCD sensor (same as the DSI II pro) and the Stellacam II is basically the same as the Watec 120N which has the Sony ICX418ALL CCD sensor.

Here are the specs for the Stellacam II:
http://www.optcorp.com/product.aspx?pid=319-325-3480&tb=2

Here are the DSI II pro specs:
http://www.meade.com/dsi_ii/specifications.html

Here are the G-Star specs:
http://www.myastroshop.com.au/guides/gstar/index.htm#SPECIFICATIONS


You can also review the Sony datasheets for these (attached). Based on my interpretation of the Sony data sheets it would appear the ICX429ALL is more sensitive.

[Tandum]

I got some stuff sent over from astrovid last week and they threw in thier magazine. I think the Stellacam 2 has been replaced with stellacam 3 and there is a peltier cooling option for it. Any cooled camera will be better than a non cooled one with a similar sensor.

[coldspace]

The g-star is a great camera for its price and I would pick it over the stellacam 2 because you will have alot more back up locally here from the many users but its only limmited to 2.5 sec intergration times. This is ok for imaging situations as you can just stack many frames to bring out more detail but it and the Stellacams are only monochrome so they are very sensitive but you will need to use filters to get colour shots but for live veiwing only monochrome will be displayed.

If you want a cooled version of an astro-vid camera then look at the Stellacam 3 or even better if you are spending that sort of money then go down the Mallincam route as these are as good as it gets for video work. The cooled cameras will be less noisy and more sensitive.
The colour mallincam is cooled and has automatic refresh exposure rated as high as 56seconds and the internal circuitry has been totally modified with higher class componets and more gain with cooling of about 50 degrees below ambient. These cameras give you a totally wow factor in deep sky viewing but are more suited for live viewing and although you can save images via a video converter to a PC if you want to get into more dedicated imaging then a DSLR or CCD camera would be a better choice.
Video systems allow you to get your feet wet with imaging as they are alot more forgiving on mounts and user experience.

Regards Matt.

[Andrew C]

To add a little bit further to the discussion, I have a Stellacam 3 and have not done any imaging to date, but for visual observing I have found it very good. I use it with an Eq mounted 150mm F5 Newtonian (compact and easy to transport), and find I use the longer integration times (say 10-30 seconds typically and sometimes longer) almost all the time for DSOs. At this aperture, a 2.5s limit would really restrict its usefulness for observing, so you might want to do some calculations if you planned to use a Gstar or Stellacam2 mainly for observing on a smaller aperture scope.

Cheers,

Andrew

[allan gould]

You an get the sellacam 3 here in Australia with a full warantee. You have to purchase it as a Watec 120N+ camera (if you PM me I can give you the distributor in Bris and Melb). This gives you unlimited integration times down to a few 1000 of a second. From what I remember the camera is abot $6-650AUD but don't hold me to it as it was a while since I bought my Watec 120N+. Its a good imager as well as a guider.

[jjjnettie]

I'd be posting this question in the Yahoo Group "VideoAstro". The members own a wide variety of Video Astro Cams and you can compare images from different cameras in their Photo Gallery.
For myself personally, I like the Gstar because the shorter integration time means I can image successfully using an Alt Azi mount.
Cooling would be nice, but dark frames remove any hot pixels.
The price is right and the back up support through both the Gstar Group and MyAstroShop is excellent.

[Andrew C]

Hi Jeanette,

For future reference in case I get into video imaging, when you image using Gstar ex with short integration times like 2 seconds or less, are you using a tracking alt az mount, or is there sufficient tolerance in the short times for a small amount of movement in the position of the objects? Also what sized scope aperture are you using?

Also, Peter,

Could you explain which parameter in the Sony specs for the CCD sensors quoted spells out the sensitivity?

Thanks, Andrew

[peter_4059]

Andrew,

I'm referring to p11 and p12 of the spec sheet where it gives the sensitivity in mV and the description of how this is measured.

Peter

[coldspace]

Andrew, others may offer more detailed responses but from my understanding of the chips sensitivity is its Quantum efficiency in turning light into electrons???? please correct me if I am wrong.
When you look down the sony sheets about half way on each of their chips you will find the sensitivity sheet and the unit of measurment is mV. The 429 chip has alot higher reading in mV so I assume its more sensitive.

The other question you have I can answer, I can use my ALT/Az LX200 scope with the Mallincam set upto 28 seconds intergration with no field rotation showing anywhere in the sky. When I jump upto 56 second intergration I can then start getting a little rotation in my images if the scope is pointed up high near zenith but none shows down 60 degrees or lower.
If you have a good Alt/AZ mount you can use these video systems for imaging.
With the G-star users capture lots of 2.5 second intergrations and stack them using RGB filters to get colour shots which gives the same level of detail as longer exposures and as JJJ says you use dark frames to get rid of noise. This works great.
The Mallincam is aimed more for instant gratification and visual use as it has longer exposures with boosted gain and cooling to get the most out of its less sensitive colour chip.
Different cameras for different uses.

You can use these video systems at around 2 seconds intergration with a dob but unless you have the worlds best hand control you will get streaking across the screen.
You do need at least ALT/AZ tracking otherwise it will become a real pain.
Some people get fantastic results using video and round table platforms with their dobs.

Regards Matt.

[jjjnettie]

Andrew, I use an alt azi mount and an 80mm scope.
You're good for exposures up to 20sec, which is what I take using a dslr with the same setup.
So the 2.56 sec exposures with the Gstar are no problem at all.
DeepSkyStacker takes care of any field rotation.
There's an article here that goes into more detail about how I capture.
http://www.ioptron.com/pdf_articles/ATT_iOptron_Article.pdf

[Andrew C]

Thanks Jeanette, Matt and Peter,

Not sure how much difference the extra sensitivity of the GStar CCD makes, but I will keep all of this info in mind. Enjoyed reading your article Jeanette. It all might just tempt me to start imaging a little sooner.

I had a great night's viewing last week here in Alice Springs: the night time temperature was mild (about 15 whereas it is normally 4 or 5 later in the winter evenings) and my polar alignment was perfect for once. Super sharp views of the Trifid and Lagoon Nebulae, Centaurus A and various other galaxies brought out more detail than I had ever seen before.

Cheers

Andrew