Hyperstar

renormalised (Carl) · #1 18-01-2009, 01:43 PM

Go and have a look at the results this youngster got from a 6" Celestron Nexstar scope and her Dad's SXVF-H9C camera. Here's the site...

http://starizona.com/acb/hyperstar/h...hyperstar6.htm

It's using the Hyperstar lens system attached to where your secondary normally would go. Even though it's optimised for those scopes that have removable secondaries and fastar scopes, you can get conversion kits for some of the other Meade and Celestron SCT's that aren't compatible.

Makes you wonder why you spend hours trying to get great shots of objects when you could do it in a matter of minutes and achieve the same results. What's worse, they're from unguided, alt-az mounts!!!

bojan · #2 18-01-2009, 03:18 PM

Quote:

Originally Posted by renormalised

What's worse, they're from unguided, alt-az mounts!!!

I seriously doubt it.

PCH (Paul) · #3 18-01-2009, 03:40 PM

Well Bojan, with the greatest of respect, it seems so.

This is fascinating. If you look at the website, they explain how this is done.

Mainly the imaging can be unguided simply because they happen around 30x faster than with an f10 sct. And the hyperstar lens has some corrector elements that correct for the stuff that spoils images taken with a typical alt-az mount.

Others will understand all the pros and cons more than I do, but it seems like a great idea on the face of it.

The young girls images are certainly very convincing

Cheers,

Ric · #4 18-01-2009, 04:35 PM

What worrys me is all that stuff that is hanging of the corrector. If it cracks under the weight then the show is over for that scope.

I'm also wondering how they get around the star rotation problem. As a general rule that was told to me if you go over 30 second images in Alt/Az you will experience star rotation in the induvidual subs without a de-rotator. I notice that the young girls images were 60 seconds subs.

Cheers

renormalised (Carl) · #5 18-01-2009, 04:49 PM

How heavy would the secondary be...2-3lbs, for a 10" scope??. That's the whole assembly, not just the lens/mirror. I'd say they'd have taken the weight into account when designing the setup.

renormalised (Carl) · #6 18-01-2009, 05:09 PM

Just found something very interesting about field rotation...

http://www.skyinsight.com/wiki/index...e_in_Alt/Az%3F

bojan · #7 18-01-2009, 05:43 PM

The reasons for my doubts are all comments posted above by others.
Also, the scale of images on the website is quite small (high resolution).
As far as field rot at alt-az mount is concerned, yes, it varies a lot depending on the direction of the scope is pointed at, in certain directions it is even null.. but that is serious limitation on what and when you are taking pictures.
It seems a marketing stunt to me.
Anyway, regardless of all this being true or false (most likely it is false or just plain exaggeration in some details), I am sticking to what I have and what I do or what I intended to do...

renormalised (Carl) · #8 18-01-2009, 05:53 PM

The only real way of knowing if the spiel matches reality is if someone out here buys one and tests it. Unfortunately, I don't have the money to do so, nor do I have a compatible scope.

Ric · #9 18-01-2009, 09:04 PM

Quote:

Originally Posted by renormalised

Just found something very interesting about field rotation...

http://www.skyinsight.com/wiki/index...e_in_Alt/Az%3F

Thanks for that link to the article, I'll give that a try with an overlay of selected objects.

Cheers

coldspace · #10 18-01-2009, 11:02 PM

The hyperstar system works a treat. I am in the Mallincam user group and most of the overseas members are getting fantastic results using the Mallincam colour video on Alt/Az mounts with 28 sec intergrations and the hyperstar system and some of the "live" views achieved are simmilar to the pictures posted except a bit rougher because no post processing or stacking.
The faster the optics the way less need for exposure time. No good on small objects such as planetaries as field of view is wide and no image scale, but for large objects the system works great. There is no substitute for longer exposures to get better,finer data such as acheived by award winning guys, but for novices and the video "live" astronomy users this system works great.
The results of my Meade at F3.3 and the Mallincam are mind blowing but when comparing some of the images achieved by members overseas using same size scope and the hyperstar at F2 or less there is no contest.
Hyperstar wins by along shot.
Yes, you do have to be carefull with the corrector plate as a few have found out the hardway but if carefull and keeping scope lower on objects then excellent results can be achieved on alt/az mounts with exposures under 60 seconds.

Regards Matt.

renormalised (Carl) · #11 18-01-2009, 11:19 PM

Thanks for that synopsis, Matt. I was just wondering, you mentioned about keeping the Hyperstar on the mount lower on objects, what would be the maximum angle you could put the scope to without unduly stressing the corrector plate??. I would imagine most of the problems the users encountered were probably when they were fitting the lens assembly.

What would be the best thing, is if they designed a hyperstar system that could replace the secondary entirely and have the scope a dedicated F/1.5-2 imaging system...or design a new scope type that had a hyperstar as a secondary. Might mean making a far more robust corrector plate that was optically 100% clear, but they could do it.

You could have a SCT type of setup, except with a fixed primary and have the hyperstar on a system where it was focused by servos...like with the Meade RCX400, but have no tube out the back and no hole in the primary mirror. Food for thought

As you said, mightn't be any good with many PN's, but you're better off doing them with a slow scope anyway, for the smaller ones at least. Beasts like the Helix and Dumbell might be a different matter, being a decent size. Ultimately, you could stretch the exposure times of your system by sticking it on a GEM or fork mounted equ', and guide it, then with the hyperstar attached you could drastically lower the amount of time needed to take those "uber" piccies. Or, take those piccies to the next level in optimum seeing conditions.

More food for thought

Omaroo (Chris Malikoff) · #12 19-01-2009, 04:01 PM

Jeepers! Time to throw away the Tak and bring out the C8 again! There are conversion kits you say? This would be great with a QHY8 Pro!

renormalised (Carl) · #13 19-01-2009, 05:48 PM

Chris, can you remove the secondary on your scope??. You more than likely can. In which case a conversion kit will set you up to attach the Hyperstar.

coldspace · #14 19-01-2009, 05:55 PM

Quote:

Originally Posted by renormalised

Thanks for that synopsis, Matt. I was just wondering, you mentioned about keeping the Hyperstar on the mount lower on objects, what would be the maximum angle you could put the scope to without unduly stressing the corrector plate??. I would imagine most of the problems the users encountered were probably when they were fitting the lens assembly.

What would be the best thing, is if they designed a hyperstar system that could replace the secondary entirely and have the scope a dedicated F/1.5-2 imaging system...or design a new scope type that had a hyperstar as a secondary. Might mean making a far more robust corrector plate that was optically 100% clear, but they could do it.

You could have a SCT type of setup, except with a fixed primary and have the hyperstar on a system where it was focused by servos...like with the Meade RCX400, but have no tube out the back and no hole in the primary mirror. Food for thought

As you said, mightn't be any good with many PN's, but you're better off doing them with a slow scope anyway, for the smaller ones at least. Beasts like the Helix and Dumbell might be a different matter, being a decent size. Ultimately, you could stretch the exposure times of your system by sticking it on a GEM or fork mounted equ', and guide it, then with the hyperstar attached you could drastically lower the amount of time needed to take those "uber" piccies. Or, take those piccies to the next level in optimum seeing conditions.

More food for thought

I think from memory only one or two guys have cracked their corrector plates when installing the system, but if you follow the directions and take care as you should always do with astro gear then I can see no problems.
When I said keep it low, this means for using the hyperstar and an alt/az mount so exposures upto 60 seconds don't get rotation. Up near zenith you can get rotation as quick as 20 seconds but a little lower and using astro video like the Mallincam or short exposures upto 60 seconds with no rotation showing.
some of the results are excellent considering such short exposures and alt/az mounts.
I was considering getting the hyperstar lense adapter for my 12 LX200R but starzona has not put one out yet. The results I get using the OPtec 3.3 reducer keeps me satisfied for the moment.
I don't knw much more about the system but one thing you have to remember is your camera is also attached to the hyperstar so therefore its hanging out the front of the scope which could be a problem.

Regards Matt.

renormalised (Carl) · #15 19-01-2009, 06:09 PM

Most of the cameras I have seen hanging off the end of the scopes have been lightweight things like the Starlight Xpress type of cameras....barrel shaped. They also say you can use the SBIG's on them too, but I wouldn't want to hang an 11K off the front of my corrector plate!!!. Although some have also hung DSLR's off the front of their scopes, so I suppose the corrector plate can carry a bit of weight.

AlexN · #16 19-01-2009, 06:31 PM

I've been looking at these for quite a while now.. Im amazed that more people haven't heard of the Hyperstar...

The item seems great... results are awesome, focus is apparently incredibly difficult, as you have to focus using the primary mirror which flops about and carries on every time you move it... It definitely would be a great bit of gear to have in your kit if you own an SCT..

The biggest problem is the price... Value for money wise, its a no-brainer, however it is a big outlay of money...

For me - $1095USD buys me the hyperstar lens, and the C11 conversion kit... its expensive... but then, $1095USD to make my 11" F/10 an 11" F/1.8 (yes, the C11 becomes F/1.8) I guess 1100usd isnt all that bad.. you get a nice wide field of view, exceptionally fast photon collection, 0 chromatic abberation.. The only things that annoy me in some images are the diffraction patterns (depending on the camera used), reflections in the images (usually defocused star reflections coming off the mirror onto the corrector that show up in images) and lastly, and this is the big one... stars almost always saturate completely in even short exposures...

That being said.. you could take a bunch of 5sec subs to get the star field, then a bunch of 5~10 min subs to get some ultra deep data of the target, then blend the star colors in somehow.. ??

Its on my want list... but its also on the "probably wont get" list..

renormalised (Carl) · #17 19-01-2009, 07:16 PM

Yeah, they're certainly worth what you pay for them. It's a pity that the Meade RCX series of scopes doesn't have the same sort of secondary as some of the other SCT with compatible secondary lens holders. The primary mirror in these scopes is fixed and it's the secondary that moves to focus. Which I think is the better way of doing it. Saves all the mirror flop problems and such with normal SCT setups. It would make using the hyperstar a lot easier... w.r.t. focusing the images and the problems with the primary mirror.

coldspace · #18 19-01-2009, 07:25 PM

I think Alex, keep putting your funds towards that CDK17 and AP1200 thats the dream setup.

Matt.

renormalised (Carl) · #19 19-01-2009, 07:45 PM

Quote:

Originally Posted by coldspace

I think Alex, keep putting your funds towards that CDK17 and AP1200 thats the dream setup.

Matt.

That would be a spec setup

AlexN · #20 19-01-2009, 09:42 PM

Matt... Trust me - every spare cent I have is in the CDK/AP1200 fund...

Got 1 year to wait for the AP1200.. I reckon I can get a most of the way to saving for the CDK by then.... Especially adding in the rough sale price of my current gear...

Hence why the Hyperstar is in my want list, but on the "probably wont get" list... No real point spending any more money on things like that when I know im a year or so away from a serious serious setup...

Alex.