Any thoughts from anyone?

[Fay]

I have been running a 8" Celestron/ Hyperstar past myself, today.

Has anyone any thoughts etc etc?

Thanks

(note to myself, start running handbags past myself)

[MarkS]

I think it is a very interesting setup.

It offers imaging at F2 which would make a HUGE difference to the speed of imaging and would allow you to go very deep - the field of view should be around 5 times the normal (very narrow) field of view.

I would be slightly worried about the fragility of the setup.  The corrector plate is not designed to withstand load so you would have to be very careful not to knock the hyperstar/camera assembly once in place to avoid damaging it.

[JohnP]

Fay - don't know much about this... Don't you have to fit the hyperstar your self (which involves taking the scope to bits...?????) Sounds expensive as well & also sounds like collimation is going to rear its ugly head.... Are you sure you want to go this route... (particular with a portable setup)... You'd be on your own as well nobody else in society has one of these...

My recommendation would be to think long & hard before jumping in.....

John

[Fay]

Hi John,


I think the scope would be around £575, Hyperstar £350.


I think you have to remove the mirror & put in the Hyperstar & the camera screws into it. Supposed to only take a few minutes!!

I can imagine everything falling to bits as I loosened the wrong screw!!!

Only running it past. Been doing a lot of reading up.

[Daniel]

I'd love to get a hyperstar, since moving to the SCT all i've been wanting to do is reduce the focal ratio, it's great for the smaller galaxy's and planets, but I've been having a lot more fun with the 80ED lately for the wider field stuff.

Combining the wide field with the added light gathering power would be fantastic, though im suprised having all that stuff in front of the apeture (camera, cables etc) doesn't introduce aberations

[Fay]

I thought that, Daniel, as Hyperstar & the CCD are fitted to the front of the telescope.

On a different note, I have enquired about the best focal reducerflattener, for my setup, from Widescreen Centre, as they have quite a choice. 

He thinks for ED80/EOS or WO ZS66/ EOS, either Meade or Celestron 6.3. 

My 0.8 is fine on both scopes using the smaller chip of the SX,
but not the EOS. He is going to talk to someone who is investigating this at the moment. 

I am thinking you have got the 6.3 Celestron.

[Fay]

So Mark, because the camera is fitted at the front, does the ccd capture an image in a different way? Like, does the ccd get the image direct from the back mirror? Or something 

[Daniel]

Fay, when you say the 0.8 isn't suitable for the Eos, do you mean the vignetting or does it not reach focus? I tried the meade 0.63 out last night (yes I know it was rubbish, last night, I ran out to set up during a brief clear spell and got about 10 minutes to try out the flattenner) and the reducer / flattener worked a treat with the adapter I got. I got a little more vignetting but that was just because I was using my older T-ring (the one im using now is fantastic, has full 2" opening, you may have noticed the lack of vignetting on the North American Image I posted, that has no flats applied) but unfortunately because the 2" push fit is built into the new adapter I can't use it with the reducer.

Anyway, i've realised i was rambling there, but to cut a long ramble short, the meade 0.63 worked a treat, I shall post some images with it as soon as I've taken some, hopefully tonight will be good (there's supposed to be a bit of clear sky tonight)

:O)

[Fay]

Daniel, ED80 ok with the Starlight Xpress, but bunching of stars in corner with EOS.
I am not very mathenatical. Is a 0.63 reducer larger tham a 0.8, & so copes with a large chip better? 

[Rocket Pooch]

No worse a focal reducer reduces the light cone so it will get worse.  They are typically combined with a flattener for SCT's, these are designed to take a curved field and flatten it, the best reducer out there is apparently the Astro Physics, they are not cheap, but you will only ever need one.

I'm in a grumpy mood today and was about to have a fit about the advise from the WSC, why don't you just get a clip in filter and use a good SLR ED Lens rather than mucking about with Focal reducers etc?  If you get something like a Sigma ED lens and the Astronomic clip in CLS your there, no mucking about.

I have the ED version of this http://www.jessops.com/Store/s26774/0/Lenses/Sigma/70-300mm-f-and-4-56-DG-Macro-(Canon-AF)/details.aspx?&IsSearch=y&pageindex=1&CatId=143&ManIds=1518,&SortBy=SkuOfferingPriceASC&IsInStockOnly=False&comp=n

You could always put this behind it http://www.astronomik.com/english/eng_eos_filter_clip_system.html

Then no field flattener, zoom ability etc, done. 

[Fay]

Thanks Chris,

what is WSC & what advise has made you in a  bad mood?


I am in a bad mood as well, today.

[RobertM]

Hi Fay,

If it helps...

Fastar/Hyperstar : If you get a fastar ready C8 then that is the easiest option, the flattener lens assembly will just slot in.  It will make a really good widefield scope ...provided a) you can align it properly and b) get used to the critical focusing - remember it's F2 and as such will have a very small critical focus range.  Another thing to be careful of is that your camera is held in the Hyperstar lens assembly directly on the corrector and will stick out a fair amount - the corrector is fairly thick but just be sure you give it a wide berth anyway !  I gleened this info as I was looking last year, I was (and am still) still tempted.

WSC - Wide Screen Centre ?

Why are you guys in a bad mood - you got the WSC blues or something !

[Fay]

OH, I understand now, Robert, about why Chris was unhappy.

I was only looking, Robert, would not want to take on more problems, got enough as it is. You know how it is, always looking at new equipment etc. & reading about it, seeing results, less exposure times.
As you say, you also take on new problems.

[Ian]

I blame the weather, I'm in a foul mood myself.

Of course, if it's not the weather, it might just, maybe, be the kids 

[Mac]

Correct me if i'm wrong, but at the moment your scope is
203mm F10 which give you a focal length of 2030mm

If you fit the hyperstar it becomes an F2.

so the focal length is now 406mm.

isn't that just a telephoto lens?

and for the price that you are going to spend on both,
you could buy a telephoto lens?

I know you wont get an F2 400mm telephoto lens for the same price.

you you can always use a telephoto lens normally?

http://www.canon.co.uk/For_Home/Product_Finder/Cameras/EF_Lenses/Fixed_Focal_Length/EF_400mm_f28LIS_USM/index.asp