hyperstar imaging

[Daniel-K]

ok so it looks like the c11 is not going to happen but im still keen on getting a c8 or c9.25 and trying the hyperstar system. hhas anyone on here tried it with a dslr if so to what effect? many thanks danny

[SixStringer]

Hi! Ok...what I know of this is that a DSLR camera is to big over the front of a SCT. I think they are for CCD cameras which do not obstruct the light path like a DSLR would. With the sensitivity of the CCD and the f/2 @ HyperStar would be awesome. I have a C8 with the HyperStar function and would love to try it at some point. For now I'm using a Canon 60Da through a reducer @ f/6.3.

Clear Skies

[gkec]

You have to specify a hyperstar adapter you need depending on the camera. I don't think DSLRs are supported on the C8 presuable for the reason sixstrings mentions but a few CCD cameras are. I think DSLRs are supported on the C9.5 -- it's all on the hyperstar website.

[JamesF]

Starizona's website suggests that you will be able to use a DSLR with the C9.25, but not with the C8, as gkec says.

James

[nightvision]

If you want to stick with the DSLR then for less money: A Boren-Simon F2.8 Astrograph would deliver similar performance.

[laser_jock99]

If you want to stick with the DSLR then for less money: A Boren-Simon F2.8 Astrograph would deliver similar performance.

If you already possess an F4 imaging Newtonian then the ASA Keller reducer/corrector lens http://www.teleskop-express.de/shop/product_info.php/info/p4685_ASA-2--Newtonian-Corrector---Reducer-0-73x.html is what is inside the Boren Simon astrograph. It would be less than any Hyperstar lens set, but could be used on many scopes.

At F2.9 deep exposures are possible in minutes instead of hours (Sadr, Cygnus 300s@ISO800).

[nightvision]

The ASA-2Korr is on my wish list, one day soon!

[ollypenrice]

When you read the websites of fast astrograph makers they focus on the virtures of ultra fast systems but not on why they are inheretly 'difficult.'

They are difficult because the ultra steep light cone emerging at fast F ratios has a quite incredibly shallow depth of field. You are out of focus in a matter of microns. The bigger your chip the more the difficulties mount because the slightest tilt anywhere in the system means one side of your chip will be focused and the other won't. It also means that the focuser on the scope needs to be ultra precise. Never in a million years can the moving SCT mirror be called a precise system. It becomes possible but still not easy when electronically controlled. Collimation is also hyper critical.

So fast astrographs need to be well made. The GSO F4 imaging Newt (only F4, note) was just not well enough made to be much use. Focusers and lens cells have to be tip top, fine and orthogonal. That is why Takahashi Epsilons, for example, are expensive.

I think this explains why most of the Hyperstar images we see are ordinary to poor though a minority are utterly stunning. If the user cracks the difficulties the system is great. That can be a big 'if.'

Basically my point is that you should go into ultra fast F ratio imaging with your eyes open. My choice would probably be the Epsilon (but I don't like the spikes!) or the OS Veloce.

Olly

[laser_jock99]

When you read the websites of fast astrograph makers they focus on the virtures of ultra fast systems but not on why they are inheretly 'difficult.'

They are difficult because the ultra steep light cone emerging at fast F ratios has a quite incredibly shallow depth of field. You are out of focus in a matter of microns. The bigger your chip the more the difficulties mount because the slightest tilt anywhere in the system means one side of your chip will be focused and the other won't. It also means that the focuser on the scope needs to be ultra precise. Never in a million years can the moving SCT mirror be called a precise system. It becomes possible but still not easy when electronically controlled. Collimation is also hyper critical.

So fast astrographs need to be well made. The GSO F4 imaging Newt (only F4, note) was just not well enough made to be much use. Focusers and lens cells have to be tip top, fine and orthogonal. That is why Takahashi Epsilons, for example, are expensive.

I think this explains why most of the Hyperstar images we see are ordinary to poor though a minority are utterly stunning. If the user cracks the difficulties the system is great. That can be a big 'if.'

Basically my point is that you should go into ultra fast F ratio imaging with your eyes open. My choice would probably be the Epsilon (but I don't like the spikes!) or the OS Veloce.

Olly

Agreed- fast imaging systems are not 'plug and play' but neither are they total 'black magic'. Anyone with sufficient patience and tinkering ability should be able to get acceptable results. I can't comment personally on the Hyperstar systems but the corrected Newtonians can give good results in the right hands (I don't count myself in that group yet).

[Daniel-K]

budget for the scope is 1K and then either a 2nd hand CCD or a modded DSLR which ever was to come up first. what would you buy for 1K as imaging scope?

[Daniel-K]

jock every time you post an image from your fast newt im astonished at how fast that thing is, but i had the 8S f4 Qattro and to be it was fast but i wernt keen on it

[Daniel-K]

thanks for the input Olly much appreciated. the thing is i love up close shots with galaxy's i have had pretty much every type of scope except a SCT. i love the long FL but hate the slow f ratio thats what made me get rid of the 6" GSO RC, so i dont know what scope to get next

[laser_jock99]

jock every time you post an image from your fast newt im astonished at how fast that thing is, but i had the 8S f4 Qattro and to be it was fast but i wernt keen on it

Fair play- at least you had a go. I'm still tweaking my F4's as I can't afford a fast apo triplet at the moment!

[ollypenrice]

thanks for the input Olly much appreciated. the thing is i love up close shots with galaxy's i have had pretty much every type of scope except a SCT. i love the long FL but hate the slow f ratio thats what made me get rid of the 6" GSO RC, so i dont know what scope to get next

There is no fairy godmother. If you want a long focal length and and a fairly fast F ratio you need a huge telescope and a mount which delivers both the accuracy and the carrying capacity necessary. Fact of life.

I had the good fortune to come across a fairy godfather, however, in the shape of a certain Yves. 14 inch ODK on Mesu Mount 200.

Olly

[nightvision]

jock every time you post an image from your fast newt im astonished at how fast that thing is, but i had the 8S f4 Qattro and to be it was fast but i wernt keen on it

Daniel could you be more specific about the Quattro and not being keen on it?

[nightvision]

Here is an example of an 8" Powernewt F2.8 image, total time 3 hours 5 minutes! It appears (as Olly said) they can be made to work....