Starizona SCT Corrector
Posted 04 May 2011 - 01:30 PM
I'd really like to see an actual comparison with a generic f/6.3.
Posted 04 May 2011 - 01:31 PM
Posted 04 May 2011 - 02:30 PM
Posted 04 May 2011 - 11:42 PM
wish i'd seen these before i bought the LX200R.
interestingly, they look like starizona's answer to the edge
which is not hyperstar compatible.
hope there's not too much conflict there
Posted 05 May 2011 - 08:51 AM
Posted 05 May 2011 - 04:41 PM
If they can do what they say they can then I expect Starizona would commission a study to quantify the advantage
Did Celestron commission a study on the HD series?
Posted 05 May 2011 - 05:40 PM
Posted 06 May 2011 - 08:15 AM
When companies (Starizona, Celestron or whoever) make these products they should do internal concept design followed by testing that is based on specs that show it hitting the perceived market need. If they do it right this can be translated into a nice marketing piece.
Posted 21 May 2011 - 06:22 AM
Posted 21 May 2011 - 09:12 AM
Just thought I'd raise this question again. Has anyone used one and would like to report back? Perhaps I should then?
From the looks of it nobody dares to buy an unproven product, which is unfortunate.
I don't have any use for one right now but I'm still curious to see how it performs when a customer uses one, I'd definitely read your review of it.
Posted 21 May 2011 - 11:24 AM
- rackem likes this
Posted 10 October 2011 - 09:00 PM
I may have to be the first? ...
Posted 10 October 2011 - 11:02 PM
Posted 11 October 2011 - 09:11 PM
That's great and thanks. I'm sure there are a number of folks who've been looking at this corrector / reducer to improve their SCT's imaging performance. The promise of reduced coma and a flatter image... is very enticing to say the least.... look forward to your report. I see you've got an ACF and the other two are HyperStar setups. Are you planning on putting the standard secondary back in the C8 and using that?
Posted 18 January 2012 - 09:06 AM
Posted 18 January 2012 - 10:10 AM
Posted 20 September 2012 - 04:50 AM
I have Celestrone C-11 telescope.
In spring 2012 my sister purchased Starizona SCT Corrector (SCTCORR75) for me. At the moment of the order I was unsure which camera I shall use, so we ordered just the corrector. Eventually I started using it with Canon 1000D and the adapter was prepared following the recommendations on the website. Precisely following the instructions, the length of the adapter plus T-ring is 46,3 mm. It is shown in the picture. According to the site's info, the correction of aberations is supposed to be excellent, taking into consideration that the size of the camera matrix is only 26,7 mm, while the corrected field of your corrector is 36 mm. However, during the process I faced strong coma in the corners of an image, as you can see it in all the corners in the foto. In my opinion, that result cannot be judged as the "corrected field". I'm asking you for your advice and help in the finding the cause and the solution for improving the results of the corrector's performance. I wrote this mail to starizona but didn't recieved any answer
Posted 20 September 2012 - 04:56 AM
The reducer itself should be attached directly to the back of the sct.
I haven't used that reducer, but I would expect it to be similar in this way to the 0.63x reducer.
Posted 20 September 2012 - 05:05 AM
It seems like if it is attached directly to the sct back and the spacing is about 90mm and the image scale shows 0.75 reduction - there might be a problem. Maybe one or more of the lenses inside is backwards.
Posted 20 September 2012 - 05:45 AM
Canon EF(-S) bayonet is exactly 44mm. So, it is 44mm+46.3=90.3mm - as need according starizona.com
I measured my images scale in arc-sec per pixel by pinpoint astrometry - it says smth. about 2020-2040mm. Concerning reduction factor - it depends from position corrector in sct-outback. It may be more or less deeper, because corrector hasn't any mechanical restrictions for place it in sct-outback or sct-focuser. In technical characteristics also there are no requirements about its arrangement in a telescope. We only need right backfocus - 90.3mm from edge of t-thread to matrix.
Posted 20 September 2012 - 06:08 AM
I agree the main thing is to have the distance from the corrector to the image plane as near 90mm as possible, but at the same time there will be some degredation if you move the corrector away from the back of the sct. The manual for the corrector says:
"Ideally, the SCT Corrector will be mounted as close to the back of the telescope as
possible. The performance of the lens does not change significantly if the SCT Corrector is
farther from the telescope, but the focal reduction factor changes, reducing the field of view and increasing the telescope's focal ratio."
Since your f/ratio appears to be 7.25, it seems close to the intended 7.5 and something seems wrong. This *is* a normal c11 - and not EdgeHD - correct? It is not expected to work with EdgeHD.
If you can confirm that it gives nearly the same results when the corrector is attached directly to the back of the sct, then it looks like something is wrong, and one possible cause would be to have a lens inside mounted backwards.