Was talking to a chap I know yesterday who has seen and used one of these scopes. His thoughts were potentially a good scope but still very much development stages. Of note the following were of concern:
- Flex in imaging train lead to focus issues.
- Diffraction rings not evident in a star test.
- Removing the dove tail results in collimation being lost and the instrument is hard to collimate.
- Figure of the mirror is a ok but not a high enough standard at present; results in soft images.
This should all be measured in light of the idea that Guan Sheng has gone to great expense to get the correct equipment to grind the mirrors and are listening to retailers on developmental ideas.
They are receptive to ideas on mounting, focusor and figure of the mirror. Tests seem to be inconsistent. Some tests come up all right and others show major defects.
All this information was gathered in October last year and some aspects of rectification seem to be already in place. From what Alex has told me the focusor looks to be heavy duty. Although I note that another extension of 50mm is necessary to reach focus on a DSLR. The Vixen dove tail is limiting and will have to be changed for my setup. I use D Saddles, so I am gonna learn all about collimation of these scopes. Surely collimation is not that critical and hard to do. Even RCOS scopes would not be well collimated on delivery.
An image I saw yesterday characterises all the above points. I have agreed not to show this image though, I will be presenting my own images in due course with my thoughts on the OTA construction and star testing. With any luck I will get a good one. If not well then it goes back. I am sure Andrews will do the right thing in that case.
Stay tuned for the next installment. I am expecting the OTA on either today or Wednesday.