I also just purchased the CFAPO102 plus 0.8x reducer, TS gave me a nice 10% discount for both before shipping, it will take about 3 weeks for delivery.
They also added a free 0.5mm M48 spacer that will bring my CMOS camera and FW to the exact 55mm of back focus from reducer M48/0.75 thread to camera sensor.
I made quite a research lately about my next imaging refractor, I was focusing on a refractor with an aperture between 100-107mm and a FL between 420-570mm, my first preference was to go with SW Esprit 100 and either Riccardi reducer 0.75x M63 or TSAPORED075 the older version of 2019 and not the current version of 2020, however, the Esprit 100 is out of stock and it will take quite a while until it will be back in stock, I also checked the option to go with TS 106/700 with Hoya FCD100 optics plus 0.75x reducer but from a user review I saw bad stars in the corners with APS-C size sensor so I ruled out this option.
I also checked about the new Askar 107PHQ and had a hard time decisions to make, the 107PHQ and CFAPO102 both have the same native f/ratio, the 107PHQ has a larger aperture, the 107PHQ does not have a proper reducer at the moment but it will be at the near future, at least that is what I have seen from what Sharpstar announced, The 107PHQ has a built-in corrector Petzval like and the image circle of 66 is quite large suitable for FF cameras and nice round stars at the corners of the frame and no need to add such spacers or adapters to reach the exact back focus unlike flatteners and reducers that back focus distance is crucial.
For me three of the main key components to decide was the optics quality, nice round stars at the edges of the frame with my APS-C size sensor and a faster system.
I finally decided to go with the CFAPO102 plus reducer because it comes with FPL55 Ohara glass unlike the 107PHQ optics which unknown to me, couldn`t find any specifications about that, I also get a faster system with reducer, the image circle is unknown but TS specified that it`s good for up to FF sensor so there shouldn`t be any problems with bad stars at the corners with my APS-C sensor.
Hopefuly I made the right decision
Time will tell!!!
BTW- Here is a very nice review by Vic Maris from Stellarvue about Optical Glass Types, worth reading and looking at the diagrams. https://www.stellarv...al-glass-types/
Lior
Edited by liors, 18 May 2022 - 09:42 AM.