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Test reports can easily lead to disagreement with methods etc. I was not buying it on the basis of a Strehl ratio. I was buying it because Suavi's images are super sharp and show an exceptional level of detail that even a larger high end telescope does not show much more at all. I judge the results not the test reports. They should match up. Suavi's images match up with the results I would expect from a top end AstroPhysics scope. Also these CFF scopes have a 1 year waiting list which tells you something about their quality as well.
I don't know that AP are making anymore APOs apart from the 92mm F6. I wouldn't bank on it. Roland stopped making the RHA astrograph I believe.
TEC also judge strehl from the green. That's for visual people. Imagers are probably more interested in the blue and the red where false colour lives. I was surprised to see the TEC180FL was weak in the red for example although I can't say I noticed that when imaging with it. But I did notice Tak TOA150 images always seemed to get a tad more detail from the same scenes. Its a shame Tak does not make a TOA 110. They probably don't want to overlap against the FSQ which is there best seller.
The alternative scope was a Tak FSQ106EDX iv. They are in short supply and are a touch more expensive. I have had an FSQ106N and an 106 EDX iii before with the reducer and its an amazing scope but just wanted something different. Mainly to replace the lovely TEC110 F5.6 fluorite oil spaced triplet.
The main issue with that scope was the lightweight focuser, it really needed a heavy duty Feathertouch. What I liked about the TEC over the FSQ was the better colour transmission of the fluorite lens. The Tak is not as "colourful". I mentioned this to someone once and he tested his as I thought perhaps the shift to a different type of lens coating created a slight colour bias in the FSQ106ED series. His testing led to the conclusion the black internal tube paint on the FSQ does create a slight green bias which is what I was seeing in a lot of FSQ106ED images. I haven't noticed it in any of Mike's images so I wonder if Tak adjusted their coatings or internal paint or not. The FSQ has the large 88mm corrected imaging circle, has a wonderful flat field. Its weak points mechanically are the poor focuser, the poor focuser lock, the weak microfocuser, the focus shift with temperature shifts due to the large air space. Nothing is perfect and the imaging capabilities are the main thing, the focuser issues perhaps are now fixed - not sure, hence the EDX iv the earlier 3 had issues with heavy imaging trains although the EDX iii I had was perfect.
There are many nice FPL53 triplet scopes offered these days - a lot are reasonably priced compared to years ago when I was first getting high end scopes.
But as usual you pay a lot more for that last 10% of performance. Its the same with cars and everything else.
So I will be comparing it to the 2 FSQ's I have had, the TEC110 F5.6 fluorite triplet, the TEC 180FL and an AP140 F7.5.
Also I bet if I asked Roland Christen, an AP quad TCC could probably work on this scope or perhaps his flattener for the Traveller if they still make them. The alternative is the Riccardi reducer.
Greg
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