Finally had "First Light" tonight - albeit a short examination of the TS Optics B1060ED and comparison with the Baader Vario Finder.
The TS was equipped with a GSO 90 degree dielectric diagonal as in the photo above, and the BVF with a T2 BBHS diagonal and helical focuser. The opposite T2 threads on the drawtube (male on the Baader, female on the TS) prevented use of the same diagonal and focuser on each.
In a nutshell - the performance seems identical to the Baader Vario Finder in most respects. The Baader shows the "red dot" center of the diffraction pattern very slightly beyond focus and I did not see that in the TS - so it appears the TS is using ED glass as claimed. (there is a discussion of this phenomenon in the 2nd edition of Suiter's Star Testing book, pages 253 & 254.) Notwithstanding, there was no visible difference in focus on Altair, Sheliak, Epsilon Lyra, or M57. There was no apparent difference in which faint background stars were detected. I could just make out the 'donut" of M57 with direct vision using the 4.7mm eyepiece (53x) and M57 was detectable with direct vision using the 14mm eyepiece (18x) - in either scope. I did not notice CA or any difference is sharpness with any of the eyepieces used (not unexpected with a maximum magnification of 53x). There was no noticeable difference in star colors or color contrasts.
The two major differences noted were:
1) the TS seems to have perhaps a 10% smaller image scale as compared to the BVF - I noticed the separation of stars (Alberio, Sheliak, and Epsilon Lyra) seemed less in the TS optics - when using the very same eyepiece. The BVF is supposed to have a 250mm FL and the TS 248mm but I would estimate about a 10% difference between the two. Probably does not matter much - but I did notice a difference, most obvious with the 4.7mm eyepiece (~53x).
2) the drawtube focus method is difficult to obtain precise focus. This was my biggest gripe (other than price) about the BVF. I'm thinking I'll switch to a T2 diagonal and helical focuser - just as I have done with the BVF.
Conditions tonight were dry and dew was not an issue, however the very short dew shield did not block glare from Luna (perhaps reflected off the house?). A much longer shield would be beneficial to eliminate stray light. The BVF is way better.
Conclusion: I was looking for something similar to the Baader but less expensive. I think this will be a success but a couple of minor changes are still needed - better focusing and a longer dew shield.
BTW - eyepieces used in both the TS optics and BVF were 24 & 16mm ES 68 and 14mm & 4.7mm ES82. The 4.7mm would show defocus in the TS Optics at about 50% field radius and seemed to remain sharp closer to the edge in the BVF - maybe to 65 or 70% but I suspect this is more a function of the ability to precisely focus the BVF as compared to the TS Optics. Similarly, the 14mm ES82 was sharp nearly to the field stop in the BVF and less so in the TS Optics. Field curvature is severe in both scopes but I plan to check this again after adding a focuser. The FC was most noticeable with the 24mm ES68 in both scopes. Remember - this is affected by my visual accommodation - your ability to accommodate (maintain focus) on field curvature is probably different.
Edited by Don Taylor, 09 November 2019 - 10:28 PM.