Tecnosky F/6 60ED

[Highburymark]

A few more comments about this excellent little scope.  I originally bought it as a hand-held scope for quick night vision sessions, but I’ve also used it extensively as a daytime spotter and an indoors optics tester - as it doesn’t require long distances with artificial stars and other indoor targets. It’s fun to study the fine print on a passport or credit card with different eyepieces. 
A £300, F/6 refractor shouldn’t be this good, even with FPL53 glass. Field curvature is of course an issue, so some eyepieces aren’t sharp to the field stop. But that’s only to be expected with such a fast scope. In every other aspect, the little Tecnosky is quite excellent. CA is difficult to coax out of these optics - only with a 2.5mm eyepiece can I see any violet fringing on leaves/branches against a bright sky. The ronchi test is textbook. An artificial star shows the lenses are very well figured. Very little colour out of focus. The diffraction rings are quite significantly clearer on one side than the other - which might suggest spherical aberration - but in use the sharpness at silly powers shows that any SA is minimal. The other day I tried a Takahashi TOE 2.5mm and a 2x barlow, producing well over 100x per inch, and was amazed how well the image held together.
These diminutive scopes are available under many brands - not all as cheap as Tecnosky. I can imagine they’d make an excellent first apo for imagers - but don’t underestimate their appeal as a very capable visual scope.