Interesting comments, guys. I have to agree that the F5 Tak FSQ 130 is not going to offer significant visual observing benefits over the F7.7 Tak 130, and it costs virtually twice as much. What I would like to know is, as the aperture is the same, how much brighter will the image be in the FSQ than its 'optically slower' brother, the TAK 130NS? And for visual purposes, will this translate to say, the equivalent in photographic terms, of 1 f-stop? Judging by what you have said, this will not be the case as one stop represents twice as much brightness, photographically speaking (eg F8 is twice the brightness of F11 and requires half the shutter speed for the equivalent exposure value at F11). Basically, this is confusing...To add to this enlightening (
) conversation, has anyone used or heard about the APM - LZOS Telescope Triplet Super ED APO Refractor 152/1200 CNC LW II ? Sounds like a beast but at 11000 euros, a lot of dough. I saw that it had a strehl of .997 at the short wavelength end of the spectrum - totally competitive with the Taks and the Astro-Physics scopes, if the data can be believed on the German website....Thoughts, anyone? Thanks again for all of your interesting and educational observations.
Cheers,
Richard