jetstream

Definitely. Exactly my thoughts too...

Baader replied promptly but declined to disclose the lens source as they don't want to give manufacturing details away. They assured me it works fine and meets their requirements.

To each their own I say and while I do explore the NV option, the views through a telescope and eyepiece give me much satisfaction. Many, many faint objects are there to see if you get things right and so far things are working out. Seeing the Crescent nebula, parts of IC1318 and the Veil (very well) with no filter is very rewarding. In this case image scale is needed (ie Blackwells research) as you indicate but it must be at the proper illumination for the eye (exit pupil)- of course extremely faint, small (in EP) galaxy cores can be a bit different, IMHO.

Increased aperture brings the potential to see more fine detail on planets etc and optical quality determines how much of it gets "through". In terms of seeing extended objects it is the optimum exit pupil at the mag needed to see them, and this in part is a function of aperture, that determines how we see them. Rayleigh criterion etc does not apply to extended objects such as the ones I mention as they are not "point source" objects to resolve. I have no idea why some refractors are better than others on these faint nebulae. There is a difference to my eyes, under my conditions and it is noticeable. My question is why?

Well...it depends on the object and size of the object that is being viewed ie large faint nebula. Louis, can you explain to me why there are differences in what I see on these faint objects between quality telescopes?

Great stuff Gavin, I love these accurate test reports. What I really want to know if there is any difference visually on faint, diffuse, extended objects between scopes testing similarly. Those color test fringe patterns are all taken of the lens assy I presume? a min .96 Strehl (red) is superb and more across the board. A future binoscope project is watching this thread closely...

I would think that the Canon fluorite is among the best available...no doubt. Baader has/had an association with Zeiss at one time and this is what intrigues me. There has to be superb glass in this scope from the reports read and the cost of the telescope IMHO. If there is Canon or Zeiss lenses in this telescope it would be my pick, for sure. There may be other top notch German lenses out there too...

I emailed Baader about the lenses, lets see if they reply. Their add says made in Germany and if the lenses are...

I was curious about who makes the lenses for the Baader refractor?

What target?! Gavin is respecting the suppliers request and Stu is supporting this respect, IMHO.

I'll be honest Peter, this scope is my best yet on this stuff- but- if I get this place finished I am going to order a second TSA120 for a binoscope... Scopes matter on this stuff as do eyepieces- if the TSA120 is hindered at all it is the low selection of eyepieces in the needed range to see these objects well. I can only imagine if I had a Nikon HW class eyepiece in the 40mm range to use in the Tak... The 42mm LVW is very good on these objects but there is better glass out there IMHO.

Another great image Yves! Excellent.

Another rain washed sky tonight going NELM 6.8 indicating a nice level of transparency. Scope used was the Takahashi TSA120 and the eyepiece a 42mm LVW. 2 filters were employed a Lumicon UHC and their OIII. This scope is proving to be superb on nebulae, man it shows these dark nebs well! While cruising M24 it hit me at how dark the border of part of it was, it seems as if on the one side a long dark nebula exists and for some reason this scope pops it and others right out. On the other side B92 and B93 were in stark contrast to the rest of the structure. You know I followed M24 too far and its look changed... I believe that I followed M24 into SH2-35 another huge chunk of emission nebulosity and it showed easily. Having such success around M24 I tried another dark neb, this time the large and black B312 near NGC 6645 and it appeared about 2.5 deg across- too little FOV and its likely to be missed- I tried the Docter 12.5mm UWA and this happened. Careful viewing caught the edges of it though. There was nebulae everywhere! Has anyone else seen the starfield with nebulosity near M11, the Wild Duck cluster? This is another great sight that is on my list. Up at IC1318 the extent shown with the OIII is boggling- yes the OIII. A few years ago I mentioned the OIII on this one and possibly raised some eyebrows as a Hb is typically recommended. I prefer the OIII for sure here. So much more seen and so long to figure it out! I must say this in closing- the lights on the AZ EQ6/battery pack and keypad definitely affect my night vision, I have to figure something out.

Excellent report Stu! Your scope is working very well and it shows from your observations, congrats!

Congrats for a fine observing session!