I have been involved in the hobby for the past 30 yrs, I understand no one telescope is going to Master all things, there is always that option to improve on all parameters from aperture to speed etc. I have searched high and low and put forth the due diligence, I have read all of Eddgie's articles to comprehend the methods, caveats, and hardware options. I have noticed a consist theme, that being the evolving choice of hardware/telescopes. Herein is my dilemma, my wife will shoot be at sunrise should I buy another telescope, I currently have a stock (no FT) Takahashi FC-100DF 2.7 focuser / F/7.4 to F/4.9 (Takahashi FC-35 "expensive" focal reducer which I currently do "NOT" own). I have enjoyed the scope immensely for Visual, no regrets, only drawback is driving great distances to get further away from New York City lights (White zone). Its time for me to modernize and evolve as so many CN'ers have done before me. I have read so many varying opinions that I am confused by the possibility of me being able to utilize my current 4" refractor. I understand some of the math, I understand "scale", imaging, framing, the self explanatory aspects to what some might opt for larger versus modest views. In my neck of the woods anything is an improvement so my expectation is both rational and practical.
To my question, I had read a review posted online about the TNVC, 55mm plossil, all married to a "Televue 85mm refractor" got me thinking; how the hell did it go from F/7 to F/1 or F/2 to achieve the speed, what math is involved here? I understand as is the case in this hobby we always achieve best results with more aperture and speed, its a never ending battle however, how do we work with what we have without always having to reinvent the wheel with a fast NEWT or some other astrograph. I realize the FC-100DF 4" refractor as designed for Visual in the ideal world where dark skies were consistent. My objective is to try and utilize with a MOD 3 but I am uncertain as how to accomplish with "decent' expectations, For the price of the Takahashi Focal Reducer I could just as well by something more cost effective, so to my original question could someone Please explain how we increase the overall speed, considering the 85mm out of the box is an F/7 focal ratio by product design.
The How to is the part that is missing. My initial expectations with a 4" refractor would be to make out nebulae, let alone galaxies i.e. M51. Is it possible to transform this FC-100DF, I do not mind being the pioneer, to date I have not found a single syllable that someone might have posted. Its one hell of a refractor under pristine skies, I would think their is someone that can educate myself how to work with what I already have. I digress, I realize one scope cannot do it all, but surely it can be versatile enough to configure to meet reasonable expectations. Any advice is welcome, I apologize for reiterating here and there but I just wanted to be for certain I was not misinterpreted, and I thank all for replying.