This is my first post on CN. I have registered here and BF so that I can learn from the experience of others brighter than me and hopefully soon be able to contribute instead of just asking questions.
I am caught in a similar problem as the OP. I am fighting whether or not to take a deal on two BA8 variants in 7x50 and 10x50 or bow up and get one FMTR-SX model.
I confess that my questions are more for terrestrial use as I use a 90mm refractor and 10" dob on the rare night that the sky is cool, clear, stable and time allows.
I was heavily leaning towards the 7x Fujinon because I want these for more impressive sharpness and brightness in terrestrial viewing under dim conditions. However, I also want to add a 10x50 to the collection and I love decent 10x binoculars on tripods. I have read a few comments about how the field flattener elements work about as well as Swarovision, which I would like to try on the cheap.
Post #44 really alarmed me. Why doesn't the 7x Fujinon have the "F" lens as labeled? Is it because a 7x doesn't have the same issues described in post #5?
Most importantly, in real/actual visual use, can the the view through the 7x be described as flat or not?
If not I will probably spend and stretch my money on the 10x Fujinon since many people seem to think it very special even within the Fujinon lineup and then cheap out and get a BA8 7x on sale for dusk/dawn applications. This is the opposite of my original plans but I was assuming that the 7x Fujinon had a flat field.
Can/will anyone help me understand if I should be concerned about this or not?
The FUJI 10x50 is a fantastic bino for astronomy, and I will never get rid of mine. However, for terrestrial views, I'm not so sure it would be ideal. If you are into bird watching and the like, the individual focus of the FUJIs might put you off a bit, and a center focus binocular might be better for you. Certainly center focus is much quicker in focusing on fleeting objects, whereas for astronomy once focused at infinity, they usually only need a tweak or two throughout the night, in my experience. I have no experience with the FUI 7x though I have owned several other 7x binos, but would not recommend that power for astronomy. Just my opinion, of ours.