Re: Field Scope vs Swaro vs Zeiss vs Leica
I haven't had the pleasure of looking through the 3 Euro's that you mention, however I do own a Fieldscope ED III which I am very happy with. At 25x the images are very bright and crisp. At 45x, the images do lose a little brightness from 25x but are still very clear and crisp. Here are some indications of it's performance from a few things that I looked at this evening around 7pm this evening. Definitely not full daylight with sunset at 7:29pm.
568yds - Could clearly see the eyeballs on turkeys at 45x
782yds - Saw a service guy at someone's house wearing a shirt with 2 patches over each of his breast pockets. I could see the lettering and distinguish that one had 2 rows of lettering, but could not read it.
1497yds - On 45x I could clearly see single strands of weeds growing on a pillar of an old train bridge.
1 mile + I was watching a groundhog in an open field and could clearly see when he raised his head from eating while still on all fours.
I'm not sure if any of this indicates a good scope, but I would imagine some can't distinguish this stuff. Overall, I would highly recommend one, the ED version that is. Someday, I would like to try and take advantage of the capability to attach a camera. I'm guessing the Euro glass is probably better, but also at considerably more money. If you get one, I doubt you will regret the decision.