8.5 vs 10 by 42...

[Elkhunter96]

So, I have one top end 10 x 42 (German made) that I have been comparing to a middle class 8.5 x 45 (Japan Made) that I own. I was really impressed how well the 8.5 pair stacked up, even in very low light conditions considering the huge price difference. I have spent almost a week comparing them in the day, in the evening and at dusk. The german made binos are only slightly more bright and crisp, but not by much at all.

So, it brought me to this question. How much difference would the power settings cause my testing to be invalid. If I could, I would compare apples to apples and use a 10 x 45, but I don't have access to a pair from that brand. Any thoughts? Is the 8.5 versus the 10 power a real big reason why they are hanging where they are not supposed to?

 

[BPKHunter]

Well, the first obvious difference is the low light. You have almost a 20% larger "exit pupil" on the 8.5's which is a primary factor in light gathering capability to your eye. A second factor that is hard to assess, is that 8.l5's will be easier to use off hand. The clarity will seem less affected by your natural shake, so if you want to judge clarity or frankly even brightness I would be sure these are both locked into a good steady tripod.

FYI, I much prefer 8x bino's for offhand, and it seems that a 5mm exit pupil is the point where the human eye starts to get full benefit, depending on your age, so unless you will use a tripod most of the time the 8.5's are a good set-up. This is no judgement on the "good" japaneese brand vs the expensive german brand as I love swaro's myself.

 

[Elkhunter96]

Thanks, I kind of figured it may have been my test comparing two different sized glasses. The 20% larger pupil would definitely explain a lot of the results I was getting.

I specifically left brand names out because I did not want to get into that argument. Sufficient to say, the german glass is one of the big three and is their best glass and the other seems to be a good Japanese made glass.

I am keeping both glasses, so I will have both a 8.5 x 45 and a 10 x 42. I wanted the extra maginfication on the better glass.

 

[BGbasbhat]

FYI, I started a good thread about this last year called "Why 10x42s?" or something like that.
Give it a search, and it might have some good insight.



"...I'd rather be tried by twelve than carried by six..."