I got a pair of Garrett Optical 10x50s recently. Great binos in my opinion, but I find that I have to re-focus them just about every time I aim them at something different, so it's a bit frustrating. I did not have to do this with my 40 old Jason 7x50s. I e-mailed Zach Garrett and he told me that the problem was that the depth of field is limited for 10x binos, and that any 10x bino was going to have this problem. He also told me that as you use more powerful binos (say going from 7x,8x,10x and so forth), the depth of field problem just gets worse and worse. Is this true? Depth of field is not a commonly discussed topic when looking at bino statistics. Is there any way to minimize this constant need to re-focus? Any brands that have any better depth of field than others? Thanks for any replies.
Clay
Clay,
It is true depth of field/focus is shallower when magnification increases. Some people notice it more readily than others. Also, the closer the distance to the object upon which you focus, the more shallow is the depth of field. Or, at long distances, the depth of field is 'deeper' and usually not noticed. Possibly the objective lens size might have an effect, but I'm not sure. Other than that, I don't think that it can be improved-upon, but I could be wrong.
Yes, can be a problem. Bright days and binocular brightness help out a bit. Don't get dim 10x, a failure of 10X Sporters, if it is a problem. Also leads to more diopter adjustment if your two eyes are very different.