Depth of field in Binoculars

[jimmyp50]

I just was in the process of ordering a pair of binoculars and the salesman told me that one pair the Nikon superior E porro prism (although not waterproof) had a better depth of field than the Nikon LX roof prism glasses. I am going to get either the Nikon SE or the Nikon LX in 8 x 32 as I cannot see the $300 or so difference between these and the Leica 8 x 32.  I guess I cannot think of a reason that less depth of field would be a big problem, but I can imagine that water getting into the SE's would be a problem.  I have looked through both glasses and both look about the same to me, they both have the effect of optically transporting me 8 times closer. I used a pair of Nikon Superior E 8 x 32's for a week and loved them, the view was astounding. Anyone care to comment about depth of field? Most use will be in Georgia, white tail deer hunting, or hiking.

[Dave in WV]

I'm not familiar with all of the Nikon models. Is the pair with the most depth of field of poro design and the other the roof type. Poro prism (the angled type) are supposed to have a greater depth of field over the roof type (the straight tube type). The poro type are harder to waterproof than the roof type.

[Graybeard]

So why are you concerned about depth of field? That's what the focus knob is all about. In general an indivdual focus binocular has a far greater depth of field than any center focus and different ones vary in how much but it ain't no biggie. Just adjust it with the adjustment. Don't let this drive your buying decision.

GB

[Naphtali]

My understanding of "depth of field" is twofold.

1. One facet is like a camera lens -- that is, single telescope -- where its meaning is the amount of close-to-far distance what you are looking at remains in focus.

2. The second facet pertains to judgments you can make about the distance. What I refer to is stereoptic focus of two telescopes -- your eyes, being two "telescopes" that are focusing on the same object from slightly different perspectives. This facet is a function of distance between the telescopes. Porro prism binoculars have greater distance between telescopes than do roof prism binoculars, so the stereoptic effect greater.

What I do not know is how significant any of this is once what you're looking at is far enough away that what you look at is focused regardless where it moves.

Parenthetically, before "laser" rangefinders, rangefinders were binocular devices with telescopes huge distances apart -- forty inches apart and greater.

If you prefer porro prisms, Steiner's military binoculars are supposed to overcome the "bolt-together" sealing problems of the Zeiss "E" body by injection molding the "E" body from one piece of plastic. If this is true, it should solve the problem.

[GBO MGMT]

Depth of field is merely the range of distance you can see clearly in focus at any given time. The how and why it is different is rather complicated and depends on the compromises each manufacturer choses for their equipment.

As a for instance. My old Steiner 6x30s with individual focus eye pieces has a huge depth of field. My Bushnells have far less but still much greater than the new Leicas I just got.

In a camera when you decrease the diameter of the aperture you increase depth of field. This is wanted especially for macro or close up photography.

GB