I already know about first and second focal planes. What is a rear focal plane? I'm guessing it's a first, in which case I won't want it.

Rear is second focal plane, assuming rear means the back of the scope. I've never heard of a rear focal plane.

A Burris scope described as having "'rear' focal plane" turned up in my Amazon "suggested" feed and piqued my curiosity.

quote:

Originally posted by egregore:
I'm guessing it's a first, in which case I won't want it.

What is your expected use, and how will the focal plane location affect your use?

The more common way of referring to the two types of focal planes is first and second, but front and rear are not unknown. The terms refer to the same things.

Out of curiosity I asked AI Gemini what manufacturers use “front” and “rear” focal plane terminology, and the answer listed several companies. When I checked individual web sites, I found that all were wrong; they all use first and second or 1 and 2.

A follow-up question referenced possible English translations of European terms that made some sense, sort-of, and as I think about it, I may be remembering terms I saw years ago before the present terminology was adopted by all companies. But of course if you saw “rear” mentioned, that indicated it was used at one time at least.

And front and rear do obviously match the first and second positions labeled in the scope illustration that benny6 posted.

Both the Amazon link and the Burris site show this. (Naturally, because the Amazon link is the Burris store). Screenshot from Burris site:


I have no plans to actually purchase this, or anything else, at this time. I already have three Sightrons that are very good for the money. I was merely curious about the wording.

This message has been edited. Last edited by: egregore,