Comments on: Swarovski Tech Blog Reveals How Scopes Work

By: Boyd Allen

Boyd Allen — Sat, 15 Jun 2013 22:33:02 +0000

Have you noticed that you can do the same thing with a fine threaded eyepiece? It just takes so many turns to get to the extremes that there is none of the snapping in and out of focus, because the change is so gradual. What you are doing is working with the entire set of lenses between the second focal plane (typically) and the retina, including the eyepiece, corrective lenses, and the eye’s lens, to focus on the plane that the reticule is in. Recently, I have been using an auxillary lens that screws onto the back of the eyepiece that not only increases magnification, but holds the field of view the same, and actually increases the sharpness of the image…for MY eyes.

By: Editor

Editor — Sat, 15 Jun 2013 18:51:15 +0000

Boyd,
You raise some good points about eye protection. Most common eyeglasses do NOT have ANSI-certified impact-resistant lenses. Eyewear with actual glass lenses can shatter dangerously on impact. That is why it’s better for someone with non-impact resistant eyeglasses to remove them and use safety eyewear instead. The Diopter adjustment will allow most folks (those who don’t require extreme correction beyond plus or minus 3.0) to see the target sharply.

Of course, you can also order custom Prescription eyewear that IS impact resistant. Such prescription safety glasses are not inexpensive.

By: Boyd Allen

Boyd Allen — Sat, 15 Jun 2013 16:52:14 +0000

Pretty much every scope that I have seen has an adjustable eyepiece. Some have fine threads that require multiple turns to traverse the full range of adjustment, which precludes any simple index system. These usually have a lock ring, and the eyepiece is rigidly attached to the scope when it is tightened. Other scopes have adjustment systems that have much faster pitch threads and complete their full range of motion in a turn or less, allowing for the use of an index system. These are usually secured more loosely with a spring providing tension against the threads, and although this would seem to be less secure, good results have been obtained using both systems.

Both styles allow considerable range of adjustment by moving the eyepiece lenses together, as a unit.

Being able to adjust a scope so that it can be used without corrective lenses presents the temptation of shooting without any protection. This is an unsafe practice that is all to commonly done by people who seem to be intelligent in all other respects, but in this one area, evidently are not.