190613
There are TWO phases to focusing a binocular, or any other instrument for that matter. The first concerns the focus mechanism—the actuation of the focus knob, diopter ring, or flip lever. That is the one seen almost exclusively by the observer.
The second is through the involuntary focusing of the EYE through the eyelens being stretched or compressed by the eye’s CILIARY MUSCLES.
A 10-year old might have as much as a 14-diopter range. By the time we reach 50 or 60 that has dropped off to 2 or 3 diopters, making a focus mechanism necessary.
In learning to STARE one can prevent the eye’s INVOLUNTARY INPUT and limit focusing to that achieved through the binocular’s focus mechanism. This leaves the observer in control of whole focusing operation as opposed to having the two aspects of the operation fight each other resulting in the observer’s resorting to fiddling with the focus mechanism while TRYING to attain and accurate focus for an object at A GIVEN DISTANCE.
With learning to STARE being critical to focusing, one might hope binocular salespeople would tell their customers about it. But for most of them it is just a paycheck and nothing more; they don’t know. Every so often, you might come across an opto-geek like Marty at Company Seven (that guy challenges me in opto-nerdiness), but, for the most part, you are on your own.
I find it disconcerting that so very many observers who talk endlessly upgrading their binocular—many of those people already owning one of the best binoculars ever made—fail to take this indispensable facet of observing into consideration.
THE BRASS TACKS
The task is learning to STARE! Or, as Peter—another super opto-geek—points out, let your eyes be at REST. “(perhaps less ambiguous).” Yeah, yeah, always the gentlemen ... a Brit thing ya know. The method you choose for accomplishing that task is up to you. ED points out the aspect of pulling the binocular away from your face. That is part of one method. I learned, while still a Navy Opticalman to stare with the bino to the eyes. This is not going to be easy at the start, but it is possible and makes precise focusing at a giving distance possible. I keep saying AT A GIVEN DISTANCE because that, too, is important. You may be precisely focused on a stellers jay in a tree 40 feet away and suddenly decide to view the northern flicker that just landed on the other side of the tree.
Although the distance to the birds might differ by 8 feet, you may see no loss in clarity. But just know that is your brain ACCOMMODATING the difference through those ciliary muscles. There’s no “free lunch” in optics. The distance was easily accommodatable but if planning to stay focused at the new distance, you might want to focus with the focus mechanism. It’s only an OPTION and will be ever so slight. You might have a pleasant image without focusing for several minutes ... or ALL DAY. But this is because everyone has different perceptions and levels of accommodation.
TRY THIS
1. Focus on a target a few hundred feet away—without the binocular.
2. Focus on the target with the binocular.
3. Without looking at the target, defocus the binocular (each eye) -1.5 to -2 diopters.
4. Return to the target without the binocular superimposed.
5. Once satisfied, QUICKLY superimpose the binocular without touching the focus mechanism.
6. If the image stays slightly blurry for a bit, you are learning to stare. If the image becomes crisp too quickly, your brain is taking over and is focusing your EYE—something you don’t want to happen.
7. Repeat the operation until your brain “gets the picture.” Please, however, understand that one size does not fit all. You may come up with what works best for you. Perhaps focusing the bino at 1 diopter would work best.
THE METHOD IS IRRELEVANT; THE RESULT IS NOT!
Ed mentions pulling the binocular away from your eyes. Do this and note the image quality. No matter the method of learning to STARE, your observing sessions will be less troublesome and your images more crisp and pleasant if you learn to do so.
Three things to remember:
1. Learning to stare will not prevent problems related to poor collimation.
2. Learning to stare will not allow a paperweight binocular to perform like one of the big three.
3. Learning to stare will not increase image brightness.
Bill
PS Ed, Peter, jring, others: right now, I am trying to restore 31,100 files—ONE AT A TIME!!!!!!—to their proper place in about 40 folders. I’m hoping to get some sleep ... sometime next month. The one and only iMac geek in Twin Falls “helped” me with a problem and created 8 or 9 other problems in the process. I’m worn out. So, if you see a reason to protect others from me, PLEASE go for it! If my files had remained in the trash, I could have used the “put back” command to restore them to their original folder. In the 90 seconds I was in the bathroom, he created another folder on the desktop that we might not, by accident, “empty the trash.” Now to use the “put back” command would only send them BACK TO THE TRASH! Directly after selling me this Big Mac, Simply Mac went out of business and left town without giving me the promised user manual. Learning about the “Time Machine” would have prevented this mess.
