Well, I collimate using the sun images method (see:
https://sites.google.com/site/rchamon/home/sun-images-method-for-collimation-of-binoculars ) using a collimation board very much like the one shown in Section 1.1 figures 1 and 2. After reinstalling the Zen Ray prism unit and reassembling the rest of the binocular and testing it on the board there was a great deal of both vertical and horizontal deviation. By adjusting the four screws (i.e. methodically loosening one screw and tightening the opposite screw etc.) I was able to reduce these deviations to practically none (well below the deviation standards given in Section 3.4) at IPD's 60 mm, 65 mm, 70 mm and 75 mm.
Hi, LPT:
By speaking in straight terms and not beating sheepishly around the bush, I am often taking as being harsh when that is, in fact, the farthest thing from my mind. You will note that Rafael references me and “Conditional Alignment” in his article. I have the deepest respect for him and he is the only practitioner of binocular alignment (except Cory) mentioned in my book. In addition, I think his groundbreaking work should be studied and practiced by each person who wants to learn about binocular collimation. Even so, Rafael freely admits his alignment method does not result in clinical collimation but “Conditional Alignment,” only. And by using his method, that is what you have performed, not 3-axis binocular collimation. There are important differences.
One of the attached images was captured on Google last night. Beyond that page, I looked at the next 31 entries on binocular “collimation.” 100% of the entries I have seen so far just deal with conditional alignment—NOT clinical binocular collimation. Sadly, some people offer this misleading advice as if they have just invented a ten-minute brain surgery technique. And it is VALUABLE, based on the bovine excrement that has been printed and embellished over the last few years.
* If I seem edgy it’s because I have been fighting—and losing—this battle for 42 years to support technical accuracy and save some folks from themselves.
I RUSH ON TO SAY that in many cases Conditional Alignment is more than adequate to make a binocular serviceable for ONE user or others with a similar IPD. But, many times those who don’t know the difference will further damage the overall alignment, if the instrument is to be used by others, by the willy-nilly tweaking of screws. The second image is the collimation convention found on many roof prism binoculars. I recall a 4-screw method for positioning prisms but not collimation adjustment.
This matter keeps rearing its ugly head so often, I thought a couple of examples would be good.
“... Fellow Opticalman shipmate, Cory Suddarth, was with me the day I took a call from a fellow who had been a repair manager at his company for many years. The essence of his call went like this:
“I just don’t understand it; I’ll get the binocular collimated, but when I move one of the barrels, it’s off again.”
“He was right; he didn’t understand it. This fellow was a conscientious technician and merchant. But being unfamiliar with the basics of 3-axis collimation, and following today’s popular but flawed alignment techniques, he and his staff had been selling conditional alignment as collimation to his repair customers all those years, forcing them—and possibly causing eyestrain—to complete the job. It was this experience that caused me to first suggest there’s a big difference between 20 years of experience and one year of experience 20 times.”
A Master Binocular Retailer
In the early 1990s, when Cory Suddarth and I worked together in the Precision Instruments and Optics Department at Captain’s Nautical Supplies in Seattle, one of today’s MAJOR binocular retailers was just beginning to spread his wings. In conversations with him, he told us he “didn’t NEED a collimator because [he] could ‘eyeball’ collimation to 100 power.”
Did he know about 3-axis collimation? No.
Did he know about spatial accommodation? No.
Had he ever heard of “Conditional Alignment”? Not until those conversations. Then he, for his company, produced 2 video tapes for sale to say, “Conditional Alignment” was a “myth.”
Finally, after I was out of the business and Cory had started S.O.R. (Suddarth Optical Repair), this fellow went to one of Cory’s binocular collimation clinics.
Immediately thereafter, this retailer put together his own collimator and bought an auxiliary scope from Cory and was in the business of knowing what he was doing. In addition, he has recently purchased one of the Mk5 collimators I sold to companies in Southern California.
Now, he has his collimator in his promo photos, professes all binoculars leaving his store are “perfectly collimated” and that he is the only retailer in the United States that has a collimator. It seems he has done a 180 on collimators and “Conditional Alignment.” Maybe someday he will remember that I left 3 collimators in working order (including a Fujinon U.B.M.M.) at Captain’s and sold 2 others to businesses in California.
And with regard to “perfectly collimated”:
Considering how so many folks on binocular forums like to split hairs and talk of things that are miles from mattering, I think the following is something to, at least, think about:
1. NO binocular is “perfectly” collimated.
2. NO binocular CAN BE “perfectly” collimated, certain comments relating to salesmanship notwithstanding. I’ve never collimated a binocular to “perfection”; Cory has never collimated to “perfection.”
3. That condition exists only by happenstance and, with changes in temperature and humidity, will only remain so for a matter of a few minutes—if that long.
— A binocular can VERY EASILY BE “perfect” FOR ALL INTENTS AND PURPOSES even through judicial conditional alignment.
— A binocular CAN BE—by someone trained in something more than haphazard screw tweaking—brought to a full collimation FOR ALL INTENTS AND PURPOSES.
— A binocular can VERY EASILY BE brought to within Panum’s Fusional Area or range of accommodation for image separation and cause ZERO eyestrain.
But “perfect” collimation? :cat:
“To dream the impossible dream ...” — Don Quixote, Man of La Mancha, 1965
Cheers,
Bill