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Bino tests? |
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Brocksw
Optics Apprentice Joined: October/20/2016 Status: Offline Points: 57 |
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Posted: October/20/2016 at 20:14 |
Does anyone have any method for testing optic (clarity, light transmission, color fidelity, etc) in an indoor setting? Is there a poster board with letters on it like at the eye doctor or some sort of contraption that would allow a person to judge light transmission?
In my experience even mediocre optics look OK when brand new, clean, and inside a well lit store. There has to be some gadgets or methods to push a binocular/spotting scopes abilities. |
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supertool73
Optics God Superstool Joined: January/03/2008 Status: Offline Points: 11814 |
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Why inside? Binos are meant to be used outside.
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Brocksw
Optics Apprentice Joined: October/20/2016 Status: Offline Points: 57 |
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Can't always get binos outside in the correct environment to look for those finer details. However, if there was a something I could look at from a distance of say 50 yards indoors that would give me some sort of measurable or consistent platform to base an opinion off of. I thought I had seen a white page with certain shapes and letters on it that was meant to be a good indicator of sharpness and color. Maybe I'm confused.
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WJC
Optics Journeyman Joined: May/28/2014 Location: Twin Falls, ID Status: Offline Points: 328 |
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You may be over-thinking the situation. This is vignette 1 from an upcoming book:
1 “WHICH IS BETTER?” When people are planning the purchase of a new binocular, or comparing what they’re now using to a friend’s, they invariably ask: “Which is better?” This is a tough question calling for many answers, usually more than the questioner had expected. Even so, the new binocular shopper will visit the phrase again and again with respect to aperture, magnification, prism type, anti-reflective coatings, and more. The list may grow as the observer tries to decide which features are most important to his or her viewing pleasure and which are being described accurately. Yet without the potential buyer revealing definite preferences, on which he or she usually has yet to decide, the answer is elusive at best and even the most experienced and thoughtful mentor can be at a loss to help. The first thing to be decided is just what constitutes good, better, or best. Does the term relate to light grasp, aberration control, weight, glare suppression, near perfect collimation, or any one of a handful of other considerations? Example: Two observers might ask if a certain binocular will provide a “good view” of Mount Rainier (It’s a Seattle kind ‘a thing). To the first observer the question means: “Can I see mountain goats from my office on the 21st floor of the Columbia Center?” To the second it means: “Can I get a view of the mountain with at least 5 or so miles on either side?” Both versions of good are valid and may represent the exact goal the observer has in mind. However, while one observer has realistic expectations, the other is looking for a level of magnification and resolution that’s unrealistic for a handheld binocular. ********************Two Binocular Views of Mt. Rainier ******************** While preparing this entry I went to a popular binocular website and, looking at the first two pages of posts, saw the following titles:* A couple of hundred bucks * Binocular bargains? * Any binocular recommendation for a beginner? * Best at 10x at $300-$500? * What is your favorite 8x42 binocular for less than $1,000? * Binoculars for under $100 * What is the best roof prism and Porro prism binoculars for birding? * Best modern medium $$ Porro choices today in 8x32? * UK Binocular deals, special offers, and bargains * Best overall 7x? * Help me choose my first binocular * Searching for a good 10x25 … …with eight more posts related to comparing this binocular to that binocular. My computer allows 25 thread headings per screen. That means within the 50 posts shown on those two pages, 40% were to inquire “Which is best?” Or possibly, “How does this compare with that?” Had I surveyed a hundred pages, the percentage probably wouldn’t have changed very much. Not only that, the questioner will sometimes offer up four or five instruments he wants compared. When one considers the features of each binocular worth comparing, it becomes plain he or she is really looking for a simple answer to a complex question. This isn’t an indictment of the observer who is just getting his or her feet wet, just a nudge toward taking things a little slower and more judiciously than one might choose. “Dear God, please make me more patient ... AND DO IT, NOW!” An Effort in Futility Will pointing to this folly make it go away; will we ever see the end of binocular “shoot outs?” No. I hope only to convince potential questioners to let others have a better idea about their goals from the outset. It’s helpful when speaking with friends and critical when speaking with a salesperson. “Which is the best?” is an enormous question. Yet it shrinks to manageable proportions when one allows his counselor to know how the instrument will be used and under what conditions. In addition, those wanting the best advice should know something about the knowledge or experience of their prospective advisor. Often, someone new to observing will take as gospel the opinion of a friend or review of a binocular written by a person enamored with only one or two facets of its design or performance. This isn’t a valid gauge. Since a binocular is a composite of all aspects of its mechanical and optical functioning, basing conclusions on one or two, especially in lower quality instruments, can be a recipe for regret.
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“Water, water everywhere nor any drop to drink.” — Samuel Taylor Coleridge
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JGRaider
Optics Master Joined: February/06/2008 Status: Offline Points: 1540 |
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OP, you an google USAF resolution chart, as that may be the one you're looking for. I still wouldn't do it indoors though. Things such as stray light and glare/flare control are very important, and you can't judge that very well indoors.
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Brocksw
Optics Apprentice Joined: October/20/2016 Status: Offline Points: 57 |
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Thanks JGRaider, that is what I was looking for. Do you have any knowledge about the best way to use it? Particular distance perhaps?
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Brocksw
Optics Apprentice Joined: October/20/2016 Status: Offline Points: 57 |
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I'd really like to know what this lady is looking at...
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Brocksw
Optics Apprentice Joined: October/20/2016 Status: Offline Points: 57 |
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pic didnt work here is the link
http://www.swarovskioptik.com/about_swarovski/innovations |
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JGRaider
Optics Master Joined: February/06/2008 Status: Offline Points: 1540 |
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Brock, I've never used that specifi chart, but I sometimes will hang up a newspaper at about 30 yards and check it out. I do most all of my real tests out in the field.
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Klamath
Optics Master Joined: May/20/2007 Location: United States Status: Offline Points: 1308 |
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If an engineer in an optical lab is measuring resolution they use a USAF chart. The chart is placed inside a large diameter, well lit tube. When I saw this done at the Kruger Optical facility while they were just up the road from me some years back, that tube looked to be about 10 feet long. They had a dual mount setup in front of the tube where they mounted an 8x monocular. They then mounted the binocular behind this monocular, and (one binocular barrel at a time) lined up the central axes of the binocular barrel and the monocular. The engineer then looked through that 64x setup and determined which was the smallest group that could be clearly distinguished. Taking that group number and looking at a chart, the resolution in arc seconds was revealed.
I use various resolution charts in the reviews I do. However I make no attempt at determining the actual resolution. I typical determine which one of several reads which group outside at the same time at the shortest distance. Sometimes, actually most times the differences are pretty minute. I can wind up measuring the different distances in no more than few inches, which I have come to regard as a waste of time. I just have a chart at about 75 feet or so and see if there are any readily observable distance differences. I do have a chart that has the USAF chart in several colors on a single sheet. I do not think it is sized quite right for proper resolution testing, but it is very useful in fading light to see how a glass holds on to which color and which binocular looses which color first. In the real world actual technical optical resolution is becoming less ans less of a big deal. That is because almost any binocular these days has technical resolution abilities reserved for the tier glass of even a few years ago. Things like how well a binocular fits your face, whether the eye cup extension and they eye relief are right for you and if it balances correctly I think play a much more significant role in user satisfaction. Then there is the holistic presentation of the image. How well does it suit you, which one do you like best and why. Contrast and resolution can be a lot more important than either magnification or resolution numbers. So use the chart. You have to use it more or less subjectively, because real objective tests require more than looking at a chart outside in fading light. |
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Steve
"Everything that can be counted does not necessarily count; everything that counts cannot necessarily be counted". William Bruce Cameron |
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