This testing stems from the MSN BPCR site/guys. All the info and test results are being kept at http://sports.groups.yahoo.com/group/CB-BOOK/, in FILES, in WORK IN PROCESS.
I just saw this place and maybe there are experts here to get us on the right path.
Thanks;
joe b
joeb33050yahoo.com


I'm looking for folks to help by doing some testing of spotting scopes.

This is everything I know about spotting scope testing, to date.

My experience is that spotting scopes have a threshold, some just don't do the job, then there are a lot that do meet the minimum requirement and vary in "goodness". Somewhere out there are the $1800 scopes. My definition of the threshold is the ability to see "most" 30 caliber holes in the black at 200 yards in less-than-perfect conditions. May be arbitrary, but I've used it for many years, looking through a lot of scopes. Certainly the red ASSRA targets are easier to see bullet holes in, but some prefer the black target.

The object of the testing is to find out something about the ability of various spotting scopes to do the job, to find out about their relative "goodness".


I wrote to Jesse Miller, a retired eye Doctor, for his input..

Jesse Miller, 11/2/07
Joe: Several factors to consider:
The brightness of the paper may have some effect.
Mirage and the other factors you listed all may at times have an effect on the results.
Also, yes the eyesight of the person doing the testing will affect the results. People with eyesight problems will not score any scope as highly as a person with good eyesight.
So I will recommend that all of the afore mentioned condititions be recorded with the results.
It would seem to me that the tests should only be done when two or more scopes can be tested at the same time under the same conditions. This would work even better if two people can independently test the same scopes. This whole thing will require some cross referencing, or maybe quite a bit. The more data you can get the more definitive your results will be.
One way to tighten the controls would be to use a limited number of testers and then have them test a number of scopes at the same time, under the same conditions.
Hope this is a help. Jess.


About the testing:
Understanding what Jesse said, I started testing and asking others to test scopes with the notion of getting some data, and maybe finding out how to design a better test.

All testing to date was done at 100 yards, and for now, we want to continue testing at 100 yards.
I try to have two or three people do the test with each scope; the owner, me, and a bystander. This sometimes tests the patience of the owner that I've inveigled into testing at the range. .
All testing was done using the 1951 Air Force resolution target which can be found at http://www.6mmbr.com/targets.html. This is a .pdf file that prints an 8 1/2" X 11" target that seems clear and is a bit confusing. To understand this, you need a copy of the target at hand.
There are several "series" of targets on the page, all numbered from 1 to 6. The largest and second largest series are not otherwise identified.
Next smallest is the series headed "-2", then the series headed "-1", then , getting smaller is the series headed "0", followed by the series headed "1".
Scopes tested to date were able to see the -2 and -1 series, and in one case the smaller 0 series.
Tests are recorded as, for example, -1, #3, meaning that the smallest target seen was in the -1 series, nuimber 3.

I measured the height of three-black-bar images for some targets. There are three black bars with two white spaces, the bars shown twice, horizontal and vertical. Here are the distances across the three bars-approximately-in inches:

Target Inches Tests with this result
-2, #1 .365"
-2, #2 .325" 5
-2, #3 .285" 3
-2, #4 .255" 7
-2, #5 .225" 3
-2, #6 .205" 5
-1, #1 .195" 6
-1, #2 .170" 4
-1, #3 .150" 6
-1, #4 .135" 5
-1, #5 .120" 1
-1, #6 .105" 1
0, #1 .095" 1
0, #2 .085"
0, #3 .075"
0, #4 .065"

The object of the test is to identify the smallest target where the black and white bars are seen clearly, where the next smallest target has the bars look like a blurry black rectangle. Ihe object is NOT to see the smallest number that can be seen.
This is important, and I've had some difficulty explaining the how-to to some participants. Again, the reader should have the sample target at hand.
Let's say that the smallest target that can be clearly and comfortably seen is in the -1 series. The tester can see the black bars and white spaces next to the number 3. On the next smaller target, number 4, the black bars and white spaces blur into a glack to gray rectangle. In this case, the test result is -1, #3.

I test with a sample target at the scope, so that the tester can point to the smallest target that he can comfortably see.

I had to include light conditions and mirage in the testing, and made up these notations:
Light conditions choices are:"Sunny", "Cloudy", "Overcast"
Mirage choices are: "None", "Some", "Heavy"

I've had some trouble identifying spotting scopes. So far all have had the maker's name, some were not identified further.
Here's what is important to record about the scope tested
Scope Maker: ex. B&L, Kowa, Tasco, etc.
Scope Model: ex Bushnell "Spacemaster", Kowa "TSN821", etc.
Objective lens diameter: These seem to come in 50MM to 100MM sizes. 50MM~2", 60MM~2.4", 70MM~ 2.8", 80MM~3.2", 90MM~3.6", 100MM~4"
Power: There are fixed power and variable power scopes, some scopes allow for interchanging eyepieces. Record the power as, for example, 20X or 20-40X or 15-60X or whatever is found on the eyepiece/scope.
Many of the scopes we've seen are marked something like: "20-60 X 60" which means that the power is adjustable from
Power used: Some variable power scopes are found to test at smaller target sizes at lower than maximum power. A 20-60X scope might test smallest target at 40X, so record the "Power used" as "40X"

Then there's the eye relief. Some scopes have a lot of eye relief, and I don't have to take my glasses off to look through the eyepiece. Other scopes have very little eye relief, and with those I must remove my glasses to use them. Now this is an annoyance, but doesn't, so far, seem to have anything to do with the "goodness" of the scope.
I added a column for Eye Relief, with "Long" meaning there's plenty, so that glasses don't interfere, and "Short" meaning that glasses interfere.

The test information required is then:
Date:
Tester's (First) name:
Light Conditions: ("Sunny", "Cloudy", "Overcast")
Mirage: ("None", "Some", "Heavy")
Scope Maker:
Scope Model:
Objective lens diameter:
Power:
Power used:
Smallest target comfortably seen:
Eye relief: ("Long" or "Short")
Other comments:


Here are some thoughts and experiences:

Side by side: Jesse and others say that testing scopes "side by side" is the proper method. I can understand that, but can't understand how to test maybe 20 spotting scopes side by side with maybe 3 testers, which is the possible test scene at bigger matches. I've tested some scopes side by side, but don't know what to say about it other than the test results.

The tripods or supports or mounts. Yes, we all know that a steady mount is best. We know. But, I haven't found one yet. There have been mounts from a flimsy table top tripod to a serious looking camera tripod to a clamp-on bench spotting scope holder. I thought I had a good one, clamp-on.
All of them vibrate in the wind, making seeing difficult. More X, more vibration. Now it might be nice to test scopes set in concrete, but that ain't how they are used.
The Winchester scope and table top tripod, with canvas bag and stuff, all in a nice hard case, cost $60, I'm told. This tripod worked as well as others, at similar powers, as long as you weren't touching it. Hard to adjust, but as steady = vibration amount as most any other. Doesn't mean it was good, just that all mounts allowed vibration in the wind. The wind blows in South FL from Halloween to Memorial day, so there won't be much mirage.
I'm starting to think that a cheap scope in a good stand is a better deal than an expensive scope in a lesser stand.

The power. I'm trying the variables out at lower powers to see if I can see better, and I can't see the target better, yet, with any scope at a lower power, except one.
EX: Redfield 20-45X, I can't see a smaller target at a lower power than 45, BUT, regular targets with bullet holes are "easier" to see at lower power. I can see "better" at 45X, but I can see well enough to see 22 holes at 100 yards at 20X. I would use this scope at 20X at 100 yards, based on the ease of using. It vibrates and shakes much more at higher powers and doesn't show bullet holes any better than at 20X.


The Range. All I have is 100 yards. I'm not sure that testing at 100 yards is correct.

The lies, or call it "wishful thinking". I can see testers trying to see smaller targets, testers who are in a competition, even right after I explain that smaller ain't better and that we want the "smallest target you can comfortably see". And I still see myself straining to see smaller targets. The only way I can think to beat this is with an eye chart kind of target,"read it to me!". This separates wishful thinking from reality.
One of my interests outside of guns and shooting is about this: There are recorded many statements from responsible individuals, frequently scientists, that are absolutely untrue. Sometimes they're telling a lie, but often enough they believe what they say. From this we see that there is something happening in their brains, that they see what is expected and the unexpected is invisible.
Examples include kitchen table cold fusion, police officers arresting the wrong guy, criminalists providing scientific proof implicating the wrong guy and prosecutors getting the wrong guy convicted.
I used a number of these examples to suggest to students that competition sometimes leads to unfortunate outcomes.
Recently I got to test a Swarovsky 80MM scope, and a Barska 20-60 X 60 scope.
I like to do the test myself, have the owner test, and get another person to test if possible.
The Barska scope was not a top flight spotting scope.
I could clearly see the -2, #6 target, nothing smaller.
After the -2 set, as they get smaller, there are the -1 set, 0 set, and the 1 set. The smallest target seen to date is the 0, #1 target.
The owner of the Barska, Armando, and his friend, Ralph, both claimed to be able to see all the 0 targets, down to #6. This after I explained what we were doing, how to pick the smallest target you could see, and that smaller was not better-this isn't a competition.
I do the test with a copy of the target in hand, so the tester can point to his smallest target.
I talked to them, had them look again, talked, looked, all to no avail. Armando claimed 20-20 eyesight, no glasses, no problem. Ralph said the same.
I have not an iota of doubt that neither of these very friendly and cooperative guys could see the targets claimed.
Something was going on, but it wasn't truth.

The time. If I wait long enough, until there's a lull in the wind, and my eyes are working best, and everything is great-I can see smaller targets. I can't wait like that to see bullet holes in an offhand match.

The Translation. We're testing against a resolution/size target, and we want to know the "ability" of a scope to see bullet holes. I'm not at all sure that these are the same, or how to make the translation.

Paper Brightness. My Office Depot package of paper has a list of paper types and "Bright*" with the note "Brightness Scale = D-65". The papers listed have Bright readings from 104 to 115.

A note: 11/28/07 a shooter asked me to look at his target at 100 yards, shot with a 25/06. Neither he nor I could see any hole in the target, we both thought that there was a hole in a certain spot in the black, but wouldn't bet on it. This through two spotting scopes. When he brought the target back to the line we saw that there was a double in the black that was what we thought we could see, and a single in the black that neither of us could see.

On 12/8/07 we tested John Austen's Kowa TSN821M with 27X eyepiece, his Konus Konusport 80 with 20-60X eyepiece, and my old Bushnell Sentry 50MM 20 X.
There were some patches of clouds rolling by, so I tested the Konus and Bushnell scopes in both cloudy and sunny conditions. Clouds went away for the Kowa testing.
The Konus, at 40X, tested -2, #5 in sunny light, and -1, #1 in cloudy light. I checked this a second time. This is a 2 step smaller target in cloudy light than in sunny light.
The Konus tested better at 40X and 60X than did the Kowa, however the Kowa at 27X tested better than the Konus at 20X.
The old Bushnell Sentry tested equal to or better than the Konus at 20 X and almost equal to the Kowa with both John and me testing
(-2 is larger than -1, #1 is larger than #2 is larger than #3 etc.)
Konus 20 Cloudy Joe B -2, #2
Konus 20 Sunny Joe B. -2, #2
Konus 20 Sunny John A. -2, #2
Konus 40 Cloudy Joe B. -1, #1
Konus 40 Sunny Joe B. -2, #5
Konus 40 Sunny John A. -1, #1
Konus 60 Cloudy Joe B. -1, #3
Konus 60 Sunny Joe B. -1, #3
Konus 60 Sunny John A. -2, #6
Kowa 27 Sunny Joe B. -2, #4
Kowa 27 Sunny John A. -2, #4
Bushnell 20 Cloudy Joe B. -2, #3
Bushnell 20 Sunny Joe B. -2, #4
Bushnell 20 Sunny John A. -2, #2