Spotting Scope Testing
Nov. 7, 2007
The bidding to date:
Jesse Miller, 11/2/07, responding to my message. Jesse is a retired eye doctor.
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 conditions 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.
I made a test target with a sentence in Times New Roman, sizes of 72, 48, 36, 24, 22, 20, 18, 16, 14, 12, 11 and 10 points. These are the sizes available on my computer.
Steven Dzupin on Cast Boolits clued me in to
(You need to Login or Register to view media files and links), where there are downloadable copies of scope-testing targets, including the 1951 Air Force resolution target.
I downloaded these into a .pdf file as recommended, and printed the AF target. It certainly looks good to me.
On Nov. 7, 2007 we did some testing.
First, the 72 to 10 type script target doesn't work. The problem is that there's nothing between 36 and 24 point, and some of us needed another choice.
Second, three people lied during the testing.
(This is one of my strongest interests and research subjects: the lies/inaccuracies and their invisibility to researchers.)
I explained how to do the tests for both targets.
Get focused on the target.
Fiddle with the power if variable, get where it looks the best.
For the type script, 72 to 10 point target, tell me the smallest line you can comfortably read.
For the AF target, tell me the smallest target on which you can see the bars and white spaces between. I had a copy of the AF target in hand for them to point at.
Two testers claimed to be able to read the 24 point line, one read it as ">>>27 point", the other as "....21 point", and I queried them.
I lied to myself, claiming that I could read the 24 point line.
I KNOW it isn't a competition, the other testers know. We have this "compete" gene.
Here are the results, after explanation and negotiation:
Bright and sunny conditions
B&L 20X, 36 point, #6 on the 3rd largest set, John
Simmons 20-60X60 at 60X, 36 point, #6 of the 3rd largest set, Tony
Simmons 20-60X60 at 60X, 36 point, #5 of the 3rd largest set, Joe B.
30X STS, 36 point, #4 of the 3rd largest set, Joe B.
30X STS, 36 point, #5 of the 3rd largest set, Tony
20X Bushnell Sentry, 36 point, #4 of the 3rd largest set, Joe B.
Kowa TSN821, 27X, 36 point, #5 of the 4th largest set, Raoul
(The Kowa was in one of those blankies, Raoul isn't real good at English. I read "TSN821" off the scope, there may be more info under the blankie.)
This is an imposition on people at the range, responses varied from "sure" to "no".
Nobody even claimed to be able to read script smaller than 24 point, nobody could read 24 point, some fibbed but were caught.
My script target is out. I'd like another script target with finer graduations in sizes, and different words-to catch the guessers.
Anyone willing to do some testing, please make a copy of the AF target, and try it out. Record the scope make and model and power, and the light conditions, for now, are:
Bright and Sunny
Cloudy
Dark and overcast
Thanks;
joe b.