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Equipment Discussions >> Binoculars

EdZModerator
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Resolution Testing and USAF Res Charts
      10/29/05 12:27 PM

Binocular Resolution Testing Using 1951 USAF Line Pair Charts
In addition to test results for about a dozen binoculars, this thread shows some comparative results for a very good semi-apo 80mm telescope. Also included is a discussion on how to use the charts and links to web access for the charts and tables.

See the chart and the tables in my gallery here
USAF 1951 Resolution Chart and Table of Constants
It is extremely important that the chart be exactly sized.
The caution here is the user must know exactly how to size the chart.
You will find sizing notes below in this post and also in my gallery.


Source for commercially available resolution charts
Edmund Optics


Conflicting Arcsecond Test Results Explained
an excellent discussion explaining the differences in various arcsecond resolution values posted various places around the internet, and how to interpret them. This discussion is relevant to understanding how to use the USAF resolution charts and how the values determined by using them is so different than point source resolution. It explains why resolution values determined by the USAF charts are significantly closer than can be achieved observing point sources.



Understanding Resolution
a comprehensive technical report on the various criteria affecting resolution


Double Stars for Binoculars - a list of doubles for all sizes from 7x35 to 40x100
a list of double stars from which you can select observation targets providing you with good indications of the maximum visual point source resolution of your instrument.



Quote:

Lens Resolution Testing
and a link to a USAF 1951 Chart with the Table of Constants.
Chart with Table of Values


I find it interesting that few if any current web links provide ALL the information necessary to use these charts.

Using this table of values linked here which shows the constants for the Groups and Elements of the Line Pairs Chart,
the forumula is 8121 / (D x LPM) where D is the distance to your target measured in inches and LPM is the value from the Constants.
The constants are the actual number of line pairs per mm for the mimimum you can see.
For instance a 10x binocular used at a distance of 125 feet that can see line pairs in Group-1, Element2 has a value of 0.561. Therefore it's resolution is 8121/(125x12x0.561) = 9.65 arcseconds.

Line Pairs Resolution CANNOT be directly compared to point source resolution. See the forum discussion.
It is extremely important to have the target sized properly. See the discussion in the forum thread.
Binocular Resolution Testing Using 1951 USAF Line Pair Charts
included is a discussion on how to use the charts and links to web access for the charts and tables.

It is extremely important that the chart be exactly sized. As a check, the three bars and two spaces in Group-2 Element 1 should measure exactly 10mmx10mm. Both the sets of bars in G2-E2 and the solid black square top center should measure 9mmx9mm.

This page was originally accessed from
http://medfmt.8k.com/mf/resolution.html
Lens Resolution Testing by Robert Monaghan
which has posted the following notation along with the information
[My understanding is that the USAF chart etc. is in the public domain as it is a government produced chart and related documentation...]








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Entire thread
Subject Posted by Posted on
* "BEST OF" the Binocular Forum - Start Here EdZModerator 01/24/04 07:51 AM
. * GOOD STUFF FOR BEGINNERS EdZModerator   01/26/07 01:48 PM
. * First Binocular Purchase? Questions? EdZModerator   01/26/07 01:47 PM
. * Binoviewer - Scope - Binocular Equivalents EdZModerator   01/26/07 01:46 PM
. * Surface Brightness of Extended Objects EdZModerator   03/17/06 04:00 PM
. * Polish Binocular Tests and Reviews EdZModerator   03/07/06 09:52 AM
. * Writing a Binocular Review EdZModerator   10/29/05 12:29 PM
. * Limiting Magnitude and NELM EdZModerator   10/29/05 12:28 PM
. * Resolution Testing and USAF Res Charts EdZModerator   10/29/05 12:27 PM
. * Chromatic Aberration, Triplets, Semi-Apo, Apo EdZModerator   10/29/05 11:41 AM
. * Dark Adaptation, Eye Pupils, Lights EdZModerator   08/25/05 10:50 AM
. * BOOKS for Binocular Observers EdZModerator   06/02/05 07:46 PM
. * Binocular Deep Magnitude Observing Charts EdZModerator   05/03/05 07:45 PM
. * Binocular Photo Gallery EdZModerator   03/28/05 11:05 AM
. * Binocular Vision Summation - Two Eyes vs One Eye EdZModerator   02/10/05 11:53 AM
. * POLLS in Binocular Forum - take a poll EdZModerator   02/10/05 11:52 AM
. * Testing Binoculars in the Store Before Buying EdZModerator   01/15/05 09:29 PM
. * In Pursuit of Cheap Binoculars. What to Expect. EdZModerator   12/30/04 12:07 PM
. * Handheld Binocular Observing EdZModerator   12/29/04 07:30 AM
. * Fixed Focus Binoculars EdZModerator   12/16/04 12:08 PM
. * BINOCULAR OBSERVING REPORTS AND TARGET LISTS EdZModerator   12/10/04 06:42 PM
. * Depth of Field and 3D or not 3D! EdZModerator   12/10/04 06:36 PM
. * What can be Seen in Various Sizes Binoculars EdZModerator   09/19/04 06:21 PM
. * Philosophy and Binocular Ownership by Bill Cook EdZModerator   09/12/04 03:30 PM
. * Affect of Eye Pupil on Binocular Aperture EdZModerator   07/22/04 11:38 AM
. * Favorite Binoculars in Various Sizes EdZModerator   07/22/04 11:37 AM
. * Best binocular overall or in a given price range EdZModerator   07/22/04 11:36 AM
. * MEASURING / TESTING Optical Aspects of Binoculars EdZModerator   03/21/04 03:30 PM
. * Contrast EdZModerator   03/20/04 08:48 PM
. * Need Binocular Collimation or Repair? EdZModerator   03/17/04 12:08 PM
. * Cleaning Lenses - Binoc Repair Eyeguards - Caps EdZModerator   03/15/04 09:36 AM
. * If They Look the Same, What Could be Different? EdZModerator   03/15/04 07:06 AM
. * Binocular Articles over on the Reviews side of CN EdZModerator   03/03/04 10:55 PM
. * ABERRATIONS AND DEFICIENCIES EdZModerator   03/02/04 06:49 AM
. * How to Focus Binoculars EdZModerator   02/07/04 10:18 AM
. * Binocular Mounts - Tripods - Adapters - Motions - Homemade EdZModerator   02/07/04 10:17 AM
. * PRISMS - BaK 4 vs BK 7 - Roof vs Porro EdZModerator   02/06/04 11:49 AM
. * Edge Performance - Sharpness of Field EdZModerator   02/06/04 11:48 AM
. * Terrestrial Viewing EdZModerator   02/05/04 06:23 AM
. * Resolution and Visual Acuity EdZModerator   02/03/04 09:10 PM
. * Aperture / Magnification relationship - Exit Pupil EdZModerator   02/03/04 09:04 PM
. * Coatings EdZModerator   01/25/04 09:31 PM
. * Zoom Binocular Cautions! EdZModerator   01/25/04 08:58 PM
. * Exit Pupils 5mm vs 7mm EdZModerator   01/25/04 07:50 AM
. * AFOV vs. TFOV and Separations for Measuring EdZModerator   01/24/04 01:48 PM
. * Twilight Factor - Visibility - Binoc Index EdZModerator   01/24/04 01:43 PM

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