Resolution comparison of Canon 10x30 IS to 14x32 IS. (1 Viewer)

[[email protected]]

Here is an interesting YouTube video comparing the resolution of a Canon 10x30 IS to a 14x32 IS with a USAF resolution chart.

 

[Tringa45]

This is interesting although some of the calculations are flawed.
Some years ago with some helpful advice from "typo" here on the forum I conducted some resolution measurements on both my birding scopes.
Attempts to do so on my binoculars with a 3x tripler were less than successful as my own eyes were probably the limiting factor, so the use of a camera is a sensible addition.
However, IS or not, the binocular should be tripod-mounted.
The resolution in arcseconds is 206,3/(d x lpm), where d is the objective to chart distance and lpm is line pairs/mm.
If one can distinguish between vertical and horizontal lines they can be considered resolved.
As I see it the 14x32 just about manages group 1, element 5, which is 3,17 lpm and the 10x30 achieves 1-4 (2,83 lpm).
These translate to resolutions of 7,2 arcseconds and 8,1 arcseconds respectively, which are rather mediocre results as the Dawes limits for 32 mm and 30 mm objectives are 3,6" and 3,9"
Perhaps the computer screen and lack of tripod mount are degrading the results..

John

 

[[email protected]]

This is interesting although some of the calculations are flawed.
Some years ago with some helpful advice from "typo" here on the forum I conducted some resolution measurements on both my birding scopes.
Attempts to do so on my binoculars with a 3x tripler were less than successful as my own eyes were probably the limiting factor, so the use of a camera is a sensible addition.
However, IS or not, the binocular should be tripod-mounted.
The resolution in arcseconds is 206,3/(d x lpm), where d is the objective to chart distance and lpm is line pairs/mm.
If one can distinguish between vertical and horizontal lines they can be considered resolved.
As I see it the 14x32 just about manages group 1, element 5, which is 3,17 lpm and the 10x30 achieves 1-4 (2,83 lpm).
These translate to resolutions of 7,2 arcseconds and 8,1 arcseconds respectively, which are rather mediocre results as the Dawes limits for 32 mm and 30 mm objectives are 3,6" and 3,9"
Perhaps the computer screen and lack of tripod mount are degrading the results..

John

You're correct. I think they should be tripod mounted also, even with IS.

 

[henry link]

Hi John,

I watched that video a couple of weeks ago. I agree that a few things went seriously wrong with that effort.

On my list the first problem is that the Samsung S5 phone camera's aperture is almost certainly too small to accept the full exit pupils of the binoculars. I don't know the exact size of the S5 camera's entrance pupil, but phone cameras like that usually have around 2mm apertures. If so the camera entrance pupil can only accept the center 20mm of the 10x30's objective lens and the center 28mm of the 14x32.

When boosted to 80x my 10x32 Canon (which should have the same resolving power as the 14x32) very easily resolves Group 2, Element 2 on the USAF 1953 at 10 meters and barely resolves Group 2, Element 3 (5.04 cycles per mm or lp/mm), which works out to a resolution of about 4.1 arc seconds, quite good for a 32mm binocular.

Notice that the measurements in the video are based on lines per mm, not line pairs per mm, so they should be twice as "good" as the same measurement expressed in lp/mm or cycles per mm, which is what the Edmund conversion method you mentioned uses. Expressed in l/mm my 10x32's resolution would be 10.1 l/mm instead of the 5.04 lp/mm at 10 meters it is on the Edmund chart and that would work out to a resolution of 2.05" instead of 4.1".

In the end what we have are measurements that almost certainly don't include the binoculars' full apertures, incorrectly convert the the raw cycles per mm figures to arc seconds of resolution and use a photographic image that doesn't have sufficiently high resolution to show the smallest resolved line pairs on the chart.

Henry

 

[Tringa45]

Hi John,

I watched that video a couple of weeks ago. I agree that a few things went seriously wrong with that effort.

On my list the first problem is that the Samsung S5 phone camera's aperture is almost certainly too small to accept the full exit pupils of the binoculars. I don't know the exact size of the S5 camera's entrance pupil, but phone cameras like that usually have around 2mm apertures. If so the camera entrance pupil can only accept the center 20mm of the 10x30's objective lens and the center 28mm of the 14x32.

When boosted to 80x my 10x32 Canon (which should have the same resolving power as the 14x32) very easily resolves Group 2, Element 2 on the USAF 1953 at 10 meters and barely resolves Group 2, Element 3 (5.04 cycles per mm or lp/mm), which works out to a resolution of about 4.1 arc seconds, quite good for a 32mm binocular.

Notice that the measurements in the video are based on lines per mm, not line pairs per mm, so they should be twice as "good" as the same measurement expressed in lp/mm or cycles per mm, which is what the Edmund conversion method you mentioned uses. Expressed in l/mm my 10x32's resolution would be 10.1 l/mm instead of the 5.04 lp/mm at 10 meters it is on the Edmund chart and that would work out to a resolution of 2.05" instead of 4.1".

In the end what we have are measurements that almost certainly don't include the binoculars' full apertures, incorrectly convert the the raw cycles per mm figures to arc seconds of resolution and use a photographic image that doesn't have sufficiently high resolution to show the smallest resolved line pairs on the chart.

Henry

Thanks, Henry, that was very enlightening.
Do I understand correctly that you conducted your measurements visually at 0,4 mm exit pupil?
Floaters start to plague me below about 1 mm so with 3x12 and 6x18 monos I now get caught between exit pupil size and adequate magnification .

John

 

[henry link]

Yes, that's right John. I guess my floaters aren't as bad as yours. I don't have much trouble with them blocking the target at 0.4mm.

Henry

 

[Tringa45]

Yes, that's right John. I guess my floaters aren't as bad as yours. I don't have much trouble with them blocking the target at 0.4mm.

Henry

Henry,
As you cannot be contacted by PM, may I draw your attention to the focussing thread?

John