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Harpia Extender (1 Viewer)

henry link

Well-known member
Nothing much would be gained at any distance from boosting the size of the smallest resolved details beyond 70x for someone like me with eyesight acuity of 20/15, which is about average. I could already see 12% smaller line pairs at 70x through the 92mm reference scope set up next to the Harpia.
 

Troubador

Moderator
Staff member
Supporter
Nothing much would be gained at any distance from boosting the size of the smallest resolved details beyond 70x for someone like me with eyesight acuity of 20/15, which is about average. I could already see 12% smaller line pairs at 70x through the 92mm reference scope set up next to the Harpia.

Hi Henry

If by "Nothing much would be gained at any distance" you mean extra detail, I wasnt refering to extra detail. I understand that you are saying no extra detail would be gained.

What I was wondering was whether the detail resolved by the standard eyepiece at maximum magnification, would be visible at greater distances than with the standard eyepiece, if there was a magnification increase.

Forgive me if you feel you have answered this but from my side it is still not clear that you have. For example your reference to seeing smaller line pairs through the other scope doesn't seem connected to my question about additional distance.

Lee
 
Last edited:

henry link

Well-known member
I'm not sure why we can't seem to connect about this. Maybe somebody else can join in.

Does it help to say that on the USAF 1951 size and distance are interchangeable? There's no difference between changing from one set of line pairs to the next 12% smaller size and just moving the larger set 12% farther away.

To put it another way imagine that a scope resolves 20 line pairs per mm on the USAF 1951 at 10 meters. If the distance to the target is doubled to 20 meters the same scope will resolve only 10 line pairs per mm on the same target. No amount of increased magnification will extend the 20 lp/mm resolvable at 10 meters to any longer distance than 10 meters.

Are we getting anywhere?

Henry
 

Troubador

Moderator
Staff member
Supporter
Yes Henry this made it absolutely clear:

No amount of increased magnification will extend the 20 lp/mm resolvable at 10 meters to any longer distance than 10 meters.

Thank you for sticking with me on this.

Lee
 

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