Re: 35 mm tube IOR\'s
Just some update info on the Night Force specs, and general comments.
All NP R2, RR, DD' are in the more desirable first focal plane.
They are all factored @ 22x, except for the 3.5-15x50, and 3.5-15x56.
First focal place recticles are much more accurate for both 'Ranging', and especially for 'Bullet Drop Compensation'. They're more desirable by knowledgeable shooters, as compared to second focal plane.
It is more complicated, and expensive to design a correct system in the first plane.
Once the basics are understood, and simple math applied, it is easy to use them.
Don't get fooled by oversized tubes, a great marketing idea. Many are just that with internal spacers. They can hold larger lenses, but that doesn't mean that they're really are worth it.
Extra adjustment range can very, very easily degrade sight picture as the light beams are bent too hard, not controling the light, and it 'washes out'. That's one reason why higher end optics have internal stops. Specifically designed into them.
Need more adjustments??? Use a different mounting system.
When I see the words "Schott glass", that just means it came from Schott. There are literally hundreds of glass types, and thousands of lens (element) combinations.
For those of you who like to play, take some surveyors stands, place some different scopes by different companies on them.
place them in the sun, with 95 degree temp, and high humidity. Scopes must all be the same finish, the same class, and basic power range.
Set a Naval resolution target at 100 yds, have the scopes set at 'optical center', put the reticle on the target center.
Starting at 10AM till 2PM every 20-30 minutes check the reticle for 'walking'. You'll be very surprised at who doesn't walk.
[ 11-19-2003: Message edited by: Guns & Glass ]
Happy Bullet Holes!