When the cross hair is in the back the light path is directly centered of the lens where the cross hairs are and the least amount of lens distortion is…
With FFP you are moving the cross hair through the path of the light to bend it…. Rut-Roo.. So the path correction is using not exactly center portion of the lense to bend it back to focus the light back to the center or the second rear plane.
Just like any other lens if it’s NOT passing directly through the center you get some aberrations
I had a national BR champ tell me that, and looked for it glass in my FFP PRS BR rig vs. a SFP model of the same type.. …. and dang it .. he was right.
It’s a TINY difference - but under pressure at 1k yards with mirage or clouds and low light - every little bit comes in to play
I don't want to be nasty, but this "explanation" was nothing but a word salad. It's complete nonsense.
