I use an MTC Viper 3-12x44 set on 10x and parallaxed at 25 yards. Under 13 yards and it's a swine but everything above that and it's clear enough. Just over 40 yards and it loses clarity but only slightly.
Actually, could everyone avoid plating the tagets under 13 yards just so I can figure how small the KZ is and aim accordingly. There is nothing like looking at a silver blur and estimating where the KZ is and still plating it.
I have more trouble being right handed and left eye dominant. That left eye of mine spends a lot of time half open but at the last couple of shots I've noticed it less and less. Maybe my brain is getting used to it.
I have been lucky to look through a Schmidt& Bender something or other mounted on a custom Remington 700 and it was like someone had turned on all the lights and you could finally see everything. That is light gathering in a high quality scope for you.
"I wanna play cricket on the green, ride my bike across the stream, cut myself and see my blood, I wanna come home all covered in mud. I'm a boy, I'm a boy but my ma won't admit it..." I'm A Boy- The Who 1966