How To Obtain 0 Degree Neutral Gimbal Tilt

I have channel 6 controlling tilt on my STorM32 gimbal over Mavlink using RC Targeting mode; channel 6 is tied to the righthand slider on my Taranis. The min and max PWM are 1000 and 2000 respectively and a midpoint of 1500. My min and max tilts are -90 and 45, again respectively. When I center my slider – 1500 PWM – the tilt is at -22.5 degrees and not 0 (looking straight ahead). If I adjust the min and max tilt values in lockstep, or move the midpoint away from 1500 on the Taranis, I can get a 0 degree neutral position however my observed min and max are no longer at a true -90 and 45; but more akin to the 22.5 degrees of offset necessary to bring the neutral tilt position to 0 degrees. How is this supposed to work where I can look straight down (-90) and half way up (45) and still have a 0 degree neutral position? Thanks!

Already replied that at RCG

You could at least share the link to your answer…

The OP knows where he asked (and wasn’t only here and at RCG), Just google his question

http://www.rcgroups.com/forums/showthread.php?t=2494532&page=12

Thanks davidbitton!
I did manage to find it myself, but this is way faster and more usefull info.