That dang POI SHIFT!

I have only had non tube style, and have seen/experienced poi shift/change. I believe it is firmware related(how the reticle position is saved). I also don't think the manufacturer(s) know the accuracy/repeatability of weapons/ammo some shooters/customers are using. So when a customer complains about a zero shift the company techs have no explanation. Perhaps their testing is mostly simulated, not actually mounted/firing on the range.
 
We have two of the Pulsar Thermion XG50 scopes. We have had zero POI issues. In fact my oldest son is 16 and the past two years he takes it off of his 308 win after thermal season is over. In Jan 2024 and Jan 2025 he has re3mounted the thermal for night season on his gun. He leaves the rings on the scope and just remounts it to the EGW pic rail on his Savage 110. Both years it has had zero POI change even after removing the scope from the gun. Both years he has set up a 2" round pill bottle full of hot water at 200yds and made it disappear the first shot. No sighting in required.
My 13 year old just got a Savage 110 and it took him 3 shots to get it on a 2" pill bottle at 200 yards. He would have done it in 2 shots but he didn't think he saved the one shot zero so he did it again. In reality he moved it twice and had to do the 3rd shot to get it back to where it should have been. LOL
 
My experience mimics bluedog69. Two pulsar thermions and no issues maintaining zero. Just took one off a centerfire bolt gun to mount it on a rimfire rifle for around the farm pest duties and it maintained zero from last year on its saved profile.
 
Some may lose POI zero. The real explanation is the number of pixels and basic resolution. Lets say you have a 640 IR and 1024 screen. Pixel resolution is about .75" @ 100. So you can't get closer than that. But the screen spreads that resolution to 1.5" - one IR pixel is 2 screen pixels. Then overlay the reticle ( several pixels thick. When you zoom, IR pixels get LARGER (more screen pixels) and effective resolution gets worse. Effectively, screen POA gets 'blurry' and appears as changed POI. That said, the scope can lose POA which is a real 'failure'.
 
The only thermal I have that doesn't exhibit poi change with digital magnification change is my lwts in clip on mode ( no digital magnification)doesn't have tje best picture but is dead on reliable, couldn't say that about my super yoter r, I had a pulsar that would change zero from hunt to hunt,( don't remember the model but it sucked, trijicon poi would also slightly change with digital magnification change
 
Haven't POI shift in any of the handful of Pulsar's(Talions,Trail 2's and Thermions) I've owned out to 400 yds from -20F to 90 degrees. I'm aware of the original Trail POI shifts that guys went through here years ago and have kept a scrutinizing eye on mine. I've also has several Sightmarks and AGM's that haven't had a recognizable shift in POI either.
 


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