Hey guys, so I have a weird occurrence with this lens. I took it out shooting one of the first nights I got it and found my infinity focus point, (between 10 feet and infinity) photos were SUPER sharp stopped down. Next day went and shot with it at a park, swapped lenses a few times, put the Samyang back on, and infinity had shifted to between the 2 and 3 foot mark.
Not sure what's going on with this lens, it seems really sharp but extremely annoying to use because I don't want to be having to find infinity for astro stuff every time I take the thing out. I didn't bump the lens, or damage it in any way, so I'm not sure why the focus would shift (we have had some temp changes here but this is really extreme). Not sure if this is normal or if I should proceed with the RMA I opened with B&H to exchange it for another one, or just give up on the thing as a whole