stupidnewbie, under the calibrate menu you can select H instead of A (auto) M (manual) and that lets you control the calibration so that it only happens when you want to and you don't have to close the lens cover. Manual is absolutely quiet, but H uses the auto function of the scope and has some sound associated with it. I personally can not hear it, but I am told it is there. When I ordered my scope, I ordered the power pack with it. It took two hours to charge the pack. I've had mine on for over five hours total time now and have had no need to recharge. I think I will just to keep a good reserve. I really questioned buying the power pak, but am very glad I spent the money for it now. I carry my rifle with the scope view screen powered down. One quick push on the on button and the screen powers up and you are good to go. I keep it powered down so the light coming out of the ocular does not give me away.
Doubleup I don't think you will be disappointed in the XD50A once you make the decision to buy one. I do not regret mine and now my Photon is gathering dust. I strongly recommend getting the external power pack. It mounts right on the left side of the scope and you hardly even know it is there. I stood outside my house at dusk this evening and watched three deer cross the field next door and played with the various power ratings. I could see and identify clearly each of the three deer at 2x trough 8x magnification. I picked them up at about 75 yds and watched them go across the field to about 450yds. Each was a buck and one had a decent rack. Somebody is going to score a nice one, I bet, when the season opens this Saturday. I could see details of the deer and had no difficulty identifying them. I turned my FLIR PS32 on and checked them with it for reference and the difference was startling to me. I could barely see the deer at distance and they were no where near as clear to see as they were in the xd50A. I am seriously thinking of selling my Flir and getting an hd38A from Pulsar.
