[Creedmoor]

What is parrallax and how important is it to take it into account? Also, is an adjustable objective the remedy for it?

[HiPower]

Parallax is an optical problem found with just about anything in front of your eyes.

For example, look at a clock that has hands straight on. Notice how the numbers look in relation to the hands. Now move off to the side and see how this relationship changes. The hands appear closer to a number than they really are.

This is also seen through a scope by your eye being displaced from the optical center of the lens. The cross hairs will not be on target where you think they are. Most scopes are set to be parallax free at only one range, usually 100 yards for most big game scopes and 50 yards for .22 scopes. For most people, this isn't a real problem because they can't hold well enough for the parallax to matter at reasonable ranges. For target shooting, this would be a bigger problem, obviously.

Not sure about the adjustable objective on target scopes, as I don't have any.

Hope this helps. :D

[Creedmoor]

Thanks HiPower. I thought it was something like that, although I had complicated it a bit more in my mind through somewhat convoluted reasoning. Your explanation was both clear and eloquent. Through other research I think I have determined that an adjustable objective allows one to set his scope (or hers, as the scope in question is my better half's) to be parrallax free at whatever range (and only that range) one dials in on the objective. Sounds like a lot of fussing around in the heat of battle though. As I think (and this is usually where I get in trouble) most of her shooting will be inside 150 yards, the less expensive (and less finicky) scopes without AO are probably the ticket.