Hay! Thanks guys Some of this is beginning to stick. If I can get it to stick long enough so I don't ask the same question in 2 weeks we will all be lucky. I like chucks comment how the defraction limit relates to the "sweet spot". I can't always remember defraction limit but I can remember "Sweet spot" because thats where you catch all the fish. I like Brents comment how appratrue related to quantity of light. I have heard the term "light bucket"; I guess an aprature no matter what the f ration will hold the same amount of light; the short one concentrates it and the long one spreads it out; or you can only get so many fish in a bucket. I like Riches comment about helping the guy with the long focal length. When I look at the moon, sometimes I like to see the whole thing. I am so new at this I haven't formed to many likes and dislikes. I do get more excided at looking at planetary nebula that I do at trying to split stars. But, no doubt, down the road of experience a ways I will go through the splitting star phase. I think Riches comment of "some of us have more than one" is a gross understatement. Rich I can't think of a fish story to along with yours. I guess I should shut-up about fishing before you guys kick me out. Jim --------------------------------- Do you Yahoo!? Yahoo! Tax Center - forms, calculators, tips, and more