So here is the deal. I got my Tokina12-24 and love it but I am confused about the depth of feild on it. I take a pic at F4.0 and then at f22 well the background should be not in detail at f4.0 right? Well when I take the same pic at f22 it sharpens up. I did a little test. I used the same shutter speed and moved the apeture from 4.0 up to 22 and every pic was a stop darker for every f stop. That means nothing is wrong right? Other than that the lens is really sharp. Way more sharp then the 80 dollar tamron 28-80 I was using... Sorry if this dosent make sense. hehe.

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