In article
>Given the same subject to background distance, does a 300mm f/2.8 >produce significantly more "background blur/larger circles of >confusion" than a 300mm f/4?
---No. you can check this out with any lens and body with DOF preview
---(one stop down from wide-open will not significantly change DOF).
>I am attempting to achieve the highly compressed TOTALLY blown out
>pictorial background effect when shooting models FULL LENGTH and I
>know this can be achieved with a 300mm f/2.8. I had purchased a 105
>f/2 with Nikon's Defocus Control hoping to achieve the same effect
>and even after extensive experimentation with the lens I have been >unsuccessful- it just isn't the same.
---I have not tried the DC lenses, but my understanding of how they
---work would lead me to your conclusion - the "feel" of the out of
---focus areas may change a bit, but the DOF won't (no magic!).
>My budget prevents me from purchasing a 300mm f/2.8 but I could
>justify purchasing a 300mm f/4. (rest deleted)
---Why not try one, especially if you qualify for Nikon's
---professional services? They lend most anything to members.
---Hope this helps.