John I use the 400 DO IS ii Mike above has mentioned........ YOU NEED TO HOLD ONE ON THE BACK OF YOUR CAMERA!! This is a very different weight to a 500, you need to hold it

!! Buddy I don't know how to stress this more with words, but if in anyway this lens is to be considered you need to hold it on your rig
It's my walk about LMAO crawl about lens . MY work ( day job) is incredibly taxing on my body John............... so even though I'm older I'm very fit,but not very strong.......... the 500 f4 would have been my go to walkabout lens ,but tis too big for me and I felt at a gut level would stop me doing what I've always done. with me beasties
This little lens is a gem buddy, you should also talk to Russ here.......... Martin and George,
For you very simply a stop of light goes south for a a gain of 60mm compared to your 500 and everything else you use stays the same. The lens just can't be far short of the 500f4 incarnates IQ wise John , I think the specular hilights might be different. back lit especially, but it's one hell of a tool !!
Ha everything else stays the same....................,nah not quite.................... not the physical drain on your body.
. i m well buddy thank you



battered sideways so tired I don't know me own name......... want to drive over the mobile phone so no one can contact me

,but good buddy
To me your simple move is to a DO ii, which I didn't mention before 'cause I'm biased, as hell

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