Well I picked Mine up yesterday afternoon! I'm not going to start ANOTHER "ZOMG I GOT MY MK3!!!!" thread so i'll post my initial thougths here I havent used it extensively yet but these are my initial feelings
Well they have really stepped up to the plate here this is exactly what i've been looking for and it's about as close as we are going to get to a grippless 1D build quality very nice very sold AND its got a proper door over the memory cards rather than that horrid plastic thing on the 5D2.
Its a little smaller than the mk2 and more rounded, the roundedness is nice and feels very modern next to the 5D2, i was a bit worried about it being smaller but its ok for me (I really would not want it any smaller though as the space between the right hand grip and the lens has shrunk a little and any smaller and it will be very cramped with fat lenses on, as it is I think its at the limit.
My hands are large so i find rebels too small peopel with bigger hands might find the 5Dmk3 a little cramped compared to the 5d Mk2.
but smaller means it fits in my bag easier too.
New on off switch position will take some getting used to as i have been used to them down the bottom on 1D and on 5D2 i know some people didnt like this for me its a non issue it is where it is
I love the mode dial lock - LOVE IT!
the new button layout seems nice and well thought out so many nice options now much more 1D like, 1 in particular is the ability to specifiy which wheel controls AV and TV in manual mode something i missed on the 5D2 so i had to reconfigure my 1D to function the same as the 5D2 and adjust my shooting.
Everything feels like the quality level has been brought up a notch or 2 - Well done Canon!
Well this was a suprise, I was expecting to be let down here and I have to say I am impressed it leaves the 5Dmk2 VF for dead,
It is soooo much bigger and brighter. For manual focusing I would put it closer to the standard 1D screen than the 5Dmk2. It handily beats the 5Dmk2 even with an EG-S screen in it. Really nice improvement!
the ability to add in grid lines in the VF - Lovely
the new eyepiece is much improved over the 5Dmk2 eyepiece but its still too close to the body so big noses still rub the screen.
even in extremely low light I could MF with my sigma 85mm f1.4 on, no problem
I dont think i will worry about a replacement screen, I may look at a brightscreen for 1 of the 5dmk2s if i keep it
Look at all those AF points! and the coverage. massive massive improvement.
Well i havent given it much of a work out but I did do some low light testing of the AF with the sigma 85 and in no light other than a TV on in the same room iso 25600 1/100 sec f1.4 AF locked on... not fast but it locked on I would say it took maybe 5 times longer than normal to lock on but bearing in mind this was in next to zero light other than light spill from a TV. outer points have no problem locking on in dim and low light - YAY!
AF point spread is so nice FINALLY! a decent AF in a non 1D body - Well done canon, this really is better than I had hoped for. I can only imagine how good the 1Dx AF is going to be!
I havent tried any AI servo or action stuff only low light at night messing around in the house after do the AF micro adjusting on all my lenses.
AF microadjust is really nice now the wide tele seperate adjusts are really really nice. I found the adjustments needed on the 5Dmk3 were very similar to those I had on my mk2.
I haven't done it super rigorously just an inital setup. Maybe i'll get that automatic AF adjust software and try that out.
both the new back and top screens are bigger and very nice bummer that the top screen lights up orange i prefer the blue of the 1D but that is hardly a deal breaker!
the rear screen is big very clear and sharp. now i just need to wait for protectors to come out for it.
Is it worth it? well In my opinion I was not very happy with the 5Dmk2 in ALOT of areas the IQ made me accept alot of compromises with that camera and I had to adapt my setup and shooting to suit the camera. I feel with this new camera that a veil has been lifted and new freedoms have been opened up. the hand brake has come off and it suddenly got a couple more cylinders firing.
For me the improvements are most definately worth the extra cost. once you feel the differences in a tangible way the spec lists that everyone has painstakingly analysed to death are completely insignificant.
I have not done any IQ comparissons yet but I will in the next few days but even if the IQ if the same as the 5Dmk2 the handling improvements alone make this worthwhile for me however looking at it my gut feel is that it's going to beat the 5Dmk2.
Now i'm going to have to get my wife one or she will steal mine!