Sorry, I'm a tad slow in answering here ... but I'll make up for it in length ... LOL!
Yes, I use an H4D/40 kit for weddings, engagement shots, and portraits (both studio and environmental location). It is the MFD camera I'd recommend for this type of shooting.
As many friends here know, I completely opted out of the V system and sold my 949 scanner. My sole concentration for MF is now H digital.
Focusing Accuracy: with the advent of True Focus/Focus Lock on the H4D, it is now faster and more accurate to use AF for off-center subject focal points than with a 35mm DSLR ... and more clinically accurate. You do not have to wheel a focus point off-center in the view finder, just point the center focus point anywhere, even the very far edge of the frame, press the TF/AF button and recompose. The camera instantaneously computes the adjustments to keep the selected subject in focus. Works in landscape and portrait modes.
Focusing speed: I used a Contax 645 ... the H is a bolt of lightening in comparison. Not as fast as most pro level 35mm DSLRs, but fast enough for
most wedding work. Hasselblad has also improved the focus assist light on the H4D cameras. The H4D is faster to lock-on in fast paced situations when using the conventional single AF setting compared to using True Focus. However, I still at least take a Sony A900 with a Zeiss 24-70 for some lower light action shots, and as back-up to the H4D/40.
Flash: I find speed-light work to be faster with the H than with any other camera I've used, 35mm DSLRs included. The H camera takes over all command of the flash, and fill-flash exposure comp is a grip button push way and visible in the viewfinder. I now do fill-flash compensation without removing my eye from the viewfinder.
Capture rate: The H4D/40 is about 50 captures a minute sustained shooting ... or a nano tad over one a second. I don't hose off shots with any camera, so have never found it to be an issue ... besides, the lights usually take that long to recycle anyway : -)
Hand-holding: When shooting lower shutter speeds, the H has an advantage being leaf shutter, leaving only mirror slap to deal with. Hasselblad has provided a menu item called mirror delay that mitigates mirror slap and allows lower shutter speeds with less vibration. It works, trust me. I also use a Camadapter Hand strap to steady the camera. If I told you how slow of a shutter speed I've gotten away with, you call me a lier : -)
See this 1/25 shutter, ISO 1600 ambient light shot done hand-held:
http://forum.getdpi.com/forum/showthread.php?t=20796&highlight=show+high+ISO+shots
ISO Performance: The H4D40 has ISO 100 to 1600 ... and 1600 is usable, not a mock ISO. It is about a stop (or slightly more) better than the H3D-II/31 I used prior ... meaning H4's ISO 1600 looks like ISO 800 from the 31, and 400 looks like 200 on the 31 camera.
White Balance: The H camera allows you to assign any user button to fire a manual WB shot. No menu to navigate, nothing, just press the button, the camera fires a shot and sets the WB. I have mine set to fire when the stop down button on the front of the grip is pressed. Fastest camera I own for manual WB ... so I use it all the time ... which in turn saves oodles of time in post.
LCD: like all MFD backs, it sucks. However there is a histogram in the grip LCD for more accurate exposure evaluation.
Processing: For any high volume processing like weddings and events, I directly use Lightroom 3.3. You do not have to use Phocus at all. I take all images shot with the H4D/40, Leica M9s, Sony A900, and my assistant's Canon 5D and download them to one file sorted by time shot. In LR I then use the meta-data sort function to select just the H4D/40 shots for processing with presets and batching. The H4D shots take a nano second longer than the M9 shots to resolve, but nothing really of issue. I use Phocus for critical shots and tethered work. Phocus was a bit slow until I upgraded my Graphics card to a Radeon HD 5770. Now it's greasy fast.
Actual usage: I generally take the H and 3 lenses ... I use a Think-Tank lens bag to carry two of the lenses and the third is on the camera. This allows mobility and to travel with the clients from one location to the next. I also use a Mono-Pod with a RRS Mono Head designed for MF cameras. The Arca QR base plate on the camera has two lugs, so I have a hand-strap on one side and a "bouncy" type shoulder strap on the other.
MFD advantages: way more ability to crop and retain the ability to make larger prints. My larger print sales increased by just showing MFD prints. More dynamic range and color depth compared to 35mm DSLRs even at the same print sizes. More head-room for manipulation. Greater separation from the 35mm toting masses. Spectacular group shot abilities ... I've shot everyone that attended a wedding (110 people) and everyone is crystal clear in large prints.
Marc
P.S., s
hots like this one below, which was a bit of a crop from the original shot (along with an even more cropped portion for review), sells like hot cakes in larger print form.
While I do mostly candid work, this type of "magazine style" imagery is becoming more popular than before (i.e.: $$$$$) ... which is why I'm taking the H to more and more weddings.
