Pentax 645D

[KevinBarrett]

I like to see good deals and competition, so when the new Pentax 645D was announced with an MSRP of $9,400, or less than half that of the new Mamiya (with the same sensor?), I was interested. Specifically, I was reminded of the relationship between the Nikon D3x and Sony a900, you know, same sensor, same speed, fraction of the price.

However, upon reviewing the specifications of the Pentax 645D, I was appalled to discover that for $9400, you get a flash sync speed of 1/125 of a second. That's one whole stop slower than an a700, and 1/3 of a stop slower than an a230! In contrast, the Mamiya syncs at 1/1600. Why did Pentax even bother?

[Greg Beetham]

Which model Mamiya 645 was that KB? the Mamiya 645 AFD III that I found (I haven't looked at Mamiya for a long while, so I'm not sure if there is a later one, but this looks like a good model), also flash syncs at 1/125 sec.
Greg
http://www.mamiya.com/645afd-iii.html#Specifications

ps. My Bronica flash syncs at 1/500 sec. but only because of the lens iris type shutter, if it was an FP shutter I'd bet it'd be quite a lot slower...I haven't kept up to date with MF, not much point really, the expense of MF generally, especially when looking at Digital, is beyond my discretionary budget, but usually most MF cameras are LOTS slower in every facet than what we are used to in 35mm SLR/DSLR style cameras. I think the fairly new Leica DSLR style, larger than 35mm FF, at full res. can scorch along at 5 frames a minute..or was it 8 frames? I forget.

pps. I just found the one you must have looked at KB, the Mamiya 645DF, and yes the leaf shutter in the lens does the trick, 1/800 - 1/1600 sec. flash sync. very fast for iris type shutters.
I've heard of that solution before, with the dual shutters, FP and lens leaf/iris type. It was fiddly to use, (switch from one to the other), in the past..so I heard, but this new model might be of a better design.

[KevinBarrett]

I should have specified, the new Mamiya DM40 uses a sensor of the same size and pixel count as the new Pentax 645D. However, while the Pentax uses 14 bit A/D conversion, the Mamiya uses 16 bit conversion to give it a 1/2 stop dynamic range advantage (11.5 vs. 12).

If you're about to invest in a new mount or format, do your homework and make sure you know all your options. I sure hope Pentax offers lenses with leaf shutters in the future. I would be very sour to find myself $10,500 into another camera system and realize I'd have been better off buying an exceedingly comprehensive kit from Sony, including:

a850
135/1.8 ZA
85/1.4 ZA
16-35/2.8 ZA
24-70/2.8 ZA
35/1.4 G
50/1.4
either one F58 flashgun
or two Alien Bees B400 Flash Units and one wildly overpriced hotshoe adapter

Sony advantages:
image stabilization
1 stop faster flash sync (1/250 vs. 1/125)
one stop faster shutter speed (1/8000 vs. 1/4000
3 FPS
complete system for the same price

Pentax advantages:
40 MP vs. 24.6 MP
14 bit A/D conversion vs. 12 bit A/D conversion

[Dusty]

Kevin I remember when we only had flash sync speeds of 1/60th sec on 35mm, so doing 1/125 on a medium format camera should be fine.

To get 40 MP as such a 'cheap' price is a real coup for Pentax. There are still plenty of film 645's out there to scarf up lenses from, so assembling a kit to do some awesome scenics or for some studio work wouldn't cost you near what a Leica S system or a Mamiya would. I could see some high-end wedding guys using such a system as well.

Of course, we will have to see how it performs, first, but those Kodak sensors are really good.

Dusty

[Greg Beetham]

Yes I agree Dusty, 1/125sec should be fine for just about all straight flash work, the only time that you're likely to need more shutter speed is in the daylight flash fill area if you want to shoot with a fastish lens opened wide for the bokeh effect...THEN I'd agree that those new Mamiya lenses would be a great boon..(Mamiya have just three in the inventory with those fast leaf shutter speeds), all the rest are standard jobs.
Anyway, I do hope Pentax succeeds with the 645D.
Greg

[Dusty]

I'm not familiar enough with the Pentax MF lines of old to know if the lenses were interchangeable between the 6x7 and the 645, but I'm pretty sure I've seen some leaf shutter lenses in the other lines.

Using them (if they fit) would make it all work fine.

Dusty

[peterottaway]

There is / was an adapter for Pentax 67 lenses to manual focus on Pentax 645 cameras.

[bfitzgerald]

I use HSS for daylight fill in at faster apertures a lot. It's incredibly useful.
All my bodies support HSS with a dedicated flashgun, that even includes the film 5. Many older bodies don't have this feature, even higher end ones.

Real boon to me, as I like to dial back the flash, to just take some shadows away. On-board flash sync speed is not an issue really.