Pentax 645 vs Mamiya 645, which is best for manual focusing?

<p>Hello! <br>

This is my first question here! :)<br>

I'm looking to purchase a 645 medium format camera and would love your opinion on either the Pentax 645 system vs the Mamiya 645 system in terms on manual focusing. How bright are either of their screens? Any preferences?</p>

<p>Thank you! </p>

<p>I've owned the Mamiya M645 1000S and TL Pro, plus the Pentax 645N and don't remember one camera's prism viewfinder being noticeably brighter than the others, but then I didn't own the cameras concurrently. Both systems offered several f/2.8 lenses, so that also helped with manual focus. The Pentax has a focus indicator in the viewfinder and optional beep to indicate focus, but I found that a little distracting; I never owned any AF lenses for it. I prefer the Mamiya's split-image/microprism focusing screen for manual focus. Pentax did offer a microprism focusing screen for the 645N, but in all the time I owned mine I was never able to find one on eBay, KEH or anywhere else.<br /> <br /> If you're considering the original manual-focus Pentax 645 (I wouldn't), Ken Rockwell in his review of it called the viewfinder dim. I suspect the finder brightness was increased on the 645N to support autofocus.</p>

The original Pentax 645 has the most accurate finder of the Pentax models for manual focus (but it is

dimmer than that of the 645N and NII because of this). Any Mamiya 645 with waist-level finder, however,

will give a brighter and larger finder image, which makes nailing focus easier. Both are comparable when

using eye-level finders, and both are easy enough to focus manually that I wouldn't base my choice

primarily on this.

<p>Only used the early Pentax 645 briefly but found it darker than the Mamiya 645 Super/Pro/ProTL series cameras. WLFs on the Mamiya 645 make shifting from landscape to portrait orientation very awkward. Their prism finders and split rangefinder dot screens are quite bright and easy to focus.</p>

<p>the Pentax-A 645 (first version) viewfinder - I find- is very bright and easy to focus. I use the standard 'split image microprism/matte' (UC-21) screen.</p>

Not used the Pentax system much but the Mamiyas are very easy to focus. The Pro or Pro. TL are the bodies to go with if you can afford

them. With the standard split screen and either of the two prisms or the waist level finder you should have no problems. If you are talking

about the later AF models they are not as good in. MF as the earlier bodies

<p>Thank you for the response! <br>

I was actually offered a Mamiya 645 afdII at a bargain price. Would adding the type-c focusing screen make things any better? <br>

I'm also confused as to what factor has a larger influence over manual focus: The brightness of the screen, or the ability to have a split prism screen. </p>

<p>From my experience screen brightness has a negative influence on focusing beyond what could be called sane evolution peaking in for example mid 80s manual focus bodies or even the "high matte" screens that must be awesome.<br>

AF bodies pushed screen brightness beyond sane to allow usage of utra slow consumer zooms with flash and framing indoors. <br>

I can focus my Mamiya TLRs quite well in a dimm pub but it takes some guess work to figure out what I might be framing (especially in the corners of the 55mm f4.5 WA lenses). - With a Super Angulon f8 in front of a plain ground glass I am lost with office style lighting at home; I need to fry the scene with hotlights, to get an impression what I am framing in the screen corners.<br>

So the desire for a bright screen depends on your subject. Nature by day should be bright enough. If you are shooting in your studio you can get matching pilot lights. Things get messy when you want to use flash in the available darkness of a cozily underlit home or pub.<br>

I have no issues using standard or portrait lenses on my nonspectaculary bright screens in "almost office" light where I can handhold them somehow (with insanely fast film &/ monopod) but WA lenses are nasty. I tried the 50mm Zeiss on a Pentacon Six too and corners were "close to guesswork" in a well lit gym (where the fleamarket happened. - Focusiing screens of the elderly SLRs / TLRs I am mentioning here probably sold a lot of rangefinders for WA work.<br>

If your split screen works with your lenses and your subject provides something to use it on, it is surely nice to have and speeds things up. - With my lightning fast 250mm f6.3 lenses I probably shouldn't bother to hunt one down. I am happy enough with the additional loupe (magnifying the center spot of my screen for precission focusing) in my chimney finder.<br>

From looking at my collection of Pentax 35mm bodies I believe the Pentax 645 should be significantly brighter than the MF bodies I am shooting, since it is based on the fairly bright Super Program, i.e. it came out a year or two later. </p>

<p><em>What factor has a larger influence over manual focus: The brightness of the screen, or the ability to have a split prism screen[?]</em></p>

<p>IMO, a split prism focusing aid is much more helpful to manual focus accuracy / ease than a somewhat brighter screen is. Of course, experiences vary. Now I have (among other things) a Mamiya M645 1000s with a metering prism with a split prism focusing aid, and grew up using my dad's Canon AE-1 with a similar split prism. I have also used a TLR with a waist-level finder without any focusing aid other than a pop-out magnifier.</p>

<p>More generally, I think other differences between the two systems are probably much more significant than any likely small differences in overall manual focusing ease / accuracy, and I suspect that within each system, there are substantial differences model-to-model and scree-to-screen, and between prisms and waist-level finders. I've never tried a Pentax 645, just my Mamiya and (briefly) a Contax 645 (which was great but very expensive)--but the Pentax seems like a solid system too. In case it matters, I don't think either Mamiya or Pentax has sold a "645"* camera that will shoot film in several years.</p>

<p>If you really have a deal on a Mamiya M645 AF-DII that's too great to pass up, go enjoy it; if you don't like it, you can probably sell it and at least break even. Just be warned that, IIRC, if you want to use solely or even primarily manual-focus lenses, you may actually have an easier time with a manual-focus body like a Pro or Pro TL, or even an old 1000s. I seem to recall there are metering and/or other issues related to iris operation when using the newer auto-focus bodies with manual-focus lenses.</p>

<p>*FWIW, the current digital so-called "645" models are not really 645, and most aren't close, which creates crop-factor issues. 645 film is 56x41.5mm (Mamiya) or 56x42mm (Pentax). The Pentax 645D and 645Z have 44x33mm sensors. The Mamiya 645 digital backs range from 44x33mm to 54x40mm.</p>

 

<blockquote>

<p>I was actually offered a Mamiya 645 afdII at a bargain price. Would adding the type-c focusing screen make things any better?</p>

</blockquote>

<p>For manual focusing, yes.</p>

<blockquote>

<p><br />I'm also confused as to what factor has a larger influence over manual focus: The brightness of the screen, or the ability to have a split prism screen.</p>

</blockquote>

<p>The latter. Counterintuitively, a brighter screen may actually be worse for manual focus; it may be too fine-grained and transparent to provide a good scattering surface where the focusing image would form. There is a good discussion of this <a href="http://www.tumblr.com/search/focussing%20screen">here</a>.</p>

<blockquote>

<p>I seem to recall there are metering and/or other issues related to iris operation when using the newer auto-focus bodies with manual-focus lenses.</p>

</blockquote>

<p>It's just the normal thing of stop-down metering and fully manual aperture control - like when you adapt a lens from one system onto another system's camera.</p>

<p>The upside is that you do get the advantage of electronic focus assistance (it tells you which way to turn the focus ring to move towards focus, and confirms when you're "there"). The older non-AF 645 bodies of course cannot do this, so it goes some way to compensate for not having their very snappy focusing screens and massive WLF view.</p>

 

<p>I used the Pentax 645 and the 645NII. The latter is a great camera but I found I needed to retrofit it with the optional split-prism screen which is hard to find. The older 645 has a split-prism screen but the user interface is not that great.</p>