[surfotog]

I got one of the Cirrus adapters. The first one had a problem, but Cirrus took it back without question and replaced it. The second one was fine. I would have no problem recommending them. They stand behind their product, and they have a US based contact in California.

[ARCASIA]

If it is the ability to shoot in low light or with faster shutter speeds, then you are pretty much constrained to use f/2.8 lenses, except perhaps if you use the 67 105/2.4 with an adapter, which only offers a marginal improvement in speed. It is not like with 35mm film, where there are a number of f/1.4 lenses to choose from. At the telephoto end, there is the Pentax 645 FA 150/2.8, a very nice lens, or the Pentax 67 165/2.8, again with an adapter. If 15mm more in focal length means anything to you, there is also the Carl Zeiss Jena (CZJ) 180/2.8 Sonnar, in Pentacon 6 mount, for which adapters to the 645 are available. I understand that it is possible to adapt the Sonnar to the 67, either with a custom made adapter, with which you lose infinity focus, or by altering the lens mount. The latter method retains infinity focus, but some precision machining is necessary to remove the Pentacon 6 mount, replacing it with one suitable for the 67.

If you are interested in beautiful out of focus rendition, or bokeh, as people like to call it today, it is possible to achieve it with f/2.8 or even f/4, maximum aperture. In my opinion, the Pentax 645 and 67 lines of lenses offer out of focus rendition that is rather neutral: it is neither outstanding nor displeasing. If you compare photographs taken with these lenses to those obtained with lenses legendary in this regard, such as the Cosina Voigtlander APO Lanthars, or the Nikon 85/1.4, 105/1.8, 135/2 and 180/2.8 AI/AIS lenses, you will see what I mean. Luckily, the CZJ 180 Sonnar offers absolutely gorgeous bokeh, and as referred above, it can be mounted on the 645 via an adapter. There is also the Carl Zeiss Jena 300/4 Sonnar in Pentacon 6 mount, which also displays very beautiful bokeh, though both of these lenses must often be used together with extension tubes, as neither has particularly close focussing abilities.

There are many other Pentacon six lenses that can be used on the 645, including those manufactured by Meyer Optik, Kiev-Arsenal and Schneider Optics, as well as some other (shorter) focal lengths by CZJ. But I think, in the end, one could find comparable quality optics in Pentax products with a lot less hassle, the exceptions being the two CZJ Sonnars for their bokeh and sharpness wide open, the CZJ 50/4 Flektogon for its stellar sharpness and beautiful colour rendition, and the Kiev-Arsenal Arsat 30/3.5 fisheye for its incomparable wide field.

[Gooshin]

I understand (and have seen on paper) that MF, even at F2.8 and F4.0 kicks ass in terms of DOF over 35mm, and most definetly over APS-C, but i havent i havent developed my first rolls yet so for now its just hoping..

but my question is simply hypothetical based on the fact that i took a super-wide-angle (in MF terms) lens, that is 1.8, and it did not vignette, that means, theoretically, that it could be done, without having to resort to large glass or funky design.

[k100d]

but my question is simply hypothetical based on the fact that i took a super-wide-angle (in MF terms) lens, that is 1.8, and it did not vignette, that means, theoretically, that it could be done, without having to resort to large glass or funky design.

it would have to be done with a rangefinder as the lens would need to be closer to the film plane to avoid making the lens huge and unwieldy.

what's left in current MF RF's? the mamiya 7ii and the bessa iii and none of those have the speed that you're looking for

[ARCASIA]

Here are a few photos taken with the Carl Zeiss Jena 180/2.8 Sonnar and the Pentax 645NII, using colour negative film. Portrait at f/5.6 and the two flower photos at f/2.8 using an extension tube.

[Ben_Edict]

I understand (and have seen on paper) that MF, even at F2.8 and F4.0 kicks ass in terms of DOF over 35mm, and most definetly over APS-C, but i havent i havent developed my first rolls yet so for now its just hoping..

but my question is simply hypothetical based on the fact that i took a super-wide-angle (in MF terms) lens, that is 1.8, and it did not vignette, that means, theoretically, that it could be done, without having to resort to large glass or funky design.

The experience you made, points into the direction of the construction problems. A 31mm lens on medium format SLR needs to be a hefty retrofocus construction to achive infinity focus. This is bulky, heavy and employs a lot of glass, even with a max. aperture of 3.5 or the like. Anything faster and you need a cart to move it around.

You can imagine what a lens monster like that would cost...

That is mainly the reason, why there is no fast short fl glass for medium format. For longer fls, the situation is different. No retrofcus design needed and log fls offer a large image circle anyway. So there are 200/2.8, 300/2.8 lenses availabe for 645.

Ben

[Ben_Edict]

Mamiya made and/or makes an 80/1.9, too, one of the things that leaned me toward this system for my MF work. I'd probably have one by now, (mostly more for the ease of viewing and focusing than for the actual speed) if my chance at good digital hadn't come along so soon.

The thing about MF is the DOF starts getting wafer-thin pretty quickly, and film flatness can be a concern, so I guess these things have somewhat limited appeal.

the 80/1.9 was the main reason I bought into the Mamiya 645 system years ago. It is a wonderful lens - not only fast, but also of very good image quality. And compared to the Zeiss, it is really cheap.

Ben