Mamiya Stills Lenses
Posted 24 April 2008 - 09:07 AM
Just wondering whether anyone could possibly help with with a query regarding the use of Mamiya stills lenses with an adapter. The lenses are fixed and are used with a Mamiya RB-67 (medium format camera). I don't have the kit on me at the moment and doubt that I'd opt to use stills lenses anyway but was just interested to find out whether or not they could be used with an adapter (P+S technik or redrock perhaps). If it's possible to use them, I'd be really keen to hear about the results. I'll try and find out the specific lens details tomorrow.
Posted 24 April 2008 - 09:35 AM
Just curious, what are you using these with? If it's 70mm, that's one thing, or MF digital MP, but otherwise, I don't think the added size and slow speed of the average RB lens will be of much use to you, as they handily out-resolve anything even 35mm equivalent could use.
So unless you really need to added bulk to cover a larger image area, I don't see the point.
One final hastle, with the 50mm wide-angle I have is that it has a floating front lens element, meaning you need to bellows-focus the lens, then focus the front element too for optimal sharpness. That's right, you need to focus the damned thing twice for the best sharpness (although it works OK if you just set the front element on infinity). This is particular fun to do hunched over on the floor in a dark, hectic wedding hall.
Posted 24 April 2008 - 09:44 AM
Mamiya 645 FFD: 63.30mm
Mamiya RZ FFD: 105mm
Mamiya RB FFD: 112mm
What camera do you wish to use it on?
Arri Mount FFD: 52mm
PV Mount FFD: 57.15mm
BNCR Mount FFD: 61.468mm
OCT-19 FFD: 61mm
As the FFD on the lens is greater than that required by any of those cameras it means the lens adapter would need to hold the lens away from the current mount, this is obviously easier than sinking the lens inside the camera. On that basis it should be technically possible make an adapter for a Mamiya lens. (Although there's not much space to put an adapter between a 645 lens and an OCT-19/BNCR camera.)
Don't forget the area of coverage for a Mamiya lens (especially for 6x7) is huge compared to the frame area of 16 or 35mm movie film. I'd guess you'd get a higher quality image by using a lens optimized for the smaller frame size. Normally any small imperfections in the lens will be offset by the image area of the medium format film, that advantage is lost if it's used with much smaller formats - also finding shorter focal lengths might be an issue.
If you're still keen to use a Mamiya lens, then I suspect it'll have to be a custom made adapter from one of the specialists.
Ah - good point Karl, I'd forgotten the 6x7 versions use bellows focusing & leaf shutters in the lens - I'm only used 645 with Mamiya!
Edited by Ian Cooper, 24 April 2008 - 09:48 AM.
Posted 24 April 2008 - 07:14 PM
In answer to your question Karl, I've been using them with 70mm.
This post was mainly out of curiosity so I haven't thought about any specific camera which I'd want to attach them to. I'll find out the specific details about the lenses soon.
Thanks again, I really appreciate the info.
Posted 25 April 2008 - 11:54 AM
My widest lens is a 50mm, but I think they do make one even wider (although it is quite pricey). The best stop you are going to get is F/3.8 IIRC. The 180mm stops down to F/4.5. Anyway, don't plan for anything better than F/4-4.5. RZ lenses are actually a stop or two better for the same focal length. They have a couple of F/2.8 lenses, so maybe you would be better off using some RZ lenses as well. For the sort of work you are doing, all you'd need is an RZ lens adapter on the adapter you have for your camera and you could interchange both lines of lens quite eaasily.
What I am not sure about is how you would figure out the exact T-stops of the lenses. Also, you have to remember that bellows extension necessitates introducing a bellows correction factor, which would be awkward to do in some situations where you'd need to rack from shallow to deep focus quickly, as you'd also need to open up some to avoid a falloff.
There's also a zoom for RB & RZs, but I don't own one of those either (zooms are for amateurs, at least in still photography ;-) ); I don't know if that is also bellows-focused, but if it isn't, then you may have to deal with focus breathing there.