MF Rangefinders the might take Digital Backs? Any ideas?

I wonder whether there are rangefinders that come to mind that have quiet shutters and that could take a digital back.

Anyone have any ideas?

Asher

For a medium format camera to take a digital back it must have a removeable back. I can't think of any rangefinder that does which kind of makes the question moot.

I'm wondering if anyone has tried to modify a Mamiya 6?

Asher

Even if you could do it, by it's very nature putting a MF back on a rangefinder will make it more or less impossible to bring to the eye for focusing and more or less ruin the portability, hand holding ability. If you're going to be shooting tripod then it would be a whole heck of a lot easier just to use a Mamiya 645 pro, far cheaper too than cutting a rangefinder up and trying to get the sensor lined up with the correct lens to film distance.

It's actually a good question though, do MFDB's have the same issues that 35mm rangefinders have had with digital, namely the vignetting issue caused by the angle with which the light hits the sensor? It wouldn't be a problem for MF SLR's but there are many LF setups using DB's where the sensor is extremely close to the lens.

I think that the relevant implication here is the difference in the basic architecture of the optics of a reflex (lets say 645 AFD) and a range finder like the 6, and that is the issue of retro-focus.

Retro-focus will sooner or later should be replaced by a better focusing and composing alternative.

The reason is that lenses could be made faster, smaller and more wider angular than the way they are now. Also the reflex system has several moving parts, requires more energy to work and is noisy etc etc.

So I think that Asher is in to something here. Now there are cameras that take non-retro-focus optics like the Alpa, Cambo Wide and Horseman, but non that I know that are made for documentary " street " photography that I know, and it may not be such a bad idea.

Probably the difference in size would be noticeable compared to a reflex system, same as the difference from that of a Nikon/Canon and Leica.

As far as I know, there is no MF rangefinder which takes a digital back. As all the MF digital backs I have seen are rather bulky and protruding, it would be difficult to look through the viewfinder , as Ben Rubinstein said.

There were at least some MF rangefinders for which polaroid backs were built, like the Fuji 690 series, so you could possibly build or adapt a digital back for them.

I am no expert in this, but it seems to me that the problem photosensors have with light hitting at an angle might be related to their size, and as 35mm or APS sensors have smaller photosensors than MF backs or LF scanning backs, you can work with a smaller distance between optics and sensor in larger formats. But then, close optics - sensor/film plane distance in MF is larger than the complete thickness of a point-and-shoot anyway.

There are some specialist non-reflex MF cameras taking digital backs, from Seitz, Alpa, Gilde and possibly others, but they are not rangefinders.

Christoph

Christoph Grabmayr said:

I am no expert in this, but it seems to me that the problem photosensors have with light hitting at an angle might be related to their size, and as 35mm or APS sensors have smaller photosensors than MF backs or LF scanning backs, you can work with a smaller distance between optics and sensor in larger formats.

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Actually, a retro-focus lens design helps in maintaining a reasonably normal/perpendicular angle of incidence. It also allows to use an anti-aliasing filter for tricky subjects, something that is much harder to utilize with shallow angles of incidence.

Bart

Actually, there is one: the Seitz 6/17

look here

The weight should be ok, 5 kg, but one need the tablet PC as well, with a gigabit-ethernet connection to the cam.

I have been at Seitz place yesterday; they told me that the first are going to be delivered, right now.

Bart_van_der_Wolf said:

Actually, a retro-focus lens design helps in maintaining a reasonably normal/perpendicular angle of incidence. It also allows to use an anti-aliasing filter for tricky subjects, something that is much harder to utilize with shallow angles of incidence.

Bart

Click to expand...

Point well taken.
I have read sometimes that a retrofocus wideangle design is inherently inferior to a non-retrofocus design due to the need for additional optical elements and thus additional refractiong surfaces. Leonardo has alluded to this in his post. So what I'm trying to say is that larger photosites in a sensor are more tolerant of light coming in from different angles

Christoph

What about the Alpa/Horseman/Combo cameras that use a digital back with lenses that are even wider than 28mm.

The problem with all of those cameras is that you have to do everything manually as in a view camera.

The idea could be to use the same glass as in the DIGITAR non-retrofocus lenses and construct a RANGE FINDER that would use Leica type focusing finder and auto lens cocking / even AF...

I don't think there is any technical barrier to do this any time. If I was Sinar I would go for it with such a model that used wide angle lenses. It was the solution that Hasselblad used to provide users with a wider cleaner lens when the mirror got in the way...



This is a non-retrofocus lens made for a retrofocus system.

A friend of mine adapted his Leaf Aptus 22 back to a Mamiya M7. In the end, he found it a better solution to use the little dedicated Alpa instead, since it offered almost the same functionality with a wider option of usable lenses.

BTW Asher, this same friend adapted his Cooke PS945 to mount on his Contax 645 and Leaf back(!) He had a mount made that allowed the lens to mount to a Contax bellows and then simply focused by racking the bellows in and out. He loved the effect, but feels the focal length is a bit long for anything but head-and-shoulder shots with the MF back.

Jack_Flesher said:

A friend of mine adapted his Leaf Aptus 22 back to a Mamiya M7. In the end, he found it a better solution to use the little dedicated Alpa instead, since it offered almost the same functionality with a wider option of usable lenses.

BTW Asher, this same friend adapted his Cooke PS945 to mount on his Contax 645 and Leaf back(!) He had a mount made that allowed the lens to mount to a Contax bellows and then simply focused by racking the bellows in and out. He loved the effect, but feels the focal length is a bit long for anything but head-and-shoulder shots with the MF back.

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Well Jack,

The Cooke would be better on a Mamiya RZ would it not. That has a built in bellows and is built like a Sherman Tank, LOL! I wonder whether on would have enough extention or need rails made by Grimes?

Asher

I suspect all you'd need is a Mamiya RB extension tube and an adapter up front to allow the Copal 3 shutter to be mounted. The tube is available, probably less than $100 and I suspect Grimes could machine the front plate for about the same. Better yet, just get a top-hat lensboard and use those tubes and front panel, and have Grimes put an RB mount at the rear. Either way, it's doable pretty cheap.