The Digital Rangefinder in My Head

[dazedgonebye]

This has probably been done here. In any case, this is the digital rangefinder that bounces around in my head.

Full frame sensor. I can deal with a crop on a DSLR. On a rangefinder, I want wide. Make that a Canon CMOS sensor while we’re at it (just take it from the 5D to keep things simple).
Frame lines from 28mm to 90mm.
Rangefinder baseline sufficient to focus 90mm f2 wide open.
Aperture priority AE.
Rangefinder displays like a Leica M5.
Manually cocked shutter like an Epson RD-1.
LCD display folding way, also like an Epson RD-1.

So, to use a full frame sensor with current technology, I think I need a flange distance equal to a SLR. Let’s go with Canon’s 44mm, since we’ll be using their sensor. That’ll make the camera thicker in the mount area by about .75 inches. (Something between M-mount and EF mount distance might work, but using SLR distances will give me access to SLR lens formulae.)
This also means I’m going to need a new camera mount. Lenses designed for SLR flange distances, but with RF coupling, manual focus and aperture rings. It also means my lenses are going to be as big as the manual focus slr lenses of old.

What would it look like?
I think if you morphed an RD-1 with a Z1 and married that to an old Cosina made Minolta…that might describe it.

Now, I don’t imagine that this idea is in any way likely or commercially viable, and I know it gives up some of what makes a rangefinder desirable, it’s just what (I think) I’d like to see.
Let me know if I’ve missed anything.

 

[sepiareverb]

Exposure compensation like the G2 or ZI? A nice simple top mounted dial.

 

[MadMan2k]

What I want, is an M3, with a cartridge you can put in and capture up to 36 full-frame pictures at once, and the cartridge costs between 2 and 10 bucks, only catch is there's a few extra steps to get to the digital part.

Seriously, what I would want in a digital camera would be basically a digital Hexar (AF). 35mm fixed f/2 lens (equivelant, since I'm not paying over 2 grand for this thing just because it has a full frame sensor), completely operable without using the LCD. It could have a swing out LCD like a lot of them have, and a monochrome one on the back for settings. Built in viewfinder, one without tunnel vision. Control wheel like Canon's SLR's on the back, focus dial on the top with an AF/MF switch next to it, and mode dial.

 

[dazedgonebye]

Oh...and I'd code the lenses and electronically couple the aperture. Lens and aperture information could be used by the camera, or in post processing to correct for many lens shortcomings.

 

[CraigK]

An updated Canon QL17 Glll with 5D sensor, fixed 1.7 35mm lens. $500.00

I'd buy two.

 

[dazedgonebye]

An updated Canon QL17 Glll with 5D sensor, fixed 1.7 35mm lens. $500.00

I'd buy two.

I think we're running afoul of the laws of physics...or at least current technology...when we try to match full frame sensors with short flange length rangefinders. Maybe it doesn't make as much of a difference at "normal" focal lengths as it does at wide...can't remember.

 

[rogue_designer]

only problem I can see, is due to the larger film/flange distance, the wides will have to be retrofocus designs - or otherwise deeply inset which will either a) sacrifice performance, or b) create the same angle of light/to sensor issues the M8 was running into.

But at least there is enough room for a proper IR cut filter inside the cam.

 

[dazedgonebye]

only problem I can see, is due to the larger film/flange distance, the wides will have to be retrofocus designs - or otherwise deeply inset which will either a) sacrifice performance, or b) create the same angle of light/to sensor issues the M8 was running into.

But at least there is enough room for a proper IR cut filter inside the cam.

Yep. Solve the angle of light to sensor problem by increasing the flange distance and you lose rangefinder advantages.

The need for a new mount is enough to make this idea a commercial non-starter.

 

[Gray Fox]

Please make mine the digital follow on to the G2 so I can use these beautiful lenses i have and they're already coded to work with an AF body. I can live with the IR filter on the chip since I do with my Nikons now. That would be a dream camera for those of us whose eyes have passed the era of rangefinder patches. That would give me a real reason to buy the 21mm I've lusted after.

 

[Al Patterson]

I'd like a digital CL or CLE. I have never gone wider than 28, so having to buy a 21 to get 28 with a 1.33 crop doesn't bother me.

 

[dazedgonebye]

I'd like a digital CL or CLE. I have never gone wider than 28, so having to buy a 21 to get 28 with a 1.33 crop doesn't bother me.

Yea...but if you want a fast 28mm equivalent, what would you do?

 

[charjohncarter]

Al, maybe it could look like a Barnack, too.

 

[VinceC]

If you can accept a smaller sensor size, you solve a lot of problems. .. You can keep legacy lenses, you can keep the "small is better" spirit of rangefinders; you can cut development costs; you can maybe convince someone like CV to build a reasonably priced 14/15mm lens with a reduced image circle to compensate for your need for a wider lens.

 

[dazedgonebye]

If you can accept a smaller sensor size, you solve a lot of problems. .. You can keep legacy lenses, you can keep the "small is better" spirit of rangefinders; you can cut development costs; you can maybe convince someone like CV to build a reasonably priced 14/15mm lens with a reduced image circle to compensate for your need for a wider lens.

I'm not sure the problem can be solved with reduced image circle lenses. Doesn't the (full circle) CV15mm vignette on the RD-1?

On the other hand, a 21mm f1.8 would go along way towards eliminating my objection to the crop.

 

[ferider]

Putting on my "engineering hat":

- I believe the MPixel race is stopping and technology development will go into sensors with more dynamic range instead (say, 24 or 32bit instead of 8 or 14 per pixel). Much like microprocessors have moved from 8, 16, and 32 to now commonly 64bit word depth.
- I believe that such new full-frame sensors could be used in an RF, and the increased dynamic range to correct for vignetting (1 stop of vignetting = 1 bit more dynamic range).

So all we have to do is wait for Kodak (IBM), Sony or somebody else to come out with a
full frame deeper sensor, for example 24bit. Then that sensor could be used as a side
application as a 16bit sensor in the M9.

Cheers,

Roland.

 

[VinceC]

>>I'm not sure the problem can be solved with reduced image circle lenses. Doesn't the (full circle) CV15mm vignette on the RD-1?<<

It vignettes on film, too.

 

[VinceC]

>>It vignettes on film, too.<<

As do my 21/4.5 Biogon and 28/3.5 Nikkor. Light falloff is inherent in many of the symetrical non-retrofocus designs.

 

[Terao]

Don't fix the camera. fix the sensor...
It will come I'm sure.
A sensor without a Bayer filter and without microlenses (i.e. high megapixel B&W) with a wider dynamic range
How about a sensor that was almost as thin and flexible as film?
Instead of offsetting the microlenses offset the whole sensor - curve the edges. Ideally you'd bend the sensor to match the lens but in practice I guess you'd have two settings - normal and wide. Bending the sensor could sort the corner falloff issue and let you use a sensor nearer to full-frame...

 

[dazedgonebye]

Don't fix the camera. fix the sensor...
It will come I'm sure.
A sensor without a Bayer filter and without microlenses (i.e. high megapixel B&W) with a wider dynamic range
How about a sensor that was almost as thin and flexible as film?
Instead of offsetting the microlenses offset the whole sensor - curve the edges. Ideally you'd bend the sensor to match the lens but in practice I guess you'd have two settings - normal and wide. Bending the sensor could sort the corner falloff issue and let you use a sensor nearer to full-frame...

I have great faith in technology. I'm sure solutions will present themselves over time. I just hope there is someone out there still standing that will be willing to put those solutions in a camera.

 

[lff]

Or what if someone made a digital cartridge that would fit in a 35mm camera but extends over the frame area with a protected sensor?

Then all 35mm cameras could be digital. Obviously this a very simple idea that might quickly get too complicated &/or expensive to be a reality. But wouldn't something like this be a most ideal situation?