June 22, 2010.  The 50mm Fujinon is the most coveted of all Fuji 6x9 rangefinder lenses.  It commands asking prices, if in a complete set (hood, lens, finder), well above two thousand dollars.  There is a tremendous amount of misinformation about the 50mm Fujinon, and very little technical discussion of what it does or does not do.  It does not, for example, make up for a $16 breakfast for two at Metro Cafe.  Perhaps we can fix that right here.  Or maybe not.

Sharpness.  Let's get this out of the way.  It's very, very sharp.  Is it APO-Digitar sharp?  No.  But if enlargement plays a role, it is much sharper than the 47mm Super Angulon.  The catch is that you have to focus the lens.  The DOF markings on the lens do not embody the circle of confusion you would use with modern web scrutinization.  That said, when you actually use the RF to focus, the lens presents astounding results, even shot at f/5.6 (wide open).  The picture at the top illustrates a lot of things about this lens, so we will use it for several different things.  First is sharpness:

Above you see a 100% view of a tiny bit of the f/5.6 picture above (LS-8000, Silverfast, glassless carrier, USMed 100%, 1 pixel, 50% - pretty conservative).  This is shot on Tri-X, so grain starts getting in the way.  But if you understand that a 100% view of a 12,500 x 8,325 image is 130 x 86" (at 96ppi, what your screen sees) or 41 x 27.75" as a standard 300 dpi Frontier print, you realize just how much resolution this lens packs.  T-Max 100 will be a better test of this.  Preliminary indications are that this lens is almost as sharp as the modern multicoated 65mm f/5.6 found in the GSW690III. 

Not surprisingly, there is quite a bit of focus field curvature.  Observe a 100% view of the coffee cup that is six inches in front of the focused subject to the baby at the far right (and a couple of feet closer) (note also that these are not USMed from the original Silverfast scan):

This is a fact of life with wideangle lenses.  You can actually use it to your advatange to get more objects in focus.

In terms of the effect of aperture and distance, this lens works best at around f/8-16 and distances of a few meters.  Smaller apertures make things less razor-sharp (diffraction?), and longer distances cause small details to blend into the film grain.

Distortion.  People are hopelessly confused about symmetrical (non-retrofocus) lenses and distortion.  The myth is that there is no distortion at all.  This is wrong.  There is little or no barrel distortion (spherical distortion) in a symmetrical lens like this one.  There is, however, geometric distortion - unavoidable on any wideangle lens.  Check out the shape of this coffee cup:

As a rule of thumb with any wideangle of any length on any camera (even a theoretically perfect one), all objects toward the edges of the frame will be stretched.  This should come as no surprise because light coming from a wider angle takes a longer path.  To defeat this, any object that needs to be undistorted should be kept inside the part of the field that corresponds to a "normal" lens.  On a G690 series camera, that is the 100mm framelines (which are essentially the same as a 42mm lens on a 35mm camera).  On a 35mm camera, you would keep things inside the 40mm field of view (since that is the closest to the format's diagonal side).  But even then, you have to watch foreground objects (witness the size of the wheels on the baby carriage):

Shutter reliability.  Yes and no.  The Seiko #0 shutter in this lens (and most Fujinons) is tough and often will keep to about 1/3 to 1/2 stop accuracy for hundreds of years (ok... decades) with no maintenance (sometimes they do slow down, as I experienced with the 50mm).  The bad news is that the M synch mechanism (originally designed to create a microscopic delay to accommodate the warmup of a flashbulb) will not function so well nearly as long - and the X/M selector is unfortunately placed on the underside of the lens (naturally, where you would grip it and accidentally switch from X to a malfunctioning M setting, hang-firing the shutter).  Cleaning and lubing the M synch mechanism is an obvious measure, and given how easy it is to switch from X, a maintenance step that should not be avoided.

Accessory viewfinders.  Fuji wideangle accessory viewfinders are well-intentioned but generally fail in the execution.  Most 50mm Fujinons are missing their finders, likely because the lack of a locking mechanism resulted in their loss in the field.  The Cosina Voigtlander 21mm accessory finder works well as a replacement, as does just about any 20mm or 21mm unit. 

A surprising number of 50mm Fujinons show up pm Ebay and Yahoo Japan packaged with Mamiya Super 23 viewfinders.  And this is in itself surprising because that Mamiya finder is huge, sticks out from the back of the camera, and features a locking mechanism that does not mesh with the flash shoe pin on the Fuji bodies.   It is, however, amazing well corrected for distortion, and the parallax correction is more appropriate to the G690's lens-to-shoe distance than most repurposed 35mm finders. 

One thing to watch is that G690/G690BL/GL690/GM670 accessory shoes are not really toleranced for finders that clamp-lock with a thumb ring.  Sometimes they don't really lock; other times, the finder ends up out of parallel with the top of the camera (which being made of easy to deform brass, is fairly easy to knock out of kilter).  For the same reason, one of the only ways to assure that a finder is truly level (or that a level is truly level) is by checking at the film plane.  Remember that most G series cameras were sold with 100mm lenses (which need neither finder nor leveling), so don't automatically assume that the various tripod socket to body to accessory shoe alignments are perfect.

If you are really creative, try a Graflex XLSW sport (wireframe) finder mounted in a double shoe with a Seculine Action Level Cross.

Flare.  This lens is vulnerable to flare- which makes a lens hood useful and useless at the same time.  The lens has a huge exposed front element (no cone like the 65mm f/8 has).  You can easily pick up a five-bladed flare by having the sun near the periphery of the frame.  This agitates for the use of the hood.  But certain pernicious flares with the sun in-frame have a tiny pentagonal hotspot in the middle of multiple pentagons.  Lens hoods are no protection against this. My advice would be to use whatever shading is necessary - and to avoid sun-in-frame at all costs.  Here is an example of flare with hotspotting.  Here is an example:

Lens hoods.  These often show up without the original lens hood.  The original hood (shared with the 65mm f/5.6) is about 23mm deep and about 86mm on its square front end.  It clamps onto the lens with one registration pin on the lens at the 9 o'clock position.  The clamp is at about 11 o'clock.  If you do not have the original hood, you can use a Nikon HK-9 (originally designed for the 20/3.5) clamped onto a standard-height filter (like a Hoya) without any vignetting.  You can't really clamp onto the lens barrel itself due to the presence of the indexing pin.

Size and weight.  The Fujinon is smaller and lighter than most Fuji 6x9 lenses - but understand that the lens plus a G690BL body and finder runs about 4.5 pounds (2,047g).  This is, conservatively, five times the weight of a Brooks Veriwide 100 (with a 47mm f/8 Super-Angulon) plus about three times the overall volume.  If your only goal in life is to plug one of these into a G body, to zone focus, and never to make an enlargment bigger than a computer screen, you might as well get a Brooks. 

The last thing to ask yourself is why you would ever want to pack a 20mm (35mm) field of view into a 6x9 frame.  A wideangle lens is best used for close quarters.  You don't have a lot of space in general:

Or you may have an improbably big object at extremely close range.  Like this bridge I could sell you if you are the credulous type.

Conclusion.  Anyway, after all of this I don't know if I have disabused you of the 50mm Fujinon or inflamed your desire for it.  The 50mm Fujinon serves a very specific purpose and requires quite a bit of discipline to use correctly. Whether it is worth two grand is more a matter of your priorities.  De gustibus non disputandum est...