Mamiya RB-67: The Soft-Focus 150mm ƒ4.0 Sekor C Lens

The soft focus lens has designed-in spherical aberration which provides excellent out of focus highlights (bokeh).  The diffusion disks are thin metal pieces that look like small metal bottlecaps.  They are fitted one at a time only, though are not required to use the lens.  They have a larger central hole with smaller holes surrounding.  The size of the central hole and the amount of light that passes the disk in total changes the apparent aperture for exposure calculation. While the smaller apparent base-aperture given by the disks does not appreciably increase depth of field, it does require compensation.  I wonder if the DoF is increased but is not apparent due to the increased softness of focus. 

The disks are, #1 (ƒ5.0), #2 (ƒ5.6) and #3 (ƒ6.3).  They are supplied in a clear plastic "filter case" style carrier with a fitted, molded soft plastic piece to hold them.  To use, unscrew the front lens cell (group of lenses held together, screwed into the shutter,) and simply slip the diffusion disk on to the back end of the cell, then return the cell to the shutter.

Using the the lens's built in aperture, the diffusion of the disks is apparent between ƒ4.0 and ƒ6.3.  Apertures ƒ8.0 and smaller shoot through the center of the lens and center hole of any of the disks, reducing or eliminating both the spherical aberration and diffusion from a diffusion disk if used, showing this to be one of the sharpest lenses built for the RB system.

Shooting Macro on the Mamiya RB System

RB and Fuji Instant Film:

The RB system will accept instant film backs. There are several made including some that require a system adapter, "P" and some that attach directly to the body in place of the rotating adapter. I've used the latter and it works quite well with stocks of Fuji Instant film. This type film tends not to be as sharp IME as slide and negative films, but renders pleasant images. You can also bleach a negative or positive image from the backing which could potentially be sharper than the print.

Tubes and Extenders:

For macro work there are two extension tubes in the system made by Mamiya and several tele-extenders made by Mamiya or others. The #1 tube adds 45mm of length (367gr), the #2 tube adds 87mm (473gr), lengths as marked on the tubes. At 840grams combined, the two tubes weigh almost 2 pounds. This is a huge amount of weight to stick on the front standard of the camera. Then put a lens, say, the 150/4.0 (799gr) and an extender such as the Kenko 2x Teleplus MC6 (657gr), and you have a long lever mounted to the camera that weighs 2,296gr (5.21 pounds!)

Light Falloff and Measuring Exposure:

Now rack the bellows all the way out and you have cut the light showing in the viewfinder by a huge amount, making it almost impossible to focus. And you have to figure a starting exposure: ƒ(exp) == (1/d^2)--T* of the extender; i.e. run a bellows-factor calculation and subtract the filter factor of the extender. This should give a ballpark exposure; I added about 3 1/2 to 5 stops to get close one time. But the lenses and extenders were so heavy that I had to find a way to support them separately from the camera.

So it's really going to depend on how macro you want to shoot as to how possible it will be to assemble, carry and use such a system with system components. The maximum rig above is probably best used in a vertical orientation with a huge amount of light to focus the subject. Longer exposures are fine if well supported, but they can be in the minutes at smaller apertures. By ƒ/32 you may be in the tens of minutes.

Alternatives to Using All RB-System Components:

An alternative to using all system components is to find a lens or chain of lenses that can deliver higher magnification and sufficiently flat field and sharpness at higher magnification while also projecting a sufficient image circle to cover the film. You would probably also want to be able to set the aperture, but at longer exposures, a shutter really isn't necessary. Most lenses extended further away from the film will enlarge the subject, so you could use anything from a 'hand' lens up to a microscope objective or eyepiece. Chances are the smaller the original imaging field design, the more image falloff or even mechanical vignetting when used for this application.

I believe it's our right as humans to demand more gas,
drive more miles,
tear up more environment,
who cares?
I don't care, I like to drive, so what?
I want bigger cars, faster cars, and more of them.
I want a new car every year, maybe twice a year.
2 or 3 cars for each person! And trucks.
We all need trucks and SUV's and cheaper gas.
What's anybody doing about cheaper gas?
And bigger roads.
We need more roads and cars and trucks and SUV's,
and more car dealers.
Car dealers shouldn't have to pay taxes.
Nobody should ever have to pay taxes.
More roads and car dealers, cars, trucks and SUV's and no taxes.
Why won't everybody else be responsible???
What is dog doing to clean up this mess????

If You Go To Gwinett County, You Better Walk Right

'contempt of cop' prosecutions lead to stronger contempt. (link)


In Gwinnett county, just north of Atlanta, Ga, USA, in May, 2004, a group of 6 policemen held Frederick Williams down, who was already not only in custody, but handcuffed and manacled and in an inner locked room in a secure lockup facility. Williams was unable to comply with their shouted demands, physically, mentally or emotionally. The group of deputies tasered Williams to death.

Williams was arrested and brought to the jail because he was acting crazy after not taking his epilepsy medication, so was not in his right mind. (I think they could have shortcut the process and shot him in the street like a dog....)

It made some great film from the overhead video recorder. It sure looks like murder, as a matter of opinion -- he died two or three days later of an arrhythmic heart thingy, after being tasered numerous times. The video, which the grand jury declined to watch, showed Frederick Williams being tasered at least 5 times within a period of one minute.

The Gutless (er, Grand) jury did not indict the popos -- they had, perhaps, a feeling that there might be some retribution on them? Defense testimony ran along the lines that the preceding events could not be definitively tied to the condition that lead to William's death, the Medical Examiner said that a definite connection between the excessive treatment was unclear, the defense claimed the jailers had no intention of harming Mr. Williams.

Well, anyway, it makes for great sport! This little parable, now a dust mote in history, shows two things:

1. Quite often is it art not evidence that prevails in courts
  (art, and lots of friends in the right places.)
2. Your best protection against thugs and bullies is a bigger stick.
  (really, it's Darwinian -- beauty, power, speed, aggressiveness are all survival traits for your bloodline.)

Critique: Harsh or Helpful?

From a critique I wrote recently:

"Snapshot, out of focus, looking down, distracting background elements, and the light is not controlled nor flattering.

Even a camera mounted flash would have opened the shadows on her face a bit. She is not engaging the camera, instead she is looking down. The portion of an arm above / right, the torso to the left, the concrete and siding behind her all detract from the subject.

It sounds harsh, but understanding what you see when you take a photo helps to realize a better result. I have learned a lot by dissecting my blunders. It helps me to build a mental checklist to use while shooting, and even more, to have concepts to think about before picking up a camera.

FWIW, it's possible to develop a style that capitalizes on things that some/many consider wrong/errors, but that takes a certain mastery or natural talent not everyone has. I've been trying to sell the notion that my biggest mistakes should be in museums for year -- no takers."

It's hard to listen to a listing of the problems with a piece of work and walk away as a better artist.

In a rural stretch of Germany, I was in a traffic jam at 115mph. Very weird -- large Mercedes, Porsches, Audis were trying to get past, and I was stuck in a very nice Renault with a top speed of only about 125mph, so I was getting out of the way.

Something like 90% of European drivers are educated about driving on highways and other roads and willingly give right of way to faster drivers. That other 10% thinks they are driving tractors in the fields. In the US, probably about 40% of the people behind the wheel are capable drivers during their entire time behind the wheel -- whether the distraction is kids, the car, the phone, texting, lack of training or desire to function properly and courteously while driving. Going slow in the left lane, failure to yield properly in most circumstances, lack of attention, or a lack of understanding and experience combine to cause most traffic and wrecks.

A for-instance: people change lanes directly into the path of faster cars without speeding up first. They are only thinking about themselves. Which is it most: a lack of courtesy, experience, poor driving habits? Speed is a much lesser danger than incapable drivers, but the problem is that people are culturally unable to grow and become better drivers.

/..

View On Monitors

Every modern photographer depends on their computer and its monitor(s) throughout the workflow, once the image is captured. Often, as much work is done here that affects the final output as in the camera.

My plain old, discount Samsung SyncMaster 203 is getting hard to start -- the bulb is taking longer and longer to warm up. But once it's going, it works great (like with most monitors, esp. LCD's, don't look for critical color and density adjustments until at least half an hour! after they start.)

So I looked into repairing it: replacing the bulb may be all it needs. This probably will require some surgery dealing with whatever I find inside: cutting out the old bulb, adapting the new one to fit, soldering in new connections, finding and matching specs on a new bulb, etc. I don't recommend trying to repair your own monitor because everyone has a different skill level and there are several levels of potential danger involved; it might be better to find a new monitor in most cases, or a repair shop.

Two bulb sources:
www.xoxide.com
http://www.lcdparts.net

It may be better to replace the current screen with a new one, so some basic understanding of the terms and technologies is a big help. This website, www.tftcentral.co.uk has lots of basic (and more advanced) info to guide the shopping process.