Why large format?  

    Making pictures vs. taking pictures.

Once asked what type of camera he preferred Ansel Adams is reputed to have answered: “the largest one that I can carry”.  Asked what was the ideal tripod he answered “ a two ton concrete block with a ¼ /20 bolt set into it”.  This was only a little tongue in cheek.  All other things being equal, the bigger the negative and the more stable the tripod, the more detail that you are going to capture.  Many famous Ansel Adams photographs were taken with medium format cameras but, by in large, 8x10 and 4x5 seem to be the preferred format. 

However another large format photographer once said: “there is nothing photogenic more than 100 yards from the car.  While Ansel Adams is the idle of today’s starry-eyed “environmentalists” it is no accident that he drove the 50’s equivalent of today’s hated SUV.  With large format, the camera is just a small percentage of the required equipment.  Light meters, (plural), tripods, plate holders, extra lenses, dark cloths, magnifiers, 90 degree viewers, Polaroid backs, lights, reflectors etc all go with me when I go out to take a large format photograph.  For me, one hour to locate the camera, focus and make the picture is really cranking out the work. 

Someone watching all that with a digital Canon “Elph” in their top shirt pocket can’t be faulted for wondering why.  Below is my attempt to answer that question.

Those that want a quicker answer, which I feel is better suited to the 35mm and medium format hobbyist, should use the following link, it is shorter. 

http://www.largeformatphotography.info/why.html

Often when I am out with a large format camera people are often amazed that I would be taking pictures with; “such an old camera”.  Mine are, but only because I can’t afford a new ones.  Large format cameras like mine are still used by professional photographers all over the world, because nothing else will do the job as well.  Many professional photographers use cameras like mine with state of the art digital scanning backs.

http://betterlight.com/eModels.asp

Not so much because digital can offer higher quality than film but the savings on the cost of film, for a professional, can pay for the back in about one year.  Beyond which, modern printing techniques require digitizing an image at some point in the process, so why not at the camera?

Detail

First and foremost, the draw to large format photography is capturing detail.  With either film or digital, the bigger the sensing media, the more information that you can capture.  As film size goes up there are losses due to optics but those losses increase mathematically while the size of the film increases geometrically.  In other words a medium format negative may be 3 times as big as 35mm but only contain twice the information.  4x5 is 13 times as big as 35mm but probably only 7 or 8 times better and 8x10 is 4 times as big as 4x5 and only about twice as good.  However, no mater what the optical losses, the detail in a large format photograph is astounding.

http://largeformatphotography.info/qtluong/example.html

Beyond the additional detail that can only be achieved with large format, most large format cameras allow the photographer to control virtually every aspect of the photographic process. 

This is exactly opposite of the marketing of modern consumer cameras, both film and digital, where automatic functions are considered features.  The camera however, to make decisions for you, has to make assumptions about what you want the picture to look like.  With what we can call snapshots, the camera is usually right, with “photographs” it is almost always wrong.

The reason for that is that with large format photography there is no right or wrong, just achieving the photographer’s vision.

The concept of “pre-visualision” was popularized, if not invented, by Ansel Adams.  The best example is a black and white photograph of red apples and green peppers.  Without photographic intervention, they will both come out an almost equal gray color, and the concept of red and green will be lost.  By using a red filter the photographer can make the red apple lighter than the green pepper. By using a green filter he can achieve the opposite.  Neither is correct, but to my mind both are better then both being equally gray.

Zone System

With his “zone system” teachings, Ansel Adams demonstrates that there is no correct exposure or development for a given photograph.  There is only what is needed to achieve what the photographer visualized when he decided to make the picture.

Both large format film (because the individual sheets allow individual processing) and digital backs, allow for “processing adjustment” of each scene individually. 

This usually takes the form of stretching or compressing tonal values. 

The real world can have more zones of brightness than we can reproduce photographically.  If for example we use our light meter to measure the brightness of the light being reflected off of a black dog and a white dog standing next to each other, we might find that the white dog is reflecting 10 times as much light as the black dog.  If we place the black dog in the shade while leaving the white dog in the sun, the difference could be over 20 times. 

Normal photography (film is better than most consumer digital) cannot capture this full range of luminescence. About 7 or 8 times is about all we can display on paper or the computer screen.  Without some type of intervention we will either “block up the shadows” or “blow out the highlights”.  In our example this means that either the black dog or the white dog will not have any texture in their coat. Here we would use exposure and development controls to compress the tonal range in the scene to fit what our film and paper can reproduce.

The opposite problem with is the black dog in the shade by himself.  Then the light areas of the dog’s coat and the dark areas might be separated by less than a “zone” (doubling of light intensity).  In a normal photograph, which would assume about 7 zones in the scene, the photograph would not show enough contrast in the dog’s coat to replicate the texture that you would see in real life.  The trick there would be to use exposure and development controls to expand the tonal range in the dog’s coat to the full 7 zone range of the film and paper.

With any photography you can compress or stretch the tonal values in the scene to match what can be reproduced on paper or the computer screen.  With film you do this by altering your development times.  Either developing longer or shorter than average.  However with roll film unless every scene on the roll has a similar tonal value, altered development is impractical. 

The ten zones as codified by Ansel Adams are:

            Zone 0 - Black, no texture or detail.

            Zone I - Can be discerned from completely black.

Zone II - Dark gray-black, possibility of slight texture

Zone III -Very dark gray, but good texture and detail can be seen.  

Zone IV - Medium-dark gray, dark green foliage, shadow side of Caucasian skin. Details plainly visible.

V - Your meter's suggested settings. Medium gray

VI - Caucasian skin in sunlight.

VII - Bright light gray, highest Zone that will still hold good details.

VIII - Light gray-white, shows texture but no detail. 

IX - Almost white. 

X - Reproduces as paper base white

This is pretty much the limit of what you can produce on photographic paper.  Zones are normally thought of as a doubling of the amount of light that is reflected.  It gets confusing when you read that film can capture 13 or 14 zones and still retain detail.  However, to display that range of zones in a manor that human beings can appreciate them you are going to have to compress them to fit the 10 zones above.

Because the human eye can discern differences in tone in smaller increments in bright light than dim, photographers tend to concentrate their attention on the shadow areas.

The saying is: Expose for the shadows develop for the highlights. This is because if you capture the information on film, you can usually do something either in development or printing to render it on the print.  Film will capture more detail in the highlights than most of us can see on the negative.  However, if you don’t give the film enough exposure in the shadows to capture detail, it simply isn’t there and there is nothing you can do once you trip the shutter to get it back.

Gamma

The term for this expansion and contraction of zones between the scene and the film is referred to as gamma.  A gamma of one would be if the range of zones in the scene exactly matches the range of zones on the negative.  A gamma of less than one would indicate a compression of the tonal range in the scene and more than one an expansion.  A more familiar term would be if we spoke of adjusting the “contrast”.

In order to exercise this type of exposure and development control the average brightness of the scene is useless to us.  About 100 years ago someone decided that the average brightness of a typical scene reflected about 18% of the light falling on it.  Cameras and light meters have been calibrated that way ever since. (The ansi standard is 16%, don’t ask me why).  This makes two assumptions that large format photographers are un-willing to live with.  First that the average luminescence is actually 18% and second that an exposure based on the average luminescence will give the optimal exposure to render detail in the elements of the scene that the photographer is most interested in. 

For example you may have a scene that overall is relatively bright, and on the average reflects 18% of the light falling on it, but what you are most interested in is the pattern of the bark on a tree.  Normal exposure might give you a “correctly” exposed photograph but you would “block up the shadows” in the tree bark and simple see a tree trunk with no detail to the bark.

Spot Metering

This is why it is almost unheard of for a large format camera to have a built in meter.  A large format photographer will typically use a hand held meter, which measures a small part of the scene at time.  (My meter measures a 1-degree angle, which off the top of my head is about a 4” spot at 50’)

You then measure the darkest part of the scene where you want to retain detail and the brightest part of the scene where you want to retain detail.  If the brightest reading is exactly 7 times the darkest reading.  You adjust your exposure so that the dark part of the scene will “fall on zone 3” and the brightest part on zone 8.  Zone 5 is 18% reflective or average, and then you would develop normally.

Typically you will find that the range of brightness is either too short or two long.  You then adjust your exposure and development times to expand or contract the range of tone in the scene to fit the paper.

Focusing

One of the major assumptions that almost all cameras other than large format make, is that every element of the scene that the photographer considers important is the same distance from the lens.

This is obviously very seldom the case.  To account for this problem advanced amateurs use “depth of field”.

We are taught that “depth of field” extends from 1/3^rd of the distance from the focal plane toward the camera and 2/3rds of the distance from the focal plane away from the camera.  We are also taught that if we set or aperture and point of focus so that the far limit of our depth of field is just at “infinity”, then everything from the hyper focal distance to infinity will be “in focus”.

Will Rogers once said that:  “it isn’t what we don’t know that gets us in trouble, it is what we know that isn’t so”.  There is no tooth fairy and there is no “depth of field”.

That is why they call it a focal plane.  It is infinitely thin.    Every object not in the focal plane is out of focus.

The concept of depth of field relies on three assumptions:

·        That you will never change your mind about how big a print you want or decide to crop the image.

·        That a resolution on the final print of 6 line pairs per millimeter will satisfy you.

·        That the film doesn’t have sufficient resolution capability to record the difference anyway.

The first two have remained relatively consistent over the last 75 years or so.  Depth of field tables or the lines engraved on your camera’s lens, assume that you will want a 4x5” print.  I have a camera that was made in the 60’s that came with a booklet of depth of field tables for different sized enlargements.

6 line pairs per millimeter resolution is the point at which the average observer at an average distance will perceive detail as “sharp”.  However, it is only about 1/5^th of the way to where an observer can tell the difference in sharpness when two photographs are compared side by side.

However, in the past, 6 line pairs per millimeter in a print was about all the film was going to provide anyway, so objects in perfect focus (at the plane of focus) weren’t going to look any better than objects within the depth of field.

Now with modern film and a large format camera, it is not beyond most diligent amateurs to get detail between 80 to 100 lppm on the film.  That means that with a 4x5 camera going to an  11x14 enlargement, I can approach the theoretical limit of perception of 30 lppm.  That means that objects at the far limit of the “depth of field” will be 1/5^th as sharp as objects at the focal plane.

In order to account for this increase in resolution in modern films, depth of field scales have to be adjusted by a factor of 3 or 4 at which time, “depth of field” as a concept virtually ceases to exist.

For some of us, leaving that much information in the field is not acceptable.

Tilt, swings, shifts, rise, fall…

With most cameras anyone has ever used, the plane of the lens and the plane of the field are parallel.  When you focus, you change the distance between the lens and the film but the top, bottom, left and right side of the lens remain the same distance from the film.  Somewhere out in space there is a third plane parallel to the first two that is the plane of focus.

If you want to use one of these cameras to take a photograph with flowers in the foreground at say 5’ and cows grazing in the background at say 75’, you have three choices.

Notice that they both can’t be in focus.  This is true no mater how many mega pixels you have or how many lithium batteries it takes to power all the bells and whistles.  You can make them both SEEM to be in focus, but with large format, as Hamlet said: “my lady, I know not seem”.

I want them both in focus.  In fact let’s add a snow-covered mountain several miles away.  A plane in geometry is defined by any three points.  In our case, flowers, cows, and mountains.

The left side of a photograph is imaged by the right side of the lens, and the right side by the left; top, bottom etc.

If we build our camera so that the relationship of the plane of the lens to the plane of the film, isn’t fixed but adjustable, we can then focus the right side of the camera on one object and the left side on another.  Top/bottom etc…In other words you can manipulate you plane of focus so that it intersects three points in your photograph that you choose.  You can in other words have three different elements of your photograph at different distances from the camera in perfectly sharp focus.

This is why you see pictures of view cameras that look like some playground bully grabbed them and twisted them like someone wringing water out of a towel.

http://www.toyoview.com/LargeFrmtTech/lgformat.html

The following link has Quick Time movies explaining this concept and they are a kick to watch.

http://www.trenholm.org/hmmerk/HMArtls.html

The above is one of the reasons that large format lenses are several times as expensive as 35mm lenses in the same focal length.  A 75 mm lens for 35mm has to capture and bend enough light to cover a 35mm negative.  A 75mm lens for a 4x5 camera has to capture and bend 13 times as much light.  Further the sharper the angle that you bend light at, the more it wants to separate into the colors of the rainbow, With a 35mm lens you only have to bend light a maximum of about 18mm from the center of the optical axis, with 4x5 you need to bend it over 75mm.  This is way more difficult to do.

Further, that only gets you to the point where you have the equivalent of an oversized normal camera with a fixed focal plane.  When you use tilts, shifts, swings etc to move your plane of focus, you actually shift the cone of light that the lens is projecting onto the film.  If your image circle is only large enough to cover the negative, you get dark corners on your film.  (Been there, done that got the tee shirt.)

Therefore with a large format camera your image circle has to be significantly larger than the size of the film. (Read more expensive.) 

Perspective Control

Unfortunately most of us have seen pictures of buildings where they look like they are falling over backwards.

This is caused by the fact that the photographer had to point the camera upwards to encompass the entire building.  When he did that the distance between the bottom of the building and the film and the distance between the top of the building and the film became different.  Just as railroad track converge as they go towards infinity, the straight sides of the building now seem to converge towards the top.

This is where an Austrian artillery officer named  Scheimpflug enters the picture.  Back before highflying airplanes, armies used spotters in tethered balloons to target their artillery.  These spotters would take pictures of the enemy’s lines and the pictures could be used to find targets. 

However because the photographs were taken from an angle to the battlefield they could not be scaled to determine the range for the guns.  Scheimpflug  realized that if he knew the angle of the angle of view of the camera to the battlefield, he could reverse the angle when making the print and the resultant photograph would be the same as one taken from directly over the battlefield.  He could then scale the photograph and kill people with less ammunition.

Large format cameras use this principle to provide perspective control.  Most large format cameras have a level somewhere on the camera and as long as the film is parallel to the building, you can then move the lens anyway you want to include the entire building and still have 90-degree corners. 

One demonstration of perspective control is using side shift to keep the photographer out of the photograph when taking a picture of a mirror.  You simply set you camera up to the side of the mirror so that you aren’t shown, and then shift the lens to the side until the image on the ground glass makes it look like the picture is being taken from directly in front of the mirror.  This really does work!  I should for example be visible as a tiny photographer in this photograph.  However, I stood to the side and used side shift to stay out of the angle of view.

http://truckgenerator.com/subdomain/sueandneal/downtowninmodern.jpg

Equipment

There are several types of large format cameras. The following list is very inclusive of manufacturers that still make large format cameras.

http://www.largeformatphotography.info/resources.html

There are basically 4 types of  large format cameras, although the lines between them are somewhat blurred.  (Lets hope the images that they make are not.

I would consider anything that used sheet film larger than 3 ¼ x 4 ¼ “ to be a large format camera.  Film size goes from there to 8x10” and anything above 8x10” tends to be referred to as Ultra Large Format. Where 16 x 20 is not uncommon. 

As a general rule, large format cameras tend to have ground glass backs where you view the image upside down and backwards under a dark cloth. 

Press cameras and technical cameras tend to have viewfinders and range finders to allow hand held use, but certainly ground glass focusing with the camera on a tripod is far more common.

Most (almost all) large format cameras have a bellows to allow focusing and movements. 

The most famous Press camera was probably the Speed Graphic. 

http://graflex.org/

The Speed Graflex was mahogany covered in leather and had two shutters.  A rear focal plane shutter which allowed racecar-stopping speeds of up to 1/1000^th of a second in available light, (The “Speed” part of the name. Crown Graphics didn’t have this shutter) and the more conventional leaf shutter on the lens which allowed more flexibility in syncing the camera to flash bulbs.  Which a good friend of mine in his 80’ points out were invented in the late 30 making all the movies set in the ‘20s showing press photographers using Speed Graphics with flash bulbs, just plane wrong.

It is my guess that up until the early 60s there were probably more award winning news photos taken with Speed Graphics that all other cameras combined.

The Speed Graphic was a very versatile camera for a photojournalist but didn’t have a lot of “movement”.  I.E. you couldn’t do a lot of extreme perspective or focal plane adjustment.  What movement it did have was limited to the front “standard” the part that holds the lens that the bellows attaches to.  They also had more limited bellows draw which did not allow the extreme close ups that technical and view cameras are capable of. (Graflex also made up to 5x7 SLR cameras which deserve a footnote in camera history because of all the famous photographers that made some wonderful pictures with them.  The RB (revolving back) Super D is enjoying resurgence in popularity with hobbyists and commanding ridiculous prices on the used camera market.)

The quintessential technical camera is probably the Linhof Technica.  It could be described as aluminum Crown Graphic.  The main differences being that it has (it is still made)  half again more bellows draw, Both front and rear movements and a rotating back to allow changing from vertical to horizontal shots without removing the camera from the tripod. 

Landscape photographers mostly prefer “field cameras”.  These are similar to technical cameras, tend to be wood, and fold up for work in the field.  They have extensive movements and can be focused by moving either the front or back standard.

View cameras tend to be a monorail version of field cameras.  They don’t fold up and protect themselves like field cameras do so they tend to reside in studios.  They are extremely versatile and modular. 

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