Tiffen Quick Reading Diaphragm Control for Argus C, C2, C3

This is one of the many gadgets made for popular Argus cameras.  The Tiffen Quick Reading Diaphragm Control was intended to make setting the aperture on an Argus Cintar 50mm f/3.5 lens a little easier.  The Argus Cintar lens made from 1938 to 1958 has a small ring with a couple of tiny pins to set the iris diaphragm.  The Tiffen control ring fit over the ring and pins and made it easier to read the f/stop and set the lens, especially when a filter or lens hood was installed.  In 1958 Argus redesigned the Cintar lens to have a more conventional aperture ring, and the new lenses no longer needed the aftermarket control ring.  As a safeguard against losing the Tiffen control ring, it is a good idea to screw in a Series V filter adapter ring such as a Tiffen #502 or a Kodak No. 18 to keep the control ring from falling off if it came loose.  The control ring came in black with white markings or silver with black markings.  I think the silver version is a little better looking.

Black with white lettering

Silver with black lettering

Instructions for the Tiffen control ring.

Bolsey Model B2

The Bolsey Model B2 is a Bolsey Model B with the addition of flash synchronization and double exposure prevention.  The camera takes standard 35mm film in cassettes.  The B2 was introduced about 1948.  Peerless Camera Stores (New York City) advertised them in the October, 1948, issue of Popular Photography for $65.90.  The camera was discontinued in 1957.

Front

Rear

Top

Bottom

Interior

Ready to take a picture

After taking a picture

The body of the camera is made from aluminum and the dimensions are roughly 4-1/4 inches wide by 2-3/4 inches high by 2-1/2 inches deep. The camera has the controls on the lens, which was normally the case on leaf shutter cameras.  The lens is an f/3.2-f/22, 44mm, coated Wollensak Anastigmat.  The shutter is a Bolsey Wollensak Synchromatic leaf shutter.  The back of the camera comes off for loading film.  The path between the film cassette and the take-up spool is shorter than usual, and Bolsey ads claimed that you could get four extra pictures on a roll of film if you were careful about loading film.

The shutter release sets and releases the shutter in one motion.  The shutter has a moving peg that pops up to stop the shutter release from resetting after you take a picture.  The peg retracts when the film is wound and this allows the shutter release to reset.  To make a deliberate double exposure you push in the peg to allow the shutter release to reset.

The back of the camera has a depth of field calculator based on a circle of confusion of 0.05mm or 1/500 inch, which was typical for a miniature camera at the time, and a film reminder dial for Panatomic X (Kodak), Daylight Anscocolor, Tungsten Anscocolor, Daylight Kodachrome, Type A Kodachrome, Ultra Speed Pan (Ansco), Super XX (Kodak), Supreme (Ansco), Plus X (Kodak) and a blank space for when there is no film in camera.  None of the films are still in production.

The flasholder plugs into the openings on the left rear of the camera and takes a #5 or #25 flash bulb.

There are no strap lugs.  If you want a neck strap you need to use the leather camera case.  You also can use a strap that screws into the tripod socket.

A filter kit with a lens hood was available.  The lens takes a 24 mm series V adapter ring.

The Bolsey B2 is small and cute.  According to "Brass, Glass and Chrome" the camera was especially popular with women photographers.  You need to be careful with the shutter release to avoid camera shake.

Cimberland Mountain State Park, Crossville, Tennessee.  Ilford HP5 film.

This example has a very stiff (basically impossible) rewind.  Curiously it rewinds better with the back off. I need to give it a DIY CLA.

Diffraction and Circle of Confusion

Because of the wave nature of light, the image of a distant point of light is not an infinitesimal point, but a finite disc surrounded by a series of concentric rings.  The Royal Astronomer Sir George Airy worked out the mathematics of the effect of diffraction on an image in 1835.  The size of the disc depends on the diameter of the lens and the wavelength of light and is given by the approximate formula 

r = 1.22 * l * f / d  

r is the radius of the disc

l is the wavelength of light

f is the focal length of the lens

d is the diameter of the lens.

f / d being the focal ratio of a lens, we can use the focal ratio, N, instead of f / d.

r = 1.22 * l * N

In photography the diameter of the circle of confusion is usually used, so the diameter of the circle of confusion produced by diffraction is twice the radius of the Airy disc.

c = 2.44 * I * N

The wavelength of visible light ranges from about 400nm to about 700nm.  Using the middle of the range, 550nm, we get

c = 0.0011342 * N (in millimeters)

or

N = 882 * c

For an image to be seen as sharp in the final print the largest circle of confusion should be no more than the resolving power of the human eye viewing the final print at a comfortable distance.  Diffraction producing that much blur begins to affect the image quality.

On a 36x24mm, full frame sensor, c is typically given as 0.03mm.

N = 882 * 0.03

N = 26

Most full frame lenses stop down only to f/16.  A few stop down to f/22 or even f/32 (to increase depth of field).    

On a 17.3x13mm, Micro 4/3rds sensor, c is typically given as 0.0.15mm.

N = 882 * 0.015

N = 13

Under ordinary circumstances you would not stop down the lens on a Micro 4/3rds camera to more than f/11.

Sensor Size and Bokeh

Photographers like to call the blurred quality of a background in a portrait "bokeh."  You can get a numerical value for the size of the blur circle (circle of confusion) from an out of focus point of light at infinity starting with the thin lens formula:

1/f = 1/u + 1/v

f is the focal length of the lens, u is the distance from the lens to the object and v is the distance from the lens to the image.  When u is infinite 1/f = 1/v.  The distance from the lens to the image is equal to the focal lens of the lens.  You could express 1/v as 1/(f+e), with e being the distance the image moves as you focus on objects closer than infinity.  With a little algebra you can derive a formula for e as

e = f^2 / (u - f)

The amount of blur you get for an out of focus distant object is 

b = e / N

where N is the focal ratio of the lens.

Finally, the blurriness of the image on the final print depends on how much the image is enlarged. A Micro 4/3rds image has to be enlarged twice as much as a full frame image to make the same size print.

Let's aim our cameras at a subject 3m (10 ft) away.  We'll use a full frame digital camera with a 50mm lens set at f/2.8 and a Micro 4/3rds camera with a 25mm lens set at f/1.4.  The 50mm lens on a full frame camera has the same field of view as a 25mm lens on a Micro 4/3rds camera.  Both cameras see the same perspective because both are at the same distance from the subject.

Full Frame (36mm x 24mm)

f = 50mm

u = 3,000mm

N = 2.8

b = 50^2 / ((3,000 - 50) * 2.8)

b = 0.30

Enlarge the image 8 times to make an 8x10 print and you get a 2.4 mm blur circle.

Micro 4/3rds (17.3mm x 13mm)

f = 25mm

u = 3,000mm

N = 1.4

b = 25^2 / ((3,000 - 25) * 1.4) 

b = 0.15

Enlarge the image 16 times to make an 8x10 print and you get the same 2.4mm blur circle.

When you set up for the same perspective and field of view, to get the same background blur you need to open the aperture twice as much on the Micro 4/3rds camera as on the full frame camera.

Pushing and Pulling Kodak Vision3 Motion Picture Film

Kodak Vision3 camera film normally is developed for 3 minutes at 41 C (106 F).  If the film has been underexposed it needs to be overdeveloped by increasing the development time (pushing the film).  If the film has been overexposed it needs to be underdeveloped by reducing the development time (pulling the film).  Kodak recommends the following developing times for all Vision3 films:

    Push +2 stops: 4 minutes 40 seconds (56% increase)

    Push +1 stop: 3 minutes 40 seconds (22% increase)

    Normal: 3 minutes

    Pull -1 stop: 2 minutes 30 seconds (17% decrease)

Rapid development times are needed for motion picture film because such large volumes are involved.  A 35 mm print for a feature film will have a mile or more of footage, and the production company may expose more camera film than will go into the final print by a factor of 4 or more.

Commercial labs use automated machines to eliminate the human factor.  For developing by hand in a small tank at home it is recommended to have developing times at least 5 minutes long to get consistent results.  Reducing the developer temperature will increase the time needed to process the film, but may result in a color shift.  Some experimentation will be needed.

Sensor Size and Depth of Field

You see a lot of hand waving explanations of the effect of sensor size on depth of field.  I thought I'd do a little math on the subject.  Let's make three hypothetical pictures of a subject with three hypothetical cameras and keep the camera parameters as similar as we can.

The perspective of our picture depends on the distance from the camera to the subject.  The field of view of our picture depends on the focal length of the lens and the size of the image sensor.  A full frame camera (36x24mm sensor), an APS-C camera (24x16mm or 22.5x15mm sensor) and a Micro 4/3rds camera (17.3x13mm sensor) will have the same perspective of a subject 10' (3m) away.  A full frame camera with a 50mm lens, an APS-C camera with a 35mm lens, and a Micro 4/3rds camera with a 25mm lens have about the same field of view.

The maximum tolerable amount of blur on our final print usually is given as a circle about 0.25mm in diameter.  To make an 8x10 (20cm x 25cm) print the images produced by each camera have to be enlarged by different amounts, and the tolerable blur circle on the sensor depends on the amount of enlargement.  The image on a full frame digital camera will need to be enlarged 8 times, making the tolerable blur circle on the sensor 0.25 / 8 or about 0.031mm.  An image from a DX digital camera needs to be enlarged 12 times, making the tolerable blur circle 0.25 / 12 or about 0.021mm.  The Micro 4/3rds camera needs to be enlarged 16 times, making its tolerable circle 0.25 / 16 or about 0.016mm.

The hyperfocal distance is the distance a lens can be focused and have objects in sharp enough focus from infinity to 1/2 of the hyperfocal distance.  The hyperfocal distance depends on the focal length of the lens, the focal ration of the lens, and the tolerable blur circle (also called the circle of confusion).  A formula for calculating the hyperfocal distance of a lens is H = f^2/(N * c).  H is the hyperfocal distance, f is the focal length of the lens, N is the focal ratio of the lens, and c is the diameter of the circle of confusion.

The near and far limits of acceptable focus depend on the hyperfocal distance (H) and the distance the lens is focused (u).  The distance to the nearest point in focus is given by R = H * u / (H + u).  The distance to the farthest point in focus is given by S = H * u / (H - u).  The total depth of field is T = S - R.

Let's take pictures of a subject 3m (10 ft) away and calculate the depth of field for each camera.  We'll set the lenses at f/2.8.

Full frame digital:

H = 50^2 / (2.8 * 0.031) = 28,802mm or 28.8m

R = 28.8 * 3 /(28.8+3) = 2.7m

S = 28.8 * 3 /(28.8-3) = 3.3m

T = 3.3 - 2.7 = 0.6m

APS-C digital:

H = 35^2 / (2.8 * 0.021) = 20,833mm or 20.8m

R = 20.8 * 3 / (20.8 + 3) = 2.6m

S = 20.8 * 3 / (20.8 - 3) = 3.5m

T = 3.5 - 2.6 = 0.9m

Micro 4/3rds (17.3 x 13 mm) digital:

H = 25^2 / (2.8 * 0.016) = 13,951mm or 14.0m

R = 14.0 * 3 / (14.0 + 3) = 2.5m

S = 14.0 * 3 / (14.0 - 3) = 3.8m

T = 3.8 - 2.5 = 1.3m

The Micro 4/3rds camera has about twice the total depth of field as the full frame camera.  The APS-C camera has about 1-1/2 times the total depth of field as the full frame camera.  In general, to get the same depth of field as a full frame camera the aperture of the Micro 4/3rd camera needs to be twice that of the full frame camera (for example f/1.4 instead of f/2.8).

A home-made remjet removal bath

An at-home pre-bath for removing the remjet layer from Kodak Vision3 motion picture film.

Start with about 800 mL of distilled water.
Add about 156 g of washing soda (sodium carbonate decahydrate) and stir until dissolved.
Add about 19 g of baking soda (sodium bicarbonate) and stir until dissolved.
Dissolve the solids completely, then add enough distilled water to make 1 L.

The pre-bath will have a pH of about 10 (alkaline).  The solids are easy to dissolve.  Washing soda and baking soda are not dangerous.   If you don’t already have them at home, you can find washing soda in the laundry section of a supermarket and baking soda in the baking section.  Washing soda and baking soda are cheap enough that the pre-bath can be used once and thrown away.  You can filter and save the pre-bath for reuse if you're frugal.

To use, load the developing tank with film, then fill the tank with the pre-bath. Agitate vigorously and continuously for about 3 minutes.  Pour out the pre-bath.  Wash by filling the tank with tap water, agitating for about a minute, and dumping the water.  Repeat the washes until the water comes out clear and wash once more for good measure.  It will take several washes.  The pre-bath and wash water need to be close to the temperature of the developer you are going to use, usually 41 C (106 F).  After the remjet is removed you can develop the film following the instructions for your favorite C-41 or ECN-2 developing kit (like the FPP C-41 Home Development Kit or the FPP ECN-2 Home Developing Kit from the Film Photography Project Store).  After the final rinse I like to dunk the developed film in Photo-Flo diluted 1:200 with distilled water before hanging it up to dry.  While the film is hanging I use Kimwipes wetted with diluted Photo-Flo to wipe off the last of the remjet from the base side of the film.  Kimwipes won't scratch or leave lint.  You can get them from Amazon and others.

My recipe is based on the sodium carbonate pre-bath recipe from the Kodak publication Processing KODAK Motion Picture Films, Module 7, Process ECN-2 Specifications, which you can download from https://www.kodak.com/content/products-brochures/Film/Processing-KODAK-Motion-Picture-Films-Module-7.pdf.  Here is the Kodak sodium carbonate pre-bath recipe:

I replaced the anhydrous sodium carbonate with sodium carbonate decahydrate (washing soda).  The molar mass of the decahydrate form is 286 and the molar mass of the anhydrous form is 106, making the required ratio of decahydrate to anhydrous 286/106.  58 times 286 divided by 106 gives 156 as the weight of sodium carbonate decahydrate needed.  Because I used distilled water, I omitted the KODAK Anti-Calcium, No. 4, which is normally used to prevent calcium scum forming due to hard water.  I also omitted the Kodak Stabilizer Additive (TRIDECETH-4 according to information in the MSDS), which is a surfactant.  It probably helps to un-stick the remjet layer from the base side of the film.  The pre-bath seems to work well enough without it.  I kept the sodium bicarbonate (baking soda), which probably acts as a buffer.  You might be able to omit the baking soda and increase the washing soda to compensate.  I used a digital kitchen scale to measure weights.  I don’t think you need to be very precise.  Supermarket washing soda and baking soda aren't exactly chemically pure, anyway.  By the way, 156 grams of washing soda is about 2/3 cup and 19 grams of baking soda is about 1 tablespoon plus 1 teaspoon in kitchen measures.

Because solutions mixed from color developing kits have limited shelf lives, it is a good idea to save up your exposed color film and process several rolls at once in freshly mixed solutions.  Some remjet will remain in the developing tank when you are finished developing.  The tank and reels will need to be washed with soap and water.

Ciro-Flex / Graflex 22 Twin Lens Reflex (1940-1956)

A twin lens reflex camera has a taking lens to focus the image on film and matching viewing lens to focus the image on a ground glass focusing screen.  The rays of light from the viewing lens are reflected straight up by a diagonal mirror to make an image on the horizontal ground glass.  The lenses are synchronized so that the image on the film will be in focus when the image on the ground glass is in focus.  The image on the ground glass is upright, but reversed left for right.  

Twin lens reflex cameras using 120 film were first produced in Germany prior to WWII, when Francke and Heideke's Rolleiflex established the basic layout of the medium format twin lens reflex camera.  The war interrupted camera exports from Germany in 1939, giving US camera manufacturers the opportunity to fill that segment of the camera market.  Ciro, Inc. was one of the first to make a TLR, bringing out the Ciro-flex twin lens reflex camera in 1940.  The Franco-American engineer and inventor Rodolphe Stahl started Ciro in Detroit, Michigan, and relocated to Delaware, Ohio, after the Second World War. The entire camera line was sold to Graflex, Inc. in 1951 and production was moved to Rochester, NY.  Graflex renamed the Ciro-flex the Graflex 22, making a few minor changes but keeping the same basic design. Graflex discontinued twin lens reflex cameras in 1956.

The original Ciro-Flex model A had an uncoated f/3.5-f/22 85mm Wollensak Velostigmat taking lens and an f/3.2 85mm anastigmat viewing lens.  The shutter was a Wollensak Alphax with speeds from 1/200 second to 1/10 second.  It was not synchronized for flash.  The camera had black leatherette and black enamel finish.  The model A was discontinued when Ciro switched to war production in 1942.

The post-WWII model B had specifications similar to the model A.  The taking lens was an f/3.5-22 85mm Wollensak Velostigmat with anti-reflection coatings ("Wocote") and the shutter was a Wollensak Alphax.  All of the post-WWII Ciro-flexes had coated lenses.

The model C had a Wollensak f/3.5-f/22 Anastigmat taking lens and a 1/400 second to 1 second Rapax shutter but was otherwise the same as the model B. 

The model D had a Wollensak f/3.5-f/22 Anastigmat taking lens and a flash synchronized Alphax (1/200 to 1/10 second) shutter. The flash synchronizer had a built-in 20 millisecond delay.

The model E was a model C with a flash synchronized Rapax (1/400 to 1 second) shutter. The flash synchronizer had a built-in 20 millisecond delay. 

The model F had an f/3.2 83mm Raptar taking lens and a synchromatic Rapax (1/400 to 1 second) shutter with a variable delay (5 milliseconds to 20 milliseconds) synchronizer for flash.

The later cameras had fresnel field lenses under the ground glass.  The field lenses corrected for the light fall-off on the corners of a plain ground glass.

After Graflex took over production there were a number of changes.  The models B and C were dropped. The Ciro-flex model D became the Graflex 22 model 200.  The model E was renamed the Graflex 22 model 400, and the model F became the Graflex 22 model 400F.  The Alphax shutter was renamed the Century shutter.  The Rapax shutter was renamed the Graphex shutter.  Graflex had already used the Century and Graphex names for Wollensak shutters on the Graphic series of press cameras.  Graflex adopted a gray color scheme for the TLRs.  The rotating cover on the ruby window was changed to a sliding cover.  A hot shoe for flash replaced the ASA bayonet.  The second tripod socket on the side was removed.

This example is a Ciro-Flex model C with a coated f/3.5-f/22 85mm Wollensak Anastigmat in a Wollensak Rapax shutter. Shutter speeds are 1/400, 1/200, 1/100, 1/50, 1/25, 1/10, 1/5, 1/2 and 1 second plus bulb and time. The Rapax shutter has separate set and release levers. Generally, on a leaf shutter you want to the the shutter speed before you cock the shutter.  

The photographer needs to look through the little red window at the numbers printed on the backing paper of the film to count exposures and space the pictures. You open the shutter under the red window, wind the film to the next number, and close the cover to help prevent stray light entering the red wind and fogging the film. There is no interlock to prevent double exposures or skipped pictures. The numbers on the backing paper for Kodak and Ilford film are faintly printed and are a little harder to see through the red window than the numbers on the backing paper for Arista.EDU Ultra film, which has numbers in bold print. Picture size is 2-1/4" (57mm) square.  There are 12 pictures on a roll of 120 film (still available today).

To focus and compose your picture you open the hood at the top of the camera and look down onto the ground glass screen.  The focusing screen is the same size as the negative, as usual with a twin lens reflex camera. The focusing screen has a fresnel field lens to improve the image brightness in the corners of the viewfinder. A flip up magnifier is there to enlarge the image for critical focusing.  For fast action shots you would open the sports finder on the front of the hood and zone focus the camera.

A new model C listed for $99.45 in 1950, equivalent to about $1,000 in depreciated 2018 dollars. The camera I have still takes a decent picture.

This picture of two readers on a bench at Sally Beaman Park, Nashville, TN, next to the Green Hills branch of the Nashville Public Library was taken with the Ciro-flex C and Kodak Ektar 100 film.

This is a Ciro-flex model F twin reflex camera made just after Graflex took over the Ciro-flex line and while it was still using the Ciro-flex name.   The camera body is formed from steel finished in black enamel paint with black leatherette and chrome knobs.  It has the typical twin lens reflex camera configuration.  1/4"-20 tripod sockets are on the bottom and the left side.  It weighs 2 lb. 5 oz. (1.05 kg) with a roll of film inside.

Normally the camera is held chest high so you look down at an image of the scene on the ground glass viewing and focusing screen.  The image appears upright, but is reversed left to right.  The camera focuses by moving the lens board.  The viewing lens and the taking lens move together so that an image in focus on the ground glass will be in focus on the film.  A fresnel lens under the focusing screen corrects some of the fall off of light in the corners that you get with a plain ground glass.  There is a flip-up magnifying glass to help focus the camera.  A folding hood shields the ground glass from stray light, but the image can still be difficult to see in bright sunlight.  A lever on the back pops up the hood.  The front of the hood folds back to make an open frame sports finder that you can look through with the camera held at eye level.  The sports finder is useful when you try to follow fast action.

The focusing knob has distance and depth of field scales for zone focusing.  The depth of field scale is based on a 0.066 mm circle of confusion.

The taking lens is a coated, f/3.2-f/22, 83mm, Wollensak Raptar lens.  The lens is a Tessar type with four elements in three groups.  It uses 1-5/16" (33mm) Series VI filter adapters.

The shutter is a set and release Wollensak Rapax Synchromatic shutter.  The shutter has a speed ring that can be set to 1/400, 1/200, 1/100, 1/50, 1/25, 1/10, 1/5, 1/2 or 1 second,  "B" for bulb or "T" for time.  A socket for a standard cable release is provided.  The flash synchronizer lever can be set to off (no flash), X-F (electronic flash or 5 millisecond delay flash bulbs) or M (20 millisecond delay flash bulbs).  The shutter speed ring and the synchronizer lever should be set before the shutter is cocked.  The synchronizer settings and shutter speeds are color coded.  The black synchronizer settings are used with the black shutter speeds and the red synchronizer settings are used with the red shutter speeds.  The flash connection is an ASA standard bayonet on the side of the camera.  If you want to use a modern electronic flash you will need to find an ASA bayonet to PC sync connection adapter.

The camera takes size 120 roll film.  To load film you open the back by pushing down the knob located near the top edge, putting the fresh film in the chamber at the bottom and threading the backing paper into the take up spool at the top.  You close the back and turn the film winding knob until you see the number 1 in the red window, which puts the first section of film in position for taking a picture.  The red window has a cover to prevent stray light from fogging the film.  You open the cover while advancing the film and close it after the film is in position for the next picture.  Because the camera does not have an automatic film counter, you space the pictures on the film by looking through the the red window at the numbers on the film.  The film advance and the shutter are not interlocked.  Accidental double exposures or skipped frames are possible.  Graflex recommended advancing the film immediately after taking a picture.  When all 12 pictures have been taken, you wind the roll completely onto the take up spool, remove the exposed roll from the camera and seal the roll.  You then move the empty spool from the bottom to the top to be ready for reloading.

This picture of a fisherman was taken from Lock Two Park, Nashville, Tennessee,  looking across the Cumberland River in the direction of the mouth of Gibson Creek.  The park is the site of a navigation lock built by the US Army Corps of Engineers in 1892-1907.  The purpose of the dam and lock was to allow the passage of steamboats over a shallow part of the river.  The old dams and navigation locks on the Cumberland were replaced by larger and more modern dams and locks after the Second World War.  The dam and most of the lock at this location were removed about 1956.  Only the lock wall on the land side is visible.

The Model F is fairly easy to use.  The image on the ground glass screen can be a little difficult to see in bright sunlight.  The lens is reasonably sharp.  

Kodak Duaflex Camera Series (1947-1960)

The Kodak Duaflex Camera is a simple 620 film camera with a large brilliant finder in a twin lens reflex configuration. Cameras were produced by Eastman Kodak Company in Rochester, New York, from 1947 to 1960.  The shutter is a single speed rotary shutter with a "bulb" setting.  The shutter speed is about 1/25 or 1/50 second. They came with two different lenses: a fixed focus Kodet lens (75 mm f/15) and a focusing Kodar lens (72 mm f/8).  The Kodet lens is a meniscus lens with an aperture stop behind the lens.  A Kodar lens is a three element anastigmat with front cell focusing from 3.5 ft. to infinity.  The Kodar lens has a lever to select an aperture of f/16, f/11 or f/8.  The stops are round holes in a metal plate, so you can't select intermediate f-stops.

The Duaflex (1947-1950) is black plastic and aluminum.  The ones with a focusing lens have a double exposure prevention device that locks the shutter button until you advance the film.  The ones with a fixed focus lens do not have double exposure prevention.  The flasholder is a dedicated model.

The Duaflex II (1950-1954) added a flip-up hood for the viewfinder.

The Duaflex III (1954-1957) added double exposure prevention to the fixed focus model.  The flash connection was changed to a pin-and-screw Kodalite connection.

The Duaflex IV (1955-1960) changed the color scheme from black to brown and tan, and added more exposure instructions to the focusing cameras.

Kodak Duaflex with Kodar lens.

Kodak Duaflex IV with Kodet lens.

A Duaflex makes the same size picture as the Brownie Hawkeye (https://fourelementsinthreegroups.blogspot.com/2018/11/front-back-this-brownie-hawkeye-was.html). It is a sunny day snapshot camera, similar to the Argus Seventy-five (https://fourelementsinthreegroups.blogspot.com/2019/09/argus-seventy-five-1949-1958-and-argus.html) or the Ansco Anscoflex (https://fourelementsinthreegroups.blogspot.com/2020/06/anscoflex-1953-1956.html). It was made for slow to moderate speed black and white (Verichrome, Plus-X) or color negative (Kodacolor) film. Current 120 films respooled onto 620 spools work fine.

Children's Memory Garden, Centennial Park, Nashville, Tennessee

The Children's Memory Garden was dedicated October 18, 2022.  It contains names of children who died violently in Nashville.  I was visiting the park this January and noticed someone had left a rose.  Kodak Duaflex with Kodar lens.  Arista EDU Ultra 100 film developed in XTOL.  Cropped from the original square to a portrait orientation.

Lithagon Lenses for the Geiss Modified Argus C4

In 1954 Geiss-America, Inc. began selling a replacement lens mounting and a series of interchangeable lenses for the Argus C4. Geiss-America was an importer of West German photo equipment. The lenses were made by Enna-Werk, Munich.

Left - Right: f/4.5 35mm, f/1.9 45mm, f/4.5 100mm, f/3.5 135mm Lenses.

Center: Sandmar Zoom-Vue Viewfinder.

The initial set of lenses included an f/4.5 35mm and an f/4.5 100mm. An f/1.9 45mm and an f/3.5 135mm lens came out later. The unmodified Argus C4 camera had a fixed f/2.8 50mm Argus Cintar lens. The modified camera got a new, interchangeable lens mounting.  The existing standard, f/2.8 50mm lens was modified to fit the new lens mounting. Geiss would modify either new or used C4 cameras. Geiss sold a Sandmar Zoom-Vue auxiliary viewfinder for the Lithagon lenses.

The large lens hood for the 135mm telephoto lens would have blocked the rangefinder.  To avoid that, the rear of the lens hood was made of glass so the rangefinder could see through it.  The alternative is to remove the lens hood.  The lens hood, being partly glass, was fragile.  You do see 135mm Lithagons without lens hoods.  Presumably the lens hoods were broken.

The 35mm and 45mm lenses will take modern 49mm screw-in filters.  Alternatively, either lens will take a 2" diameter Series VII adapter and Series VII drop in filters.  The 100mm lens will take a Series V drop-in filter between the lens and lens hood.  The 135mm lens will take a 52mm screw-in filter.

The C4 was discontinued in 1958. The next model, the C44, has a different lens mount and its own set of interchangeable lenses..

This camera has the standard f/2.8 50mm Argus Cintar modified for the Geiss mounting.

Geiss modified Argus C-4

Catch closed.

Catch Open

Lever open.

Lens removed.

Index marks on the Cintar lens.

Camera focused at infinity.

Lens reinstalled.

To change the lens the photographer put the camera on its back, then turned the knurled knob at the end of the lever to release the catch and moved the lever up. The old lens would be lifted straight out. Before installing the new lens the camera had to be set to focus at infinity. The new lens was set to line up the index marks, then lowered straight in, making sure that the gear teeth meshed. The lever would then be moved down and the knob turned to latch the lever. In use the lens mounting is more complicated than the lens mountings on modern digital cameras. It is easier to change the lens on a Geiss C4 than it is on an Argus C3. The degree of difficulty is about the same as on an Argus C44 or C33.

The lens can wobble on a camera with bent flanges on the lens mount. When you look at the mount from the side the slots under the flanges will be spread apart. They should be straight as in this "after repair" picture. Unfortunately I did not make a "before" picture. You do the fix by pressing the flange to straighten the slot. You don't even have to take the mount off the camera.

The lens mount as seen from the side.

The long, thin slot should be straight. If it is spread apart the lens will wobble.

A Geiss modified C-4 with a Lithagon f/1.9 45mm lens and the Sandmar Zoom-Vue finder.

A wedding party crossing Legislative Plaza to the War Memorial Building on a sunny but cool Saturday afternoon. Picture taken on Ultrafine Xtreme 100 on a Geiss modified C-4 with an f/1.9 45mm lens. The state capitol building is in the background.

The War Memorial Building was built about 1925 as a memorial to Tennesseeans who were killed in action during the First World War. The doric order columns make a popular background for wedding photographs.