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Mamiya TLR System Summary - Chapter 2

2 Lenses, General

2.1 Fittings

As a broad generality, all lenses will fit all bodies. But early bodies will not have focus, parallax, and exposure compensation scales for the focal lengths introduced later. The original 1/400th Seikosha-MX shuttered lenses and some Seikosha-S shuttered 180mm lenses will not fit C33 and later auto-cocking bodies. The problem with the MX series is that the lens cocking arm is located higher than on the later lenses, and the auto-cocking lever will not engage. It also fouls the lens lever for manual cocking.

Some lenses are known to fail to cock properly on later bodies. This appears to be due to the auto-cocking lever not moving the lens cocking lever quite far enough. At least one case has been recorded of the body cocking arm needing more travel than the lens shutter arm permits.

Lenses of different focal length have different back focus distances. In practice this means that the bellows extension required for infinity focus is different. This is common with bellows focusing systems, and does have the benefit of giving the optical designer more freedom.

2.2 Lens hoods

The lens hood diameter refers to the square clamp-fit Mamiya hoods. They will only fit over slimline filters. Conventional screw-fit hoods of suitable dimensions may be used in the filter thread. The Mamiya hoods are of two basic designs. The first design, used for the 55mm, 65mm, 180mm, and 250mm were square with the upper flap hinged at the front. This permitted the angle of the top flap to be set so that glare from the top of the hood was invisible in the finder. The hoods for the 80mm, 105mm, and 135mm lenses were of a circular changing to square aperture rigid type. The 80mm and 105mm chrome lenses used 42mm hoods, the 80mm and 105mm black, and both 135mm lenses used the 48mm hood. All the 180mm and the 250mm lenses used the same hood. These hoods are generally metal. There is also a telephoto lens hood for the chrome series that consists of two rigid square shades in a single plastic unit. (Compiler’s Note: This item is huge!)

2.3 Optical design

There was a change in physical and optical design between the chrome and black series lenses. One known effect is that the 105mm D and DS lenses have a different back focus from the 105mm chrome and the early 105mm black. This means that the scale on the C330 and earlier bodies is incorrect for the later lenses. The C330s (and probably most C330f) have scales for both 105mm lenses. It should also be noted that earlier bodies do not have scales for the focal lengths introduced later. The lenses will function, however. The 180mm (black) and 180mm Super (black) are different optical designs, but appear to share the same back focus.

2.4 Lens coating

This is a contentious issue, probably stemming from a lack of understanding of lens coating in general. Lens coating has been common since the Second World War, initially as general single coating, then as single coating tailored to individual lens performance, and most recently coating of internal elements and multiple coating for optimum corrections. Coating is used to reduce reflection from the surface that contributes to flare and lack of contrast. It also helps compensate for minor variations in glass batches, and in multi-coating the performance over a range of wavelengths is made more consistent.

The chrome lenses were single coated, and the black series had single coatings which may have extended to various lens elements. Some late black series lenses have had multi-coating, but there is a lack of substantive evidence as to when it was introduced, and on which lenses. The 55mm, 80mm S, 105mm DS, and 180mm Super are the most likely candidates, as these were later or more extreme designs.

Even the best of these lenses won’t have the class of coatings that appeared in the 1990’s.

2.5 Shutters and flash synchronisation

The original chrome lenses were fitted with shutters having a maximum speed of 1/400 second (Seikosha-MX). Later chrome lenses were improved to a 1/500 second top speed, giving a conventional range from 1 second to 1/500, plus B (Seikosha-S). The changeover seems to have occurred during the production life of the C2. The final black series lenses used a Seiko shutter with 1 second to 1/500th second plus B settings. Some shutters exhibit a leaf with a raised tip. This ‘anti-crash’ feature is intended to reduce the chance of the shutter blades locking when closing. It usually indicates a newer shutter, often with a blue insert in the shutter cocking arm. The 80mm f3.7 black lens had a Copal shutter. At least one Seikosha-MX shuttered 80mm lens was labelled ‘f=8cm’.

The lenses all have integral leaf shutters, providing X and M synchronisation at all speeds. Connection is via a standard 3mm co-axial PC cord on each lens. Lenses which have been in professional hands sometimes have the flash synchronisation levers fixed in the ‘X’ setting. This is usually achieved by cementing a small stop to the lens barrel. Obviously the inadvertent shift to ‘M’ with electronic flash had happened once too often! There is around 200 milliseconds delay between releasing the shutter (and closing the flash contacts) and the shutter opening on the ‘M’ setting. This delay was to allow flash bulbs time to reach full illumination. Since the delay is a mechanical process, and the M setting is rarely used, longer delays are quite common and the shutter may stick.

The PC connection on most lenses consists of a hollow stud. The centre hole is one side of the flash contact, and connects to a wire running to the shutter assembly. The outer portion of the stud is the other contact, and connects to the lens mounting through its mounting screws. Intermittent flash problems may be caused by the mounting or wire becoming loose. This can be tested using a resistance (Ohm) meter. (A resistance meter applies a negligible current and voltage across its probes. Higher voltages or currents may result in damage.) Set the lens to a slow speed (say 1 second), and cock it. Insert the PC cord in the shutter, and hold the resistance meter probes to the terminals at the other end of the cord. When the shutter is fired, the meter will register if the flash circuit is made. A slow speed is necessary to be sure the meter has time to react. Do NOT try this with the cord connected to a flash unit!

Some later lenses, such as the 105mm DS, have a shrouded PC socket that appears less vulnerable to accidental damage or loosening.

At the risk of stating the obvious, these shutters work in fixed steps. Intermediate speeds should not be set. Intermediate apertures can be set.

The most frequent sign of damage with lenses is a dented filter ring. The lens locking wire can scratch the top of the viewing lens barrel.

Weights, where quoted, may include front and rear caps.

2.6 Dating lenses (and bodies and accessories)

2.6.1 Dating Tables

The data for this section has been removed because of formatting issues with the size of the tables, and a need to re-work the information. It will be restored at some point.

The following item came up on Photrio recently (July 2023), attributed to Bill Rogers:

“Mamiya Production Date Codes

April 19, 2021

Mamiya used a couple of different date code schemes on their products. Most date codes are found on a small gold sticker affixed to the body or lens and consist of two letters. The first letter is the year of production and the second letter is the month. It is located in different spots: many lenses have this sticker on the side although RB/RZ lenses typically have it stuck onto the back of the lens. Some cameras, such as 645 Super, Pro and Pro TL, Mamiya 6/7 and RZ Pro II, have the date code as a prefix to the serial number.

From 1961-1970, the letters A-J were used. Example: AA would be January 1961.

From 1971-1980, the letters A-J were used. Example: AA would be January 1971

From 1981-2000, the letters A-T were used. Example: AA would be January 1981

From 2001-2014, the letters A-N were used. Example: AA would be January 2001

As you can see, the date will also depend on the context of the camera since (mostly) every ten years the code repeated. Knowing a little about when the camera was produced will help decipher the code.”

Compiler’s Comments

There are some discrepancies with supposed introduction dates and these sequences. However it was not uncommon for equipment to be on the Japanese market up to a year before it became available elsewhere. And these are stickers, so there’s no guarantee that they are original.

1961 is The C2/C3 introduction, 1971 is the middle of the C330 dates, 1981 is in the C330f and C220 range, while the C series production was discontinued by 2001. Note that Mamiya also produced the RB/RZ, M645, M6, and M7 cameras over part of these ranges, and receive two letter codes.

So a Bx C330 or C330f should be from 1972, a Bx C330s ought to be 1982 though the model was supposedly released in 1982. A Kx C330s should be from 1992.

This does basically agree with the observed letter pairs, and also accounts for codes that appear on cameras that should not have been around if the codes were in a single sequence.

The second letter should not be later than L in all cases, as it represents the month.

2.7 Focal length comparison

Table of 35mm format equivalent focal lengths for the lenses in the TLR range (after Scott, with permission)

The focal lengths in the body of the table are the 35mm lenses required to produce an identical image in a given final format with minimum cropping. In other words, to get a square print covering the same area as the 55mm Mamiya lens you would need a 24mm on 35mm format, while cropping a 2x3 area from the Mamiya negative would give the same rendition as a 36mm lens on 35mm format. This table is derived from original work by Ed Scott for ‘photo.net’ ( http://photo.net/).

2.8 Filters

2.8.1 Plain

Standard screw fit filters may be used, but the 49mm threaded lenses are very close together, which may make it impossible to fit filters on both lenses. Mamiya made special slim-mount filters for this purpose, but they do not seem to be readily available short of special order. The local Mamiya distributor may be able to help. Standard filters may also cause problems with the Mamiya clamp-fit lens hoods.

It is possible to file a flat on a UV or haze filter to improve clearance if it is going to be a permanent fitting on the viewing lens. Obviously the filter mount should be marked and then de-mounted from the lens before filing it!

An alternative for the viewing lens is to use one of the chrome protective rings to retain a bare UV or skylight filter directly on the lens. This requires dismantling a standard filter unless you can obtain an unmounted glass.

Some users have found that filters can be mounted inside the larger square Mamiya lens hoods. This is done by cementing an old filter mount to the inside (usually after the original mounting thread has been filed flat and the old glass removed) and using it as a threaded mount. Since old or scratched filters can be utilised for the mount this is an economic approach. In use the filter of choice is screwed to the new mount inside the hood. Obviously the maximum filter size that can be used in this manner depends on the hood size and the slimness of one’s fingers!

2.8.2 Polarising

Most of the same restrictions about fitting plain filters applies to polarising filters. Perhaps more so, since these tend to have physically larger mounts. The common method is to preview the effect by eye, or on the viewing lens, and note the position of the mount (You need a mount marked in increments to do this - you can add your own). The filter is then installed on the taking lens and set to the same orientation.

In theory, you could mount two identical polarisers in common alignment and wrap an elastic band around the rotating rims. Rotating one would move the other in synchronisation. But the physical proximity of the lenses means you’d have to use 46mm polarisers. And a circular lens hood!

Linear polarisers are perfectly adequate for these cameras. The circular versions are intended for cameras with through the lens metering which use an optical system that is itself polarising.

2.8.3 Graduated

It is difficult to preview the effect on the viewing lens and then transfer it to the taking lens, but possible. Unless you are using a 105mm D/DS lens you cannot preview the effect of stopping down. There was a sliding mount designed for the Cokin ‘P’ series, but this does not appear to be still available. See section 9.2 for the reference.

2.8.4 Filter Adapters

There is at least one design for an offset stepping ring for a 58mm filter on the taking lens on Thingiverse. Common 3D printers have trouble with fine threads, so this is a push fit design.

2.9 Self-timers

None of the Mamiya TLR cameras have self-timers on the body. Only the 105mm DS lens has a ‘V’ setting for delayed release. The only other options are to use an air release, or to try and track down a cable release mount accessory timer (usually clockwork).

2.10 Infra-red focusing

These cameras do not include infra-red focusing scales. Just how crucial this is will depend on your application. Infra-red film varies in it’s degree of sensitivity. Certainly Konica 750 and Ilford SFX have a closer sensitivity to visible light than Kodak’s (35mm) offering. False colour infra-red film has to include some visible light, otherwise you do not get a full range of colours.

The focus scales are comparatively crude, so a precise adjustment is not practical, or at least hardly repeatable. Unless working at close distances or at wide apertures the correction can probably be ignored. Should highly infra-red sensitive emulsions become available (see below), then experimentation with each lens would be advisable.

The cameras are probably infra-red safe with current emulsions. The biggest risk would come from an extended bellows, so it might be wise to retract the bellows (or close the internal baffle) when not actively photographing.

The new MACO 820c infra-red emulsion falls between the Kodak HIE and Konica 750 offerings. This is a true infra-red film (development should be in a metal or foil-shielded tank, for example), and should be treated with caution. The recommended focus adjustment is an increased extension of 1/100th of the focal length of the lens, or about 0.5mm for the 55mm, and 2.5mm for the 250mm lenses. This sort of correction is actually easier to implement on the rack and pinion bellows focusing of the Mamiyas than on helical mount lenses.

Compiler’s Note: If any reader has practical experience of infra-red with these cameras, I’d be pleased to include it here.

2.11 Focusing discrepancies

There are reports of lenses that do not provide sharp images on the film, even though carefully focused. This may mean that the lens pair is out of adjustment, but there are several alternative explanations. These are, in approximate order of increasing severity:

2.11.1 Wrong film

Using 220 film in a camera configured for 120 will cause focus errors, as the pressure plate is set for a thicker film and backing paper combination. You will probably have a strange starting position for the first frame, as the leader length on the two types is different.

2.11.2 Back incorrectly latched

The backs on these cameras are quite flexible, and must be closed using even pressure on both top corners. Otherwise the back may not latch correctly on both sides. This prevents the pressure plate from applying even pressure across the whole frame.

2.11.3 Incorrectly mounted focusing screen / wrong magnifier correction

Some screens can be disassembled when removed. If they are reassembled with the ‘glass’ upside down, the focus is wrong. De-mountable screens should be correctly fitted, though this is a gross error that should be easily spotted. Fixed screens are sometimes shimmed to adjust their height. Remove them only if necessary and with extreme care. The C330, f, and s are designed with replaceable screens.

The flip-up magnifiers and eyepiece correction lenses should be a reasonable match for your eye (with or without correction as applicable). You have to be able to focus on the screen in order to bring the image to focus correctly.

2.11.4 Incorrectly mounted lens

It is just possible to mount the lens unevenly on the lens panel, but it is unlikely that the auto-cocking feature on later models would work.

2.11.5 Distorted lens panel

If the lens panel isn’t parallel to the film plane and at right angles to the focus screen, then an error will occur. These are tough cameras, so you’d probably need to drop it to cause this fault. (Not advised.)

2.11.6 Lens pair maladjusted

It does happen, often because the retaining rings are loosened and spacing shims drop out. This is a pain to adjust, so touch the lens as a last resort.