science

Mamiya 645

Mamiya 645 is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Mamiya 645 rather than just read about it. In short: The Mamiya 645 camera systems are a series of medium format film and digital cameras and lenses manufactured by Mamiya and its successors. They are called "645" because they use the nominal 6 cm x 4.5 cm film size from 120 roll film.

Key takeaways

Mamiya 645 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Mamiya 645 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Mamiya 645 from memory before moving on to harder problems.

Reference excerpt

The Mamiya 645 camera systems are a series of medium format film and digital cameras and lenses manufactured by Mamiya and its successors. They are called "645" because they use the nominal 6 cm x 4.5 cm film size from 120 roll film. They came in three major generations: first-generation manual-focus film cameras, second-generation manual-focus film cameras, and autofocus film/digital cameras.

Mamiya 645 Manual Focus System

Mamiya 645 manual focus cameras All seven of the manual-focus Mamiya 645 cameras can use the same lenses and film inserts (film spools). The two generations use different viewfinders, grips, and other accessories that are not always cross-compatible.

First Generation The M645 was manufactured from 1975 to 1987. This was the first model to offer a 6x4.5 cm frame, allowing 15 shots on a standard 120 roll film. The M645 was a true system camera, with interchangeable viewfinders and lenses. It used an electronically controlled cloth focal plane shutter offering speeds of 8 seconds to 1/500 second in one-stop increments. The camera featured a mirror lockup, as well as selectable multi-exposure. Film was carried in cartridges that could be pre-loaded, but no capability existed to allow changing of film magazines mid-roll. A waist-level non-metered finder was available, as well as a non-metered pentaprism and three varieties of through-the-lens (TTL) metered prisms (CdS, PD and AE). The metered prisms read the aperture dial through a mechanical coupling on the lens. The standard lens was the 80mm f/2.8 C or the 70mm f/2.8 C E or the 80mm f/1.9 C. The M645 1000S was manufactured from 1976 to 1990. This camera added a 1/1000 second shutter speed to the M645, as well as a self-timer and a depth-of-field preview lever. The standard lens was the 80mm f/2.8 C or the 80mm f/1.9 C. The M645J was manufactured from 1979 to 1982. This was a stripped-down version of the M645, with the mirror lockup knob and second shutter button removed. The standard lens was the 80mm f/2.8 C or the 80mm f/1.9 C.

Second Generation The Mamiya 645 Super was manufactured from 1985 to 1993. This was a new camera with a molded plastic shell on a diecast metal frame. Its features are the same as the M645 1000s, but it added removable film backs, whereby a dark-slide could be inserted and the back removed mid-roll. The standard lens was the 80mm f/2.8 N, or the 80mm f/1.9 C (early) or the 80mm f/1.9 N (late). The Mamiya 645 Pro was manufactured from 1993 to 1998. It added a self-timer and a smoother styling. The standard lens was the 80mm f/2.8 N or the 80mm f/1.9 N. The Mamiya 645 Pro-TL was manufactured from 1997 to 2006 and is functionally similar to the 645 Pro but adds through-the-lens flash metering. The standard lens was the 80mm f/2.8 N or the 80mm f/1.9 N. The Mamiya 645E was manufactured from 2000 to 2006. This was an entry-level version of the M645 Pro without switchable backs or viewfinders. It did have a light meter built in to the viewfinder, however. The standard lens was the 80mm f/2.8 N or the 80mm f/1.9 N.

Mamiya 645 Manual-Focus Lenses

The Mamiya 645 Manual-Focus lenses will work on all manual-focus bodies. They will also work on autofocus bodies such as the Mamiya 645AF, Mamiya 645DF and Phase One 645DF, but manual-focus lenses will require light metering after the lens has been stopped down, unlike native autofocus lenses. Third-party adapters exist to use these manual-focus lenses on Nikon F mount, Canon EF mount, and other cameras. These lenses will not work on the Phase One XF unless modified. All Mamiya 645 lenses are multi-coated. Nearly all have curved aperture blades, rendering smooth backgrounds at wider aperture settings. The internal shutter in the first-generation 645 bodies only supported flash synchronization at 1/60th of a second. This made outdoors fill flash difficult, and so some lenses were equipped with a built-in leaf shutter which supported flash synchronization at all speeds up to 1/500th of a second. Leaf shutter lenses had a separate PC socket. In order to take advantage of the faster speeds the internal shutter had to be fired at 1/30th of a second or slower.

Lens abbreviations A or APO — the lens has an apochromatic (or near-apochromatic) design C — the lens is stamped “Sekor C” on the lens barrel. All manual-focus lenses for Mamiya 645 are Sekor C lenses, which Mamiya used to designate multi-coated lenses. E — only for the 70mm f/2.8 E lens sold as a kit with the original M645, apparently late in the M645's production run to differentiate it from the leaf-shutter version. Macro — the lens is optimized for close focusing and close-up (macro) photography N — the lens has a "new" cosmetic design. "N" lenses were launched with the second generation manual-focus cameras. Many "N" lenses are the same as their prior "C" or "S" lens version, but have changes to the lens coatings and a plastic aperture ring instead of metal. Some "C" lenses received a cosmetic update (removal of the chrome on the focus ring) but were not otherwise changed and did not receive a "N" marking, such as the 50mm f/4.5 and 500mm f/5.6. "N" lenses may also be called "CN" lenses. N/L — the lens has the "new" cosmetic design and an integrated Leaf Shutter. When used with the optional power drive WG-401 on second generation bodies, the leaf shutters are automatically cocked. On first generation bodies, or without the power drive, the leaf shutters must be cocked manually. S — the lens is a revised version of a "C" lens. The only lenses with "S" versions are the 45mm f/2.8 and 55mm f/2.8 (both with different optical formulas and dimensions than their predecessors), but other accessories have "S" versions, including the Waist-level Finder W, the Prism Viewfinder PD, and the #3 extension tube. Early "S" lenses may have gold "S" stickers on them, while later "S" lenses may have the "S" engraved. "S" lenses may also be called "CS" lenses. SF — the lens has a separate control ring to create a Soft Focus effect. ULD — the lens has “ultra low dispersion” glass in its design Zoom — the lens has a variable focal length

Lens table

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Mamiya 645

Start with the simplest possible case. Write down what Mamiya 645 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Mamiya 645 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Mamiya 645 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Mamiya 645

In research: Mamiya 645 appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Mamiya 645 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Mamiya 645 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 120 film cameras, Digital cameras, Mamiya SLR cameras, so understanding it makes those chapters shorter.
In everyday life: Look for Mamiya 645 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Mamiya 645 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Mamiya 645 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Mamiya 645 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Mamiya 645 in simple terms?

Why does Mamiya 645 matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Mamiya 645?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Mamiya 645.