Mamiya Sekor C 80mm f/2.8 Manual Focus Lens for 645 {58}

Mamiya's 80mm f/2.8 workhorse for 645 medium format shooting

The 80mm focal length on a 645 body sits in roughly the same visual territory as a 50mm on full frame, making this the natural choice for a standard lens. At f/2.8, you get enough light-gathering for indoor portrait work and controlled environments without a tripod, and the depth of field characteristics that medium format delivers at that aperture are distinctly different from what 35mm systems produce at equivalent settings. The 58mm filter thread keeps your polarizer and ND kit reasonably priced and easy to source.

Manual focus on medium format is not a limitation here, it's the native language of the Mamiya 645 system. The focus ring on the Sekor C gives deliberate control that suits slower, methodical shooting. Studio photographers and anyone working with a tethered setup will feel right at home. For the 645 shooter building out a kit, the 80mm f/2.8 is the lens you reach for first and most often.

Who It's For

Portrait photographers shooting in studio or natural light get the bread-and-butter focal length of the 645 system at f/2.8, wide enough for subject separation on medium format film or a digital back. Documentary and editorial shooters who want the tonal richness of medium format without the weight of a 6x7 rig will find the 645 format and this lens a workable field combination. Film photographers building a Mamiya 645 kit around a single versatile lens will find the 80mm covers the widest range of subject matter before reaching for anything else.

Key Features

• 80mm standard focal length for 645 medium format
• f/2.8 maximum aperture for controlled indoor and studio work
• Manual focus with deliberate, tactile control
• 58mm filter thread for common circular filters
• Mamiya 645 mount for all compatible 645 bodies
• Sekor C multi-coated optics
• Compact form factor for handheld or tripod-mounted shooting

FAQ

What focal length equivalent is 80mm on a 645 body?

On 645 medium format, 80mm behaves like a standard lens, roughly equivalent to a 50mm on full frame. It's your workhorse focal length for portraits, environmental shots, and general-purpose shooting.

Is f/2.8 fast enough for indoor work without a tripod?

Yes. f/2.8 gathers enough light for handheld indoor portrait work and controlled environments. Medium format depth of field at f/2.8 gives you the shallow-focus characteristics 35mm shooters chase at wider apertures.

What filter size does this lens use?

58mm. That's a common thread size, so your polarizer and ND filters are easy to source and reasonably priced across brands.

Does manual focus feel like a limitation on this system?

No. Manual focus is how 645 medium format works. The Sekor C's focus ring gives deliberate control that suits methodical shooting - studio work, tethered setups, and considered composition all benefit from it.

Should this be my first 645 lens?

Almost certainly. The 80mm is the natural standard lens for the system. It's the lens you'll reach for most often and first when building out a 645 kit.

What's the optical construction of this lens?

The Sekor C designation means it's the later C-series version of Mamiya's 645 lenses, featuring multi-coated optics and refined mechanical design compared to earlier versions.