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Mamiya 90mm f/3.8 Sekor NB Lens for RB67 {77}

Model #235374
  • $88.00

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New in box complete with manufacturer's USA warranty. Not previously owned or used.
Essentially new with no signs of use. “Open box.” In manufacturer's packaging with original accessories and instructions. 180-day warranty.
Barely used with virtually no traces of wear. Only the closest inspections will reveal slight use. Lens glass could contain light dust or debris. Excellent picture quality. Accessories usually not included, unless noted in listing. 180-day warranty.
Lightly used with limited signs of wear. Exceptionally nice but may have slight wear on finish visible. Lens glass could contain light dust or debris. Excellent picture quality. Accessories usually not included, unless noted in listing. 180-day warranty.
Noticeably used with average signs of wear. Shows moderate wear for the age of the item, with the possibility of blemishes and/or minimal dings. Lens glass may have average dust and zoom/focus ring tension may have slight looseness or tightness overall, but will not affect picture quality. Accessories usually not included, unless noted in listing. 180-day warranty.
Frequently used with above-average wear. May have dents, dings, or finish loss. Lens glass may have small scratches, dust, and blemishes, and zoom/focus ring tension may have moderate looseness or tightness overall, but should not affect picture quality. Accessories usually not included, unless noted in listing. 180-day warranty.
Heavily used with extensive visible wear. Equipment is rough, with multiple impressions in the finish, excessive finish loss and brassing. Glass will have marks, fungus and/or heavy/cloudy haze which could affect picture quality. Accessories usually not included, unless noted in listing. Not covered under KEH warranty.
Non-functional or damaged. Equipment will not work. Usable for parts. Not covered under KEH warranty and non-returnable.
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$88.00
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Mamiya 90mm f/3.8 Sekor NB, the RB67's standard workhorse.

The 90mm focal length on a 6x7 medium format frame sits close to the classic 'normal' field of view, making this lens the natural starting point for RB67 shooters. At f/3.8, it gives you a workable maximum aperture for controlled light situations, and the 77mm filter thread means you have access to a wide range of filters for darkroom-style in-camera work with black-and-white film or color correction on slide stock.

Medium format demands lenses built to that standard, and this Sekor NB is purpose-built for the RB67 system. The mount is dedicated to the RB67's rotating back mechanism, so you get the full benefit of that body's design without adapter compromises. For anyone already invested in the RB67 platform, this lens covers the focal length that gets used most.

Who It's For

Studio portrait photographers working with the RB67 will find the 90mm field of view well-suited to head-and-shoulders framing at comfortable working distances on 6x7 film. Documentary and editorial shooters who want medium format tonality in a reportage-style focal length can use this as a primary lens. Film photographers building out an RB67 kit often start here before adding longer or wider options. The 77mm filter thread also makes it practical for landscape photographers who already own 77mm polarizers or graduated ND filters.

Key Features

  • 90mm focal length standard for 6x7 medium format
  • f/3.8 maximum aperture for controlled light work
  • Mamiya RB67 mount, dedicated to rotating back design
  • 77mm filter thread for color correction and effects
  • Purpose-built Sekor NB optics for medium format image standards

FAQ

What focal length is the 90mm on a 6x7 frame?
On the RB67's 6x7 negative, 90mm functions as a standard or normal lens, delivering a field of view closest to human vision without wide distortion or telephoto compression.
Can I use this lens with other camera systems?
No. This lens has a Mamiya RB67 mount, which is dedicated to the RB67 rotating back system. It won't fit other medium format bodies without adapter solutions that compromise the rotating back's design.
What size filters does this lens accept?
The front element uses 77mm filters, giving you broad compatibility with standard circular screw-in filters for color correction, polarization, or darkroom-style effects.
Is f/3.8 fast enough for low-light work on medium format?
f/3.8 is moderate for RB67 glass and sufficient for controlled studio or daylight situations. In dim light or fast film stocks, you'll benefit from the larger negative size medium format provides, but it's not a fast lens by modern standards.
How does the 90mm compare to wider or longer RB67 lenses?
The 90mm is the RB67's standard focal length and the most versatile for general shooting. Shorter lenses expand the field of view for environments and close work; longer lenses compress space for portraits or distant subjects.
Is this lens designed to work with the RB67's rotating back?
Yes. The Mamiya RB67 mount is engineered around the body's rotating back mechanism, so this lens integrates fully with that system without requiring adapters or workarounds.
SpecificationValue
Focal Length90mm
Max Aperturef/3.8
MountMamiya RB67
Filter Thread77mm

This description was generated using AI based on KEH's internal product standards, product expertise, and knowing what customers care about most. While we strive for accuracy, details may vary by individual item.

Brand Name Mamiya
Filter Size 77mm
Focus Type Manual focus (only)
Lens Mount Mamiya RB
Lens Type Standard / Normal
Max Focal Length 90mm
Min Focal Length 90mm