Nikon 1000mm f/6.3 Reflex-NIKKOR Nippon Kogaku Japan Manual Focus Mirror Lens {Built-In Filters: L39, R60, O56, Y52}

Nikon's 1000mm f/6.3 Reflex: extreme reach in mirror form

A catadioptric design from the Nippon Kogaku era, this 1000mm f/6.3 Reflex-NIKKOR uses mirrors instead of a long chain of refractive elements to fold that focal length into a manageable barrel. The fixed f/6.3 aperture is a hallmark of mirror lens design, meaning exposure control happens entirely through shutter speed and ISO than an iris ring.

Built-in rotating filters are part of the package: L39, R60, O56, and Y52. That's a real convenience at 1000mm, where front-mounted filters would be impractical to swap on the fly and expensive to source at whatever oversized thread diameter the front element demands.

Focus is fully manual, as expected of a lens from this period, which means it rewards a deliberate shooting style than fast-reaction work. At 1000mm, depth of field is thin enough that precise manual focus technique matters more than autofocus speed ever would.

This is a specialist optic. It exists to put distant subjects large in the frame using a mirror-based optical path instead of a conventional telephoto's glass stack, and for photographers who understand its quirks, that tradeoff is the entire appeal.

Who It's For

Birders and wildlife photographers working from a distance benefit most directly, since 1000mm puts small, distant subjects at a scale no standard telephoto reaches without heavy cropping. Astrophotographers and moon/eclipse shooters gain from the same reach, using the fixed f/6.3 aperture with a tripod and manual exposure control. Photographers who shoot the same subject types repeatedly will appreciate the built-in L39, R60, O56, and Y52 filters, which stay attached to the lens than requiring separate front filters at a nonstandard thread size. Collectors and users of vintage manual-focus glass will value this as a Nippon Kogaku era piece with a distinctive catadioptric optical design.

Key Features

• 1000mm fixed focal length catadioptric mirror design
• f/6.3 fixed aperture for compact telephoto reach
• Fully manual focus with thin depth of field control
• Built-in rotating filter dial: L39, R60, O56, Y52
• Nippon Kogaku Japan era construction
• Mirrors and glass elements instead of refractive telephoto stack

FAQ

What optical design makes this 1000mm work at such a compact size?

It's a catadioptric mirror lens, which uses a combination of mirrors and glass elements instead of a long stack of refractive glass. That folded optical path lets Nikon compress 1000mm of focal length into a manageable barrel that would otherwise be impractical to handle.

Why is the aperture fixed at f/6.3?

Mirror lens design inherently produces a fixed aperture. You control exposure purely through shutter speed and ISO, not an iris ring. That's the tradeoff for the compact size at extreme focal lengths.

Does this lens autofocus?

No. This is fully manual focus from the Nippon Kogaku era. At 1000mm, the thin depth of field demands precise manual focus technique anyway, so the lack of AF becomes an asset for deliberate work rather than a liability.

What are the built-in filters for?

The rotating internal filter dial lets you swap between L39, R60, O56, and Y52 without unscrewing anything at the front. At 1000mm, that's a real convenience-front-mounted filters at that magnification would be cumbersome and expensive to acquire.

What mount does this have?

The mount type is not specified in available documentation. Verify the mount before purchasing to ensure compatibility with your camera body.

Why choose a mirror lens over a conventional telephoto?

A conventional 1000mm telephoto would require a much longer, heavier barrel with more glass surfaces and more air-to-glass interfaces. The mirror design trades some contrast and a characteristic donut-shaped bokeh for that compactness and optical efficiency.