Mirror Lenses: Lightweight Super-Telephotos that Are Affordable

When it comes to travel, landscape, and seascape photography, I always try to keep at least one long focal length lens in my bag for photographing subjects to which I either cannot get closer or—in the case of a Siberian tiger guarding her cubs—to which I have no business getting closer.

Photographs Ó Allan Weitz 2020

The definition of a long telephoto lens depends on whom you ask, not to mention what format camera they are using. For some, a 105mm lens is long. For others, it’s anything beyond 200mm or 300mm. For me, 300mm has always been the gateway lens for serious telephotos, and unless you choose a lens with a maximum aperture of f/5.6 or f/6.3, telephotos can start getting pricey—especially the ones with maximum apertures of f/2.8 or wider.

Are there longer lens options available that won’t require you to go from three meals a day down to two for the next six months? The answer is yes, and they’re called mirror lenses.

One of the benefits of using long focal length lenses is that you’re less likely to scare off your subject before pressing the shutter release.

What Is a Mirror Lens?

In a nutshell, a mirror lens is a compact telescope. Conventional, or refractive, camera lenses use formulated clusters of glass elements to gather light and transmit the focused image to the camera sensor (or film surface). Mirror lenses contain a series of angled circular mirrors that gather the light and, rather than transmit a focused image directly to the camera sensor (or film plane), reflect the incoming light back and forth, each time reflecting a narrower portion of the image until a highly magnified portion of the original image reaches the camera’s imaging sensor.

Scrapyards for old ships can be amazing places to take pictures but are difficult to access. The solution? A 500mm lens and a step stool to peer over the fence.

Also known as catadioptric lenses, or “cats,” some mirror lenses contain glass elements clustered together with no air between the elements. These are called “solid cats” and are shorter though notably heavier than their mirrored counterparts. The advantage of solid cats is that, unlike mirror optical systems, in which the mirrors can sometimes be jarred out of alignment, the glass elements in solid cats are cemented together into a single solid unit, making them far more resistant to misalignment due to impact or heavy vibrations.

All of the accompanying photographs were taken with Nikon F3s, Nikon FM2s, and a 500mm f/5 Reflex-NIKKOR on Kodachrome 64 slide film. The resulting images were scanned using my Franken-Scanner outfitted with a Sony a7R III and a 55mm f/2.8 Micro-NIKKOR Ai-S macro lens.

Fall colors surround a lone fisherman out on a lake.

The Pros of Mirror Lenses

Let’s keep it simple—they are lightweight, they are small, and they are affordable. The most expensive telephoto lens currently sold at B&H (the Canon RF 1200mm f/8 L IS USM) costs $19,990. The most expensive mirror lens sold at B&H (the Kase 200mm f/5.6 MC Reflex Mirror Lens) costs $659.95. The 1200mm Canon is 21.1"long and weighs 7.3 lb. The 200mm Kase is 4.6" long and weighs 15 ounces. The 900mm mirror lenses aren’t much larger (about 6.6" or less) and they typically weigh around 1.5 lb.

Part of the reason mirror lenses are less costly is that glass lens elements require far more production time and expensive equipment to produce, compared to cutting circles into flat sheets of mirrored glass. A big advantage of mirror lenses is that, due to their design, image files produced by mirror lenses are free from chromatic and off-axis aberrations, which are common with traditional refractive telephoto lenses.

A traditional 600mm lens and a 500mm mirror lens side-by-side. Need I say more?

The Cons of Mirror Lenses

When it comes to mirror lenses, the cons come with a one-two punch. The first punch is that they have a single fixed aperture. The sucker-punch is that mirror lenses are slow. How slow? Well, f/6.3 is considered fast, and most are f/8. Nikon made a super-fast 500mm f/5 Reflex-NIKKOR back in the early ’70s, and if you can find a clean used one—bully for you—snag it before I do! Nikon also used to produce a 1000mm f/11 Reflex-NIKKOR, which was a bear of a lens to shoot with, even when mounted on a tripod.

A couple of cute kids running through a field appear sharp against ethereally blurred trees in the background and tall grass in the foreground when captured with a 500mm mirror lens.

I should also warn you, mirror lenses tend to be about a half-stop slower than advertised and they vignette slightly toward the corners, but—IMHO—the vignetting invariably works in favor of the pictures these lenses capture.

The only other so-called downside of mirror lenses is an aesthetic issue having to do with donuts. Not the kind you dip in coffee, but the hollow circular twirls of light formed by out-of-focus specular highlights in the foreground and background of photographs taken with mirror lenses. These donuts are common to photographs taken with mirror lenses, which has to do with the way the light travels into and around the mirror system inside the lens barrel. Depending on one’s tastes, some find these circular highlights to be disturbing, but these are subjective qualifiers. From my experience the donuts usually work fine, sometimes they don’t, and in many cases they aren’t even an issue—they don’t exist.

Circular specular highlights, aka donuts, are a trademark of mirror lenses. Sometimes they work sometimes they don’t work, but the criteria for making these calls is subjective according to one’s personal aesthetics. — Circular specular highlights, aka donuts, are a trademark of mirror lenses. Sometimes they work, sometimes they don’t work, but the criteria for making these calls is subjective according to one’s personal aesthetics.

When used thoughtfully—and preferably on a tripod—mirror lenses can be used to capture bold landscapes, seascapes, cityscapes, or any other genre of photography requiring longer focal length lenses.

Who Makes Mirror Lenses?

Back in the day, every camera manufacturer produced at least one mirror lens, usually in the 500mm range. These days there are only five manufacturers of mirror lenses, and three of these are one-and-the-same lens sold under different labels.

Though most manufacturers have focused their R&D budgets on conventional telephoto lenses, the recently introduced NiSi 250mm f/5.6 Reflex lens is available for most popular mirrorless lens mounts. What makes this lens so cool—aside from its $479 price tag and compact, retro styling, is that the care taken in the optical design means the lens delivers its artistic effects without gimmick.

Nisi’s recently introduced 250mm f/5.6 Reflex Lens has a minimum focusing distance of 6.6’ and a bright f/5.6 maximum aperture. It’s also extremely affordable.

Other manufacturers of mirror lenses include Tokina, which produces reflex mirror lenses in 300mm, 400mm, 500mm, 600mm, and 900mm focal lengths for most popular lens mounts. Opteka produces a 500mm f/6.3 and a slightly slower 500mm f/8 mirror lens specifically for T-mount.

Tokina SZ 900mm f/11 Pro Reflex MF CF Lens

If you prefer a shorter focal length, Rokinon’s Reflex 300mm f/6.3 ED UMC CS is available for Micro Four Thirds and FUJIFILM X cameras, as is its kissing cousin—the Samyang Reflex 300mm f/6.3 ED UMCV CS mirror lens, available for FUJIFILM X and Sony E mirrorless cameras.

An old fishing shack on the north shore of Long Island, NY — An old fishing shack on the North Shore of Long Island, NY.

Morning sunlight glistens off the hull of a cherry-red schooner, in Bar Harbor, Maine. — Morning sunlight glistens off the hull of a cherry-red ketch, in Bar Harbor, Maine.

Though I’ve managed to capture some truly impressive photographs with mirror lenses under extremely challenging shooting conditions, I’ll be the first to tell you mirror lenses are not as sharp as their conventional telephoto counterparts. Are they sharp? Yes, they are, but they come in a close second to their faster counterparts containing glass elements. With that in mind, one of the most advanced pieces of combined technologies ever created by human beings is the Hubble Telescope, which happens to be a mirror lens. It’s a big one, but it’s a mirror lens, nonetheless.

Do you have any experience with mirror lenses? If so, what do you think of them, and—more importantly—what are your thoughts on donuts? Let us know in the Comments section, below.