Mirror lenses on mirrorless cameras might sound like a curious match at first, but in reality, it’s a pairing that offers surprising benefits for modern photographers. These once-niche optics are getting a second wind, thanks in part to the compact and adaptable nature of today’s mirrorless camera systems. But what exactly are mirror lenses, and why might they now be worth a second look?
What Are Mirror Lenses and Why Do They Matter?
Mirror lenses—also known as reflex lenses—use a clever combination of curved mirrors and lens elements to achieve long focal lengths in a compact design. Instead of relying solely on traditional glass elements, these lenses reflect light back and forth inside the barrel, effectively “folding” the optical path. The result? A telephoto lens that’s significantly shorter and lighter than its conventional counterpart.
Originally used in telescopes, this catadioptric design has been adapted for photography for decades. During the 1970s and 1980s, mirror lenses enjoyed brief popularity, but their limitations meant they never became mainstream. However, with the rise of mirrorless cameras and their excellent ISO performance, these quirky lenses have become a lot more practical—and appealing.
The Pros of Using Mirror Lenses on Mirrorless Cameras
Compact and Lightweight Supertelephoto Options
One of the biggest perks of mirror lenses on mirrorless cameras is the size and weight advantage. Take Tokina’s SZX Super Tele 400mm f/8 as an example. Weighing in at just 355 grams and measuring only a few inches long, it’s tiny compared to a traditional 400mm lens, like Canon’s 400mm f/5.6 L, which tips the scales at over a kilogram.
Mounting a mirror lens on a mirrorless body—especially when using an adapter—can give you reach without the bulk. This is especially appealing for travel, hiking, or wildlife photography where every gram counts.
Affordability Without Sacrificing Reach
Mirror lenses are also wallet-friendly. Many models from Tokina, Samyang, and TTArtisan can be picked up for a fraction of the cost of a traditional supertelephoto lens. For instance, the Tokina 400mm f/8 mirror lens is available for just over £250—less than half the price of some second-hand conventional telephotos.
Simpler Adaptation, Wider Compatibility
Because most mirror lenses are manual focus with fixed apertures, adapting them to mirrorless systems is straightforward. A simple passive mount adapter is often all that’s needed, making them compatible with virtually any mirrorless camera brand—from Fujifilm and Sony to Micro Four Thirds systems.
The Downsides You Should Know
Fixed Apertures and Manual Focusing
Using mirror lenses on mirrorless cameras isn’t without compromise. The most obvious drawback is the fixed aperture—often f/8 or smaller. This limits exposure flexibility, especially in low-light conditions. However, mirrorless cameras make up for this with excellent high-ISO performance and tools like auto ISO.
Manual focus is another limitation, but modern mirrorless cameras offer helpful features such as focus peaking and magnified live view, which make nailing focus far easier than it was in the days of film.
The Infamous Donut Bokeh
Perhaps the most polarising feature of mirror lenses is their distinctive doughnut-shaped bokeh, caused by the secondary mirror in the centre of the lens. This effect can be charming or distracting, depending on your subject and background. Learning to work with (or around) this look is part of the creative challenge.
Real-World Experience: Using a 400mm Mirror Lens on a Mirrorless Camera
Using Tokina’s SZX Super Tele 400mm f/8 on a Fujifilm X-T5 (where the effective focal length becomes 600mm), one thing is immediately apparent: the convenience of size is fantastic, but handling such a long focal length—even if lightweight—still requires care. Any shake is amplified, making precise framing tricky.
That said, in-body image stabilisation (IBIS) helps a lot, and a tripod can make a huge difference for both sharpness and ease of use. With such a shallow depth of field at long focal lengths, focusing becomes very delicate—every slight nudge of the focusing ring matters.
Mirror Lenses: A Great Option for Macro and Wildlife Too
Many mirror lenses focus surprisingly close. The Tokina 400mm f/8 can focus down to 1.15 metres, offering a 1:2.5 magnification ratio. This makes it a decent option for close-up photography—again, best done with a tripod due to the razor-thin focus plane.
Meanwhile, smaller mirror lenses like the Minolta RF Rokkor 250mm f/5.6, when mounted to a Micro Four Thirds body, deliver an effective 500mm reach in a tiny package. At just 250 grams and under 100mm in total length with an adapter, it’s a pocketable supertelephoto.
Are Mirror Lenses on Mirrorless Cameras Worth It?
Absolutely—if you know what you’re getting into. Mirror lenses on mirrorless cameras are far more viable now than they were during the film era. Digital tools make their quirks easier to manage, while modern mirrorless systems let them shine with better focusing aids and image stabilisation.
They’re not a one-size-fits-all solution, but for certain types of photography—wildlife, astronomy, macro, and even creative portraiture—mirror lenses offer something unique: a blend of compactness, reach, and affordability that’s hard to beat.
If you’re after a budget-friendly way to explore supertelephoto photography, or want to give your mirrorless camera a truly unusual lens to play with, a mirror lens might just be the hidden gem you’re looking for.
