|Phoenix/Samyang 500mm f/8 Mirror (Catadioptric) Lens|
Mirror telephoto lenses, often referred to as reflex lenses but more accurately called catadioptric lenses, are frequently misunderstood and mistaken for poor quality. In reality, the catadioptric system is an ingenious telephoto design which reduces size, weight and cost when compared to refractive designs of similar focal length. Optically, it virtually eliminates chromatic aberration. But, like all advantages, they come at a price.
At any give price point, any lens design design represents a compromise. Make a lens longer, and you sacrifice sharpness, speed and contrast. At higher price points, these sacrifices are reduced, but come at the price of increased size and weight. So, it naturally follows that any lens design that packs so much power into such a small package and at a reasonable price will be subject to the limitations of physics.
That said, the Pheonix/Samyang 500mm f/8 MC Mirror lens is somewhat of a feat in optical design.
Ignorance is Bliss
In 1976, when I purchased my first SLR, the Canon AE-1, I pined after the Canon Reflex 500mm f/8. I was intrigued by the donut-shaped bokeh that it produced, seeing it as a unique advantage that no other telephoto lens had. Since then, I’ve always had an affinity the aesthetic of reflex lenses.
Interestingly, while some complain about the quality of the reflex len’s bokeh, others seek to produce creatively shaped bokeh using custom aperture disks. Lensbaby even offers a creative aperture kit for their Optic Swap series of lenses.
I passed up several opportunities to purchase the reflex lens for my Canon AE-1, which of course would have been unusable with my present Nikon Bodies.
Newer, Cheaper, Better
Fast-forward to 2010. By comparision to the reflex lenses of old, the Phoenix/Samyang version is smaller, lighter, has a shorter minimum focus distance, and is quite inexpensive. For about a hundred dollars, you can purchase a lens which will enable you to capture images that no other lens can.
Mounted to my Nikon D90, this lens is about the same dimensions as the fully retracted Zoom-NIKKOR 16-85mm f3.5-5.6, and weighs in at 4.3 oz. less. It’s focal length however is 750mm, a 588% increase over the Nikkor! At 127.5mm, the Nikkor is actually 1-1/4″ longer, and costs over $490.00 more than the Phoenix/Samyang.
In use, it’s solid and simple. It’s satin-black anodized, all-aluminum construction is a nice departure from plastic, and the etched, color-coded, paint-filled markings harken back to the days of old. The focus ring is silky-smooth and heavily-damped, which aids in critical focusing. Once the T-mount adapter is installed and adjusted so the index mark is at top-dead-center, it mounts like any other manual focus lens.
Operation is straightforward; set the camera to manual, select an appropriate ISO/shutter speed combination, focus and shoot. If you rely completely on auto exposure and auto focus, you will find this challenging, perhaps even daunting. But, if you have experience with traditional photography, you will have no problems outside of the fact that you are attempting to hold the camera steady at 750mm. The situation would be the same if you were using a 750mm manual refractive telephoto lens. Except that you would have paid over $3,000.00 used, and be toting around something that weights 6 lbs., 10 oz. and is over 15″ long.
When properly focused, using an adequately fast shutter speed and/or tripod, this lens is amazingly sharp for a $100.00 piece of glass. The images from a mirror lens have a soft quality even though they are tack sharp, which can be deceiving at first. However, they are conspicuously void of chromatic aberration, making them very clear. Given a little effort, it is not difficult to coax excellent images from this lens. But it may simply be impossible to get any closer to the subject, or fork up any more cash. And this is were this lens shines.
If the price isn’t enough of a bargain already, the lens comes with three 30.5mm filters that attach to the rear of the lens; a skylight filter, an ND-2x and an ND-3x. While the skylight filter has a warming effect, sadly it provides very little UV suppression having failed the black light test. There are actually quite a few 30.5mm filters available, especially those suited to black and white photography.
You either like it, or you don’t. If you can’t accept the most significant compromise of mirror lenses, then they’re not for you.
- Use a Tiffen 72mm Low-Light Warming Polarizer to increase contrast and saturation; This is an ideal filter for this lens as it’s inexpensive, suppresses UV radiation, and adds only one stop to the exposure.
- For general protection, use the Hoya 72mm UV(0) Haze filter. This inexpensive, single-coated filter is more effective than the newer UV(0) S-HMC filter manufactured in the Philippines.
- Use a Hoya 72mm screw-in lens hood to increase contrast and reduce flare. With the appropriate step-up rings, this hood is ideal for all your other lenses as well, as it adjusts for three different lens focal lengths.
- If you prefer to use rear-mount filters, try the Tiffen 30.5mm UV Haze 1 filter. This filter has proven effective in suppressing UV, and is quite inexpensive. Although it is possible to purchase a 30.5mm polarizer, there would be no practical way of adjusting it once the lens is mounted.
- Motion blur may be more distracting than noise, so use a higher ISO when warranted. Noise can be reduced in post processing, but motion blur cannot.
Being almost as compact, but a little lighter than a standard zoom, it’s a joy to carry to carry around. Because it’s so small, people don’t realize you’re shooting with a very long telephoto, so you operate in a kind of stealth mode. This makes it possible to capture candid portraits without the subject knowing…great for street photography. It also enables you to capture the intimate details of distant objects, or fill the frame with objects that are very far away. Focusing is challenging, but aided by the fact that the focus confirmation works quite well, despite it only being rated for lenses of f/5.6 or faster. It helps to judge the distance by eye, and dial it in on the focus scale before composing the subject. Then, it’s just a matter of fine tuning.
It’s easy to mistake lack of sharpness with motion blur, so be sure to work with a shutter speed fast enough to overcome the shakes. 1/500th sec. works well, despite the effective focal length of 750mm on the DX format, and I’ve shot as low as 1/250th with good results. A monopod certainly helps, as does the technique of bracing the camera against a stationary object.
For nature photography, a tripod works well, even if not locked down to enable free panning, It’s the minute oscillations of hand-holding that wreak havoc, which the tripod and monopod tend to suppress. A steady hand and the body’s own ability to damp vibration are techniques that have been all but forgotten, but are most relevant here. And the mass of the camera/lens combo also plays a significant role. Due to the lens’s light weight, you might want to use a grip with heavy, high-capacity NiMH batteries installed to add vibration-dampening mass if shooting in low-light conditions.
Flash is not at all out of the question, and can be used as fill if shooting within range. However, your stealth ability goes out the window, and you may need to use it in manual mode. Not a problem with the D90, as the on-board flash allows me to dial in the precise power needed in 1/3 stop increments, as would an external flash. Plus, an external flash in good ol’ auto-aperture mode reduces the need to adjust manually.
This lens takes on a whole new purpose with digital photography. It’s subdued contrast and saturation can easily be enhanced in post-processing. If you shoot in camera raw, you can underexpose the images slightly to reduce motion blur, and increase the exposure in post. When it comes time to upgrade, this lens will only get better. Higher ISO capability in your next camera means sharper, images with less motion blur.
Although not particularly exciting, here are some sample images:
|Cable Conundrum. Handheld from about thirty feet away. If I had used a tripod, the smallest type would have been legible.|
|Security Light. Handheld, about fifty feet away. If you look closely, you can see the wire embedded in the glass behind the metal grill.|
|Suburban Safari. Handheld, braced against a building. A life-size elephant statue, from about 100 feet away.|
|Halloween Skull. Handheld from about ten feet away, indoors, built-in flash. Proof positive that this can do macro.|
Except for a fifty percent reduction in size to make them web-friendly, these images have not been post processed. However, they all respond very well to added contrast, saturation and sharpening, especially with Adobe Photoshop Camera Raw or Apple Aperture, which both apply the changes as metadata without permanently affecting image quality.
I must admit, I’m at a slight disadvantage with the D90. If this were a D300S or above, I could enter the lens information manually and have full metering capability. But it’s OK for now, as I have Chimping to fall back on. My next body will probably be the successor to the full-frame D700, and that will allow me to take advantage of full matrix metering.