The Mirror or Reflex lens must be the most maligned, joked about and misunderstood of all 35mm lenses. Granted, it has some disadvantages, chief of them being the fact that mirror lenses are fixed aperture, and cannot be stopped down beyond their built-in f/8 settings. In some lenses, the f/8 is a manufacturer’s claim, and in reality, the setting may be closer to f/11. Even if it is f/8 as claimed, if we add any correction filter, we are stopped down to f/11 or f/16 anyway, which limits us to daylight photography.
Another disadvantage is that the viewfinder is not as bright with a mirror lens, and that focusing becomes difficult for cameras that are using a split prism focusing screen, due to the fact that the center spot goes dark. But by far the most pointed out disadvantage is the fact that the lens causes the out of focus highlights (bokeh) to be annular, doughnut shaped rings of light, and that is considered undesirable by many photographers.
Other disadvantages are that it either takes a large filter size (mine takes a 77mm screw-in) or that in some cases a small filter has to be inserted at the back of the lens, making it EVEN harder to focus. Due to these disadvantages, most enthusiasts who jump in and purchase a mirror try using it one or two times, and then put it away to gather dust, or trade it in the first chance they get. There are plenty that are available on eBay, used and new… at prices that are quite reasonable.
Look at the lens from another angle — as a potential long focus hand held lens. The mirror lens is usually available in focal lengths of 400, 500 or 600mm, with the vast majority available in the 500mm range. The lens is very compact, about 4 inches long, since the mirror design folds the incoming light a couple of times. Consider that these lenses have been around for many years now, and computer aided design has made them optically very accurate, and straightforward to design & manufacture. Better than that, it can be made cheaply, and most of the non-OEM brands can be purchased new for a little more than $100, with used mirrors going for even less. It usually weighs less than 1 lb, and can be easily hand-held, and does not look odd even on a small frame camera such as an OM-1 or OM-2. Some of them even claim to be Macro, although it’s just a close focusing capability which is very useful.
In my opinion, these lenses have an undeserved bad rap. Oh, don’t get me wrong, of course I would love to be able to afford a reasonably fast OEM refractive 500mm prime lens (say f/5.6), but other than the enormous cost ($1000++ range??) that puts it beyond the reach of all but the most dedicated amateur photographers, the lenses are large, and heavy. One cannot dream of hand-held photography with such a lens and a sturdy tripod would be a necessity. A professional photographer may have the resources and justification to purchase such a lens, since his or her professional activities and heavy usage call for it.
But what of the amateur who wishes to move into photographing birds, or just wants to have the opportunity to use a super-telephoto? There aren’t many low-cost alternatives. A few possibilities come to mind, but none of them seem suitable for casual handheld photography. Let’s explore what’s out there that’s relatively cheap, and gives us what we want– ie, a super-telephoto lens that’s reasonably fast, and comes in a standard bayonet mount. Handheld is ideal, but we will settle for something that will let us use a bean bag or some similar support, without having to resort to a Tripod and long exposures. There are other long focus cheap lenses in older screw mounts still available, and I will discuss them in another post.
# Using a mid-range zoom such as the Vivitar Series 1 70-210mm f/3.5 zoom (67mm filter size) with a 2x tele-converter. The tele-converter will cause the loss of 2 stops, but we will end up with a upper range of 420mm f/8 or thereabouts. If you are familiar with the tank-like construction of the Series 1 f/3.5 lens, it will be clear that the addition of the 2x converter will make it very difficult, if not impossible to shoot hand-held. Adding a Polarizer will cut us down 2 more stops to about f/16. Cost should be around $125-$150 or so for the lens and tele-converter setup.
# A lighter mid-range such as a Kiron 80-200mm f/4.5 zoom (55mm filter size) with a 2x tele-converter. As before, the tele-converter will lose 2 stops, and we will end up with around 400mm f/8. The assembly is not as heavy as the Vivitar Series 1, but still unwieldy. The same filter factors apply. Cost approx $150
# A third possibility is the Zuiko 300mm f/4.5 prime (72mm filter size). Now, the 300mm falls into the super-telephoto range, and it is built compactly enough that hand-held photography is possible. Add a 2x converter, and you have a 600mm f/8. Hand-held is out of the question, though. Same filter factors apply. Cost varies approx $350 for the setup.
# Vivitar used to make a 75-250mm f/3.8-4.5 zoom (62mm filter size). When coupled with a 2x tele-converter, gives us a 500mm f/8 at the upper end of the range. Too big for hand-held photography, and the same filter factors apply. Cost approx $125-150 for the setup
# Tamron made a 60-300mm f3.8-5.4 and Tokina made a similar 60-300mm f/3.8-5.6 that could be coupled with a 2x tele-converter to give us an 600mm f/11 at the upper range or an approximate 500mm f/8. Still huge though, and no hand-held. Same filter factors apply. Cost varies, approx $150-200 for the setup.
Of course, if we are able to focus using the ground glass portion of the focusing screen (if you’re using a OM-1 or OM-2, you can get a 1-10 matte focusing screen, which has grid lines but no center prism.) and are willing to use a proper support/tripod, the above combinations will permit stopping down to at least f/22 or lower.
There are Digital options as well — if you have a Olympus E series DSLR and the 4/3 to OM adapter. In the Olympus E series cameras, the smaller CCD size (12mm x 18mm) affords a digital conversion factor or 2x compared to the 35mm format (24mm x 36mm), so any of the above 35mm lenses focal length will effectively be doubled – for example the Zuiko 300mm f/4.5 when fitted to the Olympus E-500 will be a fast 600mm f/4.5, and the Vivitar Series 1 75-210mm f/3.5 lens will be a 420mm f/3.5. By the same token, the 500mm Mirror will become a massive 1000mm f/8. But that’s only if you have already made the considerable investment in a DSLR. I’m not sure what kind of results we would get with hand-held photography, although I am sure that the image stabilizing technology makes life much easier. The 2x conversion applies only to the 4/3 (Four-thirds) lens system and Olympus E series cameras. The Sony Alpha (aka Minolta) has a 1.5x digital conversion factor. I am not sure what the Canon and Nikon digital conversion factors are. Perhaps 1.4x??. Here’s a beautiful example of what you can do with a 500mm Mirror with a 2x tele-converter on an Olympus DSLR. This is 2000mm equivalent Handheld!!
One other advantage we have now that the photographers in the 70′s and early 80′s did not have (back when the bad rap started) is better FILM. We have much better emulsions that provide high quality images with 400 and even 800 ASA film. So if you have been hesitating with respect to buying a Mirror lens, give it a try. Keep an open mind, and don’t compare it with its much more expensive counterparts and I can assure you that you’ll be surprised. Look for a good deal, and take the plunge. Maybe you know someone who has a mirror lens they will let you borrow for a few days. Load your camera with 400 or 800 ASA color film and go shoot. Perhaps go hiking or even birdwatching. Don’t worry about filters. If needed, you can use some simple post-processing software tools provided by Picasa to make minor adjustments.
Maybe it won’t be professional quality but at least you will not lose another super telephoto opportunity. And if you’re happy with the results, that’s all that matters. Who knows? Like me, you might fall in love with the doughnut bokeh. And by the way, mine is a very ancient, beat-up looking Soligor CD lens. Check out the setup below. :D
|500mm Mirror #1
|500mm Mirror #2
|500mm Mirror #3 – check out the bokeh
|500mm Mirror #4
||500mm Mirror #5
|500mm Mirror #6
||500mm Mirror #7
|500mm Mirror #8||500mm Mirror #9|
Photographed with an OM-2, Soligor 500mm f/8 Mirror lens, 1/125 sec, f/8; Fuji Superia 400 film. For the curious – here is my camera and lens setup. I am using a collapsible rubber Mamiya 77mm screw-in lens hood to protect the mirror lens from flare.
|OM-2 and Soligor 500mm set-up #1
|OM-2 and Soligor 500mm set-up #2
text and images © 2007 ajoy muralidhar. all names, websites, brands and technical data referenced are the copyright or trademark of their respective owners.