A few months ago, I picked up a used Canon lens that I remembered seeing many years ago that I wanted to try with the Fuji X-T1. It is a fixed focal length, 500mm f/8 FD-mount reflex lens that has proven to be a little challenging, but also is ridiculously fun.
The old Canon lens I bought is amazingly well built with a drop in filter holder at the back, a rotating and locking tripod collar, and built in lens shade which is a nice touch that you only can seem to get with the old Canon and Nikon designs. The more modern reflex lenses available from Rokinon and such are simpler with lower levels of build quality. Focus on this Canon lens is buttery smooth and feels like a nicely engineered helical focus.
Speaking of focus, this is a manual focus lens only. Every reflex lens lens I’ve ever seen has been a manual focus lens, probably to reduce cost. But technically, there is nothing that would prohibit a camera manufacturer from developing an auto-focus version of this lens. I think Sony actually made one some years ago, but the reflex lens design fell out of favor for some time which I think was a mistake as there are a number of advantages that I’ll outline below.
While there are some definite pros and cons to lenses of this design, it also makes for an ideal travel lens to pack a big focal length into a very small space as well as a not too shabby birding lens provided there is enough light available. To look at how it works as a travel lens, I took this lens with me to Greece including Mykonos and Delos and the Bay Area recently and shot quite a bit with it in those places. This is important because many of us are trying to reduce the volume and weight of our camera gear, especially when traveling and being able to pack a 500mm lens easily into a small pack that you can shove under an airplane seat is wonderful indeed.
Having smaller lenses are also important for birding as many areas that you might want to capture images of birds are not close to where you can easily park your car and the lens needs to be light weight and portable. For instance, the image of the male black chinned hummingbird above was made after hiking through very dense foliage, early one morning up in the Rocky Mountains. I don’t think there are many other 500mm lenses that I’d like to carry along a hike like that. There will be a fair number of bird images that will start to appear here on Jonesblog in the not too distant future that were made with this lens. So I’d say that for travel and birding, I’ve been pretty happy with it.
The lens design is a catadioptric design which effectively uses mirrors to fold the optical path, making a much shorter tube length than it otherwise would be with a totally refractive design. There are some advantages of this design including freedom from any chromatic aberration which is why many telescopes have used this design going back to the early 1800’s. The primary disadvantage of this lens is that you cannot use an adjustable aperture on them, thus the fixed f/8 aperture.
Ring, or doughnut shaped bokeh caused by the central obstruction in the optical lens is the other main drawback from this design making specular light sources rings of light in the out of focus areas. Some folks like this effect, others do not.
This image with a house finch at the feeder demonstrates the ring bokeh in the background. I framed the image to specifically demonstrate the effect in the background. Given the increasing power of image processing chips in cameras, I wonder actually if this optical effect could be mitigated or modified in camera? It should be possible…
This image demonstrates the bokeh in busy, high frequency backgrounds without point sources of light to illustrate what the out of focus quality looks like in other environments. Bokeh appears a little harsh, perhaps busy and not as smooth as with diffractive optics, but I don’t particularly find that unattractive.
The detail and sharpness possible with these lenses is amazing. Images coming out of this camera are much sharper with more detail than I expected and can be illustrated by looking at the fiber in the bill of the house sparrow above. Again, specular highlights are a bit sharp, but using overall scene metering rather than my typical spot metering might be helpful in balancing exposure there.
With less harsh light, exposure is more balanced and again, amazing detail is present and as seen in the 100% crop, amazing detail and resolution can be seen in the feathers.
In order to use these lenses on a modern mirrorless camera, you are going to need a converter. Thankfully, there are a number of companies that are making converters from Metabones (who also has a Speed Booster model which gives you an extra exposure stop) to companies that make simple and inexpensive non-optical adapters. I’ve tried both the Metabones Speed Booster and the non-optical Novoflex adapter and each have pros and cons. With a lens converter on my Fuji X-T1, vignetting or falloff is present and with the Metabones Speed Booster, there is strong vignetting present, but it buys me an extra stop. Though with some cropping as you might be doing with far off objects, you’d be cropping the vignetting out and you can also do some correction in software. With a standard FD to Fuji X-mount adapter, there is just very minor falloff.
The trick to using this lens successfully is to use it on a modern, mirrorless camera with a higher ISO setting to overcome the f/8 limitations and also to use focus peaking, demonstrated in the gif above to rapidly find focus. For far off items, the focus zoom feature found on many camera types is also quite useful and on the Fuji X-T1 is particularly well implemented.
The other concern that I found with the Canon version at least is if you are interested in using screw in filters on the front element, the Canon is probably not your lens as I am unable to find any filters that fit this odd, 82.5mm diameter. There is a Nikon version of this that I think has 82mm filters which are expensive, but also available.
a 500mm lens in a very tiny, light weight package.
Actually, really good, sharp optics!
Close focusing distance.
Fixed aperture at f/8.
Very narrow field of focus.
Manual focus only.
Odd, doughnut shaped bokeh.
Weighing up the pros and cons, I’m pretty happy with this lens and will be hauling this around for travel. Look for more imagery with it in the near future here.