To be clear, I’m not talking about recent history. I’m talking about his 1980s, 1970s, or even earlier SLR lenses, where lenses had manual focus and aperture rings, and the pinnacle of technological advancement was wide-open metering and automatic aperture.
Although these lenses don’t have the clarity of modern digital lenses, they have their own very distinctive rendering, making them especially popular with filmmakers looking for a vintage look.
The best mirrorless cameras are obviously designed to take advantage of modern lens designs, but they can also be very good at using older lenses. In fact, more so than the best DSLR cameras, as we’ll see.
These vintage SLR lenses also have practical benefits. These usually have a metal body, are very long, very smooth, and have a nice, weighted mechanical focus ring. There is a truly accurate distance scale, and the distance increments are small enough to make estimating depth of field or hyperfocal distance easy. It also has an aperture ring.
So what’s wrong with using it with modern DSLR cameras, with an adapter if necessary, or attaching it directly to the camera if the mount is the same?
The problem is the DSLR’s display system, which is ironic considering these lenses are designed for SLRs.
Modern digital SLR cameras are designed around autofocus rather than manual focus. Viewfinder magnification is low and there are no old-fashioned focusing aids such as a split-image rangefinder or microprism to facilitate precise focusing. Trying to manually focus on modern DSLR cameras can be a bit hit or miss. Especially if the lens is stopped down to the desired aperture, the image in the viewfinder will be darker and the depth of field will be greater, making it impossible to focus. Turn the focus ring and it will “snap” into sharp focus.
That’s another thing. Aperture control has evolved, and modern DSLR cameras no longer have the mechanical linkage that allowed full aperture focus and metering used in older lenses. Today everything is done electronically. You can use old lenses, but changing the aperture will change the brightness of the viewfinder.
Why mirrorless cameras are suitable for older SLR lenses
Mirrorless cameras solve both of these problems. First, mirrorless cameras typically offer a “punch-in” focus check that lets you zoom in on the image to see if it’s in critical focus. You could technically do this with a DSLR camera’s live view, but it’s clumsy and clunky by comparison.
Second, mirrorless cameras have auto-gain EVFs and rear displays that automatically adapt to smaller aperture settings. You can compose shots just as easily at f/16 as at f/2, although the image may be a little grainy. Again, you can do this with the DSLR’s live view, but not the viewfinder. Also, you don’t need to be glued to the rear screen all the time while shooting.
But there’s a third thing. For mirrorless cameras, you can get low-cost “dumb” adapters that fit almost any brand of older SLR lens. I use a Sony A7 II with one adapter for older Pentax K-mount lenses and one for Takumar and Pentacon lenses with M42 thread mounts. If you can find the right adapter, any of the best full-frame mirrorless cameras will work just fine.
The advantage of mirrorless cameras is that they have a much shorter flange distance than SLRs, leaving plenty of room for adapters. SLR lenses are built around a longer back focus distance to account for the camera’s mirror.
All you need is a mirrorless camera that works without an electronic lens connection. This is usually the “Fire without lens attached” option in the settings. My Sony A7 II won’t zoom in on the image for autofocus because it says the lens is not compatible (why should it be compatible?), but all other points works perfectly.
Specifically, you should use manual focus, but not manual exposure. The camera calculates exposure based on the light that passes through the lens and the image formed on the sensor. When you use A or P mode, the camera automatically adjusts the shutter speed, just like with a regular lens. In P mode, there is no linkage, so the lens aperture cannot be adjusted. Also, S mode doesn’t offer automatic exposure for the same reason.
Another thing you need is a lens that allows you to manually (not just automatically) adjust the aperture of the lens. I have some Pentax lenses from the 1990s, but they are completely useless as they don’t have an aperture ring and there’s no way to control the aperture from the camera unless you buy a Pentax body (does it still work? Check ) – and the lens in question isn’t good enough to make it worth doing.
The great thing about all this is that mirrorless cameras have brought many old lenses back to life. It doesn’t work very well with a DSLR, but with a simple “dumb” adapter and a mirrorless camera like the Sony Alpha it becomes useful again. It’s not only convenient, but also easy and practical.
