Whether you want to try using something old on your snazzy new DSLR or you want to use your dad's old lenses from when he was your age you may be wondering if you can use the old Canon standard of FD with your EOS camera body. The answer is yes, and here's how you do it and what the results will be.
All you need is an FD to EOS adapter like this one in this Amazon link.
I actually recommend the adapter that Fotodiox offers because it's the most refined one I've seen so far, but there are other sometimes cheaper options. All of these FD adapters work the same.
The back of the FD lens always has at least one protruding pin or "lever" that must be engaged in order for the F-stop to adjust as you turn the manual F-stop ring. All decent adapters will have a screw or pin that pokes out from the adapter ring to engage that lever. Once that lever is pressed down all the way you can ajust your aperture freely. Otherwise you will always be shooting wide open at the lowest f-stop. This was a feature not a bug of the FD mounting system as the camera could control the iris with this lever for the sake of metering.
FD mounted lenses have a flange focal distance (FFD) of 42mm while the EF mount has a FFD of 44mm. That two millimeters makes a world of difference when it comes to focus. the FD-EOS adapters have a removable lens that corrects the focal distance. Technically this is a 1.26x tele-converter. To most people these numbers don't matter but what you need to know is that because the rear element of a lens is the biggest deciding factor in sharpness, you are magnifying the flaws of your FD lens plus adding another piece of glass that will introduce more internal reflections and distortion to your image. But here's the good news. While haters will use this as a point of criticism, you can see by this example below that the negative results are negligible when it comes to sharpness compared to current generation lenses. The distortion and CA introduced by this rear element are not as bad as some people may tell you.
Zooming way in at a 1:1 you can see that even the distant powerlines and buildings look fine. I'm sure there's a degradation from the rear lens element but I just can't see how this is ruining the image.
The adapter screws onto your FD lens as if it were the FD camera body. The adapter engages the aperture lever when you twist it into the "lock position. From that point on the two are mated solidly together. From that point on you just screw the lens into your EOS body as if it were a normal EOS lens.
Focusing is the single hardest challenge. Some cameras will still give you the focus promps such as chirp and red dots when viewing through the viewfinder when your shutter release button is half pressed. In most cases though you either have to try your best to get sharp focus through the viewfinder or use the rear screen and zoom in to fine tune your focus.
As far as what you see through the viewfinder, literally what you see is what you'll get. When stepping down in F-stops you'll notice a difference in sharpness and depth-of-field instantly. Literally what you see through the viewfinder is what your sensor will see.
Why do this at all?
Ok, so there are some people who will be asking why you should consider doing this. After all the newer lenses made for the EOS lineup are probably superior. Right? Well maby, but sometimes the results from a quality FD lens can equal that of one of Canon's EF lenses. FD lenses can be had for under $30 on Ebay and sometimes much lower on Facebook Marketplace and Craigslist. So the value for your dollar can be very appealing.
For those who are trying to get some quality lenses on a budget this can be a great way to get started. One adapter will work with all FD lenses. This is especially exciting if you decide to get into using prime lenses since for the price of one EF lens you could buy the entire Canon FD prime collection off Ebay.
Vintage lenses also have a vintage "feel" to them that you can either love or hate.
Sometimes when shooting wide open you can get insane chromatic aberrations that make your photos look dreamy. Or you get horrendous internal reflections that ruin your photos.
But sometimes you get really appealing combinations of these things, or none of them and get a truly beautiful photo that is unique to your camera and lens combination.
Sometimes you can knock it out of the park, and you are doing it with a lens that is older than you. Using these FD lenses gives you a ton of interesting options that the current Canon lineup of lenses just don't have.
Then there's video.
Oh my sweet goodness the possibilities.
So if you ever watch a tv show from the 80s-90s on a HD monitor you'll probably notice some pretty significant chromatic aberration in areas where there is strong contrast.
Take this still from season 1 of Little House On the Prairie. The studio light is clearly visible and doing uglies. So shooting with some of these lenses can create a cinematic or lo-fi feel that is hard to reproduce. It may look like trash on still images, but for motion picture it can add a feeling of warmth or vintage. Oh, and that's for a price under $60.
many of these lenses will have buttery smooth focus that can make them even more appealing for cinematic use. if you plan to use your EOS body for video work then adapting these lenses is a very interesting option to consider.