The Canon FD 100mm f/4 macro lens is front heavy and only goes to 1:2 magnification. Despite that, the lens is sharp when stopped down to f/8.
A 50mm extension tube is needed to get to 1:1 magnification. Adapting the lens to a mirrorless camera body adds even more extension. For the lens to be usable on a mirrorless camera, a tripod collar will be needed. The amount of weight from the lens will damage a camera mount.
If you can deal with the issues of the lens being long, it does produce sharp images with no chromatic aberrations and little distortion.
|Elements Groups||5 ele. 3 gr.|
|# Aperture Blades||6|
|Aperture control||Manual, Auto Diaphragm|
|Hard infinity stop||Yes|
|Magnification||1:2, 1:1 w/ extension tube|
|Minimum Focus Distance||45cm (18”) / ?|
|Working Distance||10.5" @ 1:2|
|Weight||455, ?g w/ extension tube|
|Dimensions||⌀70mm x 118mm (2.75" x 4.625")|
Note: Price pulled from a 1985 Competitive Camera Corp Catalogue.
- Canon Extension Tube FD 50. Any 50mm extension tube can be used to get the lens to 1:1 magnification.
- There is no designated lens hood. The BW-52A lens hood will work. Generic 52mm screw in lens hoods are a cheaper option.
- The LH-C18 hard case and LS-A18 soft case are the two cases Canon made that will fit the lens.
- Canon 100mm Macro Lens 1:4 S.C. - 1975
- Canon 100mm Macro Lens 1:4 - 1979
Build Quality, Design, and Sample Variation
Thanks to the new FD mount on the lens, mounting the lens is easier than the original FD mount. The lens was used with a FD to Sony E-mount adapter on a A7.
Manually controlling the aperture requires the adapter to hold that aperture lever closed. Manually locking the aperture in place is a step that is not required for bayonet mounts, like the Nikon F, Pentax PK, Minolta MD, or Olympus OM.
Using an extension tube to get 1:1 magnification makes this an unattractive lens to adapt to mirrorless cameras. All of the elements in the lens are all located towards the front.
Focusing to 1:2 magnification moves the lens elements to the front lens. The result is a front heavy lens.
Being front heavy will put strain on the camera mount. Adding extension from an adapter and extension tube make the problem worse. A tripod collar will need so the mount is not bent or pulled out of the camera.
Cleaning the Rear Element
The rear element is deeply recessed. Flocking is in the rear of the lens to help reduce reflections and glare.
I had trouble reaching the rear element to be able to clean it. The flocking grabbed fibers from the lens wipe I was trying to use.
After cleaning the element, I then had to clean fibers from the flocking. The process was annoying, though I doubt the rear element will often need cleaning.
There is approximately 360 degrees worth of travel for the focus ring. The focus and aperture rings turn smoothly on my copy of the lens. This is good because most of the vintage macro lenses I have tested have had tight focus rings.
Half stops are between the marked apertures. A green A for auto is available for camera bodies that support that feature.
The front element is not as recessed as some other macro lenses I have tested. Changing focus does not change the distance between the front element and front of the lens. A lens hood may be necessary to prevent glare in more extreme situations.
A Sony A7 was used with a cheap Fotasy FD to E-mount adapter. There was no way to see if the adapter was locking the aperture on the lens in place.
Not having the aperture locked ruined a series of test shots. Changing the aperture on ring did not change the lens aperture. I ended up adding registration marks for visual verification the adapter was setup correctly.
Usage & Working Distance
The lens is unusable without support.
I was immediately worried about the mount on my Sony A7. Focusing at 1:2 magnification puts all the weight to the front of the lens. I could see the lens flex when it was not supported. This put me off from using the lens.
At 1:2 magnification the Canon has 26cm (10.25") of working distance. That's plenty of space, but I don't have problems with the working distance of 50-60mm macro lenses at 1:2.
Test Shot Sharpness Comparison
There was no noticeable chromatic aberration at an stop. The lens is also well corrected for distortion and provides a flat field of view.
- f/4 - Center sharpness is quite good, but the corners are not.
- f/5.6 - Except for the bottom left corner, everything is sharp. The bottom left corner is likely an error on my part.
- f/8 - Everything is tack sharp corner to corner.
- f/11 - Comparable to f/8 with no signs of diffraction yet.
- f/16, f/22, f/32 - Diffraction causes a loss of detail and dust specs start showing.
Used Prices on eBay
I found the most copies of the lens for sale on eBay. As of November 2018, prices ranged from $70 to $160 on eBay.
There is also a listing for the lens on Amazon. Check both sites to find the best deal.
The earlier S.C. version of the lens were also selling in that price range. The Canon Extension Tube FD 50 was selling for $20 on eBay.
The BW-52A lens hood sells for ~$30 if there are any available. The two later versions, BW-52B and BW-52C, are more expensive. Unless you're a collector, buy a generic 52mm screw in lens hood.
Lenses that do not need extension tubes are better choices for adapting to mirrorless cameras. Having to buy a tripod collar negates any possible savings by buying the Canon 100mm.
If you want a FD mount lens, look for the various brandings of the Kiron 105mm f/2.8 or Komine 90mm f/2.8 macro lenses.
If the lens doesn't have to be an FD mount, still look for the Kiron and Komine lenses. Just make sure that you are able to adapt the lens to your camera body of choice. Plus, you should have a wider selection of lenses.
- Vivitar 90mm f/2.8 - Made by Komine
- Lester A Dine 105mm f/2.8 - Made by Kiron
- Tamron 90mm f/2.8 SP Di
- Nikon Micro Nikkor AF 105mm f/2.8
The lens is a great choice to use on a FD mount camera. Pricing is reasonable and it is as nice to use as any other canon FD lens.
I would pass on adapting it to a mirrorless body. Usability is poor due to the length. Plus, the breech lock mount can be annoying to use.