Lens test: Canon EF vs FD 50mm f/1.8

In 1987, Canon introduced their new autofocus-capable EF lens mount for their EOS series of cameras – including today’s digital SLRs. It was incompatible with the older manual focus FD lens mount. The flange focal distance of the newer EF lenses is slightly longer meaning that an adapter for mounting FD lenses on an EF body must contain an optic to allow infinity focusing. This immediately means the image quality will be affected by the adapter. But to what extent?

I bought a Kood adapter (although there are many, many brands available) to use my FD lenses on my EF-mount EOS 450D camera. For £15, I thought it would be a fun way of getting some extra use out of my FD lenses, even if the quality wasn’t great.

Kood FD-EF adapter

The competitors

I decided to do a side-by-side comparison of my Canon 50mm f/1.8 lenses – FD and EF mount respectively. I shot at ISO400, 1/60s, f/4 with flash. (Perhaps some other time I will think of this experiment when it’s not dark, and try it in daylight.) The camera was on a tripod.  I used autofocus and centre-weighted program exposure with the EF lens. I used the same shutter and aperture settings for the FD lens, and focused manually using live view, magnified to 10× in on the LCD.

Canon FD 50mm

Canon EF 50mm

Results

For a start, you might notice that the FD lens is slightly more zoomed-in than the EF lens. This is a side-effect of the correction optic to allow infinity focus. I’ll show both photos here, including 100% crops at 1024×768. Click the images to view them at this size. Other than cropping, no sharpening or any other editing has been done on these images.

EF lens FD lens

EF lens

FD lens

EF lens (100% crop)

FD lens (100% crop)

I am honestly staggered by these results – the sharpness of the FD lens is much better than that of the EF lens. It’s possible that the autofocus didn’t do its job properly but it does prove that this third-party FD-EF mount adapter isn’t so terrible. I can only speak for mine – I’m sure there are terrible ones out there.

Pitfalls

There are some other things to be aware of though. Obviously the FD lenses don’t support autofocus, so you have to focus manually. This is no problem on a genuine manual focus SLR body, but autofocus SLRs lack the split-circle and microprisms on the focus screen, so it’s a lot harder to focus using the viewfinder. Using live view is a workaround, and it is also possible to swap out the focus screen for one with a split-circle, microprisms, or both.

While FD lenses do support an aperture controlled by an FD body, it won’t work using an adapter like this. You will need to take your meter reading using any appropriate method, and then set the aperture – this is stopped-down metering. The viewfinder will darken when the aperture is stopped down. This particular Kood adapter has a switch to flick between fully open and stopped down, which helps.

Summary

But if you are in the same position as me, with an EOS SLR and a load of FD lenses, I don’t think you’ll regret spending a few quid to be able to use them on your digital body. The quality, at least of this Kood adapter, is perfectly good – perhaps flawless.

Update

As promised, I have now added some outdoor photos taken from my window. I slightly cropped the zoomed-out version this time, to give a comparable field of view. I’ve taken a 100% crop of the unaltered original to test edge sharpness.

Both photos were taken at ISO100 and f/5.6, but the EF version was taken at 1/50 and the FD version at 1/40 as the darkness was coming in. Both are a little underexposed, I think, due to the pale sky. and the FD version is a little darker.

EF lens FD lens

EF lens

FD lens

EF lens (100% crop)

FD lens (100% crop)

On this occasion, the autofocus seems to have got it spot-on and my manual focusing isn’t quite perfect. Image sharpness otherwise seems good, especially towards the edge of the photo where you might expect softness,  and I can’t see any chromatic aberration around the chimney.

The real test will probably be using this lens in strong sunlight – which I shall try to find the time to do at the weekend. 🙂

12 Comments

  1. Harry Powney
    May 7, 2011
    Reply

    Great review and comparison. It has encouraged me to spen a couple of quid and have a play with some of my FD’s again.

    • Jonathan
      May 7, 2011
      Reply

      Great, that’s what I like to hear! Have fun 🙂

  2. Robert
    May 10, 2011
    Reply

    Any chance of some landscape and portrait comparison shots? Something that tests the contrast too would be useful.

    Great review by the way.

    • Jonathan
      May 10, 2011
      Reply

      Thanks Robert. I plan to add some outdoor shots soon – the only excuse for the boring shots of my bookshelf was that it was dark at the time… 🙂

  3. Jonathan
    May 10, 2011
    Reply

    OK, I’ve added a couple of sort-of outdoor shots. Again, more impressive results although my camera’s autofocus beat me this time. I’m not sure if the FD offers quite the same sharpness as the EF. It could be due to a difference in the lens or the adapter, or it could simply be due to the way the lens renders out-of-focus areas.

    In terms of contrast, it seems to hold its own, but this is what i expect. Despite having only the S.C. coating (rather than the superior S.S.C.) it’s still a multi-coated lens. I expect it would be a very different story using an uncoated Soviet lens from the 1950s. Actually, I might try that… 😉

  4. August 16, 2011
    Reply

    I love 50 mm lenses. They give you such good quality. Thanks for the comparison, you know your stuff.

  5. Bunna Tang
    January 17, 2012
    Reply

    I had one EF 50F1.8 mark II lens used it with my SONY NEX-3. it was awful when shooting it in dark. the DOF is too short and detail is poor when zooming to 100%. of cause I could use only manual focus and largest aperture at F1.8. But now I have lost during my holiday trip. So I now i invested again with FD 50F1.8 I feel it does it better job than EF lens.

    Coating: my previous EF lens had no any coating i can see. so it looks brighter than my FD lens where S.S.C. coating is very noticeable. but due to this coating i feel it is abit darker than EF without coating.

    DOF : FD lens seems to have better and larger DOF than EF, image quality is much sharper. you can notice that if you shoot 4 meters away at night, you will see models will have rough face/skin.

    Aperture : EF = 5 blade , FD = 6 blade. but on my Sony NEX-3 i had no chance to control the EF aperture blades or autofocus . but FD is all I want for full manual usage

    Mounting : EF lens is good and it locks via EOS-NEX adaptor, but FD it locks by an aluminum ring near Aperture control ring to FD-NEX adapter. But if you rotate Aperture ring, you have to carefully check the lock ring, in case you may unlock the lens mount and drop the Canon lens of the adapter.

    Those are my experience with my EF and FD lens. You may have different idea and interest with your lens and body.

  6. Vayoodev
    March 10, 2012
    Reply

    I’m using a FOTODIX adapter to mount my superb FD lenses onto 5D MarkII. Problem is vignetting. I get a ring of darkness around my images which is worse for 50mm lenses. I can output a RAW file and do some post processing. However that would be going against my philosophy of no post-processing escept for some crop in order to be faithful to the craft. I believe that a photographer should spent most of the time setting up a shot (I do architectural, nature or wildlife photography) and minimal time on the computer.

    So has someone found a FD to EF adapter with immaculate optics?? Any help would be very much appreciated.

  7. March 11, 2012
    Reply

    Your FOTODIX adapter looks the same as my Kood adapter. I guess they are made in the same factory. If you want quality I think you will have to pay for it! The corrective lens element in the Kood adapter is quite small and is only designed for use with APS-C crop sensors. If you’re using a full-frame camera, you might have to search for an adapter with a larger lens element – or try and find one of the very rare original Canon FD-EF adapter. I’ve heard good things about the adapter made by Elephoto/Elefoto.

    Alternatively, you could keep on using your FD lenses on a 35mm film body (like I do) and scan the negatives. Much better results than trying to attach them to a DSLR. Have fun!

    • Vayoodev
      March 30, 2012
      Reply

      Thanks I’ll look for those adapters.

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