Canon FL vs FD Breech Mount vs FD?

[snegron7]

So, I received a Canon FTb today to add to my collection of Canon FT QL's. All of my lenses are FL mount. This means that I have to use stop-down metering with these lenses on my FTb body. My understanding is that if I were to use "newer" (non-breech mount) FD lenses on my FTb body, I wouldn't have to use stop-down metering. However, if I were to use a newer FD (non-breech mount) lens on my older FT QL bodies, I would have to use stop-down metering on my FT QL bodies.

So, my question is, if I use older breech-mount FD lenses (early generation FD lenses that are breech mount), will I avoid having to use stop down metering on both my FT QL and FTb bodies?

 

[Mackinaw]

If you mount an FD lens (older breechlock or the later bayonet) on a FT, you'll need to use stop down metering. Metering with any FD lens mounted on an FTb will be at full aperture.

Jim B.

 

[mtnbkr]

@Mackinaw is correct. Any generation of FD on an FL body will require stop-down metering. Any generation FD lens (breech or nFD) on an FD body will allow full aperture metering. If you mix and match, you will default to the lowest common denominator (ie stop-down when mixing FL and FD).

The mount isn't the issue, it's the interconnect between the aperture system and the meter. FL lenses didn't communicate aperture settings to the camera, so the camera doesn't know to factor that into the exposure value.

Chris

 

[snegron7]

If you mount an FD lens (older breechlock or the later bayonet) on a FT, you'll need to use stop down metering. Metering with any FD lens mounted on an FTb will be at full aperture.

Jim B.

Thanks! I was really hoping that the older breech-lock (I mistaking referred to as breech-mount in my original post) FD lenses would be the "happy medium point" between the FL, FD Breech-lock, and FD lenses where no stop-down metering was needed. But thanks again for the info! I would now like to buy a couple of newer FD lenses for my FTb, as I'm not a fan of stop-down metering (makes the viewfinder dark). Of course, I can always use my Sekonic L-308 X-U, but I'd love to take advantage of the in-camera metering these cameras have.

 

[snegron7]

@Mackinaw is correct. Any generation of FD on an FL body will require stop-down metering. Any generation FD lens (breech or nFD) on an FD body will allow full aperture metering. If you mix and match, you will default to the lowest common denominator (ie stop-down when mixing FL and FD).

The mount isn't the issue, it's the interconnect between the aperture system and the meter. FL lenses didn't communicate aperture settings to the camera, so the camera doesn't know to factor that into the exposure value.

Chris

My understanding is that FD lenses do meter on the newer FTb body without having to stop down. It's when you mount an older FL lens on the newer FTb body that you have to use stop-down metering.

 

[Timmyjoe]

I used newer FD lenses on my FTb with no stop down issues. Mine was an FTbn, so maybe that is different from a standard FTb, but I don't think so.

Best,
-Tim

 

[mtnbkr]

My understanding is that FD lenses do meter on the newer FTb body without having to stop down. It's when you mount an older FL lens on the newer FTb body that you have to use stop-down metering.

Correct. FD lenses of any generation will meter on an FD body of any generation without stopping down. Only FL lenses or FL bodies require stop-down metering.
Where FD equals Breech-Lock FD or Bayonet FD (aka nFD)...
FL+FL=Stop-Down Metering
FL+FD=Stop-Down Metering
FD+FD=Full-Aperture Metering

Chris

 

[mtnbkr]

I used newer FD lenses on my FTb with no stop down issues. Mine was an FTbn, so maybe that is different from a standard FTb, but I don't think so.

Best,
-Tim

The FTB and FTBn are both FD-mount cameras. I don't recall what the difference is, but it's not the mount or how the lens communicates with the camera.

Chris

 

[rick oleson]

And
FD Breech = FD Bayonet. There is no functional difference between them, it was purely a styling/handling change.