Canon FD Lens Hood
In the beginning (FL lenses) the hoods were just marked "W" for wide angle, "S" for standard and "T" for telephoto, followed by the diameter of the fitting. When the FD lenses were introduced, the hoods acquired the "B" prefix (it's assumed it stands for "bayonet"), and different versions of some of the hoods were introduced for different focal lengths. For example:
- BS-52 for the 50/1.4
- BW-52A for the 35/2.8
- BW-52B for the 28/2.8
- BW-52C for the 24/2.8
Zoom lenses must have hoods which don't vignette at their widest point, which usually means that they are totally useless at the other end of the zoom scale. For example, the 35-105 f/3.5 uses a BW-72B - a wide angle hood (because of the 35mm end) which is pretty pointless at the 105mm end. The 70-210 f/4, on the other hand, uses a BT-58 - a telephoto hood (because of the 70mm end) which is actually not too bad at the 210mm end.
To see which hood you need, take a look at the FD lenses listing in the Photography in Malaysia website, or Dennis Baron's Canon FD Lens Info webpage.
Two particular hoods tend to be confused a lot, so these are detailed here:
- BW-72: for 17mm to 24 prime & zooms; fits six different lenses; beveled design about 4 1/4" outside dia.
- BW-72B: dedicated to 35-105 3.5; about 3 1/2" dia & almost straight (very slight bevel).
Canon-issued hoods have three plastic tabs which engage tabs on the front of the lens to securely lock the hood on, with only about a 90° turn twist (as opposed to lining up the filter threads and winding). In addition, they can be reversed on the lens and bayonet onto it in the storage position.
Now, leaving the hood fastening mechanism engaged for months and years causes the plastic to deform, and the hood won't ever lock on again.
The solution is: when putting lenses away, reverse the hood on the lens, but don't lock it on. Just let it sit there, freely. Then, put the lens cap on, over the hood. It will keep the hood from falling off without having to engage the plastic tabs.
