Lens Hood Fit Guide: Canon ET-73 vs ET-73B and Nikon HB-73
By Camera Wholesalers | Published: 2026-11-04
Category: How-to Guides
Learn how to fit a bayonet lens hood correctly and match the Canon ET-73, ET-73B, or Nikon HB-73 to the right lens before you buy.
Quick answer
Match the hood to the exact lens model first: the Canon ET-73 fits the EF 100mm f/2.8L Macro IS, the ET-73B fits the L Series 70-300 IS L USM, and the Nikon HB-73 fits the AF-S NIKKOR 300mm f/4E PF ED VR. Then align the hood's index mark with the lens mark and turn until it clicks into the bayonet mount.
Why the model suffix decides the fit
The ET-73 and ET-73B look similar and share a naming pattern, but Canon assigns each hood to a specific lens. The ET-73 is designed for the EF 100mm f/2.8L Macro IS, while the ET-73B is designed for the L Series 70-300 IS L USM. Treat the letter suffix as part of the model name, not a minor variant.
The same rule applies to the Nikon HB-73: it is listed for the AF-S NIKKOR 300mm f/4E PF ED VR. A hood that mounts but sits at the wrong depth or angle can intrude into the frame or fail to shade the front element properly, so confirm the lens name on the barrel before ordering.
When a non-listed lens might still work
The supplied catalog records list one lens per hood and do not include filter-thread size, hood diameter, or a cross-compatibility chart. That means you cannot confirm a fit for an unlisted lens from these records alone. If your lens is not named, check the lens manual or the manufacturer's accessory list before buying, and treat any online claim of universal fit as unverified.
How to fit a bayonet lens hood step by step
- Confirm the lens model on the barrel: Read the exact model name printed on the lens, including suffixes such as IS, L, USM, PF, ED, or VR. Compare it word for word with the hood's listed lens. If the names differ by even one suffix, stop and verify before mounting.
- Remove any filter or step ring that blocks the hood bayonet: Screw-on filters usually sit inside the hood mount and are fine, but stacked filters or adapter rings can prevent the hood from seating fully. Take them off if the hood will not turn freely. A hood that binds before it clicks is a sign of an obstruction, not a defective hood.
- Align the index marks: Find the small mark on the hood and the matching mark on the lens barrel. Line them up before applying any pressure. Forcing the hood on at an angle is the most common cause of a cross-threaded or cracked bayonet.
- Turn gently until it clicks: Rotate the hood in the direction indicated by the lens markings, usually a short quarter turn, until you feel or hear it lock. Do not overtighten. If it will not click with light pressure, remove it and re-check the model and alignment.
- Check the frame at the widest zoom and closest focus: Take a test shot at the lens's widest focal length and closest focus distance, then review the corners for darkening or the hood edge appearing in frame. Vignetting that appears only with the hood on points to a mismatched or improperly seated hood.
Hood options at a glance
- Canon ET-73 Lens Hood for Canon EF 100mm f/2.8L Macro Lens: Canon ET-73 lens hood designed for the EF 100mm f/2.8L Macro IS lens, with a no-vignetting design. It is the correct match for that macro lens, so you avoid a hood that shades unevenly or appears in the corners.
Canon ET-73 Lens Hood for Canon EF 100mm f/2.8L Macro Lens - Canon ET-73B Hood For Canon L Series 70-300 IS L USM Lens: Canon ET-73B circular lens hood compatible with the Canon L Series 70-300 IS L USM lens. Buy this version for the 70-300 L, not the ET-73, even though the names are close.
Canon ET-73B Hood For Canon L Series 70-300 IS L USM Lens - Nikon HB-73 Bayonet Lens Hood for AF-S NIKKOR 300mm f/4E PF ED VR: Nikon HB-73 bayonet lens hood for the AF-S NIKKOR 300mm f/4E PF ED VR, offered as a spare or replacement. A spare makes sense if you shoot in crowded areas where a hood can be knocked loose or lost.
