Filters (Sold separately)
You can attach filters to the filter mounting thread on the front of the lens.
![](/library/CANON/CITS_TECH_SUPPORT/Camera/Lenses/EF%20400mm%20F5.6L%20USM/warning.png) |
- If you need a polarizing filter, use the Canon Circular Polarizing Filter.
- To adjust the polarizing filter, first remove or store the lens hood.
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Close-up Lenses (Sold separately)
Attaching a 500D Close-up Lens enables close-up photography.
The magnification will be as follows:
- EF400mm f/5.6L USM (77mm)
0.91x - 0.78x
![](/library/CANON/CITS_TECH_SUPPORT/Camera/Lenses/EF%20400mm%20F5.6L%20USM/note.png) |
- Close-up Lens 250D cannot be attached because there is no size that fits the lens.
- Manual focusing is recommended for accurate focusing.
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