https://community.usa.canon.com/t5/EF-RF-Lenses/Non-threaded-hole-on-100-500-lens-collar-What-is-it-for/m-p/594576#M40004 <P>It doesn’t really need to be threaded. Some Arca-Swiss plates can use two screws. The screws can be tightened up to make a peg to go in the unthreaded hole to stop rotation.&nbsp;</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="IMG_5286.jpeg" style="width: 1170px;"><img src="https://community.usa.canon.com/t5/image/serverpage/image-id/75198i9DED8DE1D3DF8EC0/image-size/medium?v=v2&amp;px=400" role="button" title="IMG_5286.jpeg" alt="IMG_5286.jpeg" /></span></P> <P> </P> Sun, 03 May 2026 14:23:55 GMT Waddizzle 2026-05-03T14:23:55Z https://community.usa.canon.com/t5/EF-RF-Lenses/Non-threaded-hole-on-100-500-lens-collar-What-is-it-for/m-p/594565#M40002 <P>Does anyone know why there is an extra non-threaded hole on the foot of my 100-500 lens collar? &nbsp;It would be nice if it was 1/4” 20 threaded so you could use 2 bolts to keep the plate from rotating but it isn’t. But is there some other use for it? &nbsp;I’ve always wondered..</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="IMG_8531.jpeg" style="width: 1645px;"><img src="https://community.usa.canon.com/t5/image/serverpage/image-id/75192i5610193688BDCEF3/image-size/medium?v=v2&amp;px=400" role="button" title="IMG_8531.jpeg" alt="IMG_8531.jpeg" /></span></P><P> </P> Sun, 03 May 2026 13:31:20 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/Non-threaded-hole-on-100-500-lens-collar-What-is-it-for/m-p/594565#M40002 Trezmo 2026-05-03T13:31:20Z https://community.usa.canon.com/t5/EF-RF-Lenses/Non-threaded-hole-on-100-500-lens-collar-What-is-it-for/m-p/594571#M40003 <P>Some tripod heads have a spring loaded pin that is used as a stop when seating the lens collar into the mount.&nbsp;</P> <P>&nbsp;</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="March411_0-1777817249239.png" style="width: 400px;"><img src="https://community.usa.canon.com/t5/image/serverpage/image-id/75195iDBE716985C1E6255/image-size/medium?v=v2&amp;px=400" role="button" title="March411_0-1777817249239.png" alt="March411_0-1777817249239.png" /></span></P> <P>&nbsp;</P> Sun, 03 May 2026 14:09:42 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/Non-threaded-hole-on-100-500-lens-collar-What-is-it-for/m-p/594571#M40003 March411 2026-05-03T14:09:42Z https://community.usa.canon.com/t5/EF-RF-Lenses/Non-threaded-hole-on-100-500-lens-collar-What-is-it-for/m-p/594576#M40004 <P>It doesn’t really need to be threaded. Some Arca-Swiss plates can use two screws. The screws can be tightened up to make a peg to go in the unthreaded hole to stop rotation.&nbsp;</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="IMG_5286.jpeg" style="width: 1170px;"><img src="https://community.usa.canon.com/t5/image/serverpage/image-id/75198i9DED8DE1D3DF8EC0/image-size/medium?v=v2&amp;px=400" role="button" title="IMG_5286.jpeg" alt="IMG_5286.jpeg" /></span></P> <P> </P> Sun, 03 May 2026 14:23:55 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/Non-threaded-hole-on-100-500-lens-collar-What-is-it-for/m-p/594576#M40004 Waddizzle 2026-05-03T14:23:55Z