Some help with these, please.

[FrankMi]

You know what? Being that you mentioned what you did, I think it is quite possible that the 'ribbed' portion may be just that (ribbed) as opposed to threading. Thanks for the, very likely, insight .

I pretty sure that the new ones I just bought from Amazon are threaded on both sides so that you can attach a filter to the lens hood as well as attach the lens hood to the camera.

[NLAlston]

I pretty sure that the new ones I just bought from Amazon are threaded on both sides so that you can attach a filter to the lens hood as well as attach the lens hood to the camera.

Thanks, Frank. I will see what I can make of it, on my gear.