Whatsit #96

unpopular · Jun 30, 2012

A retaining ring holds optical component inside the barrel. I am guessing this is either on the front of a filter or perhaps a lens.

(http://www.edmundoptics.com/mechani.../m23-2-m27-5-tube-system-retaining-rings/3460)

I didn't think they had names for those little socket thingies. If it's what I am thinking of, it's where the spanner fits into the ring so it can be removed?

480sparky · Jun 30, 2012

No, not a retaining ring.

What is pictured is part of the lens mount.

Animaniac888 · Jun 30, 2012

I guessed lens mount! Surely that should suffice for just a part of one.

I've checked both of my NIKKOR lenses and both of my Canon lenses and haven't been able to detect anything like it... maybe I should look harder.

snowbear · Jun 30, 2012

I see one on the back of my 24mm Nikkor, but I don't know what it is. I think it is part of what locks the lens to the body. It receives the pin (attached to lens release button) from the body.

480sparky · Jun 30, 2012

snowbear said:
I see one on the back of my 24mm Nikkor, but I don't know what it is. I think it is part of what locks the lens to the body. It receives the pin (attached to lens release button) from the body.

Yepper! This one happens to be on a BR-2a reversing ring.

(I think it's call the lens stop notch)

unpopular · Jun 30, 2012

On the A-Mount that is where the lens release pin fits.

snowbear · Jul 1, 2012

Yay - I figured one out & learned something, too.

sm4him · Jul 1, 2012

Ahh...that's why I couldn't find it, even taking macro shots of my lenses...none of mine look like that. Well, actually, it turns out my macro lens' lens stop notch looks like that, but IT was on my camera taking photos of the other lenses, which don't have an open-end like that on the notch.

Good one! And by good, I mean, ridiculously impossible but interesting nonetheless... :lol: