Hello everyone

 

I notice that some diopter lenses come with an accessory or adapter ring.

 

What is this for? 

 

I notice it's available with the SMC-1 and AIO 90Pro.

 

It appears to alter the distance between the diopter and the macro port glass element. 

 

I've attached four pictures. 

First two are with the adapter (notice protruding lens).

Latter two are without. In this setup, the diopter lens sits flush with the diopter holder.

 

So the question, I guess, is,  what distance should the diopter be from the macro port glass element? 

 

 

Sharing the response I got from (barmaglot) another forum: 

 

The rear element should be as close to the lens front element as possible. These diopters are made with a protruding rear element in order to compensate for the thickness of an adapter (flip, magnetic, etc) when mounted on such, so that the rear element of the diopter gets as close as possible to the port glass. If you're mounting the diopter directly on the port, without an adapter in the way, then you use the spacer ring, or the rear element of the diopter will bump into the port glass and potentially prevent the threads from engaging.

the answer they gave you is correct, if you use the flip you need to remove the adapter ring, if you mount it directly on the door, without the flip, you need to have the adapter ring mounted

 

Thanks,  Giancarlo.