Difference between AI 16mm fisheye and AF 16mm fisheye

I snapped up an AI-s 16mm fisheye on eBay. It has not yet arrived. However, my question is about the seller's statement that the lens

does not take any filters. I was under the impression the lens was mostly identical to the AF-d 16mm fisheye, lacking only AF. The latter

takes rear mounted filters. Does the AI-s lens take rear mounted filters?

<p>According to this source it takes rear filters. http://www.photosynthesis.co.nz/nikon/specs.html#Fisheye</p>

<p>I've used a few 16mm fisheye Nikkors. </p>

<p>The f/2.8 AiS model does take the bayonet mounted filters just like the AF-D model. </p>

<p>The older f/3.5 model has a built in filter array.</p>

<p>Confirmed that it takes the bayonet rear filters. Incidentally, the filter is part of the optical design and the lens will not focus at infinity without a filter in place. Not having the filter in place does skew the minimum focus distance slightly closer. </p>

<p>Chuck -<br>

There are nominally three Nikon 16mm fisheye models:<br>

16/3.5 non-AI, AI: Has built-in internal filters<br>

16/2.8 AIS: Rear-mounted filters (must have one installed)<br>

16/2.8 AF-D: Rear-mounted filters (must have one installed)<br>

Obviously none of them have front filter threads so they can't take standard filters.</p>