With lenses not having AF, the used aperture value is stored as 0 in the Exif Data.
I have old lenses such as Carl Zeiss Jena Flektogon 2.4/35. I use these on my EOS 100D with an adapter. These lenses do not have AF, so the used aperture value is stored as 0 in the Exif Data.
When I upload such an image to irista I cannot open the detail/info view to see the Exif data.
Furthermore I cannot filter by aperture value 0 although this filter choice is offered.