22, 32, 45, 64...

Continue the number sequence yourself - if you are a former large-format photographer you will likely muse dreamily to 90 or 128...But do not expect the makers of lenses for your digital camera to follow. After 45 they will glare at you, sneer, and spit out the word " diffraction ". They will likely be far more interested in a number sequence that gets smaller; 2.8, 2, 1.4, 1.2. They will get all enthusiastic at the numbers that have a decimal point in front of them - like .095 - and their enthusiasm will be expressed in large prices - those are numbers they really like to see. As an old large-format shooter I do remember lenses that could stop down to f:45, 64, and smaller. I valued the increase in the depth of field the smaller holes gave me as well as the freedom to tilt and shift that came with the older cameras. Yes, there was diffraction at the very smallest apertures, but they still did what couldn't be done on a 35mm or 120 camera. I still value the increase in DOF that you get stopped down, and regularly exploit it in the studio with my small digital cameras - but it is rare lens that will let me hit f:22. My current macro 35mm is likely only doing f:16 - the new Fujifilm 30mm f:2.8 promises that extra stop as well as macro and is the current star of my desires. I can only assume that it will be able to work with the electronic corrections mechanism in the Fujifilm cameras that promise to improve the diffraction errors. But I guess what I would really like to plead with lens designers is the case for smaller f: stops regardless. Or even a much more radical idea - a lens that you can break apart. Not with a chisel - I want a lens that can be unscrewed at the point where the aperture blades are - or that has a slot into which additional Waterhouse stops might be inserted. The Russians at Lomo have this in their repro Petzval lenses, and even Canon have had lenses with sliding drawers to add filters into the optical line. I would like to add very small stops - made from sheet brass that has been blackened with gunmaker's matte-black solution. I've done it for large format lenses where front and back elements could be unscrewed. The lens's own aperture was cocked wide open and the brass disc slipped into a position just beside the diaphragm blades. Then you had to go under a dark cloth and let your eyes become accustomed to the gloom before you could operate the focusing controls. The result was a universal depth of field from the front element of the lens to infinity with a great deal of sharpness in it. Objects seen through his sort of tiny aperture were almost pin-pointed - but with no fuzziness. You could really have a fixed-focus lens this way and just shoot where you pointed...as long as you shot on a tripod. Note for the brave: People do disassemble camera lenses for cleaning with some of the tools that they find on the internet. Real technicians like Ernest and Daniel have no fear with this - but I would still hesitate...