Avenon P.H. 28 Air Lens

The P.H. Air Lens is a pinhole built to fit a camera’s lens mount, and there is no glass in it. A thin plate with a single hole sits in a ring at the centre of a flat disc, five slotted brass screws sit round it, and the name and serial are engraved round the rim: AVENON P.H. AIR LENS NO.W80945 on a silver Leica-thread copy. The front takes 46 mm filters, and the lens was sold with an AVENON UV 46mm filter; hamashun notes that a filter is recommended because fine dust otherwise gets in through the hole. The 28 in the name, printed on the box as P.H28, describes an angle of view rather than anything that can be set. Fotoborse, the Tokyo shop that has handled several, writes that a pinhole has no focal length as such, and nothing to adjust. Japanese Wikipedia dates it to 1996 and gives it as the equivalent of 28mm at F125 to F250, without a citation; the instruction manual, as hamashun reports it, gives about F125 to F256.

Two accounts of the maker exist, and only one line, from the Kobalux website, joins them. Japanese sources give アベノン光機 (Avenon Kohki), founded around 1982 by a Mr Abe, formerly of Sankyo Kohki, the Komura lens maker that went bankrupt in 1980. Akagi Kōichi, who met him while writing for Asahi Camera, says the name simply means the lens Mr Abe made, and that Abe was reportedly senior at Sankyo Kohki. Nakamura Fumio, writing for CAPA, says Abe had been in sales at Komura with Komura alumni doing the development, while Fotoborse and Japanese Wikipedia call him a designer. Nakamura counts a pinhole lens for Leica among the company’s products, beside finders for wide-angle lenses and conversions of Contax G lenses, and says Abe died suddenly and the company was dissolved a few years later. The one company document seen, a warranty card for an Avenon 28mm, was issued by (有)アベノン at Sotokanda, Chiyoda-ku, Tokyo. English sources tell a different story: camera-wiki describes Y.K. Optical, a small Yokohama firm, selling a 21mm and a 28mm as Kobalux and as Avenon, and it mentions no pinhole. The Kobalux website, in a passage noviplamen quotes, credits those two lenses to Abe, “who started his own company, Avenon Kohki (Y.K. Optical)”; how the companies relate is not settled. Every Air Lens seen carries the Avenon name.

Four versions have turned up. In Leica thread mount there are a silver and a black, both engraved in red; the silver copy photographed from behind has a bare brass thread, the black ones a blackened thread. In Leica M mount there is a black version with a short bayonet where the thread would be. The Contax G version is a different object, a deep black barrel engraved in white. The boxes print the mount letter, the finish and the price: L and SILVER at ¥13,500, M and BLACK at ¥16,500. The Leica versions seen are numbered between W80311 and W80945, with a letter that the plain numbers on the Avenon 21mm and 28mm copies seen do not carry; the one Contax G copy seen is W10107. It works on a G1, whose finder shows the 28mm field, but on a G2 the shutter will not release, which both shops that sold it put down to how the body recognises lenses. Gokurakudo, the Contax shop behind Fotoborse, describes mounting it and backing it off slightly so that the G2 reads an empty mount, a trick it says is at the owner’s risk. Avenon also sold a reversible adapter, ¥4,000 on its printed bag card: screwed in from the front it gives about a 21mm angle of view, fitted from the body side about 35mm. Fotoborse, trying a thread-mount copy on a helicoid adapter in 2016, found that extending the helicoid narrowed the view to what felt like about 35mm.

The results are what a pinhole gives. hamashun, shooting it on a Ricoh GXR Mount A12 in 2012, says the lens is beyond any discussion of optical performance, with blown highlights, blocked shadows and nothing that could be called focus, and that it needed ISO 800 for about 1/3 second handheld on a sunny winter day. Geoff Chaplin, who used one on a Leica MP for a Venice series published by 35mmc in 2023, calls it a standard pinhole professionally fixed in a filter mount, and values the mount for changing filters in black and white. Every original negative in that series showed a central spot, which he calls not normal for pinhole images and could not reproduce afterwards with the same lens or any other. In replies to readers his best guess was a speck of dirt stuck in the pinhole, kept there, he thought, by the filter blocking the airflow.

When buying, look at the back of the lens rather than at the title. A black copy sold in 2023 as Leica M mount has a screw thread in its photographs, and a silver copy that Fotoborse offered as a Leica L-mount lens was photographed beside a box marked M SILVER, so the letter on a box is worth matching to the mount itself. hamashun warns buyers not to pick up the Contax G version by mistake; it will not fit a Leica at all. The pinhole plate is thin and is the whole of the optics, so ask for a close photograph of it, and check whether the 46mm filter that hamashun recommends for keeping dust out is still with it. Prices sit far below the Avenon glass lenses: ¥7,920 for a silver thread-mount copy and ¥7,000 for a black M on Yahoo! Auctions in 2026, ¥6,230 for a black thread-mount copy in 2023, and ¥16,800 asked for the Contax G copy in October 2026. Chaplin, in 2025, called it no longer made and, beside a home-made or ready-made pinhole body cap, an expensive option when one turns up second-hand.