Canon f4.8 23mm from IXUS M1 on Olympus OM-D E-M5

[iangreenhalgh1]

Another one of my DIY efforts - I removed the lens and remouted the optic block in the barrel of a tiny c-mount CCTV lens. I thought this lens would be rather good, but it's not, it's sharp and contrasty in the middle, but the edges are smeary, which ruins things. The bokeh has some swirl and the colours are vivid, but it's just not a very useful lens on a M43 sensor due to those crappy edges.


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[eggplant]

Now this is very curious, because I've been eyeing up my APS film collection to use on A6000. I didn't know the edges were so poor on M4/3! I have high hopes for the Ixus L1 lens..

I'm sure this is probably an easy disassembly, I will take a look at mine later.

EDIT: Maybe the film chamber was curved? Like on a 35mm disposable. That would explain it partially.

EDIT #2: Just got the lens off a Kodak Advantix 1600, 23mm f6.6, holding it to my A6000 I found it surprisingly sharp right to the edges. C-mount might be pushing it on APS-C for vignetting so I will have to figure something else out.

For what it's worth the flange distance was very short, basically the 16mm of E-Mount.

[iangreenhalgh1]

The L1 lens is useless, it won't work on digital at all, I've tried it. It is a 4/4 design with two large very curved outer elements front and back, on digital only a small central portion is any good, the rest becomes a much and there is significant colour shift causing the outer parts of the frame to havea strong purple tint. I think this is due to the incident angle of the light hitting the sensor being too steep.

What will work well on M43 is a lens from a 110 camera, Minolta put some very high quality 4 element 26mm lenses on theirs and the Rollei E110/A110 had a truly wonderful 23mm Tessar.

[eggplant]

[iangreenhalgh1]

That's interesting about the Nuvis, I'm always keen to see and hear how others get on with these madcap DIY projects.

Canon used some quite unusual lens designs on the APS cameras it seems. the M1 lens is a tiny thing, 3/3, with the front element bing rather large and very curved, but the rear element and exit pupil being rather small - a third or less of the diameter of the front element.

I also had a failure with the tiny 4 element lens from the Kodak disc 4000, I was curious to try it as it was state of the art in the 70s with the use of an aspherical element and supposedly capable of a rather high resolution. Sadly, on digital it is a no-go as the rear element has to be almost touching the sensor.

[eggplant]

The Disc cameras are another curious one, although like you say almost touching the film plane, and made for even smaller negative.

But the use of some aspherics was/still is interesting- although now well adopted in C-mount lenses?

Here's the pic. I couldn't find screws to get the front off so I went looking under this panel- still nothing but after seeing curved film plane I put it away.



Id be curious one day to get the Canon f1.9 110 film camera, also the 110 zooms.

I will check if the M1 has a curved plane.

Curious what other remaining film compact lenses are out there - 126 film?

[iangreenhalgh1]

126 cameras generally had 40 or 45mm lenses, the best ones were tessar/xenar types, in fact, they were actual Tessars and Xenars as the best of the 126 cameras were German.

C mount lenses appear to make widespread use of all kinds of aspherics and unusual optical schemes, I took a Computar 12mm apart the other day and it had 4 air spaced elements but the layout was like nothing I'd seen before, a thin front element, then a very think, like 6 or 7mm thick but only 6 or 7mm diameter second element, then a couple more positive fairly thin elements, I doubt you'd find anything ismilar in conventional photographic prime lenses.

One camera worth buying is the ubiquitous Nikon L35AF with it's 35mm lens as it's a Sonnar type and very good indeed. These cameras can be had for next to nothing and the optical block is one piece with the paerture and shutter behind it, so pretty easy to rebarrel.