The ultra cheap plastic wonder: Yashica MG-2
Everything about the GM-2 is about cheapness. In most cameras, the lens is the most expensive part, but in this case, I think the flash and the big capacitor, was more expensive than the plastic lens. The lens has no aperture inside, but instead, a piece of plastic with a hole behind the lens that can be selected as "landscape" mode, which probably stops the lens down to about f8-f11. Normal mode, or wide open, it's roughly f5.6 when I compared it to another lens with a constant light source. Also, there is no focus, but that's a feature of being "focus free"! This plastic micro coke bottle was optimized for hyper-focal shooting, no doubt.
The lens is surprisingly easy to take apart, since the plastic body is held together by a few screws, but if you want it apart even quicker, I would recommend a hammer. The flange is very short, too short to be used even with the petite Pentax M42 focus helicoid in the normal fashion. But I can't shoot a "focus free" lens. What fun is it that everything is in focus? I had to improvise. The solution was to sink the lens deeper into the helicoid, closer to the sensor. So I cut out a piece of plastic from the back cover of the film chamber the size slightly smaller than 42mm, drill a hole in the middle for the lens, and stick the whole thing inside the helicoid. Voilà! Focus from very close to infinity. I didn't even bother with glue, just electrical tape to secure the lens to the piece of plastic and the plastic inside the helicoid is held by friction. The total cost is just the lens itself. The only downside? Flatness is not guaranteed, but I am not about to measure it with a micrometer. The whole purpose of this endeavour was to have fun, and expect the unexpected! I will be shooting the lens naked, wide open, going for that artsy LOMO effect :)
The Body Cap Lens
You know, I kinda like how the lens looks on the camera. This is like a DIY Body Cap lens, but with focus. It's much cheaper than the "real" Body Cap lens, even cheaper than a LOMO lens :)
The result is somewhat expected. The lens is more than sufficient for 4x6 inch prints, but it can't satisfy the 24MP sensor in the A7. The centre of the image is reasonably sharp, but the edges fall apart. Contrast is low, especially at infinity. Shooting without a hood, it flares easily. Surprisingly, colour fringing isn't that bad at all, probably due to the nice coating treatment on the lens. Vignetting, however, is quite severe. This could be good or bad depending on your artistic needs. It doesn't bother me; the vignette helps to hide the horrible corners. Aside from the lack of sharpness and mushy corners, the colour is also a bit weird. It's true some lenses render colours very untastefully, and this is one of those. Moreover, this lens is not kind to blown highlights. The roll off is abrupt and unpleasant. When all these negatives are combines, one would wonder, is there anything left to redeem itself?
Bokeh - Not too bad, right?
On the positive note, this lens has a couple of shining spots. One is its much better resolving power at close range than is at infinity. For macro shots, there is quite a bit details. The other nice thing about this lens, is the bokeh. Bokeh for a 34mm f5.6 wide angle lens? Yes, the helicoid makes the close focus possible, and the bokeh is actually not awful most of the time. If the background supports it, the lens can sometimes render pleasing looking bokeh, but only sometimes, and lets lower our standards for a camera/lens created to be the bottom of the rank.
Boats -- My wife does not like this one at all. She said it was too depressing. I am kinda OK with it. Moody.
So what have I got from spending the $6.77 and 60 minutes making it work on the digital camera? I had fun. A few of the pictures actually turned out ok, and, the lens with the helicoid makes a nice body cap for the camera.
Sunset at the Keating Channel