M42 Standard Lens Comparison
Last summer I acquired a K-mount to M42 adapter for my Pentax K100D DSLR. Until now I've done very little shooting with the various M42 standard lenses that I've acquired over the years. I thought it would be fun to compare the M42 lenses against each other and against the Pentax kit lens.
My comparison is hardly scientific, but I believe it is precise enough to say whether there is a significant difference in lens performance under the conditions I created. My test conditions are simple enough. Photograph a static image under incandescent light using comparable focus, aperture, and shutter speed. I set a custom white balance on my DSLR to obtain more realistic color. ISO was set to 200. The only real problem I encountered in testing was obtaining similar focus with all of these manual focus lenses. In the end, the focus was close enough for my purposes. If the focus was slightly different between shots, I simply concentrated on comparing the in-focus portion of the photos. I didn't test under a variety of conditions. That will probably come later. I'd like to test for resistance to flare and purple fringing.
Here's a chart of the tests I conducted:
Photo Lens Aperture Shutter Length Frame Number Length ============================================================================== 1 Auto Sears 55mm 1:1.4 f1.4 1/40 55 #100-8439 2 Auto Sears 55mm 1:1.4 f4 1/15 55 #100-8440 3 Auto Sears 55mm 1:1.4 f8 1/4 55 #100-8441 4 Sears Auto EE 50mm 1:1.4 f1.4 1/40 50 #100-8442 5 Sears Auto EE 50mm 1:1.4 f4 1/15 50 None 6 Sears Auto EE 50mm 1:1.4 f8 1/4 50 None 7 Cosina Cosinon Auto 50mm 1:1.8 f1.8 1/30 50 #100-8446 8 Cosina Cosinon Auto 50mm 1:1.8 f4 1/8 50 #100-8448 9 Cosina Cosinon Auto 50mm 1:1.8 f8 0.4 50 #100-8451 10 Pentax DA 1:3.5-5.6 18-55mm AL f5.6 1/6 50 #100-8454 11 Pentax DA 1:3.5-5.6 18-55mm AL f8 0.3 55 #100-8455
Click on the link below to compare images.
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| M42 50mm Lens Test |
After carefully comparing each image, the conclusion is fairly simple. Any of these old M42 lenses is great for low light shooting on a DSLR such as a Pentax K100D. The Auto Sears 55/1.4 is a tiny bit soft at f1.4, but it's difficult to know for sure given that the depth of field is so shallow at f1.4. Regardless, the images were very sharp by f4 and beyond. If you had to pin me down, the Cosina photos where very good at all apertures. The Pentax kit zoom compared quite well to the primes, maybe a little bit softer, but very good nonetheless.
When would you want to use a fast M42 prime? Well, you certainly wouldn't use it for action or following your kids, but it's perfect for most anything else that doesn't require fast focusing. Setting exposure on the K100D is as simple as pushing on a button which stops down the lens and sets the shutter speed. In addition, you get all the benefits of in-body shake reduction. The other nice thing about old M42 prime lenses is that they are cheap. Modern fast AF lenses are not cheap, but these M42 lenses with speeds as fast as f1.4 cost next to nothing. If I recall correctly none of my lenses cost more than $10. In conclusion, I've got to say that all of these old M42 standard prime lenses were a lot of fun and very useful. I hope to test them in more challenging conditions in the near future. In addition, I will be testing a few 135mm lenses.
Fuji Discovery 312 Point and Shoot
I could probably review old point and shoot cameras forever. Local thrift stores sell them for less than $5 each. Canon, Minolta, Konica, Pentax, Olympus, Ricoh, Argus.... You name it, you can find it cheap. I recently found a Fuji Discovery 312 with an EBC Fujinon lens and bought it for $1.99. I'm a big fan of EBC Fujinon lenses based on some shooting with a Fujica SLR+EBC Fujinon lens. While I can't be sure that a Fujinon in a point and shoot is the same as a Fujinon for an SLR, I was hopeful nonetheless.
The build of the Fuji 312 is nothing special. In fact, it's kind of bulky and cumbersome. Handling while shooting is nothing special. There's a significant delay from pushing the shutter release button to the time that the shutter is actually released. I wouldn't use this camera for action shots. The zoom control is fairly slow and startup/shutdown is leisurely as well. As far as tech specs go, the 312 is fairly underpowered. The top shutter speed is 1/250s and there's no exposure compensation. The zoom is decent, ranging from 38mm to 120mm.
Now, let's get down to the most important features. Image quality and exposure accuracy. I've got to hand it to Fuji, they did a great job with the lens and exposure meter. I shot a roll in overcast snowy conditions and the Fuji 312 did a great job in not being fooled by the white snow. In addition, the images were sharp and showed good detail. You would have a difficult time distinguishing the photos from this camera from photos taken with an SLR. My next photo test consisted of a few indoor flash shots. Again, the Fuji 312 did a nice job of not over-exposing and giving as natural a look as possible with an on-camera flash. I give the Discovery 312 very high marks in image quality. It's too bad Fuji didn't surround the lens with a better body.
Here are a couple of sample photos using ordinary Kodak Gold 200 processed at Walgreens.
Nikon FG
The Nikon FG is a small SLR introduced in the early 80's. Although I no longer have my Pentax ME Super, the FG appears to be very similar in size and function. That's a good thing. It makes you wonder if Nikon designers may have borrowed the design a bit. The FG is a simple SLR by today's standard, it offers program, aperture priority, and manual metering modes. In addition it offers exposure compensation via a +- 2 stop dial.
How is the FG in actual use? Very nice actually. I was surprised at the difference in size and weight after using an N90 for the past month. The FG is much easier to carry around and doesn't get in your way because of the bulk.
Despite the crazy snow we've had here in the last month, I was able to get out and snap a few shots. I was using a Nikkor 50mm f1.8 AIS. It's been a while since I've used a small fixed focal length lens. I was pleasantly reminded of the simplicity of using a manual focus lens where I don't have to worry about a bulky zoom. The center weighted metering of the FG makes it a simple matter to know if bright or light parts of the scene are influencing the metering and the exposure compensation function makes it a simple matter to adjust accordingly. Nice.
The image quality of the resulting photos was great. As expected, the Nikkor 50mm AIS produced sharp and color results. The FG is a great match for this lens.
There's not a lot more to say about the Nikon FG. It's a great little SLR, especially suited for light traveling with a couple small fixed focal length manual focus lenses.