Lens Adapters & Bridging Film / Digital Divide

How would you like to add some great glass to your lens kit for either your film SLR, Digital SLR or BOTH???

Many photographers either don't know or forgotten about the incredible variety of great old glass that can still be used (to great effect) on your SLRs, both film & digital. Sure you can buy the latest & greatest lens new but how about getting high image quality (IQ) without spending lots of money (now that is smart). Sure you will give up some features but you have a lot to gain by learning how your camera can operate perfectly fine with older classic lenses. In the process, your understanding of photography will expand, ultimately helping you to become a better photographer.

Excerpted from Do you really need a Digital lens?
"Many digital camera manufacturers see a huge dollar potential for marketing digital lenses. They are out to convince you that lenses they have previously made for film cameras won't give you the same IQ as the new ones they say are optimized for digital cameras.

Take that with a grain of salt and some awareness of the laws of physics. The only lenses that may need some redesign are extreme wide-angle lenses, where light rays hit sensors at acute angles, resulting in light falloff and some image unsharpness at the edges. For 35mm-designed normal and telephoto lenses, it's usually not a critical factor. Here's why.

Lenses are sharpest at their centers and get increasingly soft toward the edges. 35mm camera lenses are designed to cover a larger area than the sizes of most sensors found in current DSLR cameras. When using a lens designed for full-frame 35mm on a DSLR, the softer edges of the lens image extend significantly beyond the smaller picture area of the digital sensor. This results in the digital image being captured by the sweetest spot of the lens--its center. Using good quality film lenses on digital cameras has the potential to produce as good or better images than those made by digital lenses that have been designed with image circles just large enough to cover smaller DSLR sensors.

Digital lenses do have some advantages. Because their circle of coverage is smaller than 35mm, they don't require as much glass and can therefore weigh less. To lighten them even more, most of them have relatively small maximum apertures (you won't find many f/2.0 zooms for digital cameras). Finally, they are the only ballgame in town if you want to use extreme wide-angle lenses, many of which are now appearing.

I've shot images with both film and digital lenses and when large prints are displayed side by side, my professional friends won't even make a guess as to which lenses were used. In fact, some shots made with older screw-mount prime lenses are noticeably sharper than images made under identical conditions with digital zoom lenses, not surprising since prime lenses are much easier to design and manufacture to higher tolerances.

So here's my conclusion. There are good screw-mount lenses and not so good ones. Most, though, were manufactured with optical resolution specifications that surpassed what film could record and will give you perfectly sharp, undistorted, and right-on-color pictures with digital cameras. Their reasonable prices mean you can well afford to try a few and judge for yourself. My guess is you'll be hooked once you see the results from a 400mm lens (600-800mm on your DSLR) that might cost only $60."

How I Got Started--My Pentax Story
One of the great things about Pentax DSLRs is how easy it is to use older manual lenses. Not only is it simple to use Pentax K-mount lenses, you can also use lenses with other mounts by using an adapter. I have successfully used a variety of Nikon F-mount, Canon EF-mount, M-42 screw-mount and Tamron Adaptall-2 lenses on my Pentax K20D.

EBay Store-source of adapters

I just ordered a genuine Pentax M-42 mount adapter so I can use the older M-42 screw-mount lenses from a variety of lens makers. I recently found a Mamiya/Sekor 135mm f2.8, and Auto Rikenon 135mm f2.8 that I am anxious to try. What I am really excited about is the all-time classic Super Takumar 50mm f1.4--talk about fast! Just google and read the raves.

Some M42 lenses have aperture pins sticking out of the back of the lens, and some have funny protrusions. This can easily be taken care of by either glueing the aperture pin in the closed postion with superglue, cutting it off flush at the base, or removing it by opening the back of the lens (really simple and easy). Hint--you may want to look for M-42 lenses with A(uto)/M(anual) switch which allows you to control the aperture. You focus with the lens wide open and then you stop down the lens while watching your meter. Otherwise, the aperture remains wide open unless you glue the pin.

Note on lenses for digital cameras. Because lenses for digital cameras are designed for a sensor smaller than 35mm film (sometimes referred to as "crippled" like the Nikon G and Canon EF-S), they can't be used on a film SLR. However, the so-called "full-frame" DSLRs and their lenses are interchangeable. So if you ever think you may move up to a full-frame DSLR, the pre-digital lenses will work great.

The Nikon F-mount lens systems and the Pentax K-mount systems are the only 35 mm SLR camera systems (apart from the Leica M-mount rangefinder system) that allow a photographer to use a mechanical SLR camera body, a fully automatic SLR camera body, and a DSLR camera body, all utilizing the same lenses. The only aspects of these manufacturers' lenses that have changed are the addition of electronic contacts, auto-focus abilities and, in some cases, the elimination of the external aperture ring for electronic control (i.e., Nikon's 'G-type' auto-Nikkors, which cannot be used on a mechanical SLR camera body).

Canon, Minolta (Sony), Olympus, and other manufacturers have changed lens mounts. Much older Canon film cameras used the FD lens mount, which was discontinued in 1987 in favor of the EF lens mount. Olympus discontinued the OM lens mount for the OM series cameras in favor of the Four Thirds System lens mount. However, due to the size of the Four Thirds mount it is possible to fit legacy SLR lenses from any manufacturer using an adapter, albeit with manual aperture and focus control. Minolta (Sony after 2006) phased out its bayonet-mount MC and MD Rokkor lenses for a modified bayonet mount (supporting auto-focus) in 1985. I just took delivery of a Minolta lens to Four Thirds body adapter--I can't wait to see the results my friend Jay is going to get with his Olympus DSLR using my Fast Prime! Minolta 58mm f1.4 MC Rokkor-PF

For more info on lens adapters see Overview by Lens Maker

Here are a couple of highlights:

Pentax K-mount lenses will work on ALL Pentax bayonet bodies, including auto-focus and digital. For "Program" operation with some models, you will need a Series "A" or later lens.

Canon EOS film and digital SLRs can easily accept almost anything BUT a Canon FD lens with adapters: Nikon, OM, Pentax M42 Screw, and Leica SLR lenses can all be adapted. I personally have had good luck with my FD adapter.

More info on adapters