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Tuesday, March 16, 2010


One of the major advantages of Digital Single Lens Reflex cameras (DSLRs) is the option to use different lenses. Sony DSLRs will of course take all Sony lenses but they also will accept all Minolta AF lenses. In addition, third-party manufacturers such as Sigma and Tamron also make lenses specifically for Sony DSLRs. Here are lenses I use often along with approximately what I paid for them:

Sony 18-70mm f3.5-5.6 zoom(This is the kit lens that came with the camera when I bought it.)
Minolta 50mm f1.7 AF prime lens (bought used $10)
Minolta 75-300mm f4.5-5.6 telephoto zoom(used $80)
Minolta 500mm f8 AF Reflex prime telephoto(used $500)
Tamron 90mm f2.8 prime macro lens(~$650)
Sigma 10-20mm f4-5.6 wide angle zoom lens(~$700)

The photo on the left above was taken yesterday with the Tamron 90mm. That on the right was taken with the Sigma 10-20mm. Both were taken on a brief trip to Mount Douglas Park. The bumblebee was one of a half dozen staggering around fairly close together. I think they had been hibernating and were just waking up. Yesterday's prize-winning photo of the Chinatown Gate was taken with the 18-70mm zoom kit lens that came with the camera when I bought it.

Above are the lenses I use most often. But I also like to use a few other "legacy" lenses originally made for Pentax film cameras. I can use these on my Sony camera with an inexpensive (about $10) adapter.
Those most used are three Super-Takumar prime lenses:
55mm f1.8
105mm f2.8
135mm f3.5

The Super Takumar lenses listed above are completely manual - I have to set the aperture and shutter speed manually for each shot, but they are very sharp lenses that produce richly colored images with lots of contrast so it is worth the trouble if the subject is such that I have time to make the manual adjustments. Another good reason for using them is that they are cheap - less than $10 each. Although they are very good lenses they were designed for the film cameras of 30-40 years ago and most modern photographers don't want to bother with them. I picked up mine in thrift stores over the last year or so.

Why so many different kinds of lenses? I find that every lens really provides a different way of looking at things. A scene shot through a 50mm prime lens appears quite different from the same scene shot through a 10mm lens. Even two lenses of the same focal length made by different manufacturers using different materials may produce widely varying results in terms of color, contrast and clarity. Secondly, different lenses have different operating characteristics - some are very "fast" meaning they can be used when there is not much light or you need a high shutter speed. The auto-focus mechanisms of some are also much more responsive and accurate than others.

Some lenses are quite special-purpose. The 500mm reflex telephoto above is a good example. Of course it can be used for anything that is more than about 25 feet distant but it is particularly useful for photographing birds since the 300mm telephoto zooms that are the most readily available telephoto lenses are generally not quite powerful enough to bring those little creatures as close as needed to get all that beautiful detail. Similarly, my 90mm prime macro lens can be used as close as six inches from the subject making it possible to fill the frame with a single tiny flower.

If you take a lot of photos sooner or later you find yourself in a situation where you are either too far from what you want to focus on or too close. Or your subject is too big or too small for you to capture the way you see it. That's when you start to consider other lenses.

Anyone who can add will have realized that I have spent a great deal more on lenses than I did on my camera, by a factor of three or four. Mostly this has come about because the problems that I had were better resolved by additional lenses rather than by a more expensive camera. Also, I reasoned that (provided I stick with Sony) the lenses I have purchased will be equally useful when I am finally able to upgrade my camera to a more expensive model. If I decide to switch to a Canon or Nikon, I can probably sell my best lenses for good prices since good lenses hold their value well.

They have yet to develop a lens that works the same as or as well as our eyes. Every lens distorts reality in some way. The question is not about whether to distort reality or not but rather how to distort reality. When you choose your lens you are really choosing what kind of distortion you want your images to have.

Tomorrow I will continue this by discussing the software I use to process the images that come from my camera.


Dean Lewis said...

For the old 35mm SLR's, I believe a 80mm lens was considered the closest field of view to what our eye sees, even though the 50mm lens was called 'normal'.

My theory is that our eye is more attracted to images that offer a new perspective from what we are accustomed. This means a wide-angle, fish-eye, macro or telephoto will be more appealing, offering a fresherlook at things.

Any kind of distortion challenges our sensibilities, which is mentally stimulating.

I have a set of bellows that fit my old Pentax for extreme macro if you'd like to try it.

Wayne said...

That's a concise and practical explanation of what I think most photographers come to realize as they get more involved with their hobby/career.

JoJo said...

Very interesting that you got so many different kinds of lenses to achieve better results, rather than upgrade your camera. I never thought of that before.

Benjamin Madison said...

Dean - I've been looking for a set of bellows for a long time - let me know next time you're planning to go down to the Inner Harbour and I'll come down and borrow them for a bit. (I'm assuming they are M42 screw-type mounts?)

Wayne - I'm glad you find it concise - I always think I am too long-winded!

JoJo - I plan to upgrade the camera too eventually but good lenses are the first priority. In practice, every time I get a new lens it's almost like getting a new camera because everything looks so different and I can go around to all my favorite spots and shoot them again.

Dean Lewis said...

Ben, I'm on the coz most sunny afternoons, but the bellows are tucked away in storage, so I have to a little digging to come up with them. I'll let you know when I get my hands on them, maybe next week. And yes, they are thread mount. As I remember, exposure has to be increased when using them and there may be a formula according to how much the magnification is, or in-camera metering alone may address it.