The Redoubt Reporter will be hosting photo contests for our readers from time to time. We anticipate several
“Drifting in the Fog“ by Joe Kashi.
differently themed photo contests by next summer.
Photos will be judged and winners selected by a three-member panel. After each contest closes, we’ll publish and discuss some of our favorites in the Redoubt Reporter, space permitting. Next spring, if we have enough good entries, we’ll choose some of our favorite submissions from the several contests and invite those photographers to frame and hang their photos at a Redoubt Reporter June 2012 group photo show already scheduled at the Kaladi Brothers café on the Sterling Highway.
Entry rules are simple:
1. Our first theme is “Fall on the Kenai Peninsula,” and submissions must fit this theme. Entrants must be amateur photographers who are residents of the Kenai Peninsula.
2. Photographs can be of any subject fitting the theme, but must have been taken on the Kenai Peninsula or surrounding Cook Inlet area after Aug. 1, 2009.
3. If you submit photographs in which people are recognizable, you must also provide us with their written permission for us to publish any such photographs.
4. Please do not submit portrait photos. Do not submit photographs whose content would not be appropriate for publication in a family newspaper. Do not submit photos of illegal subject matter. All such photos will be deleted immediately without notice to you and at the sole discretion of the editor.
5. The deadline for submitting photos for this contest is 11:59 p.m., Nov. 1, 2011.
6. All submissions must be in high-quality digital format. Submit a total of not more than five JPEG images for this contest by email to redoubtreporterphotos@gmail.com.
7. Photographers must include their name, telephone number, email address, town of residency, and each photo’s date, location and subject matter.
8. Submitted JPEG images should be of the best possible technical quality, though originality, creativity, interesting subject matter, artistic merit and good composition will also be considered.
9. By submitting photos, you agree to our publication of them in the Redoubt Reporter newspaper and on our website. However, you will retain the copyright for all other purposes and your name will be listed if we publish any of your photos.
10. Our decisions about what’s published or selected for exhibition are final and are admittedly subjective. We’ll select photos that appeal to us for whatever reason. The Redoubt Reporter is not required to choose or publish your photographs, nor any at all, for any reason that we deem appropriate.
11. Retain your original digital files of all submitted images. We are not responsible for preserving copies of your digital images.
12. Need more info? Contact us at redoubtreporter@alaska.net or redoubtreporterphotos@gmail.com.
Plugged In: Getting up close with telephoto lenses
By Joe Kashi, for the Redoubt Reporter
Telephoto lenses are usually the first lens separately purchased by most photographers. They’re perfect for capturing Alaska’s wildlife and distant mountains.
I like using telephoto lenses for another reason — they’re often the best way to tightly frame the telling details that result in a striking photo. Optically, telephoto lenses are quite different than the wide-angle lenses that we discussed last week.
Telephoto lenses tend to compress the apparent perspective, resulting in foreground and background objects looking closer together. Distant objects are emphasized and appear relatively larger. Wide-angle lenses have the opposite effect — foreground objects are emphasized and objects in the distance, such as mountains, appear relatively smaller than they appear to the naked eye.
Telephoto lenses should, in principle, be easier to design and construct because they capture a narrow field of view that strikes all parts of the sensor nearly perpendicular. Telephoto lenses usually require fewer individual glass lens elements compared to comparably good wide-angle lenses. Despite those theoretical advantages, it’s sometimes rather difficult to find sharp but affordable telephoto lenses.
The boundary between “normal” and telephoto range lenses depends on the size of the sensor or film area. It’s about 85 mm for regular film cameras, 55 mm for typical digital SLR cameras using an ordinary APS-C sensor, and about 45 mm for Micro Four-Thirds cameras from Olympus and Panasonic.
Photos taken with these lenses have a pleasing perspective that appears correct and comparable to what our eyes see naturally. You might say that our eyes have an 85-mm to 90-mm focal length, so to speak. For this reason, professional portrait photographers use lenses with a focal length that’s equivalent to 85 mm to 105 mm on regular 35-mm film. Such lenses are often termed portrait or short telephoto lenses.
Beyond a focal length whose magnification is equivalent to a 105-mm lens on 35-mm film brings us to true telephoto magnifications. Lenses with focal lengths equivalent to about 105 mm and 150 mm are often termed medium telephoto. In this range, it’s still common for telephoto lenses to be sharp, relatively compact and easy to hold.
By 200 mm, affordable telephoto lenses are rarely tack sharp because it’s more difficult to bring all colors to a single sharp point of focus unless special (read, “expensive”) optical glass is used. Zoom lenses are especially subject to low resolution at their highest magnifications. Wide-angle and normal lenses are less susceptible to this potentially serious problem.
Telephoto lenses differ from wide-angle and normal lenses in some other important ways. Telephoto lenses are much more susceptible to blurred images caused by camera shake, which is magnified by the higher magnification of a telephoto lens. Telephoto lenses with a wide maximum aperture, like f 2.8, tend to be heavy, bulky and too expensive for most of us.
Depth of field for a given lens aperture becomes increasingly narrower as focal length increases. That’s both positive and negative.
On the positive side, using a very wide aperture, such as f 2.8 or f 4, with a telephoto lens allows you to significantly blur the background. That reduces the distraction of background details while making your sharply focused subject really stand out against the background blur.
On the other hand, there are times when you need to both magnify a distant subject while retaining sharp detail in the foreground. Achieving sharpness from foreground to background becomes increasingly difficult as focal length and magnification increase. Often, you’ll need to use a very small lens aperture like f 11 to f 16 to obtain adequate depth of field.
Using such small lens apertures brings its own unique set of problems. You’ll need to use a relatively long shutter speed, which further increases the chance that your images will be blurry unless you use a solid tripod. By f 11 and f 16, resolution starts dropping due to diffraction, an unavoidable basic physical phenomenon.
Single focal length “prime” telephoto lenses usually have the best balance of center and edge sharpness around f 5.6 to f 8. Telephoto zoom lenses usually require a smaller lens aperture, in the range of f 8 to f 11, to achieve good sharpness across the entire image.
It’s easier to make a sharp and compact single focal length “prime” telephoto lens. Despite that, surprisingly, several major camera and optical vendors do not offer a wide range of prime telephoto lenses, only bulkier zoom lenses.
Despite these issues, most photographers with dSLR cameras buy a telephoto lens, more likely sooner than later.
Pentax seems to have the best range of high-quality prime telephoto lenses in the short to medium magnification range, while Canon has a nice line of higher-magnification prime telephoto lenses in its superexpensive L professional series. L series lenses are out of reach for most of us. Nikon, Panasonic and Sony offer very few prime telephoto lenses under their own brands.
As a practical matter, then, most buyers will buy a zoom lens. These are generally affordable and often fairly good but relatively bulky. Often, the most practical zoom lenses have a slightly smaller maximum aperture, on the order of f 3.5, f 4 or f 4.5. Unless you’re a serious wildlife or sports photographer, you probably don’t always need that f 2.8 behemoth.
Unfortunately, the list of good but affordable prime telephoto lenses is too short, and that brings us to zoom telephoto lenses. As with prime lenses, third-party brands are often the best buy, with optical qualities as good or better than brand-name camera makers in some cases.
Some zoom lenses have a constant maximum aperture, such as f 2.8 or f 4, through the entire zoom range. These tend to be heavier, more-expensive lenses intended for serious photographers. Variable aperture lenses may have a relatively wide aperture at their shortest focal lengths but the maximum aperture steadily decreases to f 5.6 or so at the longer focal lengths. Such lenses are usually lighter and much less expensive. Despite the lower cost, their optical quality is often quite good.
Zoom lenses with a wide magnification range, on the order of 18 mm to 200 mm or 270 mm, simply require too many design compromises. They’re usually not sharp enough for serious work but OK for casual travel photography when traveling light.
If you’re interested in finding more information about what to look for when buying lenses, complete with photos and diagram, then set your browser to http://dpreview.com/articles/9162056837/digital-camera-lens-buying-guide.
Local attorney Joe Kashi received his bachelor’s and master’s degrees from MIT and his law degree from Georgetown University. He has published many articles about computer technology, law practice and digital photography in national media since 1990. Many of his technology and photography articles can be accessed through his website, http://www.kashilaw.com.
