Redoubt Reporter Summer photo contest
It’s time for the third Redoubt Reporter, reader-submitted photo contest.
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. Some of the selected photographers will be invited to frame and hang their photos at a Redoubt Reporter June 2013 group photo show scheduled at the Sterling Highway Kaladi Brothers coffee shop.
The deadline to enter is 11:59 p.m. Aug. 31, 2012. All submissions must be in high-quality digital format. Submit no more than five JPEG images by email to firstname.lastname@example.org.
1. Our theme is “Summer on the Kenai” and submissions must fit this theme. Summer is always interesting here in Alaska, with a vast number of photos taken. We encourage you to submit photos of what you observed over the summer. As always, we prefer photos that are fresh and unique. Frequently photographed subjects, like combat fishing, should be avoided.
2. Entrants must be amateur photographers who are residents of the central Kenai Peninsula.
3. Photographs can be of any subject fitting the theme but must have been taken of the Kenai Peninsula on or after June 1, 2012.
4. If you submit photographs in which people are recognizable, you must also provide us with their permission for us to publish any such photographs.
5. 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.
6. Photographers must include their name, telephone number, email address, town of residency and each photo’s date, location and description of subject matter.
7. Submitted JPEG images should be of the best possible technical quality. Good technique and technical quality are important, but originality, creativity, interesting subject matter, artistic merit and good composition are even more important.
8. By submitting photos, you agree to our publication of them in the Redoubt Reporter newspaper and on our website. The Redoubt Reporter will have the right of first publication of your photos. However, you will retain the copyright for all other purposes and your name will be listed if we publish any of your photos.
9. Our decisions about what’s published or selected for exhibition are final and are admittedly subjective. Space is limited, and the judging panel and editor reserve the right to choose photos at their discretion.
10. Retain your original digital files of all submitted images. We are not responsible for preserving copies of your digital images.
By Joe Kashi, for the Redoubt Reporter
Proper exposure and accurate focus are typically the most important technical factors when making any photograph. You’ll make better exposures if you understand how your digital camera’s sensor responds to light. That’s true even if you always shoot on “Auto.”
I like to think of good exposure as the correct amount of an image’s light on the dynamic range of your digital sensor. Dynamic range is the difference between the brightest white that you can capture without completely losing highlight detail, and the darkest shadow that you can capture without completely losing shadow detail.
Dynamic range is one of the most important attributes of any digital imaging sensor. When your camera’s dynamic range is high, then you have a great deal more flexibility and versatility when taking photos. You’ll also be able to fix exposure errors more readily when your camera’s dynamic range is high. Although special, “High-Dynamic Range” techniques and software that cope with extremely contrasty situations are rather popular at the moment, a camera with really high dynamic range, such as the Pentax K-5, reduces the need for special techniques like that.
Dynamic range is primarily controlled by sensor size and design. Large sensors, such as those used in APS-C and full-frame digital SLR cameras, tend to have higher dynamic range, although that’s not an absolute. Sensors made by Sony also tend to have higher dynamic range. Again, that’s not an absolute, because how a camera maker processes the data from a sensor also has a major effect upon dynamic range. Sony sensors, for example, are used in most Nikon, Pentax and Sony cameras.
Yet there’s a noticeable difference in dynamic range when a virtually identical sensor is implemented by various manufacturers. Let’s take Sony’s justly renowned 16-megapixel sensor used in the Nikon D7000, Pentax’s K-5 and K30d, and Sony’s A580 and NEX-5N cameras. Given that the sensors are virtually identical, one would expect virtually identical dynamic range and noise values, but that’s not the case. Pentax’s high-end K-5 has an excellent dynamic range of over 14 exposure values. One EV value is comparable to a traditional, one-f/stop change.
Nikon’s comparable D7000 does nearly as well. When the same, excellent, 16-megapixel Sony sensor is used in Pentax’s new upper-entry-level K30d dSLR, dynamic range, though still excellent, is about one EV lower than its K-5 big brother. Sony cameras using the same Sony sensor have even lower measured dynamic ranges.
How does the dynamic range of current cameras stack up? The data below is reproduced from the excellent http://www.dxomark.com website, the most generally accepted sensor measurements.
A 12 EV dynamic range is very good while a 13 EV or higher range is excellent. Ten EV and above are quite usable. Remember that the best, silver-based photography was hard-pressed to achieve a dynamic range of nine EV in the final print.
Model DR in EV
Full-frame sensor cameras
Canon 5D III 11.7
Nikon D800E 14.3
Nikon D700 11.2
Nikon D3X 13.7
Nikon D4 13.1
APS-C sensor cameras
Sony SLT A77 13.2
Pentax K-5 14.1
Pentax K-01 12.9
Sony NEX-7 13.4
Sony NEX-5N 12.7
Canon T3i 11.5
Canon 60D 11.5
Canon 7D 11.7
Nikon D3100 11.3
Nikon D3200 13.2
Nikon D7000 13.9
Mirrorless compact-system cameras
Panasonic GX1 10.6
Nikon 1 J1 11.0
Olympus E-PL3 10.3
Panasonic GF3 10.1
Canon G1X 10.8
Canon S95 11.3
Canon G12 11.2
Canon S100 11.6
Fujifilm X10 11.3
Figure 1 illustrates dynamic range. Again, the large-sensor Pentax dSLR does the best but the Canon S90 premium, when used at its base ISO (80) is pretty close, with an 11-stop (EV) dynamic range, that’s really quite excellent for its class. A change of one EV is the same as a one-stop (2x) difference.
At base ISO, the S90’s dynamic range is actually one stop (EV) better than the much larger sensor Olympus E-PL1. This is probably the result of Canon’s good electronic design compared to the Panasonic sensor used in the most Olympus cameras until the new OM-D, which uses a very good Sony sensor. However, all three cameras lose dynamic range as ISO sensitivities are increased, another reason to shoot at base ISO whenever possible. Decreased dynamic range results in more troublesome and inconsistent exposure and loss of highlight and shadow detail.
Because the dynamic range of the Pentax starts higher, it remains better than the smaller-sensor cameras as ISO increases. That’s another reason why good, large-sensor dSLR cameras like the Pentax work much better under low-light conditions.
Figures 2, 3 and 4 illustrate exposure compared to a camera’s dynamic range. Classically, a good photograph was supposed to have a bit of pure black, a bit of pure white and a smooth transition of tones and color shades in between. Of course, an accomplished photographer will not always adhere to this rule of thumb if he or she wants a different result.
Figure 2 illustrates that “classic” exposure set against a camera whose dynamic range is set to “linear,” where each increase in the amount of light results in a proportionate increase in the brightness of that area. This “classic” exposure uses essentially all of the camera’s dynamic range to span dark shadows through bright highlights, showing detail in each area.
Figure 3 shows an underexposed photograph. Too little light reaches the sensor and, as a result, no area has enough light to show a bright highlight. Much of the image is below the light level that would show any detail in the shadow areas. The image looks too dark and large areas are black voids without detail. That’s fine if you want a stark or abstract graphic look, but doing so should be you prior conscious decision, not a mistaken exposure. Dynamic range is compressed toward the dark tones.
Figure 4 is the reverse, an overexposed image. Too much light reaches the sensor. The image looks too bright and washed out. Brighter areas are beyond the light levels that show any highlight detail and instead show up as featureless areas of pure white. Dynamic range has been compressed toward the bright tones.
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.