|Extreme Outreach. George Lepp used a Canon EOS-1D Mark IV and a Canon EF 800mm ƒ/5.6 lens with both the EF 2X and EF 1.4X tele-extenders attached (2912mm total with the 1.3X crop magnification) to photograph this bald eagle on the nest. The critical focus was attained by using the Live View function of the camera and a Hoodman Loupe on the camera's LCD. A sturdy Gitzo GT3541 tripod was essential, along with a Really Right Stuff BH-55 ballhead. Exposure was 1⁄1000 sec. at ƒ/16 and ISO 400.|
Reaching For Sharpness
Q I photograph wildlife with a Canon EOS 40D, a 500mm ƒ/4 IS lens and often a 1.4X matched tele-extender. I consistently apply technique to maximize sharpness: I use a tripod with a Wimberley tripod head, sometimes shoot with remote release, and I try to obtain at least 1⁄500 second and ƒ/8, adjusting ISO up to 800, if necessary, to maintain the shutter speed in lower light. Image Stabilization (IS) is on and set to position #1. Despite these efforts, my results are mixed. How can I get more consistent results when using long lenses?
A Working with the big-gun lenses can be very rewarding, but it's a lot of work, and I know a few successful pro wildlife photographers who never use big glass. Everyone who does will have issues with sharpness at one time or another. But I'm always excited by the opportunity to get closer to wildlife subjects without endangering them or myself, as evidenced by the photograph accompanying this column.
In your specific case, you're working with 700mm when you combine the 500mm lens with the 1.4X teleconverter, and effectively at 1120mm when you add the 1.6X crop factor of the 40D's APS-C sensor. That's a lot of magnification.
Four aspects of sharpness are in play whenever you take a photograph of a wildlife subject in the field. The available depth of field (DOF), maintaining precise focus, prohibiting camera movement and mitigating subject movement are all critical variables. The DOF (maximum area of focus, from near to far in the subject) is determined by the focal length and the aperture; the longer the lens and the larger the aperture, the shallower the DOF. So when you're working with a long lens and want to let in more light for a fast shutter speed, you're effectively reducing the area in which you can achieve sharp focus. There's really not a lot you can do about it. DOF is minimal at 700mm using ƒ/8: at 150 feet, you have approximately 48 inches; at ƒ/16, you'll double the DOF from 150 feet to about eight feet. The DOF doubles with the stopping down of two full ƒ-stops. The closer you get to your subject, the more critical focus becomes; at 20 feet, you have only 0.75 inches of DOF! No matter how you look at this, at 700mm you have a very small range in which to apply the second variable, precise focus; that's often the reason for soft results with long lenses.
While we may think we can manually focus through the viewfinder in precisely the right spot 150 to 200 feet away, it's really very difficult. Autofocus can be more precise, but you can easily find yourself working beyond the capability of the 40D's ƒ/5.6 limit for AF. With a 1.4X tele-extender on the 500mm lens, you're capable of autofocus, but only the center focus point would be active. More accurate positioning on stationary subjects can be attained by managing framing and focus in Live View mode on the LCD screen, a feature that's available on your 40D and many other cameras from several manufacturers. Live View can be magnified by 5X or 10X for pinpoint focus. A Hoodman Loupe (www.hoodmanusa.com) will help you to view the LCD screen for critical evaluation, especially during the bright daytime. Attach the loupe to the camera with a Hoodman Cinema Strap or Crane; these free your hands to position and operate the camera.
Camera movement is controlled by a sturdy tripod and secure head. Alert readers may have questioned your use of Image Stabilization (IS) from a tripod. On the 100-400mm telephoto zoom and smaller lenses, IS always should be turned off when shooting from a tripod, but the longer image-stabilized Canon lenses, such as your 500mm, are specifically designed for use with IS on the tripod. Setting #1 should be used for stationary subjects and #2 for panning.
Both camera and subject movement are mitigated by faster shutter speeds. As you mentioned, we now have the option of using higher ISOs to achieve this. For wildlife, and especially bird photography, I sometimes use a projected flash system to put more light on the subject and stop action; combining the flash with ambient light maintains a natural look. Check out the Better Beamer at www.BirdsAsArt.com. When using a tripod, a cable release (remote) can help to minimize camera movement, and a mirror lock-up or Live View (which automatically locks up the mirror) can eliminate internal vibrations as the shutter is activated. If you're following action, I recommend against the cable release because you need to be directly connected to the camera/lens combination on the tripod.
Q I'm taking high-magnification macro images using a Canon EOS 5D Mark II with natural light, and my exposures are fairly long due to light loss. To maximize sharpness, I want to eliminate internal camera vibrations when I release the shutter, and I hear that Live View will accomplish this. Should I be working in Live View mode?
Via the Internet
A When the exposure is longer than 1⁄30 sec., mirror lock-up can improve image sharpness in high-magnification photography (both macro and telephoto). As the shutter is activated in a DSLR camera, the mirror swings up, allowing the light to record on the sensor; but that movement, along with the activation of the first shutter, causes a considerable amount of internal vibration. To mitigate this problem, the photographer can manually lock up the mirror in some DSLRs, or activate Live View mode, which automatically locks up the mirror in cameras that have this capability. This should take care of most internal vibration.
But wait, there's more! Some Canon EOS cameras go beyond mirror lockup. The EOS-1DX, 5D Mark III, 5D Mark II, 7D, 50D and 40D have a Silent Shoot Mode in Live View. Silent Shoot Modes #1 and #2 activate an electronic, rather than a mechanical, first shutter, virtually eliminating vibration within the camera. Look at the article by Charles Krebs at krebsmicro.com/Canon_EFSC/index.html for an interesting discussion of Silent Shoot Modes. Note that the capability comes with a few limitations. You can't use a non-dedicated flash (non Canon) in Silent Shoot Mode, and your camera's continuous shooting function will be slower in Mode #1 and not even possible in Mode #2. To return to normal photography, be sure to disable Silent Shoot Mode.
The Apple Of My i
Q I just ordered the "new" iPad and would like to know how I can justify the purchase as a photographic tool. You've already figured this out, right?
Via the Internet
A You bet! I've been using the iPad to support my photography and teaching since the original release in 2010. It has become an essential tool at several levels. Seriously!
The new iPad is a reasonable size, so it fits well in your camera bag. It's better than a smartphone because the screen is actually large enough to work with, and the new version has excellent resolution. Sometimes I actually leave my laptop computer behind when I travel these days because I can accomplish communications, drafting of articles, and the review and transmittal of small image files with the iPad—and I don't even need to remove it from my carry-on for TSA.
The iPad is a great field tool. I use the weather and astral apps and the compass info to plan landscape, sunrise, sunset and night sky photography. Apps that aid in identifying plants, animals and geological formations, such as mountains, help to keep my file notations accurate; GPS features keep track of where I found the subjects. Some of the reference material resides on the iPad and is always available, whether or not you have an Internet connection.
The iPad is a great teaching tool. When I'm photographing with a Canon EOS 5D Mark III and EOS-1D Mark IV, which have slots for both CF and SD cards, I can program the camera to simultaneously record a RAW capture to the CF card and a smaller JPEG to the SD card. With the iPad Camera Connection Kit, I can read the SD card quickly and check images on the iPad. That means I can set up a lesson, take the shot and show the class a large, high-resolution image within a few seconds. If the camera doesn't have the two-slot feature, it can be set to take both RAW and JPEG images at the same time; connect the camera to the iPad via a USB mini-to-USB regular cable to load the JPEGs onto the iPad using the iPad USB connector that comes in the Connection Kit. Using the same procedures, the iPad replaces a photo viewer or laptop computer for reviewing a day's work in the field, and you even can perform basic post-capture processing with apps that optimize and modify JPEG images.
And, finally, the iPad is an ideal tool to use when shopping for more photographic tools. Your accountant might buy this argument, but it probably won't work on your spouse. Seriously.
For information about upcoming seminars and digital-imaging workshops, visit www.georgelepp.com. If you have any tips or questions, address them to: OUTDOOR PHOTOGRAPHER, Dept. TT, George Lepp, 12121 Wilshire Blvd., Suite 1200, Los Angeles, CA 90025-1176 or online at www.georgelepp.com.