Photo Safaris By Region AFRICA - Masai Mara Wildlife Reserve, Kenya - Namibia—Land of the Himba - Cape Town—Photo Tour for Women ANTARCTICA - Ultimate Antarctica ASIA - Angkor Wat & Bagan - China's Winter Tigers & Giant Pandas - Japan's Winter Wildlife - India—The Palace on Wheels - Snow Monkeys & Giant Pandas - Essential China—Iconic Landmarks & Landscapes - Great Rivers & Mountains of China & Tibet - Mongolia—The Golden Eagle Festival EUROPE - Britain's Winter Birdlife - Eclectic Holland - Wildlife of Hungary & Transylvania - Transylvania—Romania of Myth & Legend - Venice - Tuscany - Turkey—Continental Crossroads - Provence - Spitsbergen—The Pack Ice Voyage - Ultimate Puffins - Albania, Macedonia & Montenegro NORTH AMERICA - Ultimate Wolves - Ultimate Yellowstone - Horses & Icons of the Wild West in Winter - Nature & Digital Photo Seminars with John Shaw - Monument Valley & Slot Canyons - Great Smoky Mountains - Grand Canyon at Havasu Falls - Predatory Animals of North America - Action & Adventure Sports - Humpback Whales of Alaska's Inside Passage - Glacier National Park Field Workshop - Denali National Park in Autumn - Brown Bears of Katmai National Park in Autumn - South Dakota Wildlife—Bison Roundup & Mount Rushmore - World's Best Raptor Shoot - Nova Scotia—Photo Tour for Women PACIFICA - Papua New Guinea SOUTH & CENTRAL AMERICA - Patagonia' Mountain Landscapes - Baja California—Whales, Wildlife & Wilderness - Easter Island & Machu Picchu - Mexico's Colonial Heartland Photo Safaris By Date JANUARY - Ultimate Antarctica - Ultimate Wolves - Ultimate Yellowstone - Angkor Wat & Bagan - Britain's Winter Birdlife FEBRUARY - China's Winter Tigers & Giant Pandas - Horses & Icons of the Wild West in Winter - Nature & Digital Photo Seminars with John Shaw - Japan's Winter Wildlife MARCH - Baja California—Whales, Wildlife & Wilderness - Monument Valley & Slot Canyons - India—The Palace on Wheels APRIL - Nature & Digital Photo Seminar with John Shaw - Patagonia' Mountain Landscapes - Eclectic Holland - Great Smoky Mountains - Wildlife of Hungary & Transylvania MAY - Grand Canyon at Havasu Falls - Transylvania—Romania of Myth & Legend - Venice - Tuscany - Turkey—Continental Crossroads - Snow Monkeys & Giant Pandas JUNE - Predatory Animals of North America in Spring - Action & Adventure Sports - Essential China—Iconic Landmarks & Landscapes - Provence JULY - Spitsbergen—The Pack Ice Voyage - Ultimate Puffins AUGUST - Humpback Whales of Alaska's Inside Passage - Glacier National Park Field Workshop - Denali National Park in Autumn SEPTEMBER - Masai Mara Wildlife Reserve, Kenya - Brown Bears of Katmai National Park in Autumn - Great Rivers & Mountains of China & Tibet - Albania, Macedonia & Montenegro - Namibia—Land of the Himba - Mongolia—The Golden Eagle Festival - Predatory Animals of North America in Autumn - South Dakota Wildlife—Bison Roundup & Mount Rushmore OCTOBER - Papua New Guinea - World's Best Raptor Shoot - Nova Scotia—Photo Tour for Women - Nature & Digital Photo Seminars with John Shaw - Easter Island & Machu Picchu - Mexico's Colonial Heartland NOVEMBER - Wet & Wild—Andean Condors and Iquazú Falls DECEMBER - No tours scheduled for December 2008 JANUARY 2009 - Cape Town—Photo Tour for Women

		By John Shaw John Shaw Nature & Digital Photography Workshops Click here for locations and dates Mexico's Colonial Heartland March 17–24, 2007 Horses and Icons of the Wild West August 26–September 1, 2007 Masai Mara Wildlife Reserve, Kenya September 7–21, 2007 Australia Wildlife November 1–20, 2007 Both Nikon and Canon now offer perspective control lenses (PC lenses) with both tilt and shift (T/S) movements. I've received some questions about these lenses, mainly along the lines of "Are they worth their price?" and "Do I need one for professional work?" I've also come to learn that there are a number of misconceptions about what these lenses actually do. Several readers have referred to T/S lenses as "increasing depth of field," which is not true at all. Let's go over the pros and cons of purchasing one of these lenses; but first let me explain exactly what they do. Here is Nikon's 85mm PC lens mounted on an F100 camera body, set at the maximum amount of tilt. Canon's 90mm T/S lens is very similar in design and function. Most lenses for 35mm cameras are designed so that the plane on which you focus is always parallel to the plane of the film. This is the normal, standard setup of 99% of all lenses, including your regular fixed focal length 20mm lens, your 80-200mm zoom lens, and your 600mm. The lens mounts onto the camera so that it sticks out at a right angle to the body. The front of the lens and the back of the camera always stay in the same relative positions, parallel to each other. When you focus the lens, you are actually focusing on one plane of your subject, which is parallel to the film, regardless of whether or not this is the part of your subject that you're most interested in photographing. In order to make things on either side of this focused plane appear sharp you must stop the lens down to smaller apertures to gain depth of field. Tilt lenses change this relationship somewhat. These are lenses which allow the user to articulate the optics or, in other words, to point the lens in a This photo was taken at f8 with a 105mm tilting lens (Nikon's 105mm short mount on a Nikon PB-4 bellows, the forerunner of the Nikon 85mm PC). Here no tilts were used, and the furthest film box is out of focus. slightly different direction than the camera body. With a T/S lens you can change the relationship between the lens and the film plane. Let me define some terms here (hang on, this is an introduction to using a view camera). Imagine a camera where you can move the entire lens assembly while keeping the film plane stationary. If you keep the lens pointing straight away from the camera body, but slide it from side to side or up and down, you have these movements: shift (left or right movement), rise (upward movement), and fall (downward movement). All these are often lumped under the shift name regardless of the direction. Shift is a movement that all PC lenses have, going back to the earliest PC lenses from any manufacturer. But the lens movement we nature photographers are more interested in using is not shift, but another one. If you pivot the lens so that it aims off to the left or right you have swing. You can swing a lens to the left or swing it to the right. (Sounds like a square dance here, doesn't it?) Do this same movement in a vertical position, rotate swing 90 degrees that Same setup as the previous shot, except that I've tilted the lens to bring in the entire subject plane. I'm still working at f8, but now all the boxes are in focus. is, and here comes tilt, the major reason nature photographers might want to consider an articulating lens. Since the lens pivots you can tilt it upwards or tilt it downwards. Swings and tilts, the same movements but in different axes, are what you'll use most with these lenses. Suppose you want to photograph a perfectly flat field of wildflowers from a normal eye-level camera position. With standard equipment you aim the camera down at a slight angle to compose the image, then stop down as far as necessary to achieve front to rear sharpness. Well, in truth there is one and only one area in absolute sharp focus and that is the plane on which you've focused the lens. When you stop down a lens you are making more of the image, some of either side of the plane you've focused on, appear reasonably sharp. There's one plane of true sharp focus, then an area on either side which is "acceptably sharp," and another area both in the front and in the rear where the image is totally out of focus. Depth of field is simply that area on either side of the focused plane that appears to be in "good enough" focus. Let me make a statement right here: there is no lens of any sort that will give you more depth of field. Depth of field depends on the aperture you use and the image size, and only these two things. Tilt/shift lenses do not magically yield more depth of field. What they do is allow you to change the location where the plane of focus falls. You can reposition that plane of focus...and that's the magic of the tilt movement. Let's go back to that field of wildflowers again, with the camera in the exact same position. This time, using a T/S lens, you can pull the entire field (assuming it's perfectly flat) into focus while keeping the lens wide open. Here's an illustration of the Scheimpflug principle. Three imaginary planes — that of the film, the subject, and the lens — all meet in a common intersection. Consequently the lens is now focused on the subject plane. You stop down for objects on either side of this plane. There's a view camera concept with the great name of the Scheimpflug principle which says to consider three imaginary planes all extending outwards: the plane of the film, the plane of the lens, and the plane of the subject. The film plane and the subject plane intersect, and if you articulate the lens so that its plane also falls at this same intersection (all three imaginary planes meet in a common intersection) you have now moved where the lens is focused onto the subject plane. That's harder to say than to visualize. Here's how you do this in the field. Look through the viewfinder and focus on your foreground; then slowly...very slowly...tilt the lens towards the subject plane. You'll see the image come into better focus. When it appears best, stop tilting and touch up the focus. You'll probably have to do this combination of movements a couple of times. Work slowly and methodically, and you'll end up having repositioned the plane where you have focused to coincide with your subject. Now stop down to pull in anything on either side of this plane. Like always, you use depth of field to sharpen up any object lying on either side of where you focus. For example, in that field of flowers there are some tall ones and some short ones, and of course the ground is not perfectly flat. You'll need to stop down to sharpen up these variations. But since you're no longer trying to bring the This photo was taken in midsummer at Colorado's Molas Divide in the San Juan mountains, just before an approaching storm. In order to fight the ever-present breeze, I used a Canon 24mm T/S lens. The scale of the picture is deceptive as the flowers are quite small; I'm only about 8 inches from the nearest blossoms. At f8 I'm covering from the foreground to the far mountains, from 8 inches to about 8 miles. whole field into focus, but just a small part, you will go down just a few stops instead of using the smallest aperture. You might end up shooting at 8 instead of 22 — and that's a big difference in shutter speeds, particularly if you're fighting the wind. And fighting the wind is one major reason to use the tilt movement with a 35mm camera. Large format shooters have no choice, they have to use lens movements. Why? All lenses of the same focal length, for all film formats, have the same depth of field at the same aperture. Think about that. A 90mm lens on a Canon, a 90mm lens on a Pentax 67, and a 90mm lens on a 4x5 camera all yield the exact same amount of depth of field at any aperture. How much depth of field is there with a 90mm lens used at 16 and focused at 30 feet? Not much. But with 35mm cameras a 90mm is a short telephoto, while with a 4x5 it's a wide angle. In fact, with 4x5 it's roughly the equivalent view of a 28mm on a Nikon or Canon. But that wide angle on the 4x5 camera has the same depth of field at any - stop as a 90mm on the Nikon or Canon. No one would use large format cameras for field photography if they could not also use lens movements, since depth of field is so limited with that film format. Thirty-five millimetre lenses actually offer more depth of field since you can use shorter equivalent focal lengths, while T/S movements allow faster shutter speeds and prime apertures to be used. So are these tilt/shift lenses worth purchasing? That all depends on (a) how much money is burning a hole in your pocket, and (b) how often you truly need such a lens. T/S lenses are not inexpensive; far from it, each one is well over $1000. Canon offers three for the EOS system: a 24mm 3.5, a 45mm 2.8, and a 90mm 2.8. Nikon now has an 85mm 2.8 and there's talk about a shorter focal length coming out this fall. Remember that in the un-tilted mode these lenses perform exactly like any lens of that focal length. For example, if you don't use the tilt movement there is no difference whatsoever between a scene taken with the 24mm T/S Canon and one shot with any other 24mm lens (or a zoom set at I was photographing at Great Sand Dunes National Monument, using a Canon 45mm T/S lens. I wanted the closest sand ripples in focus as well as the far Sangre de Cristo Range. 24mm). A 24mm is a 24mm is a 24mm however you get it. If you already own a 24mm, purchasing a 24mm T/S means you're duplicating a focal length. So do you need tilts in your photography? If you're trying to do 35mm view camera pictures, and the appropriate focal length is what you need, then you might consider getting one. But...with small reproductions you will not see any difference in your pictures. Print your image 4 x 6 inches, and you can't tell if you used a tilt movement or not. Go to big prints, or large images from a printing press, and you might want to consider spending all that cash if you do lots and lots of landscape work. If you're primarily interested in wildlife, I would think long and hard before purchasing a tilt lens. Spend the money on another wildlife trip. T/S lenses are also a little fussy to use, particularly the new Nikon version. At best they are slow to operate, absolutely demand tripod use, and must be used with the camera in the manual exposure mode. With both the Nikon and Canon lenses you should meter with the lens in the non-tilted position as any tilt movement, or shift for that matter, will throw off the meter reading with most current camera bodies. (Not true if you're still using an old Nikon F3 or an A2 EOS.) You'll discover this metering discrepancy is most pronounced when taking horizontal compositions. As you tilt in a horizontal orientation, you'll see the meter readout immediately start to show a drop in light. This is caused by the angular relationship between the lens axis and the camera's mirror, not by any actual decrease in light hitting the film. With vertical work, you can tilt up to about 5 degrees and still get a correct reading although I would urge you to meter with no movements used at all. Here's the procedure: compose your final picture, then read off the amount of tilt you're using on the degree scale on the lens. Reset the lens back to the zero position, meter and set your exposure — don't touch that focusing ring while you're doing this — then retilt back to the correct mark and make your exposure. Nikon 85mm PC owners, you have to take a few more steps. You will not get correct exposure values if you meter with the lens stopped down or, according to my tests but contrary to Nikon's instructions, with the lens absolutely wide open. I've had my best results metering with the lens set at 4, one stop down from wide open. Make sure you have the aperture plunger depressed so that the lens is actually stopped down. Now count off stops to the aperture you want to use, and adjust the shutter speed this same number of stops. Tilt/shift lenses are certainly not for everyone. They are special purpose, costly lenses but they give the 35mm photographer the closest approach there is to a 35mm view camera. So my final question is simple. Is that your type of photography? Questions and Answers John Shaw will answer readers' questions in his bi-monthly column regarding equipment and photography techniques in the field. He can be contacted via e-mail at this address: johnshaw@photosafaris.com. Due to the anticipated volume of inquiries John cannot answer questions individually, but he will cover a wide range of topics within each column. The new columns will come on-line May 1, July 1 and September 1. We look forward to hearing from you.

	Joseph Van Os Photo Safaris, Inc. P.O. Box 655, Vashon Island, Washington USA 98070 Phone: (206) 463-5383   Fax: (206) 463-5484    Email: info@photosafaris.com Copyright © 2008, Joseph Van Os Photo Safaris, Inc.