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QUESTIONS 1. How much more or less light is there in a one stop change? 2. What is a rule of thumb for the slowest shutter speed to use to get a sharp photo when handholding a camera? How about when you're using an 80-200mm zoom lens? 3. What does "TTL" mean? Name two photographic functions that are "TTL." 4. How many quick release plates should you own? 5. What is a fast lens? Are all lenses of the same aperture fast ones? 6. If Ektachrome 100 is properly exposed at 1/125 second at f/8, what is the correct exposure in the same light and shutter speed for (a) Fuji Provia 400, (b) Kodachrome 25, and (c) Velvia? 7. How did you arrive at the answers in Question #6? 8. If you're 12 feet from your subject with a 300mm lens, how far back must you be with a 500mm lens to get the same image size? 9. At what direction does a polarizer show the most effect? 10. How much does using a polarizer change the exposure from that without the filter? 11. What is an extension tube? And what is its purpose? 12. If you want to use "fill flash," what are you doing? 13. Is depth of field always parallel to the film plane? 14. What does the "automatic" mode on current flash units do? 15. If you "pull" film, what have you done? What's the most common reason you would have to "pull" film? 16. If a lens is marked as "f/4 - /5.6" what does that mean? 17. When should you use a warming filter? 18. What effect does using a slow shutter speed have on subject rendition? 19. What is depth of field? 20. What effect does focal length have on depth of field? Do wide-angle lenses have more depth of field than telephoto lenses? 21. Besides image sharpness, name one reason to use a tripod. 22. How many shutter speed jumps are there as you change from an 8 second exposure to 1/500 second? 23. Do you have to meter at the aperture you want to use? 24. Does a tilt lens give you more depth of field? 25. How do you know if you need to use a graduated neutral density filter? 26. What's the difference between a spot meter, a center-weighted meter, and a matrix or evaluative one? 27. Why should you not put unprocessed film in your luggage? 28. What's the difference between one of Nikon's "micro" lenses and one of Canon's "macro" lenses? 29. When should you not use a "remote release" ("cable release" to those of you who remember such things)? 30. If you see dark specks in your viewfinder, what most likely are these things? Will they ruin your pictures? 31. You want to use Velvia film for a photograph of a rushing stream on an overcast day with the entire scene in focus. If you do this what will happen? If you don't want it to happen, what can you do? 32. What is vignetting? What are some common causes of it? 33. What's the difference between these two combinations: lens + extension tube + teleconverter + camera body, ...or... lens + teleconverter + extension tube + camera body. 34. Name at least three reasons to use a lens hood. 35. Why would you not want to shoot on programmed exposure mode? 36. You want to use the very fastest shutter speed possible with an autoexposure mode. To which mode do you set your camera? 37. You need to use autofocus to stop wildlife action. What exposure modes and metering patterns must you use? 38. As a general rule, the subject's implied path of action should go which direction in a photo? 39. Your camera does not have a two second shutter speed. You're photographing an arrangement of brightly colored rocks in even light, and need this shutter speed for the aperture you've selected. What do you do? 40. You're photographing your friend indoors with the light from one 100-watt light bulb. You need two more stops of depth of field but cannot change film. What are some solutions? 41. What are four possible ways, depending on your camera, that you can tell if there is film in the camera?
48. What film should you use to photograph Bigfoot? 49. Which of the following questions has John Shaw been asked? A. How far does that lens see? B. What sort of socks should a professional nature photographer wear? C. How long is a one-minute exposure? D. Why don't Canons have f-stops? E. Does a "sunny-16" exposure setting work at night? F. All of the above. 50. Have you read your camera instruction manual? ANSWERS 1. How much more or less light is there in a one stop change? A: One stop is either double the amount of light, or half the amount. You can do this with either shutter speed or aperture selection. 2. What is a rule of thumb for the slowest shutter speed to use to get a sharp photo when handholding a camera? How about when you're using an 80-200mm zoom lens? A: For sharp photos, you need at least the reciprocal of the focal length in use as your shutter speed, for example 1/50 second for a 50mm lens. If you're working with an 80-200mm zoom you need at least 1/80 second at the short end of the zoom, and 1/200 second at the long. Remember that these are minimum shutter speeds. 3. What does "TTL" mean? Name two photographic functions that are "TTL." A: TTL stands for Through The Lens. Built-in camera meters read TTL, as do some flash units for both total flash and for fill-flash. 4. How many quick release plates should you own? A: You should have a quick release plate for every lens and every camera body you own. Having fewer — where you must remove a plate to mount it to another piece of equipment — means you're using a slow release system. 5. What is a fast lens? Are all lenses of the same aperture fast ones? A: A fast lens is one with a large maximum aperture which admits a lot of light when used wide open, but speed is relative to focal length. What would be fast for one focal length may not be for another. For example, the fastest 400mm lens made is f/2.8 wide open. But this is a pretty standard speed for a 24mm lens. A fast 24mm would be an f/1.4 lens wide open. 6. If Ektachrome 100 is properly exposed at 1/125 second at f/8, what is the correct exposure in the same light and shutter speed for (a) Fuji Provia 400, (b) Kodachrome 25, and (c) Velvia? A: Fuji Provia 400 = 1/125 at f/16 Kodachrome 25 = 1/125 at f/4 Velvia = 1/125 at f/5.6 if you rate it at ISO 50, 1/125 at f/5 if you rate it at ISO 40. 7. How did you arrive at the answers in Question #6? A: By counting the difference in stops between their ISO film speed ratings, then changing the exposure values by this same number of stops. 8. If you're 12 feet from your subject with a 300mm lens, how far back must you be with a 500mm lens to get the same image size? A: Working distance is proportional to focal length so 12 feet with a 300mm lens equals 20 feet with a 500mm. 9. At what direction does a polarizer show the most effect? A: When used at a right angle to the sun's axis. 10. How much does using a polarizer change the exposure from that without the filter? A: A polarizer cuts the light reaching the film between one stop — just putting it on the lens but seeing no visual results as you turn it — and two stops maximum. Your TTL meter takes this into account. 11. What is an extension tube? And what is its purpose? A: An extension tube is a spacer placed between the lens and camera body. It contains no optics. It allows that lens to focus closer, although you lose infinity focus until the tube is removed. 12. If you want to use "fill flash," what are you doing? A: Fill flash is light from a flash added to the natural light exposure. It lightens the shadow areas, "filling" them in. 13. Is depth of field always parallel to the film plane? A: Depth of field always falls on either side of the plane of focus. It is parallel to the film plane with the regular lenses most used on 35mm cameras. If you can reposition the plane of focus, as with a tilt lens or with a view camera, depth of field is still on either side of the plane of focus but no longer parallel to the film plane. 14. What does the "automatic" mode on current flash units do? A: The automatic mode on flash units is a non-TTL mode. A small sensor on the flash unit reads the light bouncing back to it, then quenches the flash output when a specific light level is reached. You can use only a few selected f-stops, and the auto mode does not take into account filters, lens extension, or the difference in flash and camera positions. TTL flash makes this a rarely used mode. 15. If you "pull" film, what have you done? What's the most common reason you would have to "pull" film? A: Pulling film — more accurately pull processing — is the opposite of pushing. Both are changes in how long film is developed. You pull process if you have overexposed the film. The most common reason to pull: you put in a roll of faster film but left your meter ISO setting at a lower number. For example, you shot Provia F (ISO 100) but didn't reset your meter from the Velvia film (ISO 50) you had been using. Mark the film and tell your lab what you did. 16. If a lens is marked as "f/4 - /5.6" what does that mean? A: It's a zoom lens with a variable maximum aperture. F-stops are a mathematical relationship between the hole in the lens, the aperture, and the focal length. If the hole stays the same physical size as you zoom then the f-stops must also change. Variable aperture lenses are easier to manufacture, and are often smaller and more compact than constant aperture zooms where the hole in the lens must physically change size as the lens is zoomed. 17. When should you use a warming filter? A: Use a warming filter when you like the effect. How to tell? Pick it up and look through the filter. 18. What effect does using a slow shutter speed have on subject rendition? A: A slow shutter speed will render any subject movement as a blur. 19. What is depth of field? A: Depth of field is how much looks acceptably sharp on either side of the plane on which you've focused. Theoretically only one plane is sharply focused, but smaller apertures allow more to appear to be in focus. 20. What effect does focal length have on depth of field? Do wide-angle lenses have more depth of field than telephoto lenses? A: Several statements are true: With any one lens, the smaller the aperture the greater the depth of field; the larger the aperture the shallower the depth of field. With any given lens at any given f-stop, the shorter the distance from lens to subject the shallower the depth of field. If your shooting distance doesn't change, the longer the focal length the narrower the depth of field. All photographs taken at the same image size and at the same f-stop will have the same depth of field regardless of focal length. 21. Besides image sharpness, name one reason to use a tripod. A: Better composition. 22. How many shutter speed jumps are there as you change from an 8 second exposure to 1/500 second? A: There are 12 speeds as you switch from 8 seconds to 1/500. Starting at 8 seconds we get: 4 seconds, 2 seconds, 1 second, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, and 1/500. 23. Do you have to meter at the aperture you want to use? A: You can meter at any aperture you want, as long as you can get a reading. Then change values to the aperture / shutter speed combination you want to use. 24. Does a tilt lens give you more depth of field? A: Tilt lenses do not yield any more depth of field. They change the placement of the plane of focus. Depth of field is always on either side of that, so consequently they also change the location of depth of field. But depth of field at any f-stop and image size is the same whether the lens is tilted or not tilted. 25. How do you know if you need to use a graduated neutral density filter? A: Meter the sunlit area and place it at the tonality you want it to appear, then meter the foreground area and place it as the tonality you want. Compare how far apart the two meter readings are, in contrast to where they should be if all the scene were in the same light. The difference in stops will be the density of ND filter you need to use. For example, you want to photograph a snowy mountain on a sunny day, but the medium toned foreground is in shade. Meter the white snow and place it as such. Now meter the medium foreground. There should be only two stops between medium tone and textured white, but the two metered values indicate an actual difference of four stops. You need to cut the light from the white snow by two stops; hence a two-stop graduated ND is needed. 26. What's the difference between a spot meter, a center-weighted meter, and a matrix or evaluative one? A: Spot meters read a small area within your photographic frame. Center-weighted meters read the central portion and give more weight to this area than the edges of the picture. Matrix (evaluative) metering subdivides the frame into many segments, meters all of these, then runs a software program. Spot and center-weighted meters give you a medium-toned placement as the answer. Matrix (evaluative) meters make a judgment as to the suggested exposure values, but they do not tell you how they have biased the exposure. 27. Why should you not put unprocessed film in your luggage? A: More and more airports are zapping checked luggage with a bomb-sniffing x-ray machine that will ruin film. 28. What's the difference between one of Nikon's "micro" lenses and one of Canon's "macro" lenses? A: Spelling. 29. When should you not use a "remote release" ("cable release" to those of you who remember such things)? A: When you're shooting action subjects. 30. If you see dark specks in your viewfinder, what most likely are these things? Will they ruin your pictures? A: They are specks of dirt on your viewfinder screen. They will not appear in your picture, but are certainly annoying. 31. You want to use Velvia film for a photograph of a rushing stream on an overcast day with the entire scene in focus. If you do this what will happen? If you don't want it to happen, what can you do? A: You're going to get the silky water effect. If you don't want that to happen you can (a) use a faster film, or (b) don't stop down and consequently not have the entire scene in focus, or (c) use a giant flash to light the scene (the sun going nova?), or (d) don't take the picture. But given the original parameters you will get the silky water effect whether you want it or not. 32. What is vignetting? What are some common causes of it? A: Vignetting is a darkening of the corners of the image. The most common causes are either using a lens hood for a longer focal length, or stacking too many filters on a lens, or using the proper lens hood for that lens but on stacked filters. I once looked though a photographer's 80-200mm zoom that had a skylight filter, a UV filter, a polarizer, and a lens hood. Vignetting to the max! 33. What's the difference between these two combinations: lens + extension tube + teleconverter + camera body, ...or... lens + teleconverter + extension tube + camera body. A: Lens + extension + teleconverter + camera = more magnification, and less working distance. In effect the teleconverter is magnifying the amount of extension. Lens + teleconverter + extension + camera = longer focal length, but less magnification. By adding the teleconverter directly behind the lens you have created a longer focal length; adding a tube lets this longer lens focus closer. 34. Name at least three reasons to use a lens hood. A: To keep light from striking the elements and creating flare; to keep rain or snow off the front element; to keep fingerprints off the front elements; or to protect the glass from possible damage. That's a total of four reasons. 35. Why would you not want to shoot on programmed exposure mode? A: The programmed mode chooses both shutter speed and aperture. How does the camera know that either one of these is what you want or need to use? It doesn't. 36. You want to use the very fastest shutter speed possible with an autoexposure mode. To which mode do you set your camera? A: Aperture priority. Set your lens wide open and this will give you the fastest shutter speed possible. 37. You need to use autofocus to stop wildlife action. What exposure modes and metering patterns must you use? A: You can use any exposure mode and any metering pattern you want whether you're in autofocus or manual focus. The exposure mode, the metering pattern, and the focus mode are mix and match. 38. As a general rule, the subject's implied path of action should go which direction in a photo? A: Into the picture frame. 39. Your camera does not have a two second shutter speed. You're photographing an arrangement of brightly colored rocks in even light, and need this shutter speed for the aperture you've selected. What do you do? A: Make a double exposure: two one-second shots on one frame of film equals one two-second exposure. 40. You're photographing your friend indoors with the light from one 100-watt light bulb. You need two more stops of depth of field but cannot change film. What are some solutions? A: Raid the house for more lights. You could either add three more 100-watt lights (assuming that all 100 watt bulbs put out the same amount of light) or switch to two 200-watt bulbs, or to one 400-watt bulb. You're just working in stop increments. Remember that to gain one stop you double the amount. 41. What are four possible ways, depending on your camera, that you can tell if there is film in the camera? A: (a) See if film shows in the little window on the back of the camera, (b) trip the shutter and see if the rewind crank turns, (c) trip the shutter and see if the frame counter changes, or (d) open the back of the camera and look inside (not recommended).
A: Compositional problems: tilted horizon; barn touching edge of frame. Technical problem: lens flare.
A: The black point: open up about 1-1/2 stops. The white point: close down about 1/2 stop. The blue point: use this as is. 48. What film should you use to photograph Bigfoot? A: Any film whatsoever.
A. How far does that lens see? B. What sort of socks should a professional nature photographer wear? C. How long is a one-minute exposure? D. Why don't Canons have f-stops? E. Does a "sunny-16" exposure setting work at night? F. All of the above. A: E. Yep, all of them. 50. Have you read your camera instruction manual? A: If you answered yes, give yourself an A regardless of the other test questions. If you answered no, have you thought about taking up bowling? |
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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. |