StoopidSavant
05-27-2006, 02:31 PM
I can see there is a lot of interest about taking quality photos at a racing event, and I for one receive a number of inquiries every year. I'll detail my limited knowledge on the subject, and I encourage every other photog here to contribute. I'm not a professional by any means, so don't take this as gospel.
The two main ingredients to shooting a racing event are:
1.) Hardware
2.) Technique
Addressing HARDWARE (and I'll be more technical now since we are a bunch of engineers)
I. Camera body
http://www.usa.canon.com/app/images/d_eos/1d_mkii_n_586x225.jpg
When photographers talk about a camera body, they mean just that - no lenses or peripheral hardware included. The body houses the light meter, imaging sensor, imaging processor, and other sensors.
An SLR (single lens reflex) camera with autofocus is the most ideal. Why? Because of the one word I mentioned before: AUTOFOCUS (AF). AF in SLRs works differently than it does in compact cameras. In a compact camera, the computer has only the main imaging sensor to get all its information (including exposure metering, focusing, etc.), and so is not as fast. In addition, the method of AF used in compact cameras is called contrast detection, which requires a feedback loop, but also does not tell the computer the exact position of the object you are focusing on. Because of this, compact cameras can have very accurate focus but terrible speed.
In comparison, SLR cameras have multiple sensors dedicated to a particular task, giving them superior performance to a compact camera. Even the most basic Canon Rebel has 7 dedicated AF sensors, while the Canon 1-series cameras have as many as 45 sensors dedicated solely to the purpose of autofocus. SLR AF sensors operate by a method called phase detection, where a prism splits an incoming image into two components and compares a transform of each resulting image. With this method, the camera knows the exact distance to focus and the exact amount of correction (and direction of correction) needed to bring the image into focus. Because this system is a feed forward design, SLR AF capability is far faster than any compact camera, although a misalignment of the AF sensors by even a few microns means that your images may be consistently back-focused or front-focused (focusing beyond your intended target). So if your images come out consistently blurry, check first that your camera is focusing correctly, and that it may need to be calibrated.
An SLR will generally have a higher framerate than a compact as well, although this gap is closing with newer and faster imaging processors and data bussing techniques. A lower end camera like a Canon Rebel or Nikon D50/D70 will be able to shoot 3 frames per second, while an intermediate camera like a Canon 20D/30D or Nikon D200 will shoot 5 frames per second. Professional cameras like the Canon 1D series and Nikon D2 series can shoot upward of 8 frames per second. In addition to framerate is mirror blackout, and again, lower end cameras will have a longer period during which the mirror will black out the viewfinder before retracting back into position - also a time during which the AF sensors cannot operate. An intermediate camera will have a viewfinder blackout of around 110 milliseconds.
II. Lenses
http://www.usa.canon.com/app/images/lens/ef600_4lisu_586x225.jpg
Glass is probably the most important purchase of a camera system (photographers don't talk about buying single cameras per se - they think about the overall package that a company can offer). The quality of a lens can usually (though not always) be observed by its light gathering ability, also known as maximum aperture, measured by the f-number. The lower the number, the more light gathering ability. Because engineering lenses with wide apertures (low f-numbers) and grinding large pieces of glass is difficult, lenses tend to be larger, heavier, and far more expensive the wider the aperture you can get. Aperture represents an exponential scale of light gathering ability, therefore an f/2.8 lens can collect four times as much as an f/5.6 lens.
In addition to the light gathering ability, a low f-number also ensures that when an image is out of focus, it's REALLY out of focus (compare a defocused region of an image shot with a compact camera versus that taken with an SLR - I'll bet the SLR image is much blurrier in the defocused regions). Lower f-numbers make it easier for the AF sensor to achieve focus lock. Many cameras, such as the 20D I use, cannot autofocus with lenses that are slower than f/5.6. Professional cameras generally cannot perform AF with lenses slower than f/8. When photographers refer to "slow" and "fast" lenses, they are not referring to AF speed, they are referring to the aperture (lower f-numbers are "fast" and higher numbers are "slow" because of the shutter speeds associated with them). A quality zoom lens generally will have a maximum aperture of f/2.8.
In older cameras, the autofocus motor was housed in the camera body, and a little lever protruded through the lens mount to control the lens. With the advent of the Canon EOS system, the trend has been to move the control electronics and hardware into the lens itself, so rather than have a mechanical interface between the camera and lens, the interface is now entirely electrical. The lens receives aperture and AF servo information from the camera and controls its own motors housed in the lens barrel for AF and aperture diaphragm. This means that the motors and servo controllers can be optimized for each particular lens. This led to some pretty clever inventions that will help us in our quest for motorsport photography perfection.
One of the more important inventions came from Canon in the late 80's (can you tell I like Canon?) with the advent of the UltraSonic Motor (USM). You see, all AF systems up until USM was invented utilized old school electric DC motors. The problem is that they are relatively loud, slow, consume power, consume space, are less accurate, and require a gear train. Because the DC motor and its transmission had to sit beside the optical path in a lens barrel, there was a limit to the size of the motor and/or optical elements in the lens. The USM, on the other hand, uses a toothed ring and a stator that surround the optical path, and sit on the circumference of the lens barrel. A piezo produces vibrations (30-50KHz) that provide the mechanical motivation to turn the ring. Reverse the phase 180 degrees and the ring turns in the opposite direction. With this, the USM consumes less space, less power, is virtually silent, incredibly fast, very accurate, and eliminates the need for a gear train. Nikon's own version is called SilentWave (denoted as AF-S lenses) and Sigma has the very originally named HyperSonic Motor (HSM). Virtually all professional lenses utilize some form of ultrasonic motor nowadays.
Another nifty feature of more expensive lenses is Image Stabilization (IS, introduced by - you guessed it - Canon), or Vibration Reduction (VR) as coined by Nikon, or Optical Stabilization (OS) and myriad other names. Basically an optical group is mounted on a pair of actuators that control X and Y motion to cancel out shakes and vibrations caused by either the photographer's hands or another source, like shooting on a moving vehicle. A pair of accelerometers (note: they are accelerometers, NOT gyros) maintains stability. Newer implementations have what is basically a "motorsports mode" in which vibrations are canceled in the Y direction, but not the X direction since you will be panning the camera with a moving vehicle.
III. Support
http://www.kirkphoto.com/bh3.jpg
A good tripod or monopod is ESSENTIAL. If you have one of those nice stabilized lenses, you can get away without one in a pinch, but your arms will get tired after holding a five pound camera for more than 10 minutes. Monopods are great for their small size, weight, and ease of mobility (I used a monopod at the 2005 comp) while tripods offer more stability and the ability to leave the camera standing on its own without having to pay attention to it during downtime. $30 tripods from Best Buy will work in a pinch, but as with all things, you get what you pay for. A photographic tripod/monopod head is ideally a ball-type head, which has a ball-and-socket type joint. The more common head is a three-axis pan head, which comes with almost all cheaper tripods and recognizable by the rear protruding stalk that's used to point the camera. These pan heads are designed for camcorders though, not photographic cameras. I use a Kirk BH-3 ballhead (http://www.kirkphoto.com/ballheadbh3.html) on Slik aluminum legs, but I'll prolly get carbon fiber legs when my finances are more in shape.
---------------------------------------------------------
So that's the main points about the hardware that's most useful for motorsport photography. Of course, just like a vehicle, don't assume that the best hardware will automatically give you better pictures any more than a more expensive car will get you lower lap times. It's all about the operator, and inexperience would probably yield results that are even poorer than if you had just stuck to using a compact camera.
As far as brands go, Canon and Nikon are probably the 800 pound gorillas in the industry. Autofocus performance is the most important aspect for a sports photographer, and I personally think that Canon has the edge (although others will argue toward Nikon), despite the fact that it was Olympus who invented AF. Watch any sporting event at all and you'll likely see the sidelines with dudes and big white lenses - those are all Canon operators. Nikon makes a fine product as well, and their new D200 is definitely a great machine for the price.
The information here is not at all comprehensive, so if there is a specific topic that you would like to know more about, don't hesitate to comment and I'll write up another post on what I know about it. Also feel free to let me know about areas that need more clarification. I again mention that I am in no way a professional, so it wouldn't be out of the question for perhaps some of this information to be inaccurate, so drop a line if you think something's not right.
Next post will be dedicated to technique, but that will come later in the evening after I've had my share of seafood and chocolate chip cookies.
The two main ingredients to shooting a racing event are:
1.) Hardware
2.) Technique
Addressing HARDWARE (and I'll be more technical now since we are a bunch of engineers)
I. Camera body
http://www.usa.canon.com/app/images/d_eos/1d_mkii_n_586x225.jpg
When photographers talk about a camera body, they mean just that - no lenses or peripheral hardware included. The body houses the light meter, imaging sensor, imaging processor, and other sensors.
An SLR (single lens reflex) camera with autofocus is the most ideal. Why? Because of the one word I mentioned before: AUTOFOCUS (AF). AF in SLRs works differently than it does in compact cameras. In a compact camera, the computer has only the main imaging sensor to get all its information (including exposure metering, focusing, etc.), and so is not as fast. In addition, the method of AF used in compact cameras is called contrast detection, which requires a feedback loop, but also does not tell the computer the exact position of the object you are focusing on. Because of this, compact cameras can have very accurate focus but terrible speed.
In comparison, SLR cameras have multiple sensors dedicated to a particular task, giving them superior performance to a compact camera. Even the most basic Canon Rebel has 7 dedicated AF sensors, while the Canon 1-series cameras have as many as 45 sensors dedicated solely to the purpose of autofocus. SLR AF sensors operate by a method called phase detection, where a prism splits an incoming image into two components and compares a transform of each resulting image. With this method, the camera knows the exact distance to focus and the exact amount of correction (and direction of correction) needed to bring the image into focus. Because this system is a feed forward design, SLR AF capability is far faster than any compact camera, although a misalignment of the AF sensors by even a few microns means that your images may be consistently back-focused or front-focused (focusing beyond your intended target). So if your images come out consistently blurry, check first that your camera is focusing correctly, and that it may need to be calibrated.
An SLR will generally have a higher framerate than a compact as well, although this gap is closing with newer and faster imaging processors and data bussing techniques. A lower end camera like a Canon Rebel or Nikon D50/D70 will be able to shoot 3 frames per second, while an intermediate camera like a Canon 20D/30D or Nikon D200 will shoot 5 frames per second. Professional cameras like the Canon 1D series and Nikon D2 series can shoot upward of 8 frames per second. In addition to framerate is mirror blackout, and again, lower end cameras will have a longer period during which the mirror will black out the viewfinder before retracting back into position - also a time during which the AF sensors cannot operate. An intermediate camera will have a viewfinder blackout of around 110 milliseconds.
II. Lenses
http://www.usa.canon.com/app/images/lens/ef600_4lisu_586x225.jpg
Glass is probably the most important purchase of a camera system (photographers don't talk about buying single cameras per se - they think about the overall package that a company can offer). The quality of a lens can usually (though not always) be observed by its light gathering ability, also known as maximum aperture, measured by the f-number. The lower the number, the more light gathering ability. Because engineering lenses with wide apertures (low f-numbers) and grinding large pieces of glass is difficult, lenses tend to be larger, heavier, and far more expensive the wider the aperture you can get. Aperture represents an exponential scale of light gathering ability, therefore an f/2.8 lens can collect four times as much as an f/5.6 lens.
In addition to the light gathering ability, a low f-number also ensures that when an image is out of focus, it's REALLY out of focus (compare a defocused region of an image shot with a compact camera versus that taken with an SLR - I'll bet the SLR image is much blurrier in the defocused regions). Lower f-numbers make it easier for the AF sensor to achieve focus lock. Many cameras, such as the 20D I use, cannot autofocus with lenses that are slower than f/5.6. Professional cameras generally cannot perform AF with lenses slower than f/8. When photographers refer to "slow" and "fast" lenses, they are not referring to AF speed, they are referring to the aperture (lower f-numbers are "fast" and higher numbers are "slow" because of the shutter speeds associated with them). A quality zoom lens generally will have a maximum aperture of f/2.8.
In older cameras, the autofocus motor was housed in the camera body, and a little lever protruded through the lens mount to control the lens. With the advent of the Canon EOS system, the trend has been to move the control electronics and hardware into the lens itself, so rather than have a mechanical interface between the camera and lens, the interface is now entirely electrical. The lens receives aperture and AF servo information from the camera and controls its own motors housed in the lens barrel for AF and aperture diaphragm. This means that the motors and servo controllers can be optimized for each particular lens. This led to some pretty clever inventions that will help us in our quest for motorsport photography perfection.
One of the more important inventions came from Canon in the late 80's (can you tell I like Canon?) with the advent of the UltraSonic Motor (USM). You see, all AF systems up until USM was invented utilized old school electric DC motors. The problem is that they are relatively loud, slow, consume power, consume space, are less accurate, and require a gear train. Because the DC motor and its transmission had to sit beside the optical path in a lens barrel, there was a limit to the size of the motor and/or optical elements in the lens. The USM, on the other hand, uses a toothed ring and a stator that surround the optical path, and sit on the circumference of the lens barrel. A piezo produces vibrations (30-50KHz) that provide the mechanical motivation to turn the ring. Reverse the phase 180 degrees and the ring turns in the opposite direction. With this, the USM consumes less space, less power, is virtually silent, incredibly fast, very accurate, and eliminates the need for a gear train. Nikon's own version is called SilentWave (denoted as AF-S lenses) and Sigma has the very originally named HyperSonic Motor (HSM). Virtually all professional lenses utilize some form of ultrasonic motor nowadays.
Another nifty feature of more expensive lenses is Image Stabilization (IS, introduced by - you guessed it - Canon), or Vibration Reduction (VR) as coined by Nikon, or Optical Stabilization (OS) and myriad other names. Basically an optical group is mounted on a pair of actuators that control X and Y motion to cancel out shakes and vibrations caused by either the photographer's hands or another source, like shooting on a moving vehicle. A pair of accelerometers (note: they are accelerometers, NOT gyros) maintains stability. Newer implementations have what is basically a "motorsports mode" in which vibrations are canceled in the Y direction, but not the X direction since you will be panning the camera with a moving vehicle.
III. Support
http://www.kirkphoto.com/bh3.jpg
A good tripod or monopod is ESSENTIAL. If you have one of those nice stabilized lenses, you can get away without one in a pinch, but your arms will get tired after holding a five pound camera for more than 10 minutes. Monopods are great for their small size, weight, and ease of mobility (I used a monopod at the 2005 comp) while tripods offer more stability and the ability to leave the camera standing on its own without having to pay attention to it during downtime. $30 tripods from Best Buy will work in a pinch, but as with all things, you get what you pay for. A photographic tripod/monopod head is ideally a ball-type head, which has a ball-and-socket type joint. The more common head is a three-axis pan head, which comes with almost all cheaper tripods and recognizable by the rear protruding stalk that's used to point the camera. These pan heads are designed for camcorders though, not photographic cameras. I use a Kirk BH-3 ballhead (http://www.kirkphoto.com/ballheadbh3.html) on Slik aluminum legs, but I'll prolly get carbon fiber legs when my finances are more in shape.
---------------------------------------------------------
So that's the main points about the hardware that's most useful for motorsport photography. Of course, just like a vehicle, don't assume that the best hardware will automatically give you better pictures any more than a more expensive car will get you lower lap times. It's all about the operator, and inexperience would probably yield results that are even poorer than if you had just stuck to using a compact camera.
As far as brands go, Canon and Nikon are probably the 800 pound gorillas in the industry. Autofocus performance is the most important aspect for a sports photographer, and I personally think that Canon has the edge (although others will argue toward Nikon), despite the fact that it was Olympus who invented AF. Watch any sporting event at all and you'll likely see the sidelines with dudes and big white lenses - those are all Canon operators. Nikon makes a fine product as well, and their new D200 is definitely a great machine for the price.
The information here is not at all comprehensive, so if there is a specific topic that you would like to know more about, don't hesitate to comment and I'll write up another post on what I know about it. Also feel free to let me know about areas that need more clarification. I again mention that I am in no way a professional, so it wouldn't be out of the question for perhaps some of this information to be inaccurate, so drop a line if you think something's not right.
Next post will be dedicated to technique, but that will come later in the evening after I've had my share of seafood and chocolate chip cookies.