Types of Flashes

Flashbulbs

Kodak Brownie Hawkeye with "Kodalite Flasholder" and Sylvania P25 blue-dot daylight-type flashbulb

The earliest flashes had of a quantity of flash powder consisting of a mechanical mixture of magnesium powder and potassium chlorate that was ignited by hand. Later, magnesium filaments were contained in flash bulbs filled with oxygen gas, and electrically ignited by a contact in the camera shutter; such a bulb could only be used once, and was too hot to handle immediately after use, but the confinement of what would otherwise have amounted to a small explosion was an important advance. An innovation was coating flashbulbs with a blue plastic coating to match the spectral quality to daylight balanced colour film and to make it look more moderate, as well as providing shielding for the bulb in the unlikely event of it shattering during the flash. Later bulbs substituted zirconium for the magnesium, which produced a brighter flash and tended to temporarily blind people. Flashbulbs took longer to reach full brightness and burned for longer than electronic flashes. Slower shutter speeds (typically from 1/10 to 1/50 of a second) were used on cameras to ensure proper synchronization. A widely used flashbulb through the 1960s was the number 25. This is the large (approximately 1 inch (25 mm) in diameter) flashbulb often shown used by newspapermen in period movies, usually attached to a press camera or a twin-lens reflex camera.

Flashcubes, Magicubes and Flipflash

Flashcube fitted to a Kodak Instamatic camera, showing both unused (left) and used (right) bulbs.

Undersides of Flashcube (left) and Magicube (right) cartridges.

"Flip flash" type cartridge

In the late 1960s, Kodak improved their Instamatic camera line by replacing the individual flashbulb technology (used on early Instamatics) with the Flashcube. Flashcubes consisted of four electrically fired flashbulbs with an integral reflector in a cube-shaped arrangement that allowed taking four images in a row. A mechanism in the camera automatically rotated the flashcube 90 degrees to a fresh bulb upon advancing the film to the next exposure. The later Magicube (or X-Cube) retained the four-bulb format, and was superficially similar to the original Flashcube. However, the Magicube did not require electrical power- each bulb was set off by a plastic pin in the cube mount that released a cocked spring wire within the cube. This wire, in turn, struck a primer tube, at the base of the bulb, which contained a fulminate. The fulminate ignited shredded Zirconium foil in the flash and, thus, a battery was not required. Magicubes could also be fired by inserting a thin object, such as a key or paper clip, into one of the slots in the bottom of the cube. Flashcubes and Magicubes are superficially similar but not interchangeable. Cameras requiring flashcubes have a round socket and a round hole for the flashcube's pin, while those requiring Magicubes have a round shape with protruding studs and a square socket hole for the Magicube's square pin. The Magicube socket can also be seen as an X, which accounts for its alternate name, X-Cube. Another common flashbulb-based device was the Flipflash which included ten or so bulbs in a single unit. The name derived from the fact that once half the flashes had been used up, the unit had to be flipped and re-inserted to use the remainder.

Modern flash technology

Today^[update]'s flash units are often electronic flashtubes. An electronic flash contains a tube filled with xenon gas, where electricity of high voltage is discharged to generate an electrical arc that emits a short flash of light. (A typical duration of the light impulse is 1/1000 second.) As of 2003, the majority of cameras targeted for consumer use have an electronic flash unit built in.

Two professional flashes.

Another type of flash unit are microflashes, which are high-voltage flash units discharging a flash of light with an exceptionally quick, sub-microsecond duration. These are commonly used by scientists or engineers for examining extremely fast moving objects or reactions, famous for producing images of bullets tearing through objects like lightbulbs or balloons. Studio flashes usually contain a modeling light, an incandescent lightbulb close to the flash tube. The continuous illumination of a modeling light helps in visualizing the effect of the flash. The strength of a flash device is often indicated in terms of a guide number, despite the fact that the published guide numbers of different units can not necessarily be directly compared. The strength of larger studio flash units, such as monolights are indicated in watt-seconds.

Flash intensity

Unlike flashbulbs, the intensity of an electronic flash can be adjusted on some units. Small flash units typically vary the length of time of the discharge, larger (studio) units typically charge the capacitor less. The disadvantage of charging the capacitor less is that the color temperature may change, necessitating corrections. With advances in semiconductor technology, there are some monolight (studio) units which can vary the time of the discharge. The flash duration is typically described with two numbers: t.5 is the length of time for which the flash impulse is above 0.5 (50%) of the peak intensity, while t.1 is the length of time for which the impulse is above 0.1 (10%) of the peak (t.3 of course, would be above 30%). For instance, t.5 can be 1/1200 sec whereas t.1 can be 1/450 sec for the same flash at the same intensity. For a small flash controlling intensity by time, the t.5 and t.1 numbers decrease as the intensity decreases. On flash units controlling intensity by capacitor charge, the t.5 and t.1 numbers increase as the intensity decreases (i.e. takes longer for the capacitor to discharge to that point). These times become important if a person wants to freeze action with the flash (as in sports). Flash intensity is typically measured in stops or in fractions (1, 1/2, 1/4, 1/8 etc.). Some monolights display an "EU Number", so that a photographer can know the difference in brightness between different flash units with different watt-second ratings. EU10.0 is defined as 6400 Watt-seconds, and EU9.0 is one stop lower, i.e. 3200 watt-seconds.

Flash LED illumination

Although they are not yet at the power levels to replace xenon flash devices in still cameras, high-current flash LEDs have recently been used as flash sources in camera phones. The major advantages of LEDs over xenon include low voltage operation, higher efficiency and extreme miniaturization.

Focal-plane-shutter synchronization

Electronic flash units have compatibility issues with focal-plane shutters. Focal-plane shutters expose using two curtains that cross the sensor. The first one opens and the second curtain follows it after a delay equal to the nominal shutter speed. A typical modern focal-plane shutter takes about 1/200s to cross the sensor, so at exposure times shorter than this only part of the sensor is uncovered at any one time. Electronic flash can have durations as short as 50 µs, so at such short exposure times only part of the sensor is exposed. This limits the shutter speed to about 1/200s when using flash. In the past, slow-burning single-use flash bulbs allowed the use of focal-plane shutters at maximum speed because they produced continuous light for the time taken for the exposing slit to cross the film gate. If these are found they cannot be used on modern cameras because the bulb must be fired *before* the first shutter curtain begins to move (M-sync); the X-sync used for electronic flash normally fires only when the first shutter curtain reaches the end of its travel. High-end flash units address this problem by offering a mode, typically called FP sync or HSS (High Speed Sync), which fires the flash tube multiple times during the time the slit traverses the sensor. Such units require communication with the camera and are thus dedicated to a particular camera make. The multiple flashes result in a significant decrease in guide number, since each is only a part of the total flash power, but it's all that illuminates any particular part of the sensor. In general, if s is the shutter speed, and t is the shutter traverse time, the guide number reduces by √s / t. For example, if the guide number is 100, and the shutter traverse time is 5 ms (a shutter speed of 1/200s), and the shutter speed is set to 1/2000s (0.5 ms), the guide number reduces by a factor of √0.5 / 5, or about 3.16, so the resultant guide number at this speed would be about 32. Current (2010) flash units frequently have much lower guide numbers in HSS mode than in normal modes, even at speeds below the shutter traverse time. For example, the Mecablitz 58 AF-1 digital flash unit has a guide number of 58 in normal operation, but only 20 in HSS mode, even at low speeds.

Source: http://en.wikipedia.org/

Photograhy Flash

A flash is a device used in photography producing a flash of artificial light (typically 1/1000 to 1/200 of a second) at a color temperature of about 5500 K to help illuminate a scene. A major purpose of a flash is to illuminate a dark scene. Other uses are capturing quickly moving objects or changing the quality of light. Flash refers either to the flash of light itself or to the electronic flash unit discharging the light. Most current flash units are electronic, having evolved from single-use flashbulbs and flammable powders. Modern cameras often activate flash units automatically. Flash units are commonly built directly into a camera. Some cameras allow separate flash units to be mounted via a standardized "accessory mount" bracket (hot shoe). In professional studio equipment, flashes may be large, standalone units, or studio strobes, powered by special battery packs or connected to mains power. They are either synchronized with the camera using a flash synchronization cable or radio signal, or are light-triggered, meaning that only one flash unit needs to be synchronized with the camera, and in turn triggers the other units. Source: http://en.wikipedia.org/

40 Examples of Panning Shots in Photography

Panning is a technique in photography that is used to capture a moving object in action.The subject of the photo is clearly caught on camera; however, the rest remains a blur in the background. Panning suggests speed and velocity to an image. To date, more and more people are into enhancing their panning skills.

Below are 40 Examples of Panning Shots in Photography that was shot by skilled and aspiring photographers as they explore and use the panning technique. These photos were mostly taken with the use of a Digital Single Lens Reflex camera. Feel free to browse through these images and be motivated!

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Source

Did we miss anything? If you have stumble upon a panning photos that was not included on the list, feel free to add the link on the comment section.

Source: http://naldzgraphics.net/

How To Panning

Panning is one of the most difficult types of photography one can employ as the learning curve is rather high. But that's not to say you can't do it. It just takes a tremendous amount of patience, practice, and be prepared to throw out lots of pictures.

Panning is an art. Most photographers have no problem shooting still life or, with incredibly high shutter speeds can capture moving objects without much difficulty.

But how do you get that coveted blur in your photos that bring out the obvious that the subject is in motion? It's sort of a two part exercise. One that I can say I haven't mastered but I can take passable photos. Sometimes they turn out great. Sometimes I end up throwing away more pictures that just didn't work.

The first thing you need to learn is how to actually pan. Panning is following an object with your camera at the same speed the object is moving. When you take pictures like the ones you see here, the cars are getting close to 190-200mph which causes you to move quickly.

The first rule is how to lead the subject while trying to keep your center focus in the same spot on the subject. Duck hunters, skeet shooters and other enthusiasts already know how to do this to bag their game. They have to aim their gun in front of their game in order to get the shot. The biggest difference between a camera and a gun is the gun shot isn't instantaneous. In other words, it takes time for the buck shot or bullet to get to the subject therefore requiring to shoot in front of the subject.

Not so with a camera. Cameras are an instant capture. So why shoot in front of the car? Two reasons. You want as much chance as possible to either catch the car coming into the frame or, if you're a tad slow keeping your focus on a single point, you still have odds of hitting the car's sweet spot as it moves into that focal point.

This is the point where you need to know how to set your shutter speed to get the desired effect. If you crank the setting up to the max you'll catch the car dead in it's tracks. You won't have any element of movement and it will literally look like the car is just sitting on the pavement.

A side note on capturing this type of photography is your cameras fps. At an absolute minimum you need 4fps. The higher the better because you're going to fire the maximum amount of shots before the shutter stops, allowing data to be written on your memory card.

Anyway, if you're starting with a very high shutter speed, practice the pan technique to keep your focus on the front of the subject. If not, you'll end up with a picture like number two where the cars are exiting the frame. You want them either dead center or entering the frame.

Once you get the still shots from the high shutter speed, begin to dial it down. Continue practicing your panning because dropping down in shutter speed is going to make your practice a little harder. After you think you've mastered a slightly slower shutter speed, dial it down again. Pan and see if you can hit that sweet spot. If every picture is blurry then you need to stay at that shutter speed and practice until you get the desired amount of movement.

Once you're satisfied with your pictures, dial the shutter speed down again and continue to repeat the process. Each time you go down in shutter speed, the more blur you're going to obtain that begins to show the subject in motion. Keep on dropping until you get the panning down as well as keeping the object in focus. Obviously you'll pan faster and faster (depending on the subject). This is perhaps the point that things get very, very difficult. Panning quickly while trying really hard to keep your center focus on the object, in this case the car, is the most difficult tasks for photographers if they haven't spent the time practicing. The lower your shutter speed, the more you'll have to move your body and camera to keep up with the speed of your subject.

This isn't limited to cars, although NASCAR is my favorite type of shooting. You can apply this technique to things like running cheetahs, trains and anything else with pretty descent speed to it.

If this type of photography interests you, be prepared to put a lot of time in practicing. Here are a few suggestions to get started.

Have someone ride a bike down the street, then pan and shoot. You'll get really good at objects moving at that speed.

Then move up to a car. Preferably with your spouse driving because going out on a back road to shoot random cars isn't the smartest thing to do since the driver has no idea what you're doing.

Have your spouse or friend drive the car down the street at a faster pace than the bike. Continue your panning technique on the faster object. Keep moving up in speed until the point you're comfortable with your technique. Pan with your upper torso only and not your whole body.

After several messed up and out of focus pictures you'll begin to get the concept and what speeds you're capable of. Continue to practice until you achieve the level of blur that your looking for. Remember, the slower the shutter speed the more blur you'll get into the photo while maintaining ideal focus on the subject.

I know a lot of photographers will never be interested in this type of photography but it's a good technique to have in your arsenal.

By: Randy Cottingham Source: http://jpgmag.com/

Manipulating White Balance For Artistic Effect

The ability to control white balance, even changing it from one shot to the next, is one of the greatest advantages of digital over film. Sure, with film you could shoot negatives and let some machine or lab technician do color corrections for you. If using slide film however, once you loaded a roll, you were stuck with that film’s color balance until you finished it and loaded the next roll.

It’s not hard to find advice online for understanding the various white balance settings found on most digital cameras. For the most part, these settings are pretty self-explanatory and most moderately experienced photographers (that would include practically all DPS readers) can figure them out simply by playing with them.

Most people approach white balance with the mindset of getting true color representation. That makes sense. You want your whites to be white and all your other colors to be true representations of the original scene as you shot it.

There is a case to be made for deliberately setting the “wrong” white balance to achieve artistic effects. For example, when at the beach on a perfectly sunny day, you might set your white balance for cloudy or even shade. This tells the camera that the ambient light has a slightly blue cast to it. The camera will compensate by adding a bit of a bronze (red/orange) tone to offset this supposed cast. The result is that your subjects get an instant suntan!

Be warned that this may not work for scenes in which the sky is visible as the color manipulation may be quite obvious in your final images.

Conversely, when photographing an icy scene, perhaps you should try setting your white balance to Tungsten. This tells the camera that the light is slightly orange so it will introduce more blue to offset that. The result is an image that simply looks “cold”.

For even finer control, it pays to develop a bit of understanding of the Kelvin scale. Many cameras will allow you to directly set a Kelvin temperature for the ambient light. Tricking the camera by claiming that the light is warmer or cooler than it actually is can allow you to very finely tune the adjustment, thus giving you the ability to make the effect more subtle. (Or more garish, if that’s what you’re after.)

By: Jeffrey Kontur Source: http://www.digital-photography-school.com/

White Balance

White balance (WB) is the process of removing unrealistic color casts, so that objects which appear white in person are rendered white in your photo. Proper camera white balance has to take into account the "color temperature" of a light source, which refers to the relative warmth or coolness of white light. Our eyes are very good at judging what is white under different light sources, but digital cameras often have great difficulty with auto white balance (AWB) — and can create unsightly blue, orange, or even green color casts. Understanding digital white balance can help you avoid these color casts, thereby improving your photos under a wider range of lighting conditions.

Incorrect White Balance	Correct White Balance

BACKGROUND: COLOR TEMPERATURE

Color temperature describes the spectrum of light which is radiated from a "blackbody" with that surface temperature. A blackbody is an object which absorbs all incident light — neither reflecting it nor allowing it to pass through. A rough analogue of blackbody radiation in our day to day experience might be in heating a metal or stone: these are said to become "red hot" when they attain one temperature, and then "white hot" for even higher temperatures. Similarly, blackbodies at different temperatures also have varying color temperatures of "white light." Despite its name, light which may appear white does not necessarily contain an even distribution of colors across the visible spectrum:

Relative intensity has been normalized for each temperature (in Kelvins).

Note how 5000 K produces roughly neutral light, whereas 3000 K and 9000 K produce light spectrums which shift to contain more orange and blue wavelengths, respectively. As the color temperature rises, the color distribution becomes cooler. This may not seem intuitive, but results from the fact that shorter wavelengths contain light of higher energy.

Why is color temperature a useful description of light for photographers, if they never deal with true blackbodies? Fortunately, light sources such as daylight and tungsten bulbs closely mimic the distribution of light created by blackbodies, although others such as fluorescent and most commercial lighting depart from blackbodies significantly. Since photographers never use the term color temperature to refer to a true blackbody light source, the term is implied to be a "correlated color temperature" with a similarly colored blackbody. The following table is a rule-of-thumb guide to the correlated color temperature of some common light sources:

Color Temperature	Light Source
1000-2000 K	Candlelight
2500-3500 K	Tungsten Bulb (household variety)
3000-4000 K	Sunrise/Sunset (clear sky)
4000-5000 K	Fluorescent Lamps
5000-5500 K	Electronic Flash
5000-6500 K	Daylight with Clear Sky (sun overhead)
6500-8000 K	Moderately Overcast Sky
9000-10000 K	Shade or Heavily Overcast Sky

IN PRACTICE: JPEG & TIFF FILES

Since some light sources do not resemble blackbody radiators, white balance uses a second variable in addition to color temperature: the green-magenta shift. Adjusting the green-magenta shift is often unnecessary under ordinary daylight, however fluorescent and other artificial lighting may require significant green-magenta adjustments to the WB.

		Auto White Balance
		Custom
		Kelvin
		Tungsten
		Fluorescent
		Daylight
		Flash
		Cloudy
		Shade

Fortunately,most digital cameras contain a variety of preset white balances, so you do not have to deal with color temperature and green-magenta shift during the critical shot. Commonly used symbols for each of these are listed to the left.

The first three white balances allow for a range of color temperatures. Auto white balance is available in all digital cameras and uses a best guess algorithm within a limited range — usually between 3000/4000 K and 7000 K. Custom white balance allows you to take a picture of a known gray reference under the same lighting, and then set that as the white balance for future photos. With "Kelvin" you can set the color temperature over a broad range.

The remaining six white balances are listed in order of increasing color temperature, however many compact cameras do not include a shade white balance. Some cameras also include a "Fluorescent H" setting, which is designed to work in newer daylight-calibrated fluorescents.

The description and symbol for the above white balances are just rough estimates for the actual lighting they work best under. In fact, cloudy could be used in place of daylight depending on the time of day, elevation, or degree of haziness. In general, if your image appears too cool on your LCD screen preview (regardless of the setting), you can quickly increase the color temperature by selecting a symbol further down on the list above. If the image is still too cool (or warm if going the other direction), you can resort to manually entering a temperature in the Kelvin setting.

If all else fails and the image still does not have the correct WB after inspecting it on a computer afterwards, you can adjust the color balance to remove additional color casts. Alternatively, one could click on a colorless reference (see section on neutral references) with the "set gray point" dropper while using the "levels" tool in Photoshop. Either of these methods should be avoided since they can severely reduce the bit depth of your image.

IN PRACTICE: THE RAW FILE FORMAT

By far the best white balance solution is to photograph using the RAW file format (if your camera supports them), as these allow you to set the WB *after* the photo has been taken. RAW files also allow one to set the WB based on a broader range of color temperature and green-magenta shifts.

Performing a white balance with a raw file is quick and easy. You can either adjust the temperature and green-magenta sliders until color casts are removed, or you can simply click on a neutral reference within the image (see next section). Even if only one of your photos contains a neutral reference, you can click on it and then use the resulting WB settings for the remainder of your photos (assuming the same lighting).

CUSTOM WHITE BALANCE: CHOOSING A NEUTRAL REFERENCE

A neutral reference is often used for color-critical projects, or for situations where one anticipates auto white balance will encounter problems. Neutral references can either be parts of your scene (if you're lucky), or can be a portable item which you carry with you. Below is an example of a fortunate reference in an otherwise bluish twilight scene.

On the other hand, pre-made portable references are almost always more accurate since one can easily be tricked into thinking an object is neutral when it is not. Portable references can be expensive and specifically designed for photography, or may include less expensive household items. An ideal gray reference is one which reflects all colors in the spectrum equally, and can consistently do so under a broad range of color temperatures. An example of a pre-made gray reference is shown below:

Common household neutral references are the underside of a lid to a coffee or pringles container. These are both inexpensive and reasonably accurate, although custom-made photographic references are the best (such as the cards shown above). Custom-made devices can be used to measure either the incident or reflected color temperature of the illuminant. Most neutral references measure reflected light, whereas a device such as a white balance meter or an "ExpoDisc" can measure incident light (and can theoretically be more accurate).

Care should be taken when using a neutral reference with high image noise, since clicking on a seemingly gray region may actually select a colorful pixel caused by color noise:

Low Noise (Smooth Colorless Gray)	High Noise (Patches of Color)

If your software supports it, the best solution for white balancing with noisy images is to use the average of pixels with a noisy gray region as your reference. This can be either a 3x3 or 5x5 pixel average if using Adobe Photoshop.

NOTES ON AUTO WHITE BALANCE

Certain subjects create problems for a digital camera's auto white balance — even under normal daylight conditions. One example is if the image already has an overabundance of warmth or coolness due to unique subject matter. The image below illustrates a situation where the subject is predominantly red, and so the camera mistakes this for a color cast induced by a warm light source. The camera then tries to compensate for this so that the average color of the image is closer to neutral, but in doing so it unknowingly creates a bluish color cast on the stones. Some digital cameras are more susceptible to this than others.

Automatic White Balance	Custom White Balance

(Custom white balance uses an 18% gray card as a neutral reference.)

A digital camera's auto white balance is often more effective when the photo contains at least one white or bright colorless element. Of course, do not try to change your composition to include a colorless object, but just be aware that its absence may cause problems with the auto white balance. Without the white boat in the image below, the camera's auto white balance mistakenly created an image with a slightly warmer color temperature.

IN MIXED LIGHTING

Multiple illuminants with different color temperatures can further complicate performing a white balance. Some lighting situations may not even have a truly "correct" white balance, and will depend upon where color accuracy is most important.

Reference:	Moon	Stone

Under mixed lighting, auto white balance usually calculates an average color temperature for the entire scene, and then uses this as the white balance. This approach is usually acceptable, however auto white balance tends to exaggerate the difference in color temperature for each light source, as compared with what we perceive with our eyes.

Exaggerated differences in color temperature are often most apparent with mixed indoor and natural lighting. Critical images may even require a different white balance for each lighting region. On the other hand, some may prefer to leave the color temperatures as is.

Note how the building to the left is quite warm, whereas the sky is somewhat cool. This is because the white balance was set based on the moonlight — bringing out the warm color temperature of the artificial lighting below. White balancing based on the natural light often yields a more realistic photograph. Choose "stone" as the white balance reference and see how the sky becomes unrealistically blue.

Source: http://www.cambridgeincolour.com/