A comprehensive overview of flash photography... procedures, equipment and technique

1. FLASH PHOTOGRAPHY… A PRIMER

3. FLASH PHOTOGRAPHY… A PRIMER

7. A FLASH PHOTOGRAPHY PRIMER The Inverse Square Law “ Light intensity falls off with the square of the distance ” Example 1: A single light in a dark room will cast 4 times the amount of light on a subject when it is 2 feet from the subject as it will when it is 4 feet from the subject. Example 2: A single light in a dark room will cast 4 times the amount of light on a subject when it is 5.6 feet from the subject as it will when it is 11 feet from the subject. Example 3: A single light in a dark room will cast 4 times the amount of light on a subject when it is 16 feet from the subject as it will when it is 32 feet from the subject. ( Do you see a pattern emerging??? Hint: Think in terms of f/stops.)

8. A FLASH PHOTOGRAPHY PRIMER Watt/Seconds vs. BCPS Watt/Seconds is a measurement of stored electrical power. BCPS (Beam Candle Power Seconds) is a measurement of actual light output. The reflector and its finish (polished, stippled or matte), shape, and size have a direct effect on the amount of light that is output from a flash head. Hence, you can achieve different BCPS output by changing the reflectors and/or light modifiers with the same amount of watt/seconds.

9. A FLASH PHOTOGRAPHY PRIMER How to Use Guide Numbers The key to using flashbulbs (or any manual flash system) is the concept of guide number . The guide number expresses the amount of energy contained in the flash in a way directly useful to the photographer, and relates distance covered to lens f-stop, as follows: F = G / D where F is the lens f-stop, G is the guide number, and D is the distance. Whereas for electronic flash (strobe lite), the guide number depends only on the film speed, for flashbulbs a guide number is stated for a certain film speed, shutter speed, and film sensitivity (B&W or color). The reason that shutter speed enters the equation is that a flashbulb flashes over a relatively long period of time, and shutter speeds of faster than 1/30s cut off some of the light from the bulb.

10. A FLASH PHOTOGRAPHY PRIMER How to Use Guide Numbers On just about any hot-shoe flash capable of manual, there's a guide number calculator built in.

11. A FLASH PHOTOGRAPHY PRIMER How to Use Guide Numbers The four flash exposure variables are: F/stop, distance, power and ISO. You plug in any three, and the calculator spits out the fourth. Play around with your buttons a bit and you will see how yours works. What I like to do is to already know my ISO, my desired shooting aperture and an estimated flash-to-subject distance. Now, by setting up my GN calculator, I just dial in the different manual power settings until my desired f/stop lines up with my flash-to-subject distance.

12. A FLASH PHOTOGRAPHY PRIMER This GN calculator is set for full power manual at ISO 200. It is telling you that, at 30-40 feet, you would get about f/4 out of this flash. And if you set the flash to 1/2 power, you'd get f/2.8 out of it at that distance. Here's the cool thing: If you zoom the head -- even on this old-design flash -- it will move the dial and adjust the result. Full power 200 ISO

15. A FLASH PHOTOGRAPHY PRIMER How to use an Automatic flash Most automatic flashes have multiple auto setting options. The one pictured to the right has four. They are color coded yellow, red, blue and purple. In the example to the right, a yellow setting on the flash sensor will give correct exposures with the lens set to f 2.8 between 50ft and 4.5ft. A red setting will give correct exposures at f5.6 between 25ft and 3ft from the subject. Blue would be good @f11 from 12ft to 1ft and purple – f16 between 8ft and 1ft.

17. A FLASH PHOTOGRAPHY PRIMER Focal Plane Shutters vs. Leaf Shutters Focal Plane Shutter Leaf Shutters Focal plane shutters have a maximum flash sync speed which is slower than their maximum mechanical speed. This is due to the fact that there are two blades in a focal plane shutter and how these two blades move at different shutter speeds. Leaf shutters will sync to flash at all shutter speeds. This is because the flash is not triggered until the shutter blades (right) are all fully open. (FLASH IS TRIGGERED)

19. A FLASH PHOTOGRAPHY PRIMER First and Second Curtain (Front & Rear) Sync. First (front) curtain sync Second (rear) curtain sync Many cameras offer the possibility to synchronize either on the 1st or 2nd curtain. With 1st curtain sync. the flash is fired as soon as the 1st curtain is in upward position while with 2nd curtain sync. the flash is fired just before the 2nd curtain moves upwards. Obviously this means that the natural (ambient) light of a scene exposes the film/sensor either after or before the flash burst. If you shoot a fast moving object with 2nd curtain sync. you'll get a blurred moving effect which will end in the (flash-) exposed object. With 1st curtain sync. it'll be the other way round.

20. A FLASH PHOTOGRAPHY PRIMER Hi-speed (FP) Flash Synchronization Focal plane (FP) flash seems to be a quite new technology but surprisingly the concept is already known for some decades. It allows faster sync. speeds than just e.g. 1/200s. With very fast shutter speeds the opening between 1st and 2nd curtain is never as large as the whole film/sensor area so a single flash burst would lead to a partially exposed film. As a solution you have to have a constant flash light for the whole exposure time. Unfortunately modern flash units have a peak emission characteristic so a single flash is not usable for this purpose. Today most manufacturers use a series of high frequency flash bursts (say 50 kHz) with reduced single light emission to simulate a (theoretically) long single constant flash burst.

21. A FLASH PHOTOGRAPHY PRIMER Flash Sync and Shutter Speeds Starting in the early and middle 1950's a number of cameras were made with a flash sync position called "FP" which means the same then as it does now. It is a high-speed flash sync for use with focal plane shutters at speeds of 1/100th second and faster, and flash bulbs. As today, this feature was found generally only on the higher end cameras during the flash bulb era, mostly professional grade models. An examples of these cameras is the Zeiss Ikon Contax IIa and IIIa Color Dial. These were introduced to the market in 1954 and had " M " sync for shutter speeds of 1/30th second and slower, " X " sync for 1/50th second (for electronic strobe flash!), and " FP " sync for 1/100th second and faster. Standard flashbulbs (designed for "M" [20ms to peak output] and "F" [5ms to peak output] synchronization) did not have a long enough peak light output for the "FP" sync even though the duration of their light output is very long compared to an electronic strobe's. A special long-duration or "FP" bulb had to be used with this sync. FP sync  X (flash) sync  M sync

22. A FLASH PHOTOGRAPHY PRIMER Red Eye Reduction What is “Red Eye”? What causes it? and what can I do to prevent or fix it? “ Red Eye” is the appearance of eyes which are red in color photographs. “ Red Eye” is caused by light which enters the eye and bounces off the blood vessels in the back of the eye. Since the pupil is actually a clear lens the effect is to give a glowing appearance to the red color of the blood. The reason that this red color can be seen in photographs is that the angle that the light from the flash enters the eye is too similar to the angle that the light leaving the eye is from the lens axis. To prevent “Red Eye”, simply move the flash source away from the lens. The thing to keep in mind here is that the angle of incidence is equal to the angle of reflection. Some flash units have a red eye reduction feature which causes a pre-flash that causes the pupil to close down thereby reducing the appearance of “red eye” when the actual photograph is taken. This causes a delay in the time that the desired expression is captured and, as a result, these expressions may be missed. If you have photographs that already have “Red Eye” this can be corrected in most photo editing programs like PhotoShop, Lightroom, iPhoto and many others.

23. A FLASH PHOTOGRAPHY PRIMER

24. A FLASH PHOTOGRAPHY PRIMER Types of Flash

25. A FLASH PHOTOGRAPHY PRIMER Types of Flash Manual

26. A FLASH PHOTOGRAPHY PRIMER Types of Flash Shoe Mount

27. A FLASH PHOTOGRAPHY PRIMER Types of Flash Automatic

28. A FLASH PHOTOGRAPHY PRIMER Types of Flash TTL, e-TTL, i-TTL, CLS

29. A FLASH PHOTOGRAPHY PRIMER Types of Flash Ring flash

30. A FLASH PHOTOGRAPHY PRIMER Types of Flash Monolight

31. A FLASH PHOTOGRAPHY PRIMER Types of Flash Studio Power Pack

32. A FLASH PHOTOGRAPHY PRIMER Types of Flash Stroboscopic

33. A FLASH PHOTOGRAPHY PRIMER Types of Flash Potato masher

34. A FLASH PHOTOGRAPHY PRIMER Types of Flash Thyristor

35. A FLASH PHOTOGRAPHY PRIMER Light Modifiers

46. A FLASH PHOTOGRAPHY PRIMER Flash Accessories

47. A FLASH PHOTOGRAPHY PRIMER Flash Accessories Sync Cords

48. A FLASH PHOTOGRAPHY PRIMER Flash Accessories SLAVES Photo Radio Infrared

49. A FLASH PHOTOGRAPHY PRIMER Flash Accessories Hot Shoe to PC Adapters

50. A FLASH PHOTOGRAPHY PRIMER Flash Accessories TTL off-camera cables

51. A FLASH PHOTOGRAPHY PRIMER Flash Accessories SCA adapters (to match a given flash to different manufacturer’s cameras)

56. A FLASH PHOTOGRAPHY PRIMER Presented by Chris Moore Media – Photography (347) 326-5154