Precaution for Nikon F90-Series/N90 users As the locking wheel is tightened, the SB-25 is firmly attached to the accessory shoe with the mount pin. Be extra careful that the locking wheel is completely loosened before removing the flash unit from the camera or it may cause damage to both units.
Replace batteries with a fresh set: With alkaline-manganese batteries replace if readylight takes more than 30 sec. to light up. With NiCd batteries remove if ready-light takes more than 10 sec. to light up.

Page 24

Adjustment Functions Using LCD Panel and Built-in Functions
Tilting/rotating flash head, built-in zoom head, LCD panel and control buttons for aperture/distance computation. The SB-25 features many convenient functions. Proper use will help you perform successful flash photography in every situation. Before practice, you should understand the adjustments and reasons behind them. Once you have learned them, you can make the most of the SB-25 for all kinds of flash techniques. Operation can be controlled manually or automatically, depending on which Nikon SLR model is used. Manual operation is described for each feature, then automatic adjustment features are described within the boxed sections (with a mark). Before proceeding: ATTACH SPEEDLIGHT TO CAMERA. TURN ON BOTH SPEEDLIGHT AND CAMERA.
Adjusting Flash Head To Horizontal/Front Position
In normal shooting situations, the flash head should face straight forward, tilted in the horizontal position. A tilted/rotated head can be used for special techniques such as close-ups or bounce flash photography.
Tilting/Rotating flash head to a position other than horizontal and straight forward Downward-tilted flash head (-7 position) is used for taking pictures of subjects at a distance of less than 1.5m (approx. 5 ft.). When the head is set at this position, the distance indicator bars blink. An upward-tilted and/or rotated flash head is used for bounce flash photography. When the head is set this way, the distance indicator bars do not appear, to show the distance indication function is not available. See Diffusing Light To Soften Harsh Shadows, pages 119 to 123, for information on bounce flash photography.
Tilt the flash head to the horizontal, until it click-stops.
The flash head locks both at the horizontal, facing straightforward (0 degree), and at the vertical, facing straight-up (90 degrees). To release from the locked position, slide the lock release lever in the > direction, then, while holding the lever, tilt the flash head.

Page 36

Chapter 3 TTL Auto Flash
Setting Up Your Camera Confirming Settings
Select one of the following exposure modes: a. Programmed auto (P or Ps) b. Shutter-priority auto (S) c. Aperture-priority auto (A) d. Manual exposure mode (M) Select a metering system: a. Matrix metering system b. Center-Weighted metering system c. Spot metering system
Perform other settings: a. For programmed auto, set lens to minimum aperture (highest f-number). b. For shutter-priority auto, set lens to minimum aperture (highest f-number), then set desired shutter speed*. c. For aperture-priority auto, set desired aperture. d. For manual exposure mode, set desired shutter speed* and aperture.
* Camera automatically shifts to the fastest synchronization speed if you choose a speed that is not within the synchronization range.
Selecting an exposure-metering system on the F90Series/N90 camera Either 3D Multi-Sensor Balanced or Multi-Sensor Balanced Fill-Flash will operate regardless of exposure meter system chosen, when the camera is used with a Dtype Nikkor, an AF Nikkor (except for F3AF) or an AI-P lens. Choose a meter to measure background exposure that most effectively meets the photo requirements you wish to achieve.
Quick reference on the relationship between usable apertures and flash shooting distance Use the table on page 142 in this instruction manual.
Look into camera viewfinder, compose and lightly press the shutter release button. Use AE-L (Auto Exposure Lock) on the camera to capture exact exposure information for your picture composition (except when in manual exposure mode). Confirm controlled aperture and shutter speed. These also appear in the cameras LCD panel. The aperture in use (shown in the viewfinder) and shooting distance indicator bars appear in the SB-25s LCD panel.
Over-/Underexposure warning (background exposure) For overexposure alert, HI or a + (positive) value appears in the F90-Series/N90 viewfinder and LCD panel. For underexposure, electronic analog displays (in viewfinder and LCD panel) show Lo or a (negative) value.

Page 38

Firing Flash
Confirm shooting distance.
Check whether subject falls within the range shown by the shooting distance indicator bars in the SB-25s LCD panel. If not, move closer to subject or select a wide aperture (in aperture-priority auto or manual exposure mode). Then, repeat steps 9 and 10.
Confirm ready-light has come on and subject is in focus. Confirm ready-light is on in the cameras viewfinder or on the SB-25. Check whether subject is in focus by using the in-focus indicator I in the cameras viewfinder.

Automatic zoom-head/aperture adjustment: AF Nikkor lens (including the latest D-Type) or Nikkor lens having a built-in CPU The aperture and zoom-head position in use are automatically set and indicated in the SB-25s LCD panel. For other lenses, set manually according to the shooting situation. See Setting Aperture Value (Manual Adjustment), pages 28 and 29, and Setting Zoom-Head Position (Manual Adjustment), pages 29 and 30.
42 value and zoom-head position
Confirm the ISO film speed has been set and appears in the SB-25s LCD panel (automatic ISO film speed adjustment). ISO speed of the film in use is automatically set. If not shown in the LCD panel, lightly press the cameras shutter release button. Confirm the aperture value chosen on the camera and zoom-head position have been set and appear in the SB-25s LCD panel (automatic aperture/zoom-head adjustment).

Page 44

Mode: For F4-Series, F-801/N8008 and F-801s/N8008s Users
Select one of the following exposure modes: a. Programmed auto (either P, PH, PH or PD) b. Shutter-priority auto (S) c. Aperture-priority auto (A) d. Manual (M) Select a metering system: a. Matrix metering system to perform Matrix Balanced Fill-Flash. b. Center-Weighted metering system to perform Center-Weighted Fill-Flash. c. With the F-801s/N8008s, Spot metering system to perform Spot Fill Flash. d. Any metering system can be chosen to perform Standard TTL Flash.

F4-Series

F-801/N8008 and F-801s/N8008s
Look into camera viewfinder, compose and lightly press the shutter release button. Use AE-L (Auto Exposure Lock) on the camera to capture exact exposure information for your picture composition (except when in manual exposure mode). Confirm controlled aperture and check that the shutter speed falls between 1/60 sec. and 1/250 sec. With F-801/N8008 or F-801s/N8008s, these also appear in the cameras LCD panel. The aperture in use (shown in the viewfinder) and shooting distance indicator bars appear in the SB-25s LCD panel.
Overexposure warning (background exposure) For overexposure alert, HI appears (together with lens minimum aperture for the F-801/ N8008 and F-801s/ N8008s). in the position that indicates the cameras shutter speed.

Page 46

Check whether subject falls within the range shown by the shooting distance indicator bars in the SB-25s LCD panel. If not, move closer to subject or select a wider aperture (in aperture-priority auto or manual exposure mode), then repeat steps 9 and 10.
Fully depress the shutter release button to fire flash. Check again whether ready-light is blinking. Controlled shutter speed and aperture in Matrix Balanced Fill-Flash/Standard TTL Flash When the SB-25 is set at position (for flash sync mode selector), the camera automatically controls the shutter speed and aperture between 30 1/250 sec. in programmed auto and aperture-priority auto exposure mode.

Cameras Exposure Mode Programmed auto (PDUAL, P or PHI) Aperture-priority auto (A) Manual (M)
AI-S type lenses (including AF Nikkor and AI-P) 2)
1) Suitable lenses and use depend on the camera; see instruction manual for information. 2) Except AF lenses for F3AF cameras. For Programmed TTL Auto Flash, use only AI-S lenses, which include AF Nikkor, Nikkor lenses with a built-in CPU and Series E lenses.
You can choose Programmed TTL Auto Flash against Standard TTL Flash by setting camera to a programmed auto exposure mode (either PDUAL, P or PHI). Check charts on the previous page. Before proceeding: ATTACH SPEEDLIGHT TO CAMERA. TURN ON BOTH SPEEDLIGHT AND CAMERA. USE SINGLE-SERVO AUTOFOCUS (S) OR MANUAL FOCUS (M). USE SINGLE-FRAME SHOOTING (S) FILM ADVANCE MODE. USE FILM WITH A SPEED BETWEEN ISO 25 AND ISO 1000. USE AN AI-S LENS (AF Nikkor, Nikkor lens with built-in CPU or Series E lens).

2 Flash sync mode

selector at NORMAL

3 ISO speed 7 Aperture

To distinguish AI-S lenses from others Look for an orange mark on the minimum aperture scale of the lens.

Page 66

Setting Up Your Camera Confirm Settings
Mode: For F-501/N2020 and F-301/N2000 Users
Select one of the following exposure modes: a. Programmed auto (either PDUAL, P or PHI) to perform Programmed TTL Auto Flash. b. Aperture-priority auto (A) to perform Standard TTL Flash. c. Manual exposure mode to perform Standard TTL Flash. Perform other settings: a. For programmed auto, set lens to minimum aperture (highest f-number). b. For aperture-priority auto, set desired aperture. c. For manual exposure mode, set desired shutter speed* and aperture.
Set ISO speed of film in use. Usable film speeds are ISO 25 to ISO 1000. For instruction, see Setting ISO Film Speed (Manual Adjustment), pages 27 to 28. Set the built-in zoom head position.
For instruction, see Setting Zoom-Head Position (Manual Adjustment), pages 29 to 30. Shooting indicator bars in the LCD panel move as the figure input changes.
Set aperture in the SB-25s LCD panel*.
For instruction, see Setting Aperture Value (Manual Adjustment), pages 28 to 29. In programmed auto exposure mode, aperture is automatically controlled by the camera. Choose a value, using Shutter speed/aperture settings in Programmed TTL Auto Flash in the following page. In aperture-priority auto or manual exposure mode, set the aperture value that you have set on the camera (from step 6). Once aperture is set, indicator bars show the shooting distance range.

Push button for a test firing (see page 110) when you are not sure whether subject is within the flash shooting range. If ready-light blinks for a few seconds after test firing, flash has fired at its maximum output but light might not have been sufficient. Select a wider aperture or move closer to subject.
Look into the camera viewfinder, compose and lightly the press shutter release button to confirm that subject is in focus. Check that ready-light is on in the cameras viewfinder or on the SB-25.
Exposure compensation Exposure compensation in Non-TTL Auto Flash mode is achieved by purposely setting a different aperture value on the camera (actually on the lens in most cases) than on the SB-25. Use an aperture 1/3 to one stop smaller for an entirely dark background (low reflectance). For backgrounds that include a highly reflective object, use an aperture 1/3 to one stop larger. Note that shooting distance range indication corresponds to the aperture value set on the SB-25 not on the camera. In general, you may want to take a series of pictures using exposure bracketing.
If ready-light blinks for a few seconds after shooting, flash has fired at maximum output but the light may have been insufficient. Reconfirm shooting distance and, if necessary, move closer to subject or select a wider aperture to compensate underexposure.

Page 84

Manual Flash
Mode Manual Light-Output Control
Before proceeding: ATTACH SPEEDLIGHT TO CAMERA. TURN ON BOTH SPEEDLIGHT AND CAMERA. USE APERTURE-PRIORITY AUTO OR MANUAL EXPOSURE MODE. USE SINGLE-SERVO AUTOFOCUS (S or A) OR MANUAL FOCUS (M). USE SINGLE-FRAME SHOOTING (S) FILM ADVANCE MODE. Set Up and Practice
With the SB-25s flash mode selector at , you can perform manual flash photography. For manual flash photography, it is important to choose an appropriate aperture and shooting distance to achieve your desired effect. To help approximate these variables, you can use the SB-25s LCD panel and control buttons as a calculator, or use guide numbers (see page 118). To enhance this feature, the SB-25 lets you manually adjust flash output levels from full power (1/1) to 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, and FP1 and FP2.

at Manual Flash

Choose position (flash mode selector). Confirm appears in the LCD panel. Choose tor*). position (flash sync mode selec-

6 Aperture

position is used for Rear-Curtain Sync Flash, and only with the F90Series/N90, F4-Series, F-801/N8008, and F-801s/N8008s. For details, see page105.

4 Flash output level

Set ISO film speed and the built-in zoom head position.
For instructions, see Setting ISO Film Speed (Manual Adjustment), pages 27 to 28, and Setting Zoom-Head Position (Manual Adjustment), pages 29 to 30. Automatic ISO film speed/zoom-head position adjustment: F90-Series/N90, F4-Series, F-801/ N8008, or F-801s/N8008s used with an AF Nikkor lens (including the latest D-Type) or Nikkor lens having a built-in CPU The film speed and zoom-head position in use are automatically set and indicated in the SB-25s LCD panel. For other lenses, set manually according to the shooting situation. See Setting ISO Film Speed (Manual Adjustment), pages 27 to 28, and Setting Zoom-Head Position (Manual Adjustment), pages 29 to 30.

Page 86

Chapter 3 Manual Flash Mode
button to choose desired light output.
You can choose an amount ranging from full power (1/1) to one sixty-fourth (1/64). LCD indications change as: -. With the F90-Series/N90, indication , and then will appear after. At the same time, appears next to. This applies exclusively to FP High-Speed Sync Flash and is discussed in the following pages (see pages 98 to 103).
Fine light-output adjustment: F90-Series/N90 with AF Nikkor lens (including the latest D-Type) or Nikkor lens having a built-in CPU Additionally, you can manipulate light output in finer increments of 1/3, as long as light output is set between and. Press button and confirm appears in the SB-25s LCD panel. By pressing button, you can increase the light amount by +1/3 (blinking below the mark), by +2/3 (blinking ), or by +1 (blinking ). To decrease, use in the same manner; blinking numbers change from (by -1/3) to (by -2/3) to (by -1).
Automatic aperture adjustment: F90-Series/ N90, F4-Series, F-801/N8008, or F-801s/ N8008s used with an AF Nikkor lens (including latest D-Type) or Nikkor lens having a built-in CPU The aperture in use and an indicator bar are automatically indicated in the SB-25s LCD panel. With other lenses, you must operate manually and follow steps 6, 7 and 8. To skip steps 6, 7 and 8, check that subject is standing at the location suggested by the LCDs measurement scale. If not, change aperture by turning the lens aperture ring to adjust the bar.

Determining shutter speed with number/speed of flash Frequency (Hz) represents the number of flash fired per second. For example, 10Hz will fire 10 times in one second. Or, because firing the flash five times takes 1/2 sec. at 10Hz, the shutter speed must be adjusted to at least as slow as 1/2 sec. For another example, firing six times at 8Hz takes 6/8 sec. to occur. However, because your camera does not have a shutter speed of 6/8 (0.75) sec., you should set it to the closest slower shutter speed, which is one second. The following equation can be applied to calculate an appropriate shutter speed: [Number of flash per frame] [Shutter speed] [Speed of flash (Hz)] where the result (shutter speed) must be rounded off to the closest slower shutter speed available with your camera.
Number of repeating flashes per frame (shown with blinking ) : Figures indicate use with External Power Source hyphens SD-7 or SD-8 Light output amount Flash speed per second Hz Hz Hz 40 93

Page 94

Set the same aperture value in the SB-25s LCD Panel that you set on the camera (step 7). For instruction, see Setting Aperture Values (Manual Adjustment), pages 28 to 29. An indicator bar appears to show appropriate shooting distance for the selected aperture.
Automatic aperture adjustment: F90-Series/ N90, F4-Series, F-801/N8008, or F-801s/ N8008s used with an AF Nikkor lens (including latest D-Type) or Nikkor lens having a built-in CPU The aperture in use and an indicator bar are automatically indicated in the SB-25s LCD panel. With other lenses, you must operate manually following steps 8, 9 and 10. To skip steps 8, 9 and 10, check whether subject stands at the location suggested by the LCDs measurement scale. If not, change the aperture by turning the lens aperture ring to adjust the bar. Finally, perform minus exposure compensation* to prevent overexposure of overlapping imagesuse the aperture ring to choose another aperture one or two stops smaller than indicated above.
* The aperture indicated by the LCD provides a correct exposure with the very first flash, whereas overlapped images are illuminated from the second flash on. It is advisable to take a few additional shots at different apertures (exposure bracketing).
If necessary, press or button to reset the indicator bar so it points at the measurement scale that matches or nearly equals the actual flash-to-subject distance (can be read this from the lens barrel). Manipulating the indication bar causes aperture value in the LCD panel to change. Reset aperture value on the camera.
Look into camera viewfinder, compose and lightly press the shutter release button to confirm that subject is in focus. Check that ready-light is on in the cameras viewfinder or on the SB-25. Fully depress shutter release button to fire flash.

Use an aperture one or two stops smaller than the LCD panel indicates. This will prevent overexposure for overlapping images (minus exposure compensation).*
* Subject will be correctly exposed with the very first flash, but successive overlapping images (form the second flash on) will not be properly exposed, unless you perform minus exposure compensation as indicated in steps 9 and 10. We recommend you take a few additional shots at different apertures (exposure bracketing).
Background brightness and subject overlap Use as dark a background material as possible (e.g., black curtain or cloth). If the overlapping exposed images are too weak or too strong, try repositioning subject at the location suggested by the indicator bar (or adjust indicator bar). Conditions vary for each situation try experimenting.

Page 96

Chapter 4
Flash-Shooting Applications

Page 98

FP High-Speed Sync Flash Flash Photography At Higher Shutter
Unlike other Nikon SLR models the F90-Series/N90 camera and the SB-25 allow you to use faster shutter speeds up to 1/4000 sec. for flash synchronization. Ordinarily the flash fires only when the curtains are fully opened in regular flash syncs. With FP High-Speed Sync Flash, the flash consecutively emits light at an extremely rapid cycle, while the shutter curtains travel to expose the entire film surface but the curtains are never fully opened (i.e. exposure with a slit). By using a high-speed shutter and flash simultaneously, you can create light flow from a rapidly moving subject. In outdoor photography, it also enables you to use both a wider aperture and a faster shutter speed to achieve a shallower depth of field and purposely blur the subjects background. Note that a guide number for FP High-Speed Sync Flash varies with the selected shutter speed and it is smaller than for regular flash synchronization (i.e. smaller light output). Furthermore, we recommend you use shutter speeds between 1/250 and 1/4000 sec. to avoid uneven exposure. Before proceeding: ATTACH SPEEDLIGHT TO CAMERA. TURN ON BOTH SPEEDLIGHT AND CAMERA. USE MANUAL EXPOSURE MODE. USE SINGLE-SERVO AUTOFOCUS (S or A) OR MANUAL FOCUS (M). USE SINGLE-FRAME SHOOTING (S) FILM ADVANCE MODE.

Speeds

Choose position (flash mode selector). Confirm appears in the LCD panel. Choose tor)*. position (flash sync mode selec-
* FP High-Speed Sync Flash operation can be performed regardless of the flash sync mode selector setting; for simplicity, always leave the switch at this position.

To unlock, press the same buttons simultaneously for a few seconds until the indication stops blinking or totally disappears.
Automatic zoom-head position adjustment: F90Series/N90, F4-Series, F-801/N8008, or F-801s/ N8008s used with an AF Nikkor lens (including the latest D-Type) or Nikkor lens having a built-in CPU
The SB-25 automatically adjusts the zoom-head position to provide an angle of coverage that matches the focal length of the lens in use. For details, see page 30.

Page 114

AF Assist LED Autofocus Flash Photography in Dim Light
The SB-25s AF assist LED enables you to perform autofocus flash photography in dim light or even total darkness with some Nikon AF cameras. When ambient light is insufficient for autofocus operation, the AF illuminator automatically turns on to start operation and give contrast to a dark subject, allowing the cameras autofocus system to function as though it were daytime. If ambient light is sufficient, the AF illuminator does not light up. Before proceeding: ATTACH SPEEDLIGHT TO CAMERA. TURN ON BOTH SPEEDLIGHT AND CAMERA. USE SINGLE-SERVO AUTOFOCUS (S or A) USE SINGLE-FRAME SHOOTING (S) FILM ADVANCE MODE Hints and Notes In Rear-Curtain Sync Flash with the F-601/N6006, a light pattern from the AF assist LED sometimes affects the picture. To prevent this, confirm that the LED light pattern has disappeared before shooting. Usable autofocus lenses are: With Nikon F-501/N2020: AF Nikkor lenses from 35mm to 105mm (including the latest D-Type) With other cameras: AF Nikkor lenses from 24mm to 105mm (including the latest D-Type) Notes on AF assist LED Autofocus distance range with AF assist LED depends on the lens in use and subjects reflection ratio. For example, with an AF Nikkor 50mm f/1.8 lens (including the latest D-Type lens) and a subject having 35% reflection ratio, you can perform autofocus from approx. 1m (3.3 ft.) to approx. 8m (16.4 ft.), at 20C (68F). If the ready-light does not stay on after the AF assist LED activates, replace batteries.
Check that the SB-25s ready-light has come on. Lightly press the cameras shutter release button to activates the AF illuminator LED. Do not use autofocus lock function. APPLICABLE NIKON SLR MODELS F90-Series/N90 F4-Series F-801/N8008 F-801s/N8008s F-601/N6006 F-601M/N6000 F-401x/N5005
F-501/N2020 Nikonos V F-301/N2000 F3-Series F-401/N4004 F2-Series F-401s/N4004s FM2 FA FG-20 FE2 FG
Confirm whether in-focus indicator LED I in the cameras viewfinder appears. If the in-focus indication does not appear inside the viewfinder, the subject is beyond the autofocus distance range (see at right Notes of AF assist LED); focus manually on the clear matte field.

Page 116

Power Switch Standby (STBY) Position To Conserve Energy and
Setting the power switch to STBY position turns on the SB-25, but the SB-25 will also automatically shut off to conserve flash battery energy. When you will not use the SB-25 for a long time, however, it is recommended to set the power switch to OFF. Hints and Notes

Shorten Recycling Time

When using a remote cord with the FA or FE2 connected to Nikon Motor Drive MD-12, camera remains on as long as the MD-12s power switch is on. In this case, the SB-25 will not turn off in STBY position. Use OFF position to turn it off manually. You cannot use the STBY position to turn on the SB-25 when using it with an FA, FE2 or FG set on a mechanical shutter setting (M250 or B setting with the FA or FE2, M90 or B setting with FG or Nikonos V). Use ON position to turn it on manually.
With the SB-25s power switch on standby (STBY) position, the unit turns off to conserve energy approx. 80 sec. after the cameras meter has turned off. To turn the SB-25 on again, lightly press the shutter release button to turn the cameras meter on, or push the SB-25s open-flash button. APPLICABLE NIKON SLR MODELS F90-Series/N90 F4-Series F-801/N8008 F-801s/N8008s F-601/N6006 F-601M/N6000 F-401x/N5005

Page 118

Guide Number To Calculate a Proper Aperture
The guide number helps you determine a correct aperture or f/stop value for using the SB-25s Manual Flash and Repeating-Flash mode. (See Guide number chart, page 139.) Use the following equation for your calculations, and check the following chart for guide numbers at various film speeds. [guide number] [f/stop] = [flash-to-subject distance] For example, when shooting a subject located 9 m (approx. 30 ft.) away at 1/1 (full) light output in (Manual Flash) mode, with a zoom-head position of 35mm and a film speed of ISO 100, you will obtain a guide number of 36 (or 118) from the same chart on page 139. If measuring in meters; 36 [f/stop] = 9 = 4 Or, if measuring in feet; 118 [f/stop] = 30 = 3.You should then choose f/4 as the proper aperture. For films other than ISO 100, multiply the above figures by the factors shown in the following chart:
Adjustment factors for other ISO film speeds ISO film speed Factor 100 xx 1.xx 2.x4
Diffusing Light To Soften Harsh Shadows
With a subject in front of a wall, a direct flash causes harsh and unattractive shadows. By bouncing the light off the ceiling or walls, or by diffusing the light with card(s) or paper, you can soften harsh shadows and create attractive portraits. The SB-25 comes with a built-in diffuser. You can use it alone or with a combination of other reflecting surfaces for advanced application. There are a few ways to diffuse light: 1. Bounce light off a broad reflective surface such as the ceiling. 2. Use both the ceiling and the built-in diffuser card to create a catchlight for subject's eyes. 3. Use a diffuser between the flash and the subject.

ISO film Speed and coefficient ISO film speed Coefficient* 100 or lower 4 (14) 8 (26) 500 or higher 11 (36)
Position the SB-25 so light from the head covers the subject. Mount the built-in flash adapter. The zoom-head position is automatically adjusted. Confirm the LCD panel shows with indication. Use aperture-priority auto or manual exposure mode. Choose position (flash mode selector) for TTL Auto Flash operation. For further instruction, see the TTL Auto Flash Mode section relating to your camera type. APPLICABLE NIKON SLR MODELS F90-Series/N90 F4-Series F-801/N8008 F-801s/N8008s F-601/N6006 F-601M/N6000 F-401x/N5005
* Numbers in parentheses ( ) represents coefficients for foot measurement system.
Determine the aperture or f/stop value using the following equation and chart, then set on the lens. The SB-25s LCD panel cannot be used to compute shooting distance. [coefficient] [f/stop] [flash-to-subject distance]

Page 126

Multiple Flash Photography Using More Than One Speedlight
If you have another flash unit, you can use it as a secondary light source for multiple flash photography. When you use only one flash unit in front of a subject, harsh shadows may be produced or light may not reach the background. Using more than one flash unit helps you solve these problems. Carefully consider the number of flash units to use and their locations. For better results, position each unit so its light can brighten a shadow created by another. See also System Chart for TTL Multiple Flash, pages 130 and 131.
Precaution for Rear-Curtain Sync Flash Rear-Curtain Sync Flash can be performed in multiple flash photography only with the F-601/N6006 and F-601M/N6000 cameras. Rear-Curtain Sync Flash cannot be performed in multiple flash shooting with F90-Series/N90, F4Series, F-801/N8008 and F-801s/N8008s cameras.
Caution To avoid damage to flash units or incorrect operation, never mix Nikon Speedlights with flash units of other manufacturers.

Page 128

Chapter 4 Multiple Flash Photography
TTL Multiple Flash Photography
type) or AI-P lenses to perform Center-Weighted or Spot Fill-Flash, or (3) performing Standard TTL Flash.
* Because 3D Multi-Sensor and Multi-Sensor Balanced Fill-Flash take advantage of the SB-25s Monitor Preflash and the cameras TTL Multi-Sensor, it is difficult to manage such fill-flash operations for TTL Multiple Flash Photography, especially when using the SB-25 as a master flash unit with other slave flash unit(s). The Sensor system is designed to analyze Monitor Preflash reflection from a single SB-25 (ideally, mounted on the camera) and to control light output from that particular unit, but not from the other slave(s).
Manual Multiple Flash Photography
Use the ON position to activate a slave flash unit; the STBY does not function (SB-25, SB-24, SB-22 and SB-20). The SB-23 offers only OFF and TTL/STBY positions for power switching. This means it cannot be used as a slave.

Shooting distance range in TTL mode: 0.6 20m (ft.). A mode : For Non-TTL Auto Flash operation, light is measured via light sensor in front of the flash unit. Usable apertures in A mode: f/2, f/2.8, f/4, f/5.6, f/8 and f/11 (at ISO 100) Shooting distance range in A mode: 0.6 20m (ft.). M mode : For Manual Flash operation, light output amount can be varied from 1/1 (full) to 1/64 output (total of 18 steps in 1/3 increments). Flash sync mode selector: position is used for front-curtain sync with all the cameras listed in this manual. position is used for Rear-Curtain Sync flash with F90-Series/N90, F4-Series, F-801/N8008 and F-801s/N8008s. Red-eye reduction control: Preflashes are fired to reduce the likelihood of red-eye effect when used with F90-Series/N90. AF assist LED: In insufficient light, automatically fires LED beam toward subject when performing autofocus with Nikon F90Series/N90, F4-Series, F-801/N8008, F-801s/N8008s, F-601/N6006, F-401x/N5005, F-501/N2020, F-401/ N4004 or F-401s/N4004s.
Ready-light/Open-flash button : Indicates recharged battery power (ready-light). In TTL Auto and Non-TTL Auto Flash mode, indicates possible underexposure by blinking. In Non-TTL Auto Flash mode, can be used as a test-firing button for lightamount detection. In Repeating Flash mode, can be used as a test-firing button for preset strobo flashes. Built-in diffuser card: In bounce flash photography application, creates natural lighting for catchlight in subjects eyes. Mount pin: Fixes F90-Series/N90 on the hot shoe. LCD panel illuminator: Activated with button. Illumination lasts approx. eight seconds; same button turns illumination off. Flash shooting distance scale: Measurement systems can be switched between meters and feet using the lever inside the battery chamber. FP High-Speed Sync flash: Available with the F90-Series/N90. Enables higher shutter speeds (1/250 sec. or faster) for flash synchronization. Monitor Preflash: Available with F90-Series/N90 cameras when used with an AF Nikkor lens. Other features: External power source terminal, TTL multiple flash terminal and Sync/multiple flash terminal.
Dimensions (W x H x D): Approx. 79 x 135 x 101mm (3.1 x 5.3 x 4.0 in.) Weight (without batteries): Approx. 380g (13.4 oz.) Accessory provided: Soft Case SS-24 Specifications and designs are subject to change without notice.

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Usable Aperture/Flash Shooting Distance Ranges In TTL Auto and Non-TTL Flash Modes
ISO film speed 1600 2.5.2.5.400 1.2.5.200 1.2.5.Zoom set at 20mm 2.1.1.0.0.7 7.0 0.6 5.0 0.6 3.5 0.6 2.5 0.6 1.7 0.6 1.2 Zoom set at 24mm 3.2.1.1.1.0.7 7.5 0.6 5.3 0.6 3.7 0.6 2.6 0.6 1.8 Shooting distance range (in meters) Zoom set Zoom set Zoom set at 28mm at 35mm at 50mm 4.4.5.2.3.3.2.2.2.1.1.1.1.1.1.0.7 8.0 0.8 9.0 1.0.6 5.6 0.6 6.3 0.7 7.4 0.6 4.0 0.6 4.5 0.6 5.2 0.6 2.8 0.6 3.2 0.6 3.7 0.6 2.0 0.6 2.3 0.6 2.6 Shooting distance range (in feet) Zoom set Zoom set Zoom set at 28mm at 35mm at 50mm 9.6.7.8.4.5.6.3.3.4.2.2.3.2.2.2.2.2.2.2.0 9.2 2.2.2.0 6.5 2.0 7.3 2.0 8.6 Zoom set at 70mm 6.4.3.2.1.1.0.8 8.4 0.6 6.0 0.6 4.2 0.6 3.0 Zoom set at 85mm 6.4.3.2.1.1.0.8 8.8 0.6 6.2 0.6 4.4 0.6 3.1