Nikon D90

Trying Multiple Exposure Is A Fun Shooting

Multiple exposure lets you combine two or more exposures into one image without using any post processing software like Photoshop. This option is only available in P, S, A and M mode. Sometimes it’s fun to do an experiment with your camera settings and if you are planning for fun shooting, trying multiple exposure is one good option. Nikon offers a feature called "Multiple Exposure" which combines two or more images inside the camera using the RAW data from the sensor, producing images that are blended together smoothly. If you are interested to try this feature on your camera, let’s go and see how to setup the camera to blend multiple exposure shots in a single frame.

Camera settings for Multiple Exposure

Multiple Exposure Menu on Nikon D90

Multiple Exposure Menu on Nikon D90

1. Go to the Shooting menu by pressing the Menu button on the back of your camera.

2. Choose Multiple Exposure from the Shooting menu.

3. Select the Number of shots you want to combine into a single frame. Nikon D90 allows you to select up to 3 shots.

Multiple-Exposure-No-of-Shots.jpg

4. Choose Auto Gain and select either ON or OFF. When ON is selected, Nikon D90 will divide the total exposure of the image by number of shots specified above. For example if you specified number of shots 2 and Gain is ON, each shot will get ½ of the total exposure. If Gain is OFF, total exposure is applied to an individual shot.

5. Press OK to set the Gain.

6. After you are done with these settings, scroll up to the Done and hit OK. Upon completion, you will see the Multiple Exposure icon (overlapping rectangle) on the LCD screen.

7. Now you are ready for the shot. When you take the first shot, Multiple Exposure icon on the LCD screen starts blinking until you finished shooting all the series (no of shots you specified). If you are in a continuous shooting mode, all the series will be shot in single burst shot. When you have taken all the series, blinking icon disappears and camera will turn off Multiple Exposure feature automatically.

Here are the couple of shots I took today to try out the Multiple Exposure. I set the number of shots 2 and shot couple of pictures with the Gain OFF and again I took another couple pictures with the Gain ON. I took all the series of the pictures with the exact same exposure settings. I didn’t use a tripod for these shots and that is why you can see little overlapping between the two frames when combined to a single shot. When you take two shots, camera will process itself and combine them into a single shot giving you the Multiple Exposure effects in a single image. I have seen people creating ghost effects using this technique which looks pretty cool.

Gain ON

Multiple Exposure Gain On

Multiple Exposure Gain On

Focal length : 24mm     Exposure : f/3.8     Shutter Speed : 1/60sec     ISO : 800

Gain OFF

Multiple Exposure Gain Off

Multiple Exposure Gain Off

Focal length : 22mm     Exposure : f/3.8     Shutter Speed : 1/60sec     ISO : 800

I used only one teddy bear to get this shot. What I did is, first I put the teddy bear on the left side and took a shot. Then, I put the same teddy bear on the right side and adjust a frame so that both can fit into a single frame after camera combines two images into one and took the second shot. After camera combined both shots, this is what I got as a result. It's not a perfect shot as I didn't use a tripod and didn't align the pictures properly but you can get an amazing effects using this technique if applied properly. Nice thing about this feature is that you don't have to use any software to get the effect, your camera will do it for you automatically.

How To Set Custom White Balance

White balance is the tool to help get the colors in your images as accurate as possible. White balance setting is based on the color temperature while shooting and those color temperatures are measured in a Kelvin scale. Higher the temperature, more blue light exists and lowers the temperature, more red light exists. You can take an example of fire; lower temperature fire produces red flame whereas higher temperature fire produces blue flame. As a photographer it is important to know that any light below 4000k starts to appear as a red light and any light above 7000k or so starts appearing bluish. In photography, you have to understand that warmer light means red or yellow and cooler light means blue light. You have to judge the environment and lighting condition where you are shooting and adjust the white balance accordingly to get the nice and pleasant effects to your photographs.

White Balance Menu on Nikon D90

White Balance Menu on Nikon D90

Nikon DSLRs come with the pretty standard predefined settings like Auto, Incandescent, Fluorescent, Direct Sunlight, Flash, Cloudy, Shade, Color temp and preset manual. Auto White Balance (AWB) works pretty well most of the time but sometime you need to change your settings to different available options. It's pretty easy to change the white balance option to one of the predefined settings. You just have to navigate through the white balance option from the menu button on the back of the camera (button location depends on your camera model) and select whatever value you want to set. If you are shooting under tungsten light bulb, you may want to change the white balance to Incandescent and if you are shooting outside, you may want to choose the direct sunlight and so on.

white-Balance-preset-manual-D90.jpg

If you want to set the custom White balance rather than what is already provided with your camera, you have an option in Nikon camera and it's called Preset Manual. If you scroll all the way down to the white balance setting, you will see the last option as a preset manual denoted by 'PRE'. If you have not setup custom white balance using the preset manual before, you will see bunch of blank memory slot denoted by d-0, d-1, and d-2 and so on. These are camera's memory slot to store the data from which it reads the white balance data if you choose to select the preset manual white balance instead of other predefined values we discussed earlier. Now let’s discuss how to set the custom white balance.

How to set the Custom White balance using Preset Manual?

1. Set your camera into P, S, A or M mode.

2. Press and hold the WB (White Balance) button while rotating the rear command dial to select 'PRE' in the control panel and then release the WB button. When white balance is in 'PRE' mode, you can use front command dial to change the memory slot from d-0 to d-1, d-2 or others if you want.

3. Press and hold the WB button for few seconds again and you will see 'PRE' starts blinking on the top LCD screen.

4. While 'PRE' is blinking, take a shot of white or grey index card (Note: 'PRE' blinks about 10 seconds and you have to take a picture while it is blinking).

5. If the camera was successful to get the white balance data from your photographs, it will display 'Good' on the LCD screen and if not, it will display 'no Gd' and you have to try again with the proper exposure.

6. After you complete the process and set your custom white balance, your camera will take the reference of that image while applying the white balance to your shots unless you have set your white balance to some other settings than PRE.

Choosing A Flash Sync Mode On Nikon D90

Nikon D90 has five flash sync modes but not all of the sync modes are available in every exposure modes. Depending on which exposure mode you are currently using, you can choose one of the available flash sync mode. These flash sync modes can be set by using a quick setting screen on the back of the camera or holding down the flash button on the front of the camera (near the lens mount on the left side) and rotating the main command dial (also known as the rear command dial) while the button is still being pressed. When you select a sync mode, you can see the currently selected mode on the LCD screen indicated by the corresponding icon as shown below.

We have already discussed about the front curtain sync and the rear curtain sync in detail in my previous blog post. And, in this blog post, I will describe all of the flash sync modes in brief and will see which mode is available in which exposure setting.

1. Front Curtain sync

Front-Curtain-Sync.jpg

In this mode, flash fires as soon as the front curtain opens completely. The shutter then remains open for the duration of the exposure, which is until the closure of the rear curtain. If you are shooting a moving subject, it will produce a stream of motion blur lights effects, also known as the ghost effect, in front of the subject. The reason behind this effect is - when the flash is fired at the beginning of the exposure, it freezes the subject with enough lights in the scene and then subject continues to move, which creates a blurred effect.

2. Rear Curtain sync

Rear-Curtain-Sync.jpg

When the flash is in rear sync mode, the front curtain opens completely and then remains open for the duration of the exposure. At the end of the exposure, the flash is fired and the rear curtain closes. If the subject is moving, you will get the ghost effect behind the subject because the flash light at the end of the exposure will freeze the subject.

3. Red-eye reduction

Red-eye-Reduction.jpg

In this mode, there is a one second lag after pressing the shutter release button and before the picture is actually taken. During the delay, camera’s red-eye reduction lamp lights which causes the subject's pupil to contract and thus reducing the potential red-eye effects.

4. Slow sync

Slow-Sync.jpg

Slow sync mode allows the camera to use the shutter speed as slow as 30 seconds when the flash is attached, which helps to balance the exposure of the overall scene by illuminating the background with the ambient light and the subject with flash light. It's better to use a tripod to avoid the camera shake if you are using a flash in slow sync mode.

5. Red-eye reduction with slow sync

Red-eye-reduction-with-Slow-sync.jpg

This mode combines the slow sync with the red-eye reduction behavior when using the Program or the Aperture priority exposure mode.

Which sync mode can be used with which exposure mode?

In Program, or Aperture Priority mode, you can use all five flash sync modes. In Shutter Priority, or Manual Exposure mode, you can use front curtain sync, rear curtain sync and red-eye reduction modes. And in auto, or portrait, or closeup, or scene mode, you can only use auto (same as front curtain sync) and red-eye reduction mode, whereas in Night Portrait mode, you can only use slow sync and red-eye reduction with slow sync mode.

Understanding Nikon's Flash Metering Mode

Metering is the technique, which is used to determine the optimal exposure for the subject and the overall scene based on the information camera gets from available light sources. Nikon uses the flash metering system to determine the flash output when the flash is set to auto (also called TTL or i-TTL) mode, and the camera metering system to determine the overall exposure of the image if the camera is set to A, S or P exposure mode. In manual (M) mode, you would take the reading from the camera metering system as a reference whether it is negative (underexposed) or positive (overexposed) and set the exposure values (Aperture, Shutter speed and ISO) manually to adjust the exposure. Nikon D90 and most of the other Nikon DSLRs support three types of Metering Modes, and they are Matrix Metering, Center-Weighted Metering and Spot Metering, which we discussed in previous blog.

In TTL mode, the built-in flash, as well as the external flash unit attached to the camera, adjusts the flash power to properly expose the scene by using the information from one of these three available metering modes. When the flash is set to TTL mode, choice of the camera metering mode determines whether the flash metering system, which shares the same metering sensor with the camera metering system, should consider the ambient light and balance the overall exposure or ignore the ambient light all together and only count the light from the main subject to determine the flash output power.

What is TTL mode?

Nikon’s latest DSLRs and the flash units use the TTL technique to determine the amount of lights reflecting from the scene and adjust the flash power accordingly. TTL stands for Through The Lens and it refers to the process of gathering information through the lens and passing that information to the metering system in order for the camera to deploy the appropriate flash power. Older camera systems either used manual calculations to determine the flash exposure or used a sensor in the flash itself rather than the metering sensor in the camera. And, i-TTL (intelligent-TTL) refers to the latest TTL flash system from Nikon. In latest Nikon cameras, TTL refers to i-TTL by default and I am using TTL and i-TTL interchangeably in this blog.

There are two types of i-TTL methods used in Nikon’s lighting system and the DSLRs, which are iTTL Balanced Fill-flash and Standard iTTL Fill-flash. Now, let’s talk about these two different TTL methods and discuss how they work differently.

1. iTTL Balanced Fill-flash (i-TTL/BL or TTL/BL)

Nikon's i-TTL (intelligent through-the-lens) Balanced Fill-Flash automatically balances the output of the Nikon Speedlight to match with the scene's ambient light. This flash mode is selected by the camera automatically when the flash is in TTL mode and the camera metering is in either Matrix Metering mode or Center-Weighted Metering mode. If the camera is set to A, S or P exposure mode and the flash is in i-TTL/BL mode, Nikon Speedlight fires the series of pre-flashes to determine the exposure value for the subject by taking the ambient light into account and send that information back to the flash metering system in the camera. The flash metering system then combines that information with the metering information from the camera metering system and the focal length information from the D or G lens to analyze and calculate the final flash output in order to balance the overall exposure. All of this complex processing happens in a fraction of a second, before each exposure, to provide unprecedented levels of flash precision and performance. This is a very powerful and easy to use technology from Nikon and probably one of the best in the industry.

iTTL Balanced Fill-in flash

iTTL Balanced Fill-in flash

In short, using this technology, Nikon DSLR measures the available light and then adjusts the flash output to produce a natural balance between the main subject and the background. It will reduce the harsh shadow as well as the highlights in the subject caused by the over powered flash.

2. Standard i-TTL Fill-flash

This mode is activated when the flash is in TTL mode and the camera metering is in Spot Metering Mode or if you are using the external flash and the flash is set to standard mode. In this mode, the flash output is adjusted only for the main subject in the frame, and the brightness of the background is not factored in while calculating the flash power. If the standard i-TTL Fill-flash is chosen by the camera by dialing the camera metering into the spot metering mode in A, S or P exposure mode, the background light is ignored and the camera will fire the flash to give you the correct exposure for the main subject only. If the overall exposure for the scene and the main subject is properly balanced without using the flash (shooing outside in bright daylight for example), using the standard i-TTL Fill-flash may overexpose the subject by adding the extra light to already properly exposed main subject. You should use this mode only when the flash is main source of the light for the subject (shooting in dark room for example) and you want to emphasize the main subject at the expense of the proper exposure for the background.

Standard i-TTL Fill-flash

Standard i-TTL Fill-flash

In this picture above, the exposure on the main subject was metered by the flash metering system by firing the pre-flashes on the main subject and then analyzed the light reflected from the main subject along with other information that camera provided, including the metering mode and the focal length. The flash metering system then adjusted the flash power and fired the flash just to illuminate the main subject. If you notice the background, which is relatively darker, was metered by the camera metering system and exposed by the ambient light only. The flash power was calculated by the flash metering system to expose the main subject only which was weakened by the time it reached to the background, and hence flash didn’t contribute for the background exposure at all.