Oct
14

Use ND filters for flash

by
Rebecca Greig

Professional portrait photographers generally favour underexposing the ambient light by two stops or more whenever they are using off-camera flash for outdoor portraits

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Professional portrait photographers generally favour underexposing the ambient light by two stops or more whenever they are using off-camera flash for outdoor portraits.

However, this makes it very difficult to simultaneously achieve shallow depth of field, which is also often preferred. Underexposing the ambient light requires apertures of around f11 or smaller, so the background behind your model will be in reasonably clear focus.

Though ND filters are often associated more closely with landscape photography, professional portrait photographers and videographers often make use of them to enable wider apertures to be employed when the ambient light is bright.

The only thing you need to keep in mind is that the ND filter will also limit the effective power output of the speedlight, so you’ll need to set it to a higher value and this will in turn cause the recycling time to increase. Fresh batteries will help with this, however.

If you’d like to apply this technique to your own photography, keep reading as we reveal the steps involved in the next few pages.


What you’ll need

DSLR
ND filter
Speedlight
Wireless triggers
Light stand
Light modifier


Shooting steps

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1  Switch to full manual mode With your camera activated, start off by turning the Mode Dial to ‘M’ to activate the full manual shooting mode. Next, set the shutter speed to 1/100sec, the ISO to the lowest value (usually 100) and finally dial in the widest possible apeture value – for our lens, this was f2.8.

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2  Setup your flashgun You’ll want to use your speedlight in its Manual mode, usually inidicated with an ‘M’. There’s a good chance you’ll end up on full power (1/1) in order to correctly expose your model, but start on half power (1/2) to see if that’s suffificient.

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3  Attach the triggers To shoot wirelessly, you’ll need a radio trigger unit for both the speedlight and the camera’s hotshoe. You must ensure that both devices are set to the same group and frequency values or the system won’t work. Take a test shot to check that everything fires correctly.

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4  Set-up and position the flash Secure the flashgun to the bracket on the lightstand. If you’re using a modifier, attach this now. Having the speedlight near your subject makes it more efficient in terms of power and makes the light softer, but don’t get it too close or it may be visible in your images.

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5  Pre-focus the portrait If you are using a stronger ND filter, composition and focusing may be difficult to do once it’s been attached. If so, frame the portrait and focus on your subject’s face beforehand. Be careful not to move position, switch the lens over to MF and then attach the ND filter.

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6  Take some shots Review your initial results using the LCD screen on the back of the camera. If they’re too dark, either move the flash closer to your model or increase the power of the flash. Another option is to increase the ISO sensitivity to 200 or higher. Carefully review the focus, too.


Use a modifier

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For that professional studio-style lighting, a light modifier is essential

If you’re serious about achieving pro-quality lighting effects then investing in a light modifier for your off-camera flash setup is an absolute must. A light modifier allows you to soften the light generated by the flash and create a much more pleasing light with less harsh shadows.

Modifiers come in a host of shapes and sizes, including photographic umbrellas, softboxes and beauty dishes. For this tutorial, we opted for a beauty dish as it’s perfectly designed for portrait headshots and is a great way of creating a softer, directional light. It’s worth bearing in mind that in order to start shooting with a light modifier you may need to invest in a flash bracket that offers support for the attachment of a light modifier.


Editing steps

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1  Remove blemishes With your image opened in Photoshop, grab the Spot Healing Brush tool from the toolbox and with a soft-edged brush carefully brush over any spots or blemishes on the model’s skin to swiftly remove them.

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2  Boost the contrast Head up to Image>Adjustments> Brightness/Contrast and in the window that appears, increase the Contrast slider to a value of around 25 to give it a boost. Click OK to confirm the changes.

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3  Brighten the eyes Grab the Dodge tool from the toolbox, then at the top of the screen set the Range to Highlights and the Exposure to around 5%. Now, gently brush over the model’s eyes to brighten them.

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4  Sharpen and finish Go up to Filter>Sharpen>Unsharp Mask. In the window, start off by setting the Amount to 50%, followed by the Radius to 2.0 pixel. Leave the Threshold at 0 Levels, but adjust this to suit the image.

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