Rear-Sync Flash Photography

I have just been investigating my Canon 430EX Speedlite's functionality, as I only ever use the flash for quite basic lighting techniques.  I decided to work on my rear-sync flash technique, so thought I'd share with you what I now know!

What is rear-sync flash?


Your camera shutter is actually made up of two curtains - a front curtain and a rear curtain.  When you take a photograph, the front curtain reveals your sensor and then the rear curtain comes across to cover your sensor again.

Your flash will normally go off when the first curtain goes up.  This lights the scene immediately and will freeze the action at that moment.

With rear-sync flash - you've guessed it - the flash fires at the end of the shot, just before the rear curtain closes.  It is often also known as rear-curtain flash.

What happens in practice is that your camera shutter will open and begin to record the movement of you scene on the sensor, quite  blurry.  Then, when the flash fires, a sharp image is recorded over the blurred information of any subject that is within the flashes firing range.

How do I do it?


Firstly you usually need an on-camera flash, although some camera models may have a rear sync flash option.  In small point and shoot cameras, this is effectively what Night Portrait or Party mode is doing.

• This works best at night.  Try taking a friend/model out into a fairly busy area where there is a lot of motion or if, like me, you head out alone, look for a still subject in front of a moving scene.
• Take a tripod, although this is not essential.
• Set your flash to rear sync mode.  In Canon cameras, this is done by pressing the H button on your flash until three fast forward triangles are revealed. In Nikon, press the flash symbol button on your camera body, and your LCD will cycle between various modes until it reads REAR.  Refer to your manual for rear-sync if in doubt.
• Set your camera to TV or S mode and select a slow shutter speed, I found that anything from 0.5" works. 
• Place camera on tripod.
• Focus on your subject and take the shot when motion is detected behind - e.g. car passes, crowd passes.
• Play with different shutter speeds for different effects.
• Take the camera off the tripod and try shooting whilst you are moving for more creative effects.

Why would I use it?


This technique gets you away from the boring shots where your flash exposes your subject but the  background is in darkness.  It allows ambient light into the background that is filled with motion.

It is often used to great effect at weddings to get the bride and groom sharp but an active background.   I've also seen some great shots where it is used to accentuate the idea of motion, e.g. the blur of an arm frozen at the last minute, e.g. in a chopping or violin action.

Go on, be adventurous and give it a go, it's easier than it seems and the unpredictability of the shots is quite exciting!

Happy snapping,

Nic

Top 5 Night Photography Tips

If you are a beginner photographer, night photography is often one of the most appealing, yet most daunting new adventures you can undertake.  This shot was taken at this year's Vivid light festival in Sydney, showing what you can achieve with a slow shutter speed and a tripod.

In this article are some tips to get you started, break the fear barrier and go out and have some fun! All you will need are some warm clothes (at this time of year in the Southern Hemisphere at least), an SLR camera, a charged battery, a tripod and heaps of enthusiasm.  I usually take some coffee and snacks too... erm, pretty much everywhere I go actually!

1.  Invest in a good quality tripod

Many camera shops offer all-in packages these days which include a tripod - beware!  These are often poor quality aluminium tripods that will blow over in a slight gust of wind!  I am a huge Manfrotto fan, and if you can afford it, invest in Manfrotto every time.  They do a great dual head which combines a ball and socket motion with a joystick panning motion, which means you can shoot any angle as well as panoramas.  Perfect.  I am still saving up to replace mine!!

2.  Shoot on time delay or with a cable release

When shooting at night you will inevitably be shooting at a slow shutter speed.  You will get all excited about taking long exposures, only to find that when you press the shutter release button, you are causing the camera to shake slightly, and all of your shots will be blurred.  Use the time delay option (the one you use when you try and get pictures of yourself with your family on holidays, where you set it and run in front of the camera like a madwoman, only to discover you have 9 and a half seconds left to pose...).  This will enable the camera to stabilize after you've pressed the shutter, before it takes the shot.  If you're feeling fancy, get a cable release.  Buy a branded one.  I got one from Ebay and it was rubbish.

3.  Turn off your flash

Flash photography won't help you too much shooting scenic photography at night.  The flash only travels a few metres, and so will often light random objects in the foreground, leaving your beautiful scene utterly black.  The only time to use it is if you want to highlight some people or an object in the foreground.  Even then, use sparingly - In a later article I will explain how you can reduce the amount of flash you use so you just add a touch of light to the scene...

4.  Set your camera to AV or A mode

AV mode allows you to choose the Aperture, or size of the opening through which the light enters your camera, whilst the camera selects the shutter speed.  As a beginner, you don't really know what shutter speed you want to use to capture your shots - this way, the camera does all the work for you - fabberlus!

Options:

a) If you want to ensure you get everything in the scene nicely in focus - Use an aperture of 22 or F22 and focus on an object about one third of the way into your shot.

b) If you want a nice sharp shot, aim for an aperture in the middle of your zoom lens range - around f8 or F11 - on most lenses this is a sweet spot, and usually generates the sharpest images.  It obviously varies from lens to lens, so I recommend you try and Google sweet spot and your particular lens brand and discover what people say is the best aperture to shoot at for your lens model.

c) If you want only part of your image in focus and other parts soft to draw attention to a particular subject, use a small aperture number - around F2.5 - F5.6.  This will give you what is known as a shallow depth of field, i.e. only part of your image is in focus (This will be discussed further in future articles).

Remember, your camera will do all the work with the shutter speed, so you can just relax.

5.  Experiment with exposure times

Once you have taken one shot with your chosen aperture, vary it up and down the range, you should have a range of around F4 to F22 to play with.  This will speed up and slow down your shutter speed and give you varied effects, especially if your subject is moving. (The title image is the streaking lights of the ferry passing the harbour bridge).

Ok, have fun and please post some images, how you got on and your own tips!!!

Until next time folks,
Nicola