Why Flash Sync Speed Matters

I don't usually bother with camera settings.  Knowing the principles behind each control in my camera and how they work together is often enough for me and I just try to make adjustments on a case by case basis.  Every lighting condition is different and therefore requires different lighting strategies and adjustments.  Getting stuck to a formula or set of numbers is a very rigid way of working - you'll find it hard to adapt to situations most particularly when shooting outdoors.


For the purpose of illustrating the point of this blog, I'm giving the settings to the photos featured here.  As an OCF (off-camera flash) shooter, for me, the main weakness of the todays' most advanced DSLR is maximum flash sync speed. 

From Nikon - D3000, D5000 and even the mighty D90 can only sync at 1/200.  D700, D3, D3s and D3X will syncs at 1/250.  D300 and D300s also sync at 1/250 but can max out at 1/320 with "reduced GN" (whatever that means).

From Canon - EOS 1000D and the xxxD series syncs at 1/200.  But you might be surprised - the high-end 5D Mk II also syncs at only 1/200.  EOS 40D, 50D, 7D and 1Ds MkIII also syncs at 1/250.  Of the current camera models, the EOS 1D MkIV has the highest maximum sync speed at 1/300 - unconditionally.

Nikon's older models - D70 and D70s had a max flash sync speed of 1/500.  Why Nikon did not carried over that feature into the next generation of their DSLR's, is rather puzzling - especially in these days when off-camera flash photography is so popular.  A DSLR with that capability would have been perfect - off-camera-flash photography speaking.  Amazingly, high-end compact cameras like Canon's G-series can sync flash a lot faster.

I'm sure you're asking - why do I need a higher flash sync-speed?  This is one of those self-discoveries I learned in the 2nd Fuwairit photoshoot.  Sunlight, even diffused by clouds are often too strong for our tiny speedlites to overpower.  There are situations when you need to expose for the sky and a shutter speed of 1/250 are oftentimes not enough.  We have learned from the previous blog that shutter speed controls your ambient exposure.  However, we are limited by the camera's highest flash sync speed.  Set a higher shutter speed and you'd just simply kill off your flash.  It wouldn't matter whether you set your flash to its full power.

The main photo above is a good example why you would want to shoot with a faster shutter speed.  The sky is just awesome to just blow-out when it could be really used to add drama to the picture.

Photo taken with a Canon Powershot G7. 1/500 sec. f/5.6 ISO 80. 1-580EX II front right + 1-580EXII behind the models as kick-lights. Both set to 1/4 power.

Photo taken with an EOS 40D - a DSLR.  1/250 sec. f/9, ISO 100.  Same flash setup as above.  Models were properly exposed with flash but the clouds in the background have disappeared to over-exposure due the DSLR's flash sync speed limitation.

Photo taken with an EOS 40D.  1/400 sec. f/11, ISO 100.  With this setting a little bit of detail in the clouds were achieved but the shutter speed setting  failed to sync the flash properly.  Note that the girl's face is partly lit but the rest of her and the male model was not lit at all.

Here's a better example of what I'm trying to say in the previous picture.  Flash went through the lens but the faster shutter 1/320 (just 1/3 stop faster than 1/250) has partly blocked flash light.  It didn't mattered whether I redirect the flash to avoid the blocked part.  All pictures taken at this speed appeared consistently like this.

At the moment, it seems we're stuck with 1/250 - as far as DSLR is concerned and standard flash sync is concerned.  There is a work-around this problem by using the "high speed sync" function of your Speedlites (both Nikon and Canon) to make your camera sync to as fast as their maximum shutter speed (1/8000?).  But there are drawbacks and another topic for discussion.  Right now, in this department, enthusiast compacts outgun DSLR's.  With a 3rd party trigger like my Phottix Tetra, my 3 years old Canon Powershot G7 can flash sync as fast as 1/800 sec.  That's pretty amazing.  Although I've read of other compacts that will sync at 1/1000 sec.

Cheers,

alexdpx

Note: Please verify the quoted flash sync speed of the camera models mentioned above with their respective manufacturers if you are intending to purchase any one of these.