Over the days leading up to the 25th of December I’d like to give something to everyone who stops by my blog. These tips cover camera settings, flash, lighting, software and gear. I’ll be providing a pair of tips each day until 25th December.
#47 – Using group mode for off-camera flash
Group mode is available when using the Canon radio wireless flash system. Group mode adds capabilities that are not possible with other modes.
Firstly, you can configure up to five separate flash groups for either highly complex lighting setups, or for very simple changes of setups, as might be required when you only have limited time to take a couple of significantly different shots.
Secondly each group can be switched to one of three exposures modes independently of the others. You can use E-TTL automatic flash with flash exposure compensation for the group. There’s manual mode, where you determine the flash power. Both E-TTL and manual mode can be used with high speed sync flash too. There’s also external auto metered flash (Ext.A). This sets the Speedlite 600EX flashes to use their built-in light sensor. You can also turn off any group you don’t need.
I took this photo with three separate groups of Speedlites, each set to a different mode. For the light on the model’s face E-TTL was used, the light on her shoulder on the left of the image is set to manual mode, and finally external auto was used for the flash that illuminated the background behind her. It was important to ensure that the sensor on the front of this last flash was pointed towards the background.
#48 – Anti flicker shoot
Continuous shooting speeds have reached the point that in some light you will see a variation in the brightness or colour of your pictures. This happens when AC powered lighting is being used, like in a gymnasium or football stadium at night. AC powered lights, vary in light output and sometimes colour too as the alternating current cycles. The frequency is 50Hz in Europe and 60Hz in USA/Japan, but the camera will work with either.
Canon introduced anti-flicker shooting to automatically detect the flickering light, and optimise continuous shooting speed in order to reduce the frame-to-frame variance in brightness or colour. Most people only notice the indicator in the viewfinder, which does appear even if the anti-flicker shooting is turned off, it’s simply indicating that the current light is flickering. The anti-flicker icon in the viewfinder can be switched off if you wish.
With anti-flicker shoot enabled there are two main effects on your camera. First the frame rate may be modified to fit with the frequency, usually the adjustment is fractional, so 10fps is not likely to get much below 9.5fps, though the time gap between frames may change from frame to frame. Secondly the shutter release lag may increase as the camera waits for the optimum light before taking the photo.
So if you’re lighting with flash or daylight, then you don’t need to use anti-flicker shoot. When you shoot action indoors, or under ac powered light there is some benefit.