Alice Springs Photographer Blog

5D MKII & Flash Control

5D MKII with 430 EX FlashAnother thing that I've learnt about the 5D MKII is the flash control settings.

I have my first paid job tonight, not to get all worked up about it, and I was doing a bit of research about the flash and the cameras flash control settings. I'll be shooting indoors in at art gallery with ample lighting but I would like to add a bit of flash to create a lead light highlighting the subject. I rarely use flash as I shoot landscapes more than anything else and only use available light to shoot them in.

To cut a long story short I spent an hour or so yesterday practicing my flash techniques in my living room with a basket ball on a tripod as a subject, my girlfriend is away for a few days so it was the next best thing. I found out a few things that I would like to write about especially the 5D MKII's "Custom Functions" that control the flash.

On the 5D MKII  we have 3 settings to choose from -

1. Auto,
2. 1/200 - 1/60sec Auto
3. 1/200sec (Fixed).

Auto is pretty well self explanatory but its the other two settings that I found to be very useful for creating the effects I wanted.

The second function, 1/200 - 1/60sec Auto, is a pretty useful function. As the 5D MKII manual states

1/200 - 1/60sec Auto.
When flash is used with aperture priority AE, this prevents a slow flash sync speed from being used in low light conditions. Effective for preventing subject blur and camera shake. The only problem is that while the subject will be properly exposed with the flash, the background will come out dark.

I tried this setting for some time during the test shooting and like it says the backgrounds come out way to dark for what I want to achieve. I want to illuminate the subject while still having an amount of background detail because the art is what we are there for. I'll shoot for a few minutes with this function just to see the real world results and maybe just to mix it up a bit. During test shooting all images were being shot at 1/60sec which is a little slow when you have a 70-200 on the front.

The Third Function, 1/200sce Fixed, is what I'm after as far as a shutter speed is concerned.

1/200sec Fixed.
The Flash sync speed is fixed to 1/200sec. This better prevents subject blur and camera shake that with setting 1. However, the background will come out darker that with setting 1.

This is the setting I want as far as having a fast shutter speed but the background is important to how I want to shoot so what can I do. I shot many test shots with every combination of camera settings and the critical setting for achieving the effect I want turned out to be ISO.

Yes ISO, the best shots came out using a higher ISO, ISO 800 - 1200. I think that this is because with a lower ISO of lets say 100 - 400 the flash has to do much more work namely send out a much stronger flash to illuminate the subject. This can down out the background light and create very noticeable shadows. But with a higher ISO the flash has to do less work, as a result there is reduced shadows and the camera is more able to record the backgrounds with its natural light.

Here are the test shots.

Lens - 70-200 f/2.8L IS USM
Focal Length - 105mm
Aperture - f/8

70-200 f2.8L @ f/8 ISO 10070-200 f2.8L @ f/8 ISO 1600







Lens - 70-200 f/2.8L IS USM
Focal Length - 90mm
Aperture - f/8

70-200 f2.8L @ f/8 ISO 100

70-200 f2.8 @ f/8 ISO 1600







Lens 24-70 f/2.8L USM
Focal Length - 27mm
Aperture - f/8

24-70 f/2.8L @ f/8 ISO 10024-70 f/2.8L @ f/8 ISO 1600







Lens 24-70 f/2.8L USM
Focal Length - 70mm
Aperture - f/8

24-70 f/2.8L@ f/8 ISO 10024-70 f/2.8L @ f/8 ISO 1600