Focusing on Digital Photography
22 May
This week, I’ve taken delivery of a new Canon Speedlite 430EX flash gun and a Sto-Fen Omni-Bounce flash diffuser. The purpose of the Omni-Bounce is to provide a bare bulb effect. This means that light will be scattered in almost every direction with some reaching your subject after having been reflected off another surface. This ought to provide similar results as bouncing a bare flash, but throwing light directly onto your subject can help to distinguish it from the background as well as provide a catch-light.
Today, I set about testing different flash photo set-ups with my helpful test monkey.
Colour-wise, my test environment wasn’t ideal since the walls are coloured, but the purpose of this testing was really to get a feel for the effects of angling and diffusion of the flash, to see how subjects would be lit, and to see the effect on any shadows cast.
The flashgun was hotshoe-mounted onto my 40D (with EF 100mm f/2.8 macro lens) and all of the shots were taken in portrait format in order to fill the frame with the subject, which was about 1.5m away from the camera, and have side-shadows to better show the effect of the flash set-up.
The results of my testing were as follows:
Minimal processing was carried out on these images; just straight out of Lightroom and labelled in Photoshop without any additional sharpening or colour processing.
Used with the flash pointing directly at the subject, the Omni-Bounce can help to soften the light and shadows to a small extent. Sto-Fen say the Omni-Bounce should be used with the flash gun at around a 45-degree angle in order to get the best from it, but if you’ve no reflective surfaces nearby then pointing your flash directly at your subject might be the next best option available.
Using the Omni-Bounce at an angle offered a nice level of light, but there were still shadows apparent due to the flash light providing a direct light source.
For the most evenly lit and shadow-less photos you really do need to bounce your flash light in order to get as big a light source as possible and you don’t need a diffuser for that.
3 Responses for "Canon Speedlite 430EX with Sto-Fen Omni-Bounce"
Very interesting. Another thing apparently against using the diffusers is that it seems to muck up the exposure if you manually set the aperture. Camera - Canon 450d. Setting the aperture at f11 for depth of field - subject fairly close - about 2.4m or 8′. Without diffuser - nice shot. With diffuser - underexposed by about 4 stops.
Do you have any explanation for this. Is there something that I am missing?
Hi Ian,
What flashgun are you using with your 450D?
With Canon Speedlites, the flash should automatically vary the flash output so that sufficient light reaches the sensor for a correct exposure.
As long as your flash is powerful enough to offset the light-dampening effect of a diffuser then I wouldn’t expect you to see any problems with under-exposure.
It could be that you’re using a flashgun that’s incompatible with the 450D’s E-TTL II flash exposure system or perhaps it’s just not capable of outputting enough light energy to meet the required exposure setting.
What kind of environment are you shooting in at f/11? Where’s your diffuser sending the light? Are there light coloured walls and ceiling nearby to bounce indirect light towards your subject?
Thanks for th reply. Turns out that it the difficulty experienced was due to flash strength. Diffuser seems to take out about 1 stop of light under current testing circumstances, otherwise it seems o.k.
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