Experimenting with Flash

I always enjoy photographing fungi and mushrooms in the Autumn months.  Last Autumn (2009) I decided to experiment with two things in the macro field, that I had not greatly tried with fungi before.  First I decided to shoot more wide open shots with less depth of field (though not all the time), and secondly to get my flash lighting to look more “natural”.

Now to clarify what I mean by “natural” look, I’ll show you an example of the unnatural effect that I have taken before, which gives a dark background.  (Not that this is wrong or I don’t like it, in fact in some cases I think it looks better).  This black background is caused by the flash light lighting up the foreground well, but due to short length of time the shutter was open (1/250 sync) and the power of the light, not enough light emits in the background to register in the frame.  Hence the “black effect”.

Canon EOS 50D (100mm, f/8, 1/250 sec, ISO100)

Now to counter this black effect, I decided to enlist the help of another flash unit, my Canon 430ex.  This was to be a slave unit controlled by my Canon MT-24ex Twin Macro flash mounted on my camera.  The 430ex stands alone on its own stand and is controlled by the infra-red link to the macro flash.  I also diffused this flash unit with a home made “orange juice container” diffuser, that I had used on the macro flash before purchasing some Sto-Fen diffusers for it.

Now to say this was the only change I made how I was taking the fungi, made is far from the truth.  Firstly in the past I normally had been shooting and relying on my cameras ETTL to work out the lighting, with occasional flash compensation.  This I was finding with the single flash gun, and now dual flash setup to be unreliable and a more predictable level was to manually set the flash output on the flashes.  This is fairly straightforward, in that all I had to do was to turn the main unit (the Twin Flash) into manual mode, and then set the flash ratio of the 3 flash lights, and experiment with different power settings.  This is one advantage of using fairly static objects such a fungi to practice on!  I found generally that having the background flash (430ex) emitting a stop less more light to produce the better results.

The following image was taken at F8, using this type of setup.  Those of you in the know will also point out that the background is quite close here so the black effect would be reduced without the third light anyway, but it is not totally negated, and the green background effect here is the result of the extra flashlight.

Now as some of you reading this may know, I post some of my macro shots on some photography forums, and following some good advice from some, and more research I looked into other methods of getting a “natural” looking flash background shot.  The next step I took was to move the flash light and lens on to a tripod (and focusing rail).  You may now ask why I would use flash when I could now rely on natural light as I was not had holding.  Well three things really, this was about flash experimentation, some of the days were raining and really dreary, and lastly I don’t think that natural light shots can always fully light the gills of fungi fully, particularly if there’s no means of bouncing light onto them with a reflector.

Now this next step also allowed me to set the timer on the camera and move around with the slave flash gun to more accurately light some areas, and additionally use a non-macro lens as well.  This next shot is taken on a 17-40mm Canon Lens with the slave unit lighting under the gills of the near mushrooms (The twin flash lights were not used in this case by angling them away).

Canon EOS 50D (31mm, f/9, 1/4 sec, ISO100)

Now the last one is also using an additional technique that I stumbled upon, in this experimentation process,  that I’ve also used in the following shot taken with just the twin macro flash unit below on my 100mm macro lens, this is to set the cameras flash sync to auto in the cameras menu.  I have options of 1/60, 1/250 and Auto sync.  Now the first two fix the shutter speed at those fractions of seconds, the last leaves the lens open until enough light has entered to render the usage of a background flash non-essential.  Ok with these fairly static subjects, but the exposure time can be fairly long, in this case 1/3rd of a second, so for creepy crawlies the extra flash is probably the answer. (Along with making the difference to the background shorter, which you can cheat by moving bark/leaves closer to the subject).

Canon EOS 50D (100mm, f/16, 1.3 sec, ISO100)

The only annoying thing about this shot, is that having taken so long in setting up the flash, composing the shot, focusing etc.  I completely missed the bracken in the background.  But for the purpose of the flash experiment I think it works well.