The Size of the Light - Thoughts on the Big Octa


When I first started learning about lighting a long time ago, my master (I was an apprentice and he liked being the master) said it very succinctly, "big light up close is good light".  Of course there are  situations where this could be untrue but since I've been tagged as a  lighting geek, I've found that most of the time he was right.  Later, when taking a class with Joe McNally, I asked the dumb ass question, if you could only have one light with one modifier what would it be, he said "big octa"  Then he showed the class why.  This past Sunday, I did a seminar at Henry's Newmarket on getting started with studio flash and I demonstrated a bunch of modifiers.  But due to time and space, I didn't show my favourite.  One of the attendees had heard me speak about the big octa in the past and asked why it is so good.A big diffused source, in close makes for very soft light, but not necessarily flat light that is boring as all get out.  It has dimension and almost a flavour to it.  So the last couple of evenings, I made some space in the studio and erected the Bowens Big Octa.  It's the first really top end soft box I ever bought and while it is large and cumbersome, the light is just magical. bw1650_octo150_front_three_quarter_shot_3Bowen calls this modifier the Octo 150 because it is 150cm across.  Unlike my Elinchrom Deep Octa (called the Deep Throat in Europe, I guess NA is too PC for that) the Octo 150 is a relatively shallow bowl shape as you see in this image.

So that's a five foot in diameter octa box.  It's large and a bit heavy.  You can see the manipulator arm coming out of the back of the mount as well.  This is important because the studio head is mounted inside the Octo 150 and fires backward into the bottom of the bowl. The area around the mount takes a white reflector panel to prevent hot spotting off the internal silver reflector.  This then bounces the light around and out the single front diffuser.  As you see in the image, the white diffuser is a perfect circle, masked away from the octa frame.

Bowen say you can mount any studio strobe in this Octo 150.  Yes, but you need the proper mount adapter for your strobe.  Mine came with, as expected the Bowens S Type mount for the head.  The sample images herein were all shot with a Bowens 500 Pro head with PW Radio Receiver.  The head power was controlled with Bowens IR remote by peeling back the front to make changes.  I kept the modelling lamp off after positioning to keep the heat down.

So why does a big source matter?  There's this thing I hear that light from a big source "wraps around" a subject.  Light doesn't actually bend unless in the presence of a gravity well much bigger than you will find in your studio, but the giant bowl makes for lots of different angles of incidence exiting the front diffuser to give the appearance of "wrap".  All those different angles of incidence also produce a softness you cannot get from a smaller source.

So I asked my regular model Sondra if she would sit for images from the big octa.  As usual, she was completely silent but held the same facial expression for every shot.

1Dx 70-210/2.8, face 3 feet from front of Octo 150

1Dx 70-210/2.8, face 3 feet from front of Octo 150

1Dx 70-210/2.8, face 3 feet from front of Octo 150

1Dx 70-210/2.8, face 3 feet from front of Octo 150



Sondra has very dark brunette hair but one of the real benefits of the big octa is that you get wonderful range of colour tones without having to use masks or over expose the shot.  All these are out of camera as RAW tethered into Capture One and exported as 1024px JPEGs at 72dpi for the web.  No other processing was done.   I moved Sondra only marginally and the Octo 150 not at all, primarily myself and the focal length to obtain different looks.  Even in her painted on eyes you can see the lovely round catchlight from the big octa.

The other benefit is the quality of the shadows.  We want shadows because they give dimension, but the enormous size of the source makes the shadows less harsh and there is a much wider tonal range available across the shadow range.  The big source also has a softening effect overall making it ideal for portraits.

You can certainly do full body shots with a big octa, it has the range to give you reach.  This was powered to factor 4, where the Bowens 500 Pro goes from 1 to 7 so this was three full stops under full power and even then I was getting between f/11 and f/13 depending on the position of Sondra.

The camera was of course in manual mode, which is how I always shoot studio strobes except for the my Profoto B1 Airs that do very good TTL.  I used a Sekonic 478DR flash meter with the PW trigger built in to pop the flash and take meter readings.  I know that you can get to a good exposure with no flash meter in a couple of shots with experience, but I like the convenience and speed of the flash meter.  McNally never uses one, but another teacher of mine, Frank Doorhof swears by them.  For big flash I find them handy.

If you shoot portraits against a neutral backdrop with the intent to put your subject on a different backdrop in post processing the incredible softness of the big octa also makes the placement on a variety of different backgrounds more simple because you are fighting to correct heavy shadows or light that is too harsh.  Back in the day when I apprenticed and backgrounds were stripped out of the transparencies so other backgrounds could be placed, the photographers always went with big soft lights, mostly big white umbrellas in those days, to make the lift more simple.

The Octo 150 is Bowens' version.  Every major studio modifier maker has their own big octa.  Elinchrom does a reverse firing one like the Bowens and Profoto also has a giant octa.  No matter what studio head setup you choose, a big octa is going to produce incredible light quality and you will get great return from the investment.