FLASH OUTDOORS

This weeks post is a demonstration on combining natural light and flash in an outdoor setting. The aim was to create a lifestyle portrait using flash as the main light on the subject and underexpose the ambient light by approximately one stop. This session was an opportunity to update portraits of our youngest son, at the same time prepare a presentation on outdoor lighting for a seminar I gave last week at “August Exposure 2010”. This is an annual 4 day premiere photography conference held at Seaworld on the Gold Coast in Australia. Lots of learning and fun, plus a chance to catch up with friends.
The image above is the finished colour portrait (rare for me, as 95% of my portraits are in black & white) , but the clouds and sky balanced with the blue of the bike. So I decided to go with colour, although I couldn’t resist a black & white version, shown below.
First off, the location is nothing special. It’s a fire break with power lines running through it and has become a dumping ground for builders refuse, not the prettiest location. I chose it because I wanted a location that would look similar to a motocross track and as it was only 3 minutes from home, I could do it at short notice on a day when the clouds were more dramatic. A clear blue sky would not look as as good in my opinion.
Below is my starting point.

Next was to check the ambient light level and find my best perspective. The ambient reading was F5 @ 1/100s. Fairly flat light with little direction, but the setting sun behind the clouds (to the far right) was an indication of where the main light was to be positioned. It is best to place the flash on the same side and angle as the existing main ambient light is coming from, this will create a more natural look, rather than recreating a new direction of light, which usually looks unnatural.

So the flash unit was placed to the right, at approximately 45 degrees to the subject and at a height just above the subjects head and angled down. A good starting point is to place the soft box or umbrella, so the bottom of the of the light modifier is level with the top of the head (as shown below). Then check to see where the catchlights are in the eyes by using the modelling light if available or simply take a shot and check the histogram (catchlights should be approx. at 10 o’clock or 2 o’clock position). But before that we need to correct the flash power and settings. The unit is an old Lumydine portable flash unit I’ve had for 17 years. I resurrected it for this shoot, put some new batteries in it and it works perfectly. It does have a modelling light, but I didn’t use it, as it uses too much battery power if left on too long. Also I used and old Quantum Radio Slave unit to trigger the flash and sync to camera.

More about equipment further on.

To get the flash reading, I took an exposure of the calibration chart as shown. The technique is to fill the viewfinder with the calibration target and take an exposure. You could also use a gray card, the ultimate is a flash meter, but I find most wedding and portrait photographers these days don’t go there.

So to keep this achievable for all, I’m doing it this way, basic and manual.

Now to the exposure, it should show a spike dead centre on the histogram to represent the correct exposure for mid gray. This was also the same technique used for the ambient light reading. The aim is to get both the ambient reading and flash reading to balance with the same F stop. By matching the spikes in the centre is a quick easy calculation, I did change the shutter speed from 1/100s to 1/200 s (max sync speed) to avoid the possibility of ambient light effecting the flash reading.

So the ambient light is F5 @ 1/100s and flash reading is F5 @ 1/200s – the F stops match, but the shutter speed is one stop less exposure, causing the ambient light to be one stop darker. This is an ideal exposure difference as I can control the final darkness in photoshop. If I went too dark by having a two or more stop difference it can look too unnatural.

To achieve the balance with the flash, I moved the flash in and away from my son taking different exposures until the spike was in the centre. The flash was at its lowest power setting (50ws) so F5 exposure was as close as I could get without using neutral density material to lower the output.  The closer the light is to the subject the softer the light and shadow transfers from highlight to shadow. Unfortunately any closer then the light stand came into view.

Final consideration was the angle of view and lens choice. Originally I had set up with a 50mm lens and was kneeling, but this was not dynamic enough. I chose the 24L F1.4 and sat on the ground and this proved to have much more impact.

ABOVE LEFT

This shot was my base image to for composition. While it was a good starting point, it lacked the impact I wanted.

ABOVE RIGHT

I simply moved my position around to the right and instead of leaning him forward onto his elbow, I had him stand taller. This lowered his right shoulder, allowing his head to be in a stronger position. Note the left arm doesn’t merge into the body now and I believe it creates a better sense of balance.

Also recomposing him to the right and placing the back wheel towards the bottom corner creates a much more interesting portrait.

ABOVE

In Photoshop, after usual adjustments, I created a second DNG copy for the sky. Without turning this post into a photoshop tutorial, I simply merged the original image over the darker copy and brushed the sky through to the top original, creating a more dramatic sky.

The rest of the post production was done in layers with selected curves and hue & saturation adjustments.

Final image in black & white – selinium tone ( Nik Color Efex Pro)

EQUIPMENT

I used a basic lighting set up that could apply to any flash unit that has manual settings. You don’t need to have expensive lighting to try this technique. A loan or hired flash meter would be an advantage, but a gray card or calibration target will also do the job. Although I own a couple of flash meters and a colour temperature meter, I wanted to present this as an example, that if you don’t own expensive equipment, you can at least experiment with this technique at a lower cost. Then if you want to continue down this path you can buy better and more expensive equipment.

LOWER COST ENTRY EXAMPLE

Flash unit from camera manufacturers such as Canon (580EX II)  Nikon (SB 600-900) a white umbrella, light stand and umbrella adjustable support and sync cable. Other flash units such as Sunpak.

Of course second hand from reputable dealers and there is always eBay.

EXPENSIVE / QUALITY ENTRY

Such equipment as Profoto and Elinchrom Quadra Ranger portable flash units and Softboxes, Sekonic flash meter, Skyport and Pocket Wizard radio slaves. Mono pod or a heavy duty light stand.

SUMMARY

Preferably set the camera to manual mode, select the F stop you want to work in (eg: F4 or F5.6) Take an ambient light reading off a gray card or calibration target and set the camera for correct exposure, (be in light where the shutter speed does not exceed the flash sync speed) Then take a photo of the gray card, check the histogram and if the spike is not centred, adjust the shutter speed and continue taking exposures of the gray card until the spike on the histogram, representing the gray card, is dead centre.

Next, set the flash to the lowest power setting (eg: 1/32 : 1/16)  and move the flash with umbrella or soft box in place to approximately 1 meter to 1.5 meters from subject (portraits – the closer, the softer) leave the camera set at the previous correct ambient setting and change the shutter speed to fastest sync speed – check camera instructions. This will override any ambient light.

Then take a series of images of the same target, as close to it as possible, moving the flash in and away, checking the histogram until you have the spike in the centre matching exactly the ambient test. If there is not enough power, simply increase the output.

I recommend recording the exact distance with a piece of string. Just tie a length of cord (eg 3 meters) to the monopod or light stand. So this distance becomes your set aperture. Say your test was for F5.6 at 200 ISO simply pull the string out from the stand to your subjects face and tie a knot.

This distance is now your marker for any future portraits at this aperture and ISO combination. You can even tag the knot with the info on a piece of tape. Primitive, yes, but it works consistently and saves setting up calculations every time.

To achieve the darker background, just increase the shutter speed one to one and a half stops. Example – Ambient setting F5.6 @ 1/100s to F5.6 @ 1/200s (one stop underexposure for ambient light)

This will result in the subject being lit by one stop more light than the ambient light, creating an almost subtle spot lighting effect.

I can hear some people say, “go a buy or borrow a flash meter”. Fair comment, but these blog tips are aimed at helping photography enthusiasts and professionals of all levels and many are not in a position to purchase expensive lights and meters at this point. But, I would suggest that your next equipment purchase should be a ambient / flash meter before a new lens.

I hope you try this style of dramatic lighting, it will at least make you stand out from the flash on camera style which is usually flat or over filled. My natural light portraiture is by far my favourite, but having resurected this style again, I will use it more often, especially when I want more “punch” to my images.

until next week, happy shooting

Wayne

2 Responses to “FLASH OUTDOORS”

  1. Barry Cheeseman Says:

    Thank you for your clear description of the process and equipment used.

  2. Gaye Edwards Says:

    Agree with Barry’s comment. Brilliant description of the concept and the process. Thanks.

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