How can I shoot in a studio at the widest apertures?

Question

I ran into a limitation while shooting a newborn baby this weekend. I was indoors next to a set of windows. I was also using an off camera flash on a stand through an umbrella. The flash was a Canon 430EX, set to manual, 1/64 power. My shot ended up being with a Canon 50mm f/1.4 lens, shot at f/1.8, 1/160sec, ISO 100. The camera is a Canon 6D which has a maximum sync speed of 1/180sec. My problem is that I wanted to push the aperture even further, to f/1.4 or even f/1.2 for even more shallow depth of field. Doing so would have either blown my highlights or pushed my image beyond the sync speed. Later in the shoot, the ambient brightened up a bit, and I was even forced to drop my aperture down to f/2.2. What could I have done differently or should I do in the future to allow these portraits at wider apertures?

Here is the image with EXIF intact: http://www.properspective.com/photos/i-C5W7p9h/0/O/i-C5W7p9h.jpg

Answer 1

You could use an ND filter or even a polarizing filter (which you probably already have) to give yourself another couple of stops.

Answer 2

Great photo! This is a common difficulty that is even more of a problem when shooting outdoors.

The simplest solutions, as outlined above, would be using a reflector rather than a flash (this could work really well as you have a big window) or using a sheet to reduce the incoming light from the window and either something similar over your flash, or moving the flash further away (doubling the distance will reduce the power toe 1/4 of what it was - the inverse square law).

Alternatively, there are two direct ways you can get round this problem while still using the flash.

The first is to increase your sync speed. Although you're at the maximum sync speed for your camera, the Canon H430ex is capable of high speed synchronisation (HSS). This means the camera fires several pulses of light in order to synchronise at a higher shutter speed.

Note that reducing the shutter speed, however, will not reduce the exposure of the flash, which, as you've got the flash and ambient already well balanced, you need to do - as above you could either move the flash or put more between it and the subject.

(You may also read that using HSS reduces the power output of your flash - it does, but my understanding is that it reduces the maximum available output, i.e. not necessarily whatever power you happen to have selected. So as you're already using 1/64 this effect probably won't come into play.)

The problem with this method is that it won't work with normal wireless radio triggers. As a solution to this, you could either get a long TTL cable to use, or you could buy pocket wizard triggers.

The alternative would be to try using a neutral density filter. This will directly underexpose the whole image, and as you've already got the ambient-flash balance right this will work fine. There is a 1 2/3 stop difference between f2.2 and f1.2 according to (http://imaginatorium.org/stuff/stops.htm) so a 2-stop ND filter should do the job. Note that a 2stop filter is a 4x darkening factor. (Be wary of variable ND filters unless you're prepared to buy a really good one, they tend to be of poor quality)

Finally you could try achieving a shallower depth of field with a more telephoto lens, such as an 85mm or 70-200mm lens, however you would need to be further away from the subject which looks like it wouldn't be easy with this shot. Additionally this would result in less included in the background, so you probably wouldn't be able to see the edges of the bench in your picture. And if you really wanted to go for it you could get a medium format camera which would help achieve a shallower DOF, but that's probably the most unrealistic of all the options!

Answer 3

First off, that's a really lovely photo :-)

Secondly, did you need to use flash at all? Could you maybe just use a reflector to reflect the ambient light onto the baby? And if you did, you could consider bouncing it off the ceiling or wall to further reduce its power. Or instead of a white umbrella, you can get black ones too that would absorb more of the light generated by it...

Answer 4

You have a couple of options to cut down on the amount of light.

• An ND filter on the camera
• Add more diffusion to the existing lights
• Use a trigger with TTL capabilities - This one is only useful if the flash is what is causing your light to be too bright. If the natural light alone is too bright than you will have to take one of the first two options. With TTL, the flash will only provide the amount of light needed for the exposure, which means lower power than what you can set manually if necessary.

To add diffusion you can

• Use something like a white sheet to cover the window
• Put something like a small white cloth or tissues over your flash.

Answer 5

My first suggestion would be to try using HSS (High Speed Sync) and angling the flash to try and get the desired bounce angle (or use a sync cable to use the umbrella.) At 1/64th power, I doubt that you will have an issue maintaining the power for HSS (though I personally only have the 320 and 600 flashes, so I don't have any hands on experience with the 430.)

If that doesn't work, then an ND filter is the only other thing I can think of to reduce the amount of light entering the camera and thus allowing slower shutter speeds to capture less light. You could also try a ND film over the window depending on how large the window is.