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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

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  • Reducing light level from the window would achieve what you want. I have not tried this but I'd think that eg white fine mesh curtain material in N layers would give you level reduction with variations due to muliple light paths being very well sorted out a metre or so from the material. But, maybe not. – Russell McMahon Apr 23 '13 at 0:23
  • You wanted to push a 50mm f/1.4 to f/1.2? Wow... – BBking Jan 16 '14 at 22:18
  • I wasn't... Trying to be? Are you also using different lenses? – BBking Jan 20 '14 at 22:13
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You could use an ND filter or even a polarizing filter (which you probably already have) to give yourself another couple of stops.

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  • Thank you for your comment. This idea came to mind(among others), but I wasn't sure if this was the standard practice or the best option. Is this what portrait photographers do in studio to shoot at very wide apertures? – dpollitt Apr 22 '13 at 17:25
  • in a normal studio setting i guess you wouldn't have a window - rather you'd use another light (and a modifier). you could then simply put the lights on low power and move them further away in order to make them less bright when falling on the subject. you'd also be able to stand a reasonable distance away and use a more telephoto lens if you so wished. – Rich Apr 22 '13 at 17:32
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    I use an ND filter with the same lens (f1.4 - 2.2) when outdoors all the time. Works pretty well for me. Nice shot BTW! – Jakub Sisak GeoGraphics Apr 22 '13 at 17:43
  • You can also try an ND fader filter or even two polarizer's stacked for the same effect. dpreview.com/forums/thread/3455638 and bhphotovideo.com/c/… – Jim Apr 22 '13 at 18:36
  • You probably shouldn't go more than a couple of stops of ND because you'll have trouble actually seeing what you're shooting if the finder gets too dark. But yes, that's the only option when you can't fully control ambient light. – BobT Apr 22 '13 at 18:44
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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!

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  • If you're not easily able to hang something in front of the window, and you don't want to buy either a TTL cable, pocket wizards or an ND filter, a combo solution could be to put the flash on the camera, use HSS and bounce the flash from the wall or the ceiling - depending on the room size and ceiling/wall colours you could probably achieve something similar to using the umbrella doing this. Also the baby will appreciate not being flashed directly! – Rich Apr 22 '13 at 17:26
  • Note that keeping the same subject size and same aperture with a longer focal length does not reduce the depth of field. – mpr Jan 17 '14 at 3:46
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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...

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  • Thank you for your comments. I used the flash to give a nice rounded amount of light rather then just rely on the single source from the window, or to fill the other side of the face. I did not use a reflector but that is something I could try to reduce it further then 1/64. And yes my umbrella was white. – dpollitt Apr 22 '13 at 17:28
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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.
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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.

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