Off-camera lighting 101: the ‘five things’

I frequently get asked about lighting: specifically, how does one best approach the daunting challenge of knowing where to put what lights, how to set them up, use modifiers etc. I’ve written about some of this in the past but realise that I never tackled conceptually where to start. Fear not: in true Ming style, it’s now a list of Five Things 😉 Though the whole process of conceptualisation and setup becomes increasingly intuitive over time and practice, I still find that this list helps quite a lot when you’re either a) working with very complex setups where multiple lights can start creating interference with each other, or b) trying to simplify. Remember, a shadow does several things: it provides spatial context for three dimensional placement of subjects in a two dimensional presentation; it creates texture; and it provides separation and definition from the background. The more complex the lighting setup, the less well defined the shadows are going to be. Ultimately, the purpose of any controlled lighting setup is to place the shadows where you want them to go, and control the relative brightness of the subject elements, allowing you to precisely manipulate the structure of your image so that it is ‘read’ by your audience in a certain way.

1. Where is the primary source?
Put another way: where do you want your shadows to be? Where is the ‘face’ of the subject? Note also how the light will fall on other elements, and how this affects apparent separation between subject and background. This is also the reason there are few situations I can think of where you want your light source to be from the same direction as the camera – this creates no visible shadows and thus no separation and a very flat image. The more oblique the angle of the primary light, the longer the shadows. Similarly, don’t forget that shadows can also be used as visual texture and compositional elements, too. The most critical point though is generally there should only be ONE primary source: everything else is either fill or local or ambient. There are some exceptions where having two or more equal-strength shadows can be visually interesting, but remember this can also be spatially confusing…

2. How much contrast do you want?
The more intense and directional your light source, the harder the shadows (i.e. greater contrast between light and dark sides). Contrast can be varied by diffusion, intensity/brightness (i.e. relative brightness to ambient) and use of fill – either reflectors or secondary sources from the opposite side to the primary source at lower power. Not everything works with hard light, and vice versa – choose the most appropriate technique for your creative idea. A note on fill: I tend to prefer to use reflectors because you can be absolutely sure they will not overpower the primary source; I started doing this to ‘save’ lights if you have a large or complex setup and run out of hardware. Conversely, I’ll use separate lights for fill in only three situations: if I need targeted specific local fill that I can’t achieve with a reflector (these tend to be global contrast-lowering devices rather than precisely aimable); if the reflector would be physically visible in the shot (and this is undesirable); and lastly, if I need a different color temperature for fill (either creative or due to ambient).

3. How much ambient should there be?
Fill and contrast/ambient are related, but not the same thing. Contrast can be altered with fill or relative control of ambient; fill is still targeted, and ambient is whatever else is visible in the setting that might not be intentionally placed in the composition. If you are on location and want to preserve context, then some ambient is desirable; the more context, the more ambient. In a studio where everything is controlled and isolated, ambient might be zero. There’s only one way to change this: when shooting flash, you are always at ambient exposure or lower; the closer you are to ambient, the more will be visible. Anything over about 6-7 stops lower than ambient will effectively render that invisible or at least unnoticeable. Generally, 1.5-2.5 stops down is about right to preserve some background but still make the subject pop in a not too unnatural manner. Important note: make sure the direction of your controlled light isn’t the same as the ambient, or you’ll land up with overexposure and/or no real difference to if you didn’t use lights.

4. Is there a difference in color temperature?
I touched on this briefly before during the subject of fill: you may find a big difference between ambient (e.g. incandescent) and flash (i.e. closer to daylight) color temperatures; the best option is to set your camera WB to ambient and then gel your lights to match, but if this is not possible – then you can always shoot two separate images from the same tripod position, shift the white balance in post so both are natural, and composite them later. Of course, differences in color temperature also provide the opportunity to deliberately introduce a difference in mood or subject isolation by separating the feel of subject and background…

5. (bonus) Practice by deconstructing existing images
Not every image that appears to have controlled lighting used actually does; nevertheless it can be an interesting exercise to try to reverse engineer images you find attractive to figure out how they were lit: ‘ambient’ isn’t an adequate answer, because this is not controllably replicable. At least identifying direction, intensity/diffusion (and any potential modifiers) can be helpful, along with ambient balance – even if some things are not physically possible to do in reality (like lighting a 40-story building). In the spirit of things, the images in this post were lit as follows:

Flashes: This is a bit of a trick image, as the primary source is actually the centre flash: it’s at +2 stops over the other two, and firing off a rear reflector. There are no other sources other than what you see already firing in the frame – the two flanking ones for context, and the centre one as primary. The reflector is large and matte, creating the soft shadows you see towards the bottom of the frame.

Fruit: A tightly gridded and barn-doored soft box from left; this to create strong directionality without ambient spill (and associated reflections) but still some diffusion (hence the soft box). The background areas are all draped with black velvet drop cloths to avoid any reflections and back fill to provide that kind of ‘Dutch master’ painting feel.

Mammomat: Primary source a large umbrella upper right, secondary source from back through a frosted glass window. The primary provides soft facets on a hard machine surface, and the secondary fill is very close to the intensity of the primary with the intention of creating a softer, non-threatening overall feel. The secondary source is gelled blue to provide color separation from the subject and a bit more overall depth to the image.

Watch movement: At these distances, getting diffusion + directionality + working distance is already very difficult; there is just a single diffuse source very close to the watch from directly above and in front.

Apartments: No lights, but if we were to place them – it would be above and slightly to the left (the angle of the shadow is of course the giveaway)

Watch: I’ve saved the most complex for last. This is a very long exposure for ambient (the luminous hands and dial markings) with a diffuse but small source from above and slightly left to provide definition on the case and bracelet, and a second low intensity UV source to provide color fill of background and to make the luminous (and UV-responsive) material pop even further. The amount of ambient here has to be very precisely controlled so that you have details and definition on almost all of the watch, but without appearing that it’s just a normal exposure subsequently reduced in post (you can’t do that, the contrast distribution is different) and with the challenges of working with very dim sources and long exposures – if ambient isn’t precisely managed, it can easily overpower your controlled sources and provide a lot of unintentional fill.

As always: practice, practice, practice! MT

__________________

Visit the Teaching Store to up your photographic game – including workshop videos, and the individual Email School of Photography. You can also support the site by purchasing from B&H and Amazon – thanks!

We are also on Facebook and there is a curated reader Flickr pool.

Images and content copyright Ming Thein | mingthein.com 2012 onwards unless otherwise stated. All rights reserved