Technology Tutorials

Portraits with Two Lights: Adding a Fill Light

harsh overhead sunlight portrait

A second mild supply — often referred to as a fill mild or fill flash — can enormously enhance portrait lighting. It reduces the depth of shadows and softens the looks of facial options, amongst different traits. Better of all, a fill mild is straightforward to create: both a easy on-camera flash or a reflector is usually adequate. Nevertheless, a second mild supply can simply as simply hurt portraits. This tutorial subsequently focuses on how one can management the situation and depth of the fill mild so as to produce a desired portrait look.

harsh overhead sunlight portrait

overhead sunlight portrait with a fill flash

If you have not achieved so already, additionally take a take a look at the primary a part of this tutorial:
Introduction to Portrait Lighting: One Light Supply


With a single mild supply, crucial issues have been its path and obvious measurement. Whereas these have the identical impact with a second mild, they are not sometimes different unbiased of the primary mild. As an alternative, what’s often adjusted is the relative illumination of the secondary mild in comparison with the primary mild. This controls how a lot the second mild will “fill in” the shadows from the primary mild, and is why a secondary mild is often known as the fill mild or fill flash:

diagram: harsh overhead sunlight portrait

diagram: overhead sunlight with a fill flash

observe: diagrams present the impact of a fill mild, not essentially its preferrred place (extra on this later)

Maybe the most typical lighting state of affairs is to make use of an on-camera flash because the fill mild, and daylight as the primary mild. One might additionally use a secondary flash as a fill mild within the studio, or might even use ambient mild because the fill mild and as an alternative have the flash be the primary mild. There are numerous prospects. The hot button is figuring out how one can management the qualities of your fill mild — no matter what supply is getting used to create it.


The phrases “flash ratio” and “fill light ratio” describe* the relative quantity of sunshine from the primary and secondary mild sources, and successfully decide the general distinction. For instance, a worth of 1:four signifies that the fill mild is a quarter the depth of the primary mild. Extra balanced ratios produce weaker shadows:

no fill light

Fill Light Ratios:


no fill mild


weak fill light

1:eight – 1:2

weaker fill mild


strong fill light

1:2 – 1:1

stronger fill mild

comparison of different fill light ratios

Select a Fill Light Ratio:






Portraiture sometimes seems higher with a flash ratio close to 1:2. That is robust sufficient to supply delicate shadows, however not so robust that it eliminates shadows solely (inflicting the topic to be seem flat).

Nevertheless, one ought to all the time be cautious of such seemingly strict guidelines in images. Much less fill mild is usually used for darkish, “low key” type portraits with well-defined shadows. Equally, extra fill mild may be essential to render a brighter “high key” type, or simply to offer a softer look (corresponding to with a photograph of a child). When unsure although, the 1:2 ratio is a protected start line.

*Observe: These phrases might be a little complicated, as a result of a “fill light ratio” refers back to the ratio between the secondary and first sources of sunshine, whereas the “flash ratio” refers back to the ratio between the sunshine from the flash and ambient mild. To make issues worse, typically the ratio is used to explain the ratio between complete mild (ambient+flash) and that from flash alone. The numbers are typically additionally reversed, however the smaller quantity all the time refers back to the fill mild. We’ll keep on with the identical definition all through this tutorial, and since we’ll solely talk about situations the place flash is weaker than different mild sources, each phrases are synonymous.


In contrast to the primary mild supply, the only location for a fill mild is close to the digital camera’s line of sight (“on-axis”), however not so shut that it seems in your picture. That method, any shadows forged by the fill mild will not be seen from the digital camera’s perspective, so it will not matter if these seem exhausting (on account of a small supply). Maybe the simplest approach to obtain one of these fill mild is to make use of a built-in or on-camera flash.

on-camera fill flashOn-Axis Fill Light
(shadows fall behind the topic)
off-camera fill flashOff-Axis Fill Light
(shadows fall throughout the topic)

However, an on-axis fill mild is perhaps too proscribing, and has a greater probability of manufacturing direct reflections off the topic. Many subsequently use a fill mild which strikes their topic from a course which partially opposes the primary mild (“off-axis”). This targets major mild shadows extra effectively — even when the fill mild ratio stays unchanged — and is subsequently additionally much less more likely to have an effect on the general publicity.

off-axis versus on-axis fill light
lighting diagram of off-axis vs on-axis fill lights

a Fill Light:




The sq. mild represents the primary mild, and the octagonal disc represents the fill mild.
Above instance makes use of a 1:1 fill ratio so as to enhance visibility of fill shadows.

Nevertheless, off-axis fill has its personal disadvantages, with maybe the worst being that one now has to fret concerning the look of shadows from the fill mild. If these aren’t made sufficiently delicate, they will trigger unrealistic-looking double shadows. To counteract this, the farther a fill mild is positioned from the digital camera’s line of sight, the bigger that mild supply must be. Transfer your mouse over the choices above to see this impact.

Notice the second shadow to the best of her nostril with the “off-axis hard” fill lighting. Additionally word how the on-axis fill mild avoids producing double shadows although it’s a small (onerous) supply, however that it does not get rid of the shadows as completely (regardless that it makes use of the identical 1:1 fill mild ratio).

Additionally take into account that off-axis fill lighting requires a extra complicated lighting association, and is subsequently often reserved for portraits in a studio. An off-axis fill mild additionally technically is not a true fill mild, because it can’t lighten all shadows seen to the digital camera — simply these from its path. For instance, within the above portrait, the off-axis mild is unable to scale back the shadows behind the hair on the higher proper.


camera force flash icon

Many solely use flash when their scene has inadequate mild for a hand-held photograph, however doing so misses out on maybe an much more helpful perform: fill flash. Though it might sound counter-intuitive, portrait flash is probably most helpful when there’s loads of daylight. Luckily, most cameras default to utilizing their flash as a fill flash when the topic is well-lit* — however provided that you pressure the flash to fireside.

Cameras often default to a flash ratio close to 1:1, however this may be considerably off as a result of it depends in your digital camera’s metering system. To fine-tune this ratio, you will need to apply flash publicity compensation (FEC). This modifies the quantity of flash that your digital camera would in any other case emit, whereas leaving the opposite publicity settings unchanged.

*Word: Properly-lit signifies that your digital camera does not deem digital camera shake to be a menace, which often interprets into having an publicity time that’s shorter than about 1/60 of a second.


Different necessary fill mild methods and issues embrace:

Pure Fill Lighting. To date we have targeted on situations the place pure mild is the primary mild supply, and the digital camera’s flash is used because the fill mild. Nevertheless, these roles might simply be reversed. The supply of pure mild often must be smooth although, akin to from an overcast day or a topic within the shade. One additionally sometimes wants an off-camera or bounced flash to ensure that this to supply optimum outcomes (see the dialogue about lighting path within the tutorial on portrait lighting).


Reflectors. These make a single mild supply illuminate a topic from a second course. The reflection is dimmer than the primary mild, so reflectors are mostly used as a fill mild. An additional advantage is that this mild can simply have the identical white stability as the primary mild, if desired. Nevertheless, a drawback is that reflectors typically do not present sufficient mild (even for a fill mild). That is extremely depending on the reflectivity of the fabric, along with its distance from the topic. To extend illumination, reflectors are subsequently often positioned as near the topic as potential — typically simply outdoors the picture body.

Topic-Background Separation. With pure mild portraits, a fill flash will help create further subject-background separation, because the flash is probably going to offer a lot extra illumination to the (nearer) topic than the (farther) background. You’ll be able to management the power of this impact by (i) shifting nearer to your topic and/or (ii) shifting your topic farther from the background.

high contrast portrait with low ambient light

low ambient mild

Ambient Light. All scenes have some quantity of fill mild — no matter whether or not this has been added deliberately. Light from the primary supply bounces off partitions and different objects, which collectively acts as a fill mild. Shadows are subsequently by no means absolutely black, and the precise quantity of fill mild is often a little greater than that offered by your fill flash. Nevertheless, studio lighting can nonetheless obtain very excessive distinction.


General, an important fill mild decisions are:

  • Location: whether or not to put the fill close to your digital camera’s line of sight (on-axis), or off to the aspect (off-axis). On-axis fill is simpler since one does not have to fret about how shadows seem, however off-axis fill provides extra flexibility with placement and management over the looks of reflections.
  • Fill Ratio: the relative power of your fill mild, as in comparison with the primary mild. A superb start line is usually one half fill mild for each two elements primary mild (denoted as a 1:2 ratio), however this may even depend upon the place your fill mild has been situated.

For background studying on this matter, additionally see half 1 of this tutorial:
Introduction to Portrait Lighting: One Light Supply

For different comparable subjects, additionally go to the next tutorials: