Crossed Strobes or Inward Lighting?

In this episode of the Underwater Photography Show, Matthew Sullivan and Alex Mustard discuss the differences between cross lighting and inward lighting, and when to use each technique.

In underwater photography, we give names to different types of lighting and strobe positions to help people learn and remember them. The naming is a memory aid and a way to understand the technique, as strobe positioning is a continuous movement, and these names refer to specific points in that movement. Both inward lighting and cross lighting can be used for wide-angle and macro photography, with slight differences in positioning for each. [0:53]

Cross Lighting

Cross lighting is a setup that creates a double side-lighting effect. Side-lighting is the best way to get the most texture in a picture, but using only one strobe can result in very uneven lighting. Cross lighting, or double sidelight, gives you lots of texture with even lighting. It is a very useful and flexible technique that can create powerful images easily.

In a macro setup, you want the strobes in line with the subject, shooting straight in from either side. Cross strobes are also valuable for creating texture in subjects like a warty frogfish or spiky coral.

For wide-angle photography, cross strobes is a close-focus technique. You get the strobes as far out and as far forward as possible without creating flare. The strobes are positioned wide and pointed at the subject. If the subject is off-center, you can turn down the strobe on the closer side to even out the light. [2:35]

Inward Lighting

Inward lighting is an extreme form of cross strobes. Instead of aiming the strobes at the subject, you rotate them so they are shining back towards you. The subject is illuminated by the inward edge of the strobe's beam. Most of the light misses the subject, and the very edge of the light catches it.

This technique creates an illuminated subject with an immediate transition to a black background. It's used when a subject is against an ugly or distracting background that you want to isolate. If a subject has natural isolation, cross strobes is often enough. Inward lighting is a more refined version for when you need to isolate a subject that isn't naturally separated from its surroundings. It can also be done with snoots, which can produce a cleaner effect. [3:42]

For wide-angle shots, inward lighting is also a close-focus technique where the strobes are pushed as far forward as they can be without causing flare. Using a beam restrictor can help to create a hard edge of light to work with. The strobes are rotated so they are mostly firing behind the camera housing, and you use the edge of the light to catch the subject. [5:29]

When using inward lighting, we recommend using back button focus. Set your focus point and then use that fixed focus to fine-tune the lighting. This allows you to make adjustments to your strobe position without taking a completely different picture. [7:49]

A common mistake we see is not having the strobes far enough forward, which results in the area in front of the subject being lit but not the subject itself. It's crucial to get the strobes as far forward as possible. [9:24]

For us, inward lighting has become a go-to technique, especially in places where the subjects are cool but the backgrounds are not. It feels more naturalistic than using a single snoot as a spotlight, even though both techniques isolate the subject. When you get it right, inward lighting is an incredibly powerful technique that can feel like magic.

Want to listen to the entire discussion? Watch the original episode below: