Controlling specular reflections

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What are specular reflections and why do we want to control them?

A specular reflection is a reflection of a light source, for example the catchlights in the eyes are specular reflections,  and we see them in nearly all of our shots.  People often refer to specular reflections as ‘sparkle’ when they like them and ‘glare’ when they don’t… Glare is usually something photographers try to avoid because excessive glare is distracting and obscures surface detail.

It’s nearly impossible to completely avoid specular reflections, although quite a lot of beginners try to avoid them by photographing things in light tents, but all they end up with is photos that are ‘dead’ and which nobody wants to look at – the trick is to CONTROL the reflections, not to do away with them, just as good photographers control shadows, not avoid them. And some people try to reduce or avoid them by polarising the light, either with a polariser on the lens or on the light, or both. Sometimes that can help, but often a shiny surface is one of the defining features of a subject and should be enhanced, not eliminated.

I decided to choose a really difficult subject for this demo, and it doesn’t get much harder than my subject, a handful of tomatoes, plus a pepper. Tomatoes are difficult simply because they have a fairly complex, convex shape that really makes life difficult!

To make life even more ‘interesting’ I treated my shiny new chopping board to a coating of vegetable oil and placed it onto a ‘black glass’ background, which is a polished sheet of smoked glass. This created a very strong reflection of my subject; very few things are shinier than that, and as the shoot progressed I sprayed the tomatoes and pepper, plus the chopping board, with fine droplets of water from a plant sprayer, just to make life even more difficult!

The black background was in fact just an off-white wall. You’ll see that it photographs as black and this is because no light is reaching it, except in the first shot, with an on-camera flashgun. All the photos are as shot, except for re-sizing. They do need a bit of retouching but I never retouch photos used to illustrate my tutorials.  The header photo is retouched though, to give you an idea of the finished product.

Anyway, I started off with the worst possible lighting, an on-camera flash, and this, on the left,  is what I got.
The lighting is flat, and the specular reflections are both small and hard. You can’t see through these specular reflections to the product beneath them.
Also, because the flash is on the camera, it’s also lighting the background accidentally, which I don’t want.
It’s horrible!

 

Well, just putting the light overhead will help. For a start, an overhead light will put the specular reflections on the top of the subject instead of putting them on the front, it will create some shadows and it won’t put any unwanted light on the background.

In all the shots that follow, a single Lencarta ElitePro 300 flash head was used directly above the subject, mounted on a boom arm. In this shot, I fitted the flash head with a standard reflector, which has a diameter of 7″, and I mounted it 3′ above the subject.

Well, this shot is… striking and at least by placing the light overhead there is now no unwanted light spilling onto the background, but those specular highlights are still very small, bright and harsh. And the shadows are small and hard too.

The reason for this is simple. The light is too small, because if we want to get diffused specular highlights that we can see through and which don’t dazzle us, we need a really large light source, such as a softbox. Nothing else will do the job.

As most people know, a large diffused light source such as a softbox creates a softer light quality. The larger or closer a diffused light source is to the subject, the softer the light.

Another, perhaps less well known, quality of a large diffused light source is its ability to control the intensity, size, shape and TRANSPARENCY of specular reflections.

So, in this photo I changed to a 60 x 60cm softbox, and placed it about a foot away from my subject. The softbox is bigger than the subject – it needs to be – and is fairly close, so that should help…

And it does help, you can see that the specular highlights are bigger and not as bright.

And although this tutorial isn’t about shadows, you can see that the shadows are bigger and less strong as well.

But we’re not there yet, the softbox isn’t big enough, and it’s too far away.  To get diffused specular highlights on most subjects, the softbox needs to be at least 3 times the size of the subject and so close that it’s only just out of shot. And with convex shapes like these, it needs to be even bigger!

Time now to bring in the big guns, so I swapped to a 150cm Profold Octa Softbox, the largest one I have, which is my tool of choice for subjects like this one.

You can see that the specular reflections are now much larger and  they are also transparent. Transparency is important, because instead of distracting us with their brightness, transparent reflections allow us to see through to the subject itself. The centre of the cut pepper is still showing as white, but that is its true colour.

Job done, in the sense that you can now see exactly how to achieve diffused specular highlights and avoid glare. Of course, we can do more, but this single-light-shot has taken care of the problem.

One thing that we can do though, without adding an extra light,  is to add a bit of fill at the front. I used a 5-in-1 reflector to pick up a bit of ‘spare’ light from the softbox to fill in the shadow areas a bit. It’s subtle but it’s there.

And to finish off, I added a second light too, another flash head, fitted with a standard reflector, a  20 degree honeycomb and a blue gel, pointed at the off-white background, just to give the shot a bit of depth.