I often get asked for a white background to my studio head shots, product shots and more. Why is that? The web of course. Many web pages are white so it makes sense to have your images matching the paper white background rather than some sort of off-white Dulux blend. (Natural White is our current favourite in the Dulux range by the way!)
So what does it mean. It means 255 on the RGB scale. Now going back a bit, a pure white background would have been frowned upon as lacking in texture. The around 220 might have been considered white enough.
So I set about trying to find out how to do it. I asked photography masters at workshops, I scoured the internet and searched books. Guess what. It’s not as easy as you might think at first. The general consensus is that you light the background separately from the foreground subject. Easy peasy, let’s do lunch.
Actually it might be relatively easy if you have a huge studio (by that I mean around 15 metres long from backdrop to camera position). If you have , then throw some light onto the white backdrop (ideally seamless variety), put your subject about 10 metres in front of the backdrop and position the camera another 3 to 5 metres in front of the subject and light them as you normally would for your chosen light pattern.
Now, what, if like me (and many others out there I suspect) you only have a small room or garage studio with maybe 5 to 6 metres to play with. Will the first method work.
In my experience, NO. The main why not that I have found is that the light reflected from the background screen (usually set at about two-thirds to one stop brighter than the foreground lighting combination), will bleed around the back of you subject. This is similar to a contra jour or backlighting scenario that you may encounter outdoors. There is a high risk of camera flare (similar to lens flare except it is occurring inside the camera). This results in loss of contrast, and even colour change. I have seen navy blue mens business suits turn to purple around the sleeves and shoulders and look like you had just applied about -80 on the Clarity slider in Lightroom.
So can it be fixed? My workaround is to set up a floor to ceiling foam core “wall or V-flat”, painted matt black (another Dulux colour!!) on one side and left white on the other. I have them on each side of the subject at about 2 metres from the backdrop. Behind them I have a light source (in my case a strobe with strip box…could be an umbrella or just a Speedlite even), pointed at the opposite third of the backdrop thus creating a cross over pattern. I set both lights to give me as close as possible to the same reading across the frame.
Now I have created a sort of door opening between the two flats. With the modelling lights turned up full, I can see the extent of the reflected light pattern on the floor. It seems to creep about 60 cm (2 feet) forward of the opening. My subject must be further forward or the creepy light dude will get them. The more forward they are, the better the result. Make sure the “door” is wide enough for you subject so that only a white background shows behind them. Otherwise expect much cloning in Photoshop.
Now straight out of the camera this works well. However, you may need to tweak a little in post. The quickest method that I have found is to paint higher exposure or shadows with the Adjustment Brush in Lightroom.
With the Auto Mask feature turned on, paint over the white background with a medium sized soft brush. If you have the highlight warning triangle selected you will get the red as shown (not sure what Dulux colour that is!). And if you are the type that is never satisfied with software defaults then it might not be red on your screen. If you overstep the mark slightly you will get a very bright over exposed spot on your subject. Not usually desirable so with the Option key (Mac) or Alt ket (Win) pressed, paint back over the subject to restore the blemish.
When you export your image to Photoshop you should have a 255 background colour ready to be finished off.
That’s my preferred method as I say. I usually find the the floor nearest the feet of my subject is less than pure white but it only takes a quick brush up to fix it.
I also use another method which involves Nik Software’s Viveza plug in. (Now owned by Google)
Apply a Control Point as above, enlarge it as below left to cover the area to be brightened, increase the Brightness slider and click OK. The result will be as bottom right, 255 background
A third and more tedious option would be to deep-etch the subject off the background altogether and create a new pure white layer beneath. In some circumstances this may be the best option. It’s up to you.