Making the Background Dark
My brother in law recently took home a bunch of mayana plants from their vacation home up north. Mayana plants also go by the name Coleus. I've seen these plants around but have never really looked into them. These plants come in different colors and also appear to have some medicinal benefits. Decided to do a quick shoot and give some photos to share with our local online marketplace, since he plans to sell these.
I figured the best way to showcase the colors is to shoot these plants with a black background.
When I say black background I don't necessarily mean I placed a black cloth at the back of the plants. What I do is a method called "killing the ambient light".
This is the same method I used for the shoots I did during the 77 day quarantine imposed in Metro Manila from March to June.
Anyway, this recent shoot I did with the mayana plants was shot at my brother in law's garage on a rainy Sunday afternoon. It was dark and cloudy but there was still a decent amount of light. Here is how it looked like. I did place a black plastic board under the plants just to cover the wooden bench.
Killing the ambient light means setting the exposure such that the only light that registers on the sensor is the studio light or the flash. This method gives the photographer absolute control over the light or lights that hit the subject. You can add, move, adjust the lights depending on what you want.
I used a two light set-up. One key light, a Godox AD200 with a gridded beauty dish. The second is a rim light, another Godox AD200 with a grid and barn door attached. I'll do another post with these lights and the modifiers I use. The grids and barn doors are important since these modifiers let me control where the light hits.
This two light set-up ensures that the key light captures the detail upfront while the rim lights provides a nice outline to the subject. This is the same light set-up I used for the Forbes covers and athlete portraits I shot in the past. This is a tried and tested set-up and always gives good results with the first click.
Here's the exposure and histogram from one of the images taken. The key and rim lights were powered at 1/16th.
Shutter speed - I normally set this to 1/125 or even 1/160. Going any faster doesn't really do much in terms of how much light hits the sensor. It can further darken the background but since I already had a black background at 1/125 sec, I really didn't need to go any faster.
Aperture was set at f/14 - now this is what makes the background pitch black. Wide open apertures (f2 upto f5.6) tend to let more light in, while smaller apertures like f8 and higher will let less light into the sensor. The added benefit of this very small aperture is that I get more of the plants in focus. I used the 135mm f2 DC lens which is a telephoto lens. Telephoto lenses tend to have very shallow depth of field (DOF) when shot in the lower apertures, shooting at f/14 makes the DOF deeper (i.e. more of the image is in focus).
ISO was set at 400. Lower ISO lets less light in and higher ISO lets more light in. I could've gone with ISO100 but I also didn't want to use too much power from the strobes. I mentioned I was shooting at 1/16th power. Going with a lower ISO would mean I would need to increase the power. This is really all a matter of preference. I'm used to conserving batteries since a lot of the shoots I do are location shoots. There is no downside to shooting at ISO 400 since the image at this ISO is still very clean with no distinguishable noise or grain.
The histogram (that graph to the right of the image) just shows how much of the image is bright and how much is dark. The histogram is skewed to the left which means a lot of the image is underexposed. This is good.
So with these settings and the existing light conditions in the garage I was already able to create a black background. No need to bring in any backdrops or do any photoshop work trying to mask out the background. The next step is to do some minor edits.
I do my file management and editing in Adobe Lightroom. Once in lightroom, I use a custom adjustment brush setting I named blackout. This one has the exposure and the black points all the way down to -4.00. I then paint around the image to further darken the black parts.
To check if these black areas are indeed black, click on the shadow clipping point on the histogram. The dark areas will turn blue. Clipping point means these areas have lost detail - you can have a shadow clipping point (very dark) or a highlight clipping point (very bright). In this case our goal is to have the black areas in the shadow clipping point.
After these edits, I added some sharpening, S curve, clarity and that's it. All in all this was a quick shoot with a quick edit.
Give it a try.