Happy Father’s Day (in the USA).
The day started off cloudy and rainy which ruined my planned morning photography outing. But in the afternoon the sun came out, and being of bored mind I wandered around my backyard and decided that I would take close-up photos of some lantana flowers.
I went and grabbed my camera with an extension tube and a 24-120mm lens and went back out. The lantana was getting full sun and there was only a slight breeze, so these were optimum conditions for extension tube close-ups. My first hand-held attempts didn’t work out as it was too difficult to focus and hold still. So, I went to get my tripod.
The normal center post in my tripod doesn’t allow the tripod to get low to the ground, so I put in the short center post. For the lens set-up I put a 36mm extension tube between the lens and the camera and had the lens zoomed out to 120mm and as close to the flowers as I could get it without casting a shadow on the subject. This allowed me to fill the sensor with the flower. I also removed the lens hood to reduce the shadow cast on the flower.
When you use an extension tube, you get a very narrow depth of focus close to the lens. The flowers just a couple of centimeters from the front lens element will be in focus but focus will drop off quickly beyond that.
Also, auto-focus does not work well with an extension tube so you have to manually focus. And shooting such a close-up means that any small movement of the subject is magnified as well. My focusing process was to:
- set the camera to live view mode
- set the lens to manual focus
- use the digital zoom control to zoom in to the place where I wanted to focus
- wait patiently for the breeze to die down
- manually focus and shoot.
Light is usually a problem when shooting with an extension tube, but with so much direct sunlight I was able to stop the aperture down to f/8 to get a little better focus depth and sharpness. The photo below was shot at 120mm, f/8, 1/250s, ISO100. I checked the histogram in camera to make sure that the highlights didn’t get clipped.
The leaves and dirt in the background blur out to a nice natural background setting for the flowers. The little bundle of flowers almost look as if they are just floating above the background thanks to the very shallow focus depth.
One problem that I found using extension tubes for this close up is chromatic aberration or color fringing on the edges of subjects. You can see this on the blue edges of the flower petals in the crop of the uncorrected image below. This is caused by different wave-lengths of light being defracted by different amounts by the lens elements. This is ordinarily corrected in the lens design, but I think that using the extension tube defeats the correction.
To fix this in LightRoom, I used the Defringing tool in the Lens Correction – Manual adjustment panel. I zoomed in on the edge of the flower petal and used the eye-dropper to select the offending fringe. The fringe can then be adjusted with a slider control. In the final images, earlier in the post, the fringing is mostly corrected though it is not perfect. This is probably one good reason that a macro lens is superior to the extension tube technique.
Other than that, I adjusted the exposure and gave a little saturation to the pinks and purples, gave it a square crop, and hit export.
Below is the little trailing lantana in a flower bed in my backyard taken with my phone. The flowers are very small and it would be difficult to get a good close up of them without a macro lens or using extension tubes.
Thanks for reading and have a nice week.