Macro photography essentially is close-up photography in which the image projected on the film plane is close to the actual size of the object itself. The lens used for macro photography is optimized to focus on a small area sharply, approaching the size of the film frame. Most 35mm format macro lenses approach 1:2, that is, the image on the film is half the size of the object being photographed. Generally, the 35mm macro lenses are 1:1, which means that the image on the film is the same size as the object being photographed. These lenses are at their sharpest at macro focus distances.
Macro photography underwater involves shooting small objects at close range at 1/3 to ½ the actual size. Housing cameras don’t require framing and capture what is being seen. Underwater macro photography can be challenging and requires the knowledge of aperture and depth of field, macro settings for the digital cameras and underwater macro composition. Apart from these, the other factors that should be kept in mind include:
- Selection of a macro subject – While zeroing in on your subject of interest, consider factors like backgrounds, compositions, light falling on the subject and the choice of lenses. Brightly colored subjects are best for macro photography.
- Moment to be captured – Once the subject of interest is selected, the best moment for its capture can be gauged. For instance, if the subject is a nudibranch, the best moment can be when its gills are completely out.
- Macro composition – Shooting low, keeping the subject in focus and the background colored or camouflaged works best. The foreground should however be sharp and have a proper separation from the background.
- Strobe position – Texture of the subject and water clarity decide the strobe position as to whether it should be front lighting, side lighting or backlighting, also keeping the backscatter in mind. Diffusers soften the light and that looks good in macro photography.
- Background – The color of the background plays an important role and it should be decided if it will be in focus or blurred. Lembeh sticks can be used to move the subject to a desired background, if needed.
- Focus – Locking focus on a desired part and recomposing is essential. If the camera provides a moveable focus point, the arrow keys can be used accordingly. This needs to be changed frequently when the subject is in motion. Continuous and single shot focus modes can be used wherever necessary.
- Exposure – The histogram should be checked for a proper exposure and TTL converter comes as a great help when shooting macro.
- Depth of field - It is related to the aperture of a lens used, the focal point and your closeness to the subject. It should be selected properly according to the composition chosen, the background intended and the ambient light. A large aperture blurs the background and a small aperture brings it into focus.