Teleconverters for your Underwater Photography
Using teleconverters for macro and supermacro
By Scott Gietler
Every photographer will benefit from teleconverter and should have one. In this article we'll discuss what a teleconverter is, what types are out there, and why you should use one. We'll also talk about which lens to use them with, brands to purchase, and port and lighting considerations.
What is a teleconverter?
A teleconverter is a small lens that is placed in between your primary lens and your camera body. It enlarges the center portion of the image, effectively magnifying the image.
Tamron 1.4x teleconverter on the left, diopter on the right
What types of teleconverters are out there?
A teleconverter can magnify the image by 40%, 50%, 70% or 100%. These different teleconverters are referred to as 1.4x, 1.5x, 1.7x, or 2.0x teleconverters respectively. You want a teleconverter that will auto-focus with your lens. The vast majority of people end up choosing a Kenko Teleplus Pro 300 1.4x tele, or a Tamron SP AF Pro - both of which appear to have the same internals, but only differ cosmetically.
Nikon 60mm lens at 1:1 - no teleconverter Same shot at 1:1 with Kenko 1.4x tele.
Why use a teleconverter?
If you are shooting with a macro lens that does 1:1 macro, a teleconverter will allow you to take supermacro photos.
For topside shooters, teleconverters are commonly used with F2.8 or F4 lenses for shooting birds, wildlife or sports when further "reach" is needed for a subject that cannot be approached closely enough, such as a small bird.
Some underwater photography examples
Juvenile fish from Bali, photo by Kevin Lee. All photos taken with a Nikon 60mm macro (non AF-S version) lens with a 1.4x teleconverter, unless otherwise noted.
Juvenile Fish, Bali
Juvenile frogfish, Anilao, Philippines
Gorgonian polyps, Catalina Island, California. Taken at F25
Should you use a teleconverter with a 50/60mm or 100/105mm lens?
99% of the time I use my teleconverter with a 60mm lens. Olympus dSLR shooters usually use it with the 50mm lens. Using a 100mm or 105mm lens with a tele can work for very skittish subjects such as gobies and garden eels, but you're shooting through a lot of water.
Using a teleconverter with other lenses
People have sometimes used a teleconverter with a fisheye lens such as the Nikon 10.5mm lens or the Tokina 10-17mm lens. Now that the Tokina fisheye is available, there is no need to use the Nikon 10.5mm / teleconverter combination. When using the teleconverter with the Tokina, you'll need a modified zoom ring that will work with the new setup, and you'll want your port extension to be increased another 20mm. Personally I think a mid-range zoom like the Sigma 17-70mm lens is a better alternative than using the Tokina with a teleconverter.
I use the 60mm + 1.4tele combo in the same port that I use for my 105mm lens, it fits in quite nicely.
Don't be afraid to move your strobes around to try front lighting, side lighting and backlighting. When using the 60mm lens with a tele, you can get very close to the subject, making different strobe positions easy to accomplish. For supermacro subjects, I find that extreme front lighting often works well - getting your strobes very close to the port. Backscatter is often not an issue at close distances.
Using a focus light
You'll want a good focus light to help your camera achieve focus properly. Although I find that my Nikon 60mm + 1.4 tele focuses easier than using my 105mm lens, autofocus is slower with a teleconverter, especially when you reach 1:1 or greater magnification.
Tips for using a teleconverter
Only use your teleconverter with a prime macro lens that has a maximum aperture of F2.8 or F4.
I often use continuous focus mode, so the camera does not need to lock focus before taking the shot. I release the shutter when the focus looks good in the viewfinder.
Move your focus point around to achieve focus exactly where you want to on the subject
When I dive with my 60mm + 1.4x tele, I can shoot supermacro, skittish fish, small fish, and small nudibranchs. It has become one of the most popular underwater combinations for many macro photographers in Southern California, especially when visibility is less than ideal.
The Canon 60mm lens will need a 12mm extension tube to work properly with a teleconverter. The new Nikon AF-S 60mm lens will *not* work with a teleconverter (I use the old model). I haven't tried it with an extension tube.
Other ways to achieve supermacro photography
Diopters are also commonly used in supermacro photography. I also use diopters, but not as often as I use teleconverters. However, some underwater photographers exclusively use diopters, especially wet diopters.
More underwater photography examples with a teleconverter
Small nudibranch, Seraya, Bali. Photo by Kevin Lee
Colmani Shrimp, Anilao, Philippines. Taken at F20
Hopkins Rose Nudibranch, Catalina Island. Taken at F16
Pygmy seahorse from Raja Ampat, photo by Kevin Lee
Imperial shrimp, photo by Bill Van Antwerp. Canon 100mm lens, Kenko 1.4x tele. Taken while muck diving in Ambon, Indonesia.
Canon 60mm lens, 12mm extension tube, Kenko 1.4x tele. Photo by Bill Van Antwerp, taken in Ambon, Indonesia.
Flatworm from Catalina Island, crawling on a starfish. Nikon 60mm lens + 1.4x Tamron teleconverter. Taken at F20
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