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Flash Extenders
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| In wildlife portrait photography, one of the often overlooked details that can make a difference between having an image suitable for publication or just a snapshot of a wild animal is recording catchlights in the eyes of the animal. | |
| As in human portraiture, the eyes are a key element of a successful shot, especially if they convey something of the subject's inner self. Catchlights put that sparkle in the eyes of the subject that makes most viewers feel attracted to an image because catchlights give to the subject an intelligent and lively expression. |
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| Moreover, catchlights are almost a necessity if you attempt to photograph dark-furred or dark-skinned animals or animals whose eyes are deeply recessed in their skull and therefore generally in deep shade. In these instances, catchlights serve the purpose of making the eyes visually distinguishable from the rest of the head of the animal, which would otherwise appear as a uniform dark toned shape. | |
| Catchlights can be obtained either by exploiting the reflection of the sun in the eyes of the subject (but obviously both the sun and the animal must be cooperative for this to happen) or by using fill flash. In the latter case, one of the major problems that wildlife photographers face in the field is having a speedlight that is powerful enough to reach a subject that can be fifty or sixty feet away. | |
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| The main factors influencing flash range are the flashgun's guide number, the aperture and the focal length you select and the ISO value of the film or digital camera. Very broadly speaking, the lower the guide number, the smaller the aperture, the shorter the focal length and the lower the ISO value, the lesser the coverage of your speedlight. | |
| For instance, in order for a Nikon SB-80DX flashgun on a camera set at ISO 100 and with a 105mm lens (having a guide number of 184, in feet, or 56, in meters) to properly light a subject that is 50 feet/15 m. away would require an aperture of f/3.7, while if the subject were 60 feet/20 m. away, the required aperture would be f/3. Considering that at those distances you would normally use a 300mm or longer lens, maybe coupled with a teleconverter, the required maximum apertures mentioned above would not be available but in the fastest lenses on the market. | |
| So, what to do if your speedlight's maximum range is not enough to create catchlights in your subject's eyes? A flash extender is probably the most convenient and effective solution in the field. | |
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| A flash extender is basically an additional fresnel lens that velcroes to two plastic prongs that can be fixed to the flashgun's head with the help of an elastic band. When not in use the whole thing folds flat into a small, light package that you can fit anywhere in your photo bag or backpack. | |
| Flash extenders work best with lenses having a focal lengths of 300mm and longer and they increase the flash output by as much as two to three stops. The maximum effect is obtained with the flashgun at its 50mm setting. Moreover, the good thing about flash extenders is that you are not required to make any adjustments to the settings of your flash when using them: your camera will keep calculating the correct flash exposure in TTL and you can keep shooting at your desired fill flash settings but with far more reach than without an extender. | |
| So,
a flash extender may actually be your answer to increase the range of
your flash as a fill light when you're doing long telephoto wildlife
shots. However, make sure that you have a clear visual path between your
flash and your subject, in that anything in between is likely to appear
overexposed in your image because of the Inverse Square Law. Pursuant to
the Inverse Square Law, the intensity of the light generated by a fixed
source falls off as the square of the distance from the object or, put
in simpler terms, if anything (e.g., a branch or a bunch of leaves)
stands between your flash and the subject, it will get four times the
light your subject is going to get. So be always mindful of the
conditions you are shooting in when using a flash extender. |
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| One more warning: when you are in the field always remember that you have a fresnel lens in your hands, that is something which pretty much works like a magnifying glass. I'm saying this because I once forgot and inadvertently lined it up with the sun with the result that the concentrated sun rays burnt some pretty nasty holes in my trustworthy Nikon SB-28 flash (which however kept working flawlessly notwithstanding the scars)! Take care of what you are doing with your flash extender! | |
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| Among the available brands of flash extenders, I chose the Flash X-Tender from Visual Echoes which is distributed, among others, by Kirk Enterrprises (www.kirkphoto.com) but you can also consider the Project-A-Flash from Tory Lepp (http://www.leppphoto.com/Project-A-Flash/): they both come in various versions to accommodate different flash makes and models. | |
| Give it a try next time! | |
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