John Freeman’s Guide to Telephoto lenses 3
Using an extender as an alternative
An alternative to an ultra telephoto is the use of an extender. Depending on the manufacturer, these come in different strengths. The one that I always use with my Canon kit is the 2x extender. When I fit this to my 70-200mm lens it gives me a maximum telephoto equivalent of 400mm. The only drawback is that I lose some speed as the maximum aperture available falls from f2.8 to f5.6.
So far I haven’t found this to be such a drawback and, when you take into consideration the cost factor, it is a piece of kit well worth having. Both the autofocus and image-stabilising elements of the lens still work when using the extender. If you consider that this extender costs under £300 and a 400mm f/5.6 lens costs nearly £1000 you can see why it’s such an economical alternative.
John’s Top Tips! Telephotos
1 Use wide apertures to your advantage by making the background go out of focus, thereby giving greater emphasis to your subject.
2 Because long telephoto lenses compress your shot, interesting effects can be achieved which will enhance your composition.
3 Although telephoto lenses have less depth of field than normal or wideangle lenses it is still possible to increase this by stopping down to f22 or even f32.
4 Use the shutter priority setting on your camera. This allows you to select the shutter speed while the camera selects the aperture. This gives you far
greater control over camera shake.
5 When using these lenses to track subjects that are moving towards or away from the lens, use the AI Servo function to keep the subject pin sharp.