For the vast majority of people that own a DSLR, shooting with prime telephoto lenses is something that they can only dream of. That is why our pool of rental equipment has proven to be so popular for photographers who cant justify the capital outlay and would rather rent a lens for a special trip. Many of the people that rent these lenses for the first time are not fully aware of how to handle and shoot with what are often heavy and large lenses compared to what they may be used to.
Support & Stability
Unless you are built like Gerry and are training cross fit 5/6 times a week, the chances of you hand holding any of the prime lenses for an extended period of time are very slim. It is vital that you take every precaution possible to eliminate any chance of camera shake when using prime telephoto lenses. Lets take a 600mm on a Canon 7D for example. With a crop factor of 1.6x your effective focal length is 960mm. Even the slightest movement of the lens will be exacerbated by the enormous focal length.
Image stabilising technology go’s a long way to reducing camera shake but Using bean bags and specific tripod mounts like these will almost certainly eliminate camera shake and will keeping your shoulders in tact!
We all know the golden rule that your shutter speed should ideally be at least 1.5/focal length. Therefore, if you are shooting at a focal length of 200mm you should have a shutter speed of 1/300. This is easily forgotten when shooting with the prime telephoto lenses. Don’t forget to take the crop factor of your camera into account and don’t forget to push your ISO as high as necessary to get a good sharp image!
Depth of Field
As you should no by now, depth of field is determined by a number of variables which interact with one another.
- Aperture: small number, shallow depth of field, large number, greater depth of field
- Distance from camera to subject: The closer the camera is to the subject, the shallower the resultant depth of field will be given a constant aperture value and focal length
- Focal Length: as with the previous variable, the greater the focal length, the shallower the resultant depth of field given a constant aperture and distance of subject from the lens.
The tendency when shooting with primes like the 300mm f2.8 or 600mm f4.0 is to shoot wide open (f4.0), creating a beautiful soft blurred background whilst simultaneously achieving fast enough shutter speeds at lower ISO’s. This is great but one needs to remember the effect of focal length and aperture on depth of field.
Here is an example of an image I took from a hide in Marievale last year. I was shooting off a Canon 1D MK IV (1.3 x crop sensor) and a canon 800mm F5.6 lens. Sitting roughly 6.5 metres away from my subject (I remember only just being able to focus on this chap with the minimum focussing distance of 6m on the 800mm lens) even at F7.1 the depth of field is a fraction of a centimetre. Have a look at the 100% crop insert in the image below:
Do you notice how only the eye and some of the facial features are sharp? Baring in mind that the beak of the Malachite Kingfisher is only a couple of centimeters long the depth of field is incredibly shallow. Using the Online Depth of Field Calculator we can see just how shallow the resultant depth of field is.
What should you be keeping in mind then? Well, shooting wide open on prime lenses is great when you are 100% sure that the resultant depth of field is deep enough to ensure that your subject is sharp and in focus. Especially when working with focal lengths greater than 500mm, you will need to think carefully about how close your subject is to you and what aperture value you will dial in in order to capture a sharp detailed image.
You will also need to be aware that as a subject which is approaching you head on gets closer to you, you will need to compensate accordingly as your depth of field will become smaller the closer your subject gets to the camera!
As if you didn’t already have enough on your plat with all of the above factors you will also need to be acutely aware of your composition when shooting with prime telephoto lenses. You dont have the luxury of being able to pull back or zoom in anymore and this means that you will need to position yourself very carefully in order to get the shot.
One of the biggest problems that occurs when shooting with prime telephoto lenses is that you end up clipping parts of your subjects like this vulture below. A decent shot had it not being for the wing to the right of frame.
It is also not that easy to compose birds in flight correctly when tracking with telephoto lenses. You may end up with some beautiful, detailed, sharp images but when they are boxed in to the top right of your frame like this one thre is not much you can do to salvage the image.
How can you avoid this? Spend some time watching the behaviour patterns of your subjects. Birds often fly regular paths, returning to the same perch over and over again. See where they are landing and flying and then position yourself accordingly if possible. Always err on the side of caution and leave a bit more space in the frame which will allow you to crop to your perfect composition at a later stage.
Anticipation and Preparation
Its not all hard work with telephoto lenses and sometimes they really do make photography a lot easier. This image was taken in the Kgalagadi Transfrontier Park early one morning. I knew that these two lions were mating and rather than jostling for a position with the other vehicles stopped right next to them, I opted to head a little bit further down the road where I knew I would have a better angle.
With a 600mm lens I was able to compose my shot with enough space for the Male to move around when dismounting the female and i got the shot.
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