Lenses #5 - Telephoto

[RichardTaylor]

Lenses #5 - Telephoto lenses

They start around 50mm (for a crop camera) or 75mm for a full frame camera

Disadvantages
They can be very expensive.
They can be big & heavy. I use a mono pod on long shoots, mainly to ease the strain on my arms.
They may require high shutter speeds to prevent the effects of camera shake. Using a mono pod or tripod or image stabilisation may reduce the need for high shutter speeds.

Advantages

(1) They allow you fill the frame with subjects that you can't physically get close to. This may be any thing from wildlife & sports to architectural detail & flowers & bugs.
I love the ability to just "reach in" and grab things.


Camera Canon EOS 40D
Exposure 0.008 sec (1/125)
Aperture f/6.3
Focal Length 400 mm
ISO Speed 800

(2) They are capable if achieving very shallow depth of field (DOF), great for isolating subjects from the background.
Also because of the smaller field of view there is less background to be isolated and because the out of focus background appears to be closer it "appears" even more out of focus.


Camera Canon EOS 40D
Exposure 1/6400 sec
Aperture f/2.0
Focal Length 135 mm
ISO Speed 100
Exposure Bias -1 EV
Flash Off, Did not fire

(3) They can be very fast. Like F2 or faster to 200mm or F2.8 to 400mm.
This makes them very handy for shooting moving subjects, even at a distance, in very low light.
Example, shot at a theatre.


Camera Canon EOS 40D
Exposure 0.005 sec (1/200)
Aperture f/2.0
Focal Length 135 mm
ISO Speed 3200

(4) Because you may be shooting at longer distances subjects will appear to be compressed (perspective depends on shooting
distance). For portraits when shooting with lenses around 80mm-100mm (for a full frame frame camera) this can be very
flattering. Also great for those "stacked" 'scapes.

In this example the buildings in the background are a fair way from the shooting location at the Sydney opera house, across the water of Circular Quay.


Camera Canon EOS 40D
Exposure 0.002 sec (1/500)
Aperture f/10
Focal Length 150 mm
ISO Speed 400

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Some thoughts on telephoto zooms.

70-200mm.(I own a Canon 70-200 F4). These are great for a general purpose long lens. The fast ones (F2.8) are good for low light action captures (Indoor sports?) however they may be big & heavy. The slower ones (F4) are basically good light lenses.

I mostly use mine for head shots when shooting street fairs/parades/events in good light and sport when I will be close to the action. They are usually too short for smaller wildlife and wildlife in the wild.

70-300mm (I own a Canon 70-300 F4.5-5.6 Image stabilised lens). The 55-200/250 are the equivalent for crop cameras.
Relatively compact and good when you want a bit more reach than 200mm. Not good, because of the small maximum aperture for capturing action in low light. They can be OK for some wildlife but will be way too short for smaller bird etc.
I use mine for a back up lens on critical shoots and a a vacation tele lens when I am not specifically shooting wild life.

80/100-400mm (I own a Canon 100-400 F4.5-F5.6 image stabilised lens, and have owned a Tokina 80-400mm). They can be a bit big
& heavy. They can be very versatile good light lenses where you want a fair amount of reach. In good light they are great for wild life & sport. The 100-400 is my most used lens as I shoot a fair bit of motor sport and birds. It is still to short for very small birds, unless you can real close to them.

Keep in mind, if you are willing to use high ISO (like 3200 up) the slower lenses can be used in relatively poor light.
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How many MM do you need?
These figures (from this site) will give you an idea.
What lens should I bring today? (Dimensional Field of View Calculator by focal length for DSLR) | myLensDB.com

For a 1.5 crop camera (Not full frame)
70mm @ 8m(26') will give you a field of view of 2.74m(9')x1.8m(almost 6')
150mm @ 17m(56') will give you a field of view approximately the same.
200mm @ 23m(75') will give you a field of view approximately the same.
250mm @ 29m(95') will give you a field of view approximately the same.
300mm @ 34m(112') will give you a field of view approximately the same.
400mm @ 45m(148') will give you a field of view approximately the same.
500mm @ 57m(187') will give you a field of view approximately the same.

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Lenses #1 - Introduction to DSLR lenses.
Lenses #1 - Introduction to DSLR lenses.

Zooms & primes.
For a good introduction to zoom and prime lenses see this post (on this site).
http://www.digital-photography-schoo...which-are-best

(2) "Standard" zooms -
Lenses #2 - Standard lenses

(3) Superzooms:
Lenses #3 - Superzooms.


(5) Wide angle zooms.
Lenses #4 - Wide angle.

(6) Telephoto - This post.

(7) Fast lenses -
Lenses #6 - Fast lenses
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Thanks for looking.
Feel free to ask questions and feedback would be appreciated.

Richard