Super-Telephoto Lenses, 400mm - 800mm and Beyond
We've all seen them at major sporting events: banks of photographers with long white or black lenses delivering pictures that are the envy of many. Costing the price of a small car, they are the lenses of choice for wildlife and sports photographers as well as photo journalists around the world, offering incredible quality both in terms of design and the resulting images. Perhaps it’s just curiosity, but they also attract interest wherever they're seen or taken. At the annual Photography Show at the NEC in Birmingham, visitors gather around the manufacturers’ stands to try out their super-telephotos, picking off unsuspecting visitors like a sniper.
Buying one however is a considerable investment and certainly not to be taken lightly, but unlike camera bodies a well looked after lens will hold its value. Consider the cost of an 800mm f/5.6 today compared to say 5 years ago. Then consider the value of a Canon 1DsMK3 to day against it's launch price. The point is simple - lenses are a better financial inestment.
Using one opens up new perspectives normally associated with binoculars or small telescopes with a narrow angle of view and compression of distance between objects. Over the past 20 years I've owned all of Canon's super-tele's at some point, and today have the 400mm f/2.8 and 800mm f/5.6 versions. Optically, these lenses are as good wide open as they are stopped down to, say, f/8, both at the centre and edge of the frame. The use of high end, ultra low dispersion, optical glass and Fluorite contribute in reducing optical aberrations that can be present in other lenses. Their wide apertures, typically f/4, let in double the amount of light compared to a typical 400mm f/5.6 zoom, which makes auto focusing not only faster but more accurate given the prevailing sensitivity of AF points.
If you want the very best optics available with a long focal length then the super-teles are the way to go. But owning one comes with its own unique challenges (not to mention the credit card bill!) and they aren’t for everyone. Let's have a look into the world of owning and using one.
My Canon 800mm f/5.6 mounted on a Gitzo 5541LS and Wimberley Head.
Getting to know a super-telephoto
The first thing you notice when holding a super-telephoto is its size and weight. While the number of optical elements is similar in a telephoto zoom of 100-400mm to a 400mm prime f/2.8, the super-tele is close to double the prime’s diameter and length. This is because the super-tele is holding a lot more optical glass for the same focal length.
When lifted by the tripod collar the super-telephoto seems quite manageable as a dead weight, but attach one to a camera body and hold it for more than a few seconds, and you’ll find that one of your arms will be screaming for relief. To put it into context, my 600mm f/4 weighed four times that of my 70-200mm f/2.8 at almost 12lbs – that's six bags of sugar! Try holding that with your arm out-stretched and you'll get the general idea!!
Even the new 'lighter' versions weigh over 8½lbs, so even handholding that mass for more than a few seconds will quickly place stress on the elbow joint. For some circumstances handholding is unavoidable; my own military aviation work in the low flying areas is one example. Trying to rotate the super-telephoto through 180 degrees around a tripod/monopod on the side of a hill with a jet approaching at 450mph just doesn't work – I know, I've tried it. Thankfully (in this case), the jets are gone within a few seconds.
So what are the alternatives? The more popular would include: tripod, monopod and beanbags, with the decision really based on the subject matter and budget! A beanbag is by far the cheapest option but also the most limiting in that it generally can't be used for anything other than a stationary subject, or one slow moving at a distance. The monopod is ideal and certainly the preferred choice of the sports photographer/photo journalist: it not only offers good support, but can also be used to carry the lens over short distances. Alternatively, a tripod with appropriate long lens head (such as the Wimberley) is perfect if the photographer is going to be in one place. Trying to carry a tripod, Wimberley head and camera lens/body is both uncomfortable and difficult over anything more than a short distance.
Image stabilisation and vibration reduction
Of course, there will be times when support isn't practical or when prevailing circumstances require a relatively slow shutter speed. In these cases, using a super-telephoto can run the risk of inducing camera shake since small arm/hand movements are magnified by the longer focal length, which can be a contributing factor in blurred images.
One solution is to engage the Image Stabilisation/Vibration Reduction function found in most bodies nowadays. Introduced in the mid 90s, stabilisation sensors can detect camera shake and adjust the optical system to stabilise the image with a proclaimed benefit of around 4 stops. I've met many photographers who never use it, claiming they don't want any moving parts within the optical elements. Others swear by it and always leave it On.
Personally, if I can achieve a shutter speed of the reciprocal of the focal length then I'll turn it Off as the stabilisation has reached its effective limit. However if I'm panning at, say, 1/200 sec with a 400mm f/2.8, it will be turned On. Equally, and even with the lens tripod/monopod mounted, if a shutter speed of less than 1/focal length is selected then my preference is to normally have it selected.
Portability vs mobility
Okay, so you've taken the plunge and bought or rented one; how are you going to carry it? These lenses come with a very strong, robust carry case that is ideal for storage or if the lens has to be carried a short distance. For anything else, a good quality rucksack is required.
Carrying a super-telephoto, one or two camera bodies, perhaps a mid-range zoom and associated accessories – not forgetting food/drink – is going to weigh quite a lot. A good rucksack that securely holds everything in place is frankly a necessity.
Choosing one that incorporates a waist belt and chest strap can make a difference in spreading the load and ease the burden on aching shoulders. As ever there's plenty of choice, but my preference is for those made by ThinkTank, especially when travelling, and for Lowepro (600 AW) when I want to carry loads of kit.
While all of the super-teles carry an UltraSonic/Silent Wave Motor to help drive the auto focus in an almost silent manner, perhaps one of the key benefits of these lenses is their Aperture size for the focal length. At f/4 twice the volume of light is entering the lens than at f/5.6, which not only means a brighter viewfinder, but also more light hitting the AF sensors on the camera body, resulting in both faster and more accurate auto focus.
From my own experience, I know that my 800mm f/5.6 'needs' a lot of light for the AF to work quickly. If it's a very dull overcast day then the AF will be comparatively slow and can, on occasion, 'hunt'. This can often be overcome by engaging useful functions built into the lens such as Focus Preset, which allows a preset focus point to be memorised and quickly returned; and by setting the Focus Range Limiter Switch to an appropriate distance.
In comparison, my 400mm f/2.8 lets in four times the volume of light as the f/5.6, making AF lightning fast and accurate. One can understand why that lens is so popular amongst sports photographers around the world.
Using a super-telephoto
Given their focal length, super-telephotos open a new range of possibilities that other lenses can't. Beyond the most obvious of bringing a subject closer, I've categorised them into three areas: Image Compression, Depth of Field and Resolution.
A super-telephoto allows the scale/size of a subject to be communicated. The compression delivered by the image of a US Airways Airbus 330 crossing in front of the Moon is a case in point. With a 600mm lens plus extender, the sheer scale of the moon is portrayed in contrast to the jet. The Moon is over 230K miles away, the airliner 7 miles, but the lens has compressed the distance between the two dramatically!
Similarly, but this time over 7,000ft up in the Swiss Alps and four F5 Tigers from the Patrouille Suisse are in 'Shadow' formation. Look again if you can only see three! 1D Mk III, 500F4 LISUSM, 1/100 sec handheld.
Depth of field
For a given distance to subject, a super-telephoto captures shallower depth of field than other lenses. At relatively short distances this can lead to wonderful, buttery smooth background blur and superb isolation of the subject. Yet it also brings its own challenges, as wafer thin depth of field could lead to misinterpretation of camera/lens focussing issues.
I took the image to the right in my garden at home to illustrate this point. With a super-telephoto and a relatively short distance to subject of around 20ft; my lawn is completely out of focus and allows the subject to be isolated.
1DMKIV, 800F5.6 LISUSM, 1/320, F8, BeanBag for lens support
The image right shows the creative effect of throwing both the foreground and background out of focus to isolate a subject. The low point of view allows the foreground grass to soften while retaining sharp focus on the eyes. The long focal length and wide aperture deliver results just not possible with medium telephoto lenses at the same distance.
Minimum focus distances can be an issue at short range, but the ubiquitous extension tube can quickly help resolve that.
Raccoondog - 1DMKIV, 400F2.8 + 1.4x, 1/800, F4, BeanBag for lens support
In summer of 2011 I was invited to the Orleans Forest in France to photograph ospreys as part of the ongoing conservation work. One of the challenges was to identify (photographically) the metal ring on one of the birds from around 200m away. Such rings, supplied by the National History Museum in Paris (M.N.H.N), measure under one centimetre in width, and the engraved numerals only a few millimetres. The image far right shows the view from my hide, taken at 100mm on a full frame camera. The osprey can be seen perched to the right of the nest.
Using an 800mm lens on a Canon 1D Mk IV mounted on a Wimberley head on top of a Gitzo tripod, a series of images were captured that showed the full code inscribed on the metal ring. The image right, cropped to 100 per cent, illustrates the capability of the lens in rendering such detail at distance. Timing of the shot was of course crucial: we chose an hour before sunset to let the temperature cool, as trying to shoot this image at 2pm would have been akin to shooting through a swimming pool. These lenses will capture atmospherics our eyes might not see.
Buying a super-telephoto
Making the decision to purchase a super-telephoto requires a lot of time, research and thought; they're not cheap. Unless you know for absolutely certain one is for you, I'd encourage trying one first. Renting is fairly easy these days or, better still, ask someone who owns one if you can join them for a day and try it out. If you have a special holiday such as a safari planned then do consider renting, say, a 500mm f/4. The quality of images you'll make will be far superior to nearly all zooms and will last a lifetime.
Speed vs Weight
Be aware of the crucial balance between focal length, auto focus speed and weight. For those not wanting to spend thousands of pounds, both Canon and Nikon offer zooms up to 400mm focal length that are relatively light and portable. Used on a camera with a smaller than full frame sensor is going to provide an extended 'effective focal length' due to the crop factor. So a 400mm could become effectively 600mm on a 1.5 Nikon sensor. Of course, the apertures aren't large and are typically f/5.6 at the full focal length. But being aware of the limitations of each lens and adjusting accordingly will make a huge difference. Back off the zoom and close the aperture by a stop and the image quality will improve, after all the noise performance on DSLRs is improving all the time and is much easier to resolve than a soft or out of focus image.
Adding An Extender
Another cost-effective option used by many is to add an extender to the lens. These lightweight, versatile add-ons multiply the focal length by anything from 1.4 to 2 times the original length, at the expense of 1 or 2 stops of light. While they'll attach to all lenses, care should be taken that the camera itself will be able to auto focus with one attached (refer to your manual). Extenders can be a great addition to your kit when weight and space are a concern.
For example, if used on a 300mm f/4 prime the photographer has not only a 300mm f/4 lens, but also a 420mm f/5.6 with a 1.4 extender and a 600mm f/8 with a 2x extender. This is one of the reasons I think the 400mm f/2.8 is such a versatile lens; not only is it exceptional as a 400mm, but it is superb with a 1.4 extender attached, giving a 560mm f/4 and useable with a 2x at 800 f/5.6.
Throw in a combination of using both a full frame and a cropped body, and the range of 'effective' focal lengths increases again. Considering such permutations is prudent, eye-opening – and confusing! We will of course leave any debate around the merits of cropping into an image from a full frame sensor against that from a cropped sensor and their inherent pixel density for another day!
The fun really starts when one adds an extender to an 800mm. The image on the right was taken at a focal length of 1,120mm (800mm + 1.4x) on a full frame body at 1/100 sec with the lens/camera mounted on a Wimberley head attached to a Gitzo tripod.
C130 Hercules | Head-On Low Level
I hope to have removed some of the mystique and offered some insights into these eye-catching lenses. If anyone has any questions please do get in touch.