All About Lenses
As you get deeper into photography, you may become susceptible to another of the pitfalls of distraction that can lead you off the path of tending to your vision, namely the acquisition of lenses. There are many, many different lenses for all the camera systems and choosing a lens can become just as frustrating as choosing a new smart phone these days.
When I bought my first SLR camera in year 2000 it came with a 28-80mm “kit” zoom lens. In older times the lens you normally found on a 35mm system camera was the 50mm f/1.8 or 35mm f/2.8 standard (or fixed focal length) lens. These days zoom lenses are much more popular than primes and as such you’re likely to find them on many of the cheaper range of cameras and they all pretty much provide the same angles of view: moderate wide angle to moderate telephoto.
Back when I started photography the 28-80mm zoom lenses were considered to be somewhat crappy and one of the first bits of advice I read when I started looking at the photography forums on usenet was to get rid of the kit zoom lens and buy something a little better. Like a 50mm prime. I had very little idea what that meant at the time so I scratched around on websites and read a lot of photography books to try and decipher what all these foreign (to me) terms were. It turned out that not all lenses were created equal. Fancy that? And there I was happily snapping away roll after roll of film on my Nikon F60, totally oblivious to this nugget of information.
Then something happened.
A neighbour of ours worked at an insurance company and she had somehow acquired a Nikkor 35-70mm f/3.3-4.5 zoom lens from her company that she gave to me, since she knew I had recently gotten into photography. It was at that point that I became acutely aware of just what a difference a lens can make to the look of your photos. The 35-70mm zoom was so much sharper than the 28-80mm that came with the Nikon F60 that I could hardly believe my eyes. Whaaat?
I scoured the rec.photo.equipment.35mm forum daily. looking for information from other photographers on what they thought were the best lenses out there. And so I opened Pandora’s Box. From that point it all began so slide downhill for me. I was no longer interested in making pictures. I was interested in acquiring lenses. Taking pictures almost became secondary to my mission of finding the next best lens. It was probably no coincidence that my interest in my managerial position at the bank head office I had been working at began to take a back seat to this ongoing quest for more and more lenses and cameras. I even began buying and selling cameras to colleagues to fund my ongoing obsession with gear.
Anyway, the point I want to make with this digression is that while it is true that a better lens will improve the quality of your image, it will not improve your vision. As I like to say to people when I am discussing the merits of HD television, crap in HD is still crap regardless of how much sharper it appears on my screen. And so it is with photography. Putting more emphasis on getting the best lenses before you are able to even properly compose a scene is very much like putting the cart before the horse.
That said I do think it is important to understand a little about lenses and what they do for your photography before you get into the business of taking pictures. So, if you are new to photography, what lenses should you be wanting to get?
General Purpose Zoom Lenses
The lens that you are most likely to find on entry level cameras these days is very similar in focal length range to the one I described at the beginning of this lesson. It’ll be a zoom lens that gives you a moderately wide angle to moderately telephoto range of view. Depending on the size of the sensor (format) you’ll see different numbers on the zoom range. For the full format 35mm system you’ll most probably not get a kit lens as these are more professional cameras and as such they are seldom sold with a lens. However, the general purpose zoom lens options usually range from 24mm up to around 85mm or sometimes 120mm for this format (eg. 24-85mm, 24-120mm).
For the smaller APS-C formats you’ll usually find an 18-55mm zoom lens comes with the camera and for the micro four thirds format there are either 14-42mm or 12-50mm options available. Now these kit lenses are not to be scoffed at. Compared to the kit lenses around in the days when I first came to photography they are very capable performers and I have seen images from some of them that are indistinguishable from those made with much more expensive pro zoom lenses. It all depends on how you use them.
The big difference between the kit lenses and the professional zoom lenses comes down to the size of the lens aperture and whether or not it is a variable aperture, depending on the focal length you are using.
Professional zoom lenses usually have a constant f/2.8 wide aperture throughout their zoom range. We’ll get into the concept of apertures and what they do in a later lesson, but for now all you need to understand is that the smaller that f-number is, the bigger the hole (aperture) in the lens is that lets light pass through. If that aperture stays the same throughout the zoom range it basically means that exposure time is going to stay the same as you zoom.
The consumer grade zoom lenses have what is known as a variable aperture in the zoom range. You’ll see this expressed like this on most consumer grade zooms: f/3.5-5.6. What it means is that as the lens zooms into its subject, the aperture gets progressively smaller and the net result is that the exposure time between the wide angle and the telephoto angle is accordingly increased (which has an effect on susceptibility to camera shake, or blurry images because you are not holding the machine still enough). In daylight photography, or photography where there is a controllable external light source, such as a flash, this doesn’t really matter so much, because you’re probably going to be shooting your lens at what we term a “stopped down” aperture value anyway, something like f/5.6 or f/8.0. The constant and large aperture of a pro zoom lens is usually used in low light or when a photographer wants to shoot “wide open” to blur out the background of a subject.
Compared to their consumer grade counterparts, pro zoom lenses are seriously expensive, in most cases they will cost more than the camera you’ve bought. They are also significantly larger and heavier than the consumer grade lenses and depending on their design they will be sharper when using the biggest aperture. Those are the main differential features between the two.
These days most camera starter kits come with both a general purpose zoom lens like the 18-55mm, and a 55-200mm telephoto zoom lens. These two lenses will give the average user the ability to cover most of the subjects they are going to want to photograph, from general outdoor scenery to close-ups of their kids running around on the sports fields. It’s only once you find yourself wanting to do more specialised types of photography that you will begin to see a need for more specialised lenses. Enter the “prime”, or “fixed focal length” lens.
Prime Lenses (Fixed Focal Lengths)
Zoom lenses are called that because they allow you to change the angle of your view by zooming in or out of a subject. A prime lens has only one view. If you want to get closer to your subject you will need to move closer by zooming with your feet.
So why would anyone want to use a lens that is less convenient than a zoom lens? Well, prime lenses usually offer other specific advantages, such as wider or longer views than zoom lenses, as well as offering a faster aperture (bigger hole to let in more light). In the old days the standard prime lens that came with an SLR camera was the 50mm f/1.8, which is still considered by many to be one of the most useful lenses available. They are sharp, small and give you a perspective not dissimilar to what you see with your own eyes. Renowned photographers such as Henri Cartier-Bresson only used 50mm lenses and produced a body of work that is still considered to be beyond reproach.
Typically the prime lens is used in applications where a zoom lens cannot match the optical performance. A good example of this is in wide angles. If you were to take the average kit zoom lens and compare its wider end to that of an equivalent wide angle prime lens you would see less distortion and sharper corners. It’s not always the case with pro zoom lenses, some of which can more than hold their own with primes, but for the most part if you want to photograph architecture you’d probably want to invest in a wide angle prime lens.
Another example of where a prime lens is often used is in portraiture. On a full format 35mm system the ideal portrait focal length is at around 85mm to 105mm. There are zoom lenses that cover these focal lengths, but they are likely to have slower apertures (smaller holes) which means that the subject doesn’t stand out as much from their surroundings as when photographed using a prime lens like an 85mm f/1.8 or f/1.4. That doesn’t mean that you can’t make those kinds of photos with your kit zoom lens, it just means that they will look slightly different to those made with the prime.
There is a school of thought amongst many advanced and professional photographers that you only need two or three prime lenses to make 90% of the photos you are likely to take, so if you are looking at getting more serious about your photography you should consider this approach rather than spending a lot of money on the pro zoom lenses. For example, well known editorial photographer, author and online personality Zack Arias proposes using 35mm, 50mm and 85mm primes on a full format 35mm system. I tend to agree with him. Those lenses, or their equivalents, can usually be had for very little money when compared to something like a Nikkor/Canon 24-70mm f/2.8. The downside is of course that you have to swap out lenses more often, which may not always be practical. If you find that you are spending more time on portraiture than on reportage this is probably not an issue, but for an event photographer like me, nothing is quite as convenient as a zoom lens, because fast moving events won’t slow down for you while you change from an 85mm to a 35mm lens (assuming I only had one camera).
Other specialist prime lenses include those used to make macro (or extreme close-up) photographs. I’ve never personally been into macro photography myself, but somehow over the years I have accumulated more macro lenses than any other prime lens. Don’t ask me how this happens. The first prime lens I ever owned was a Sigma 105mm f/2.8 macro which offered a 1:1 reproduction ratio (this basically means that the item being photographed would appear life sized on the film/sensor plane). It was as slow as molasses to auto focus, but it was incredibly sharp. That lens got me my first paying gig as a product photographer way back in 2001. Since then I have always owned a macro lens and my current favourite is the Leica designed 45mm f/2.8 Macro-Elmarit for the micro four thirds format I use. This lens lets me get really close to the subject and throws the background into a wonderful blur. It provides a similar angle of view to that of a 90mm lens on the full format 35mm system. Macro lenses can make wonderful portrait lenses but be aware that because they are so sharp they are likely to show up just about every imperfection in your model’s face, which with older models tends to win you no compliments on your photographic ability!
The best telephoto lenses are usually prime lenses, especially for things like sports and wildlife photography. If you are looking to get into this sphere of photographic interest you can never go wrong with a good quality 300mm f/2.8 prime lens. It will most likely cost several times what most people spent on their first car, but it will give you a lot of photographic options should you wish to get into sports or wildlife. The sharpness on this type of lens (particularly the OEM brands) is mindblowingly good and it is also possible to increase the focal length of the lens by using a teleconverter without losing too much in terms of optical quality. A 2x teleconverter will turn your 300mm f/2.8 lens into a 600mm f5.6 lens and while you lose 2 stops of light, you’ll still be making amazing images of subjects in the distance with wonderfully defocused backgrounds.
The other options for top end prime telephotos are the 400mm f/2.8, 500mm f/4.0, 600mm f/4.0 and more recently the big names have been offering 800mm f/5.6 primes. Price wise these lenses are made of solid unobtainium for most of us, and my advice is that unless you have already sunk yourself deep into GAS (gear acquisition syndrome), or you earn a ton of money, you should rent them rather than buy them because they are not likely to be used as often as you’d like to use them, plus the insurance on a lens like those mentioned is bound to be millstone-like on your monthly budget. Having said that, there is seldom any problem selling these lenses for good resale because photographers know just how good they are.
Be warned though, if you are looking to buy one second hand, that they need to be thoroughly tested for any underlying issues before you part with your money. If the previous owner dropped the lens it might have some centering issues (images may appear sharper on one side than the other), the auto focus might need to be tweaked, if the lens was used in a humid climate it might have developed fungus if left unused in a case for some time. A couple of years ago I bought a 300mm f/2.8 Nikkor that seemed perfectly fine when I tested it at the seller’s house, but when I got it home I noticed that the front element was covered in some weird kind of pock-marks which I found increased flare (and thus reduced contrast) when I shot towards a light source. Fortunately the seller happily refunded me my money but I have heard of other people who were not so lucky. So if you are buying a used telephoto lens sight unseen, tread carefully. Also, if the price seems too good to be true, it probably is. These lenses are often stolen and find their way into the used market at prices that most of us would jump at. If you find something fishy like this online, rather do the right thing and report it to the authorities than succumb to the temptation of using stolen goods, also known as “ill gotten gains”. It’s not worth it.
Third Party Lenses
There are a number of lens manufacturers who specialise in producing lenses for the major camera brands. You’ll come across names like Sigma, Tokina and Tamron most often. These are usually cheaper than the original equipment manufacturers (OEM) lenses and for the most part there is nothing wrong with those lenses. When I was starting out I found that many "brand snob" photographers turned their noses up at anything that wasn’t OEM, but to be honest, they do so to their own detriment. In recent years Sigma have been making lenses that are often much better than the OEM lenses. They are also making some exotic zoom lenses that I found extremely useful, such as the 120-300mm f/2.8 and 12-24mm f/4.0-5.6, lenses that don’t have any counterpart in OEM terms.
You will often hear talk in photography circles of quality control issues and sample variations when it comes to third party lenses. By sample variation I mean that if you were to put two of the same lenses on your camera you would get varying degrees of sharpness and light fall off between samples. This isn’t always the case and it isn’t always limited to the third party brands. In some instances there have been significant sample variations reported on OEM lenses too. The sensible thing to do if you're considering a third party lens is test out as many of them as you can before committing to buying one. If you buy it from a retail outlet make sure that they have a good returns policy should you get one delivered that doesn't quite meet your expectation. Dramatic sample variation in modern lenses is quite a rare thing to experience though.
In my experience of buying lenses from all three of the main manufacturers over the years, I have found that the Sigma’s were the best performers, the Tamron’s come in second and in a distant third place are the Tokina’s. Strangely though, some of the best lens build quality I have ever encountered in lenses has been seen in the Tokina brand. I just haven’t been lucky with their optics at all though, which is a great pity.
There are also third party manufacturers who make premium priced lenses for the main camera brands, such as Zeiss and more recently Cosina Voigtländer. Zeiss lenses for the main mounts are usually manual focus only but they do offer an electronic interface with the camera body, which means that the EXIF information seen on your image files will show the lens and the aperture used at the time of taking the shot. It also means that you can control the aperture from the camera body. The Zeiss glass is fantastic! I got to use the 135mm f/2.0 briefly on one of the safaris we organise where a guest had brought it with him. I was truly impressed with the sharpness and quality of the out of focus areas. Cosina took over the Voigtländer brand some time ago and they produced a range of APO lenses that have become firm favourites amongst serious photographers. For a while I used to own an Angenieux 28-70mm f/2.6-2.8 auto focus lens in Nikon mount which was a very nice and somewhat rare lens.
Before I moved from Nikon to Olympus I used a range of Sigma lenses and I never found myself missing anything that the OEM equivalents had. In some cases, such as the 105mm macro options from both makers, I sold the Nikkor and kept the Sigma. I found that the Sigma was less cumbersome to use and also was optically on a par with the Nikkor. At the time I made the move my main safari telephoto lens was the 120-300mm f/2.8 OS which is one helluva nice lens. The newest Sports line version of it is made to the same build quality levels as those seen on Zeiss lenses in my opinion. The Art line of Sigmas is equally impressive build wise.
So, third party doesn’t always mean inferior to OEM. Look around at the options and keep an open mind if you are wanting to invest in a specialist lens. The one drawback (or advantage, depending on which side of the fence you are sitting on) of third party lenses is that they don’t have as good resale value as an OEM lens does. The drawback is if you are the seller who bought new you're going to lose a significant amount of the purchase price, but the advantage is if you are a smart buyer who has done his research properly, you may pick up a bargain that you can keep on using it for as long as you like without losing much should you sell it later.
Final Thoughts On Lenses
At the outset of your journey into photography you should have a fairly clear idea of what you would like to accomplish visually. For most people having a better camera than the one in their cellphone means that they have more than just a casual interest in making photos, but it doesn’t mean that they need to go nuts and splash out on the best lenses right at the outset. In fact, it would probably be better for them to use an inferior lens at first so that when they actually get better at their technique they will be pleasantly impressed by seeing just what happens when a better lens is slapped on the front of the camera. All too often folks with more money than patience give up on photography after buying the best gear, simply because they never get to grips with better technique and end up blaming their gear for their poor results. Never blame your gear unless it fails completely.
My advice for beginners is to shoot the daylights out of your kit zooms first, then if you find you are beginning to gravitate towards one or other type of photography (portraits, landscapes, wildlife, etc), start looking at the lenses that will give you the most utility in that genre of photography. I’d be inclined to recommend the prime lenses before I recommend the pro zooms, mainly because they will be available at more reasonable prices. I’d also advise looking at the third party options, particularly the newer Sigmas, which can be had cheaper than the OEM versions.
If you have any questions about this lesson please feel free to add a reply.
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Edited by Dallas