A camera can be simply defined as a light-proof box. The camera holds the medium in which the light will come into contact with become it becomes a photograph. Film of any size or an electronic sensor of any size, and sometimes photosensitive paper is loaded into the light-proof box such as when used in the pinhole camera http://www.kodak.com/ek/US/en/Pinhole_Camera.htm. The medium is exposed correctly using settings that are based on the exposure triangle that includes aperture, shutter speed, and ISO or the sensitivity of the medium being used. A lens is not required although the lens has been the subject and focus (pun intended) of many discussions about the quality and characteristics of a photograph. Lenses are generally made of one or more elements of glass that may be coated with various substances to prevent lens flare and improve clarity or other measurable dimensions of the lens. Lenses and materials have evolved and improved over the roughly one hundred-and-fifty-year history of photography although it’s mostly the technology used to create them where the real gains have been made. The aspherical lens, for example, contains multiple layers or elements that reduce or practically eliminate distortion and other unwanted side-effects of bending light through multiple layers of glass and directing it towards the medium that is required in the process of making images. There is a plethora of information available on the pros and cons of various types of lenses, materials, and physics involved in lens construction. Full frame versus crop sensors or other film sizes is another dimension of the discussion of lens that is worthy of mention. However, the technical aspects of lenses will be beyond the scope of this blog entry. Instead, here I offer an introduction to the camera lens, and present some various factors for the photographer to consider when selecting lenses for a various applications.
Focal length is essentially the size of a given lens as measured as the distance from the medium within the camera body to the front element of the lens. The general categories of lenses from smallest to largest with correlating sizes measured in millimetres are as follows: super wide angle, wide angle, standard, telephoto. A focal length of about 35mm or 28mm is considered a wide angle. Super wides are smaller such as 21mm, 18mm, or even 12mm sizes. A standard or prime lens is the 50mm and considered an “honest” lens due to the fact that humans see in the field of vision or angle of view of around 40 degrees that is normally represented by the 50mm lens. For more on the science and technical aspects of the physics of lenses, click here: https://en.wikipedia.org/wiki/Angle_of_view.
The 85mm lens is generally ideal for portraits in which the photographer seeks to separate the subject from the background. This focal length (as well as 50mm) can blur the background and create the generally pleasing effect of isolating the subject through this blur or bokeh https://en.wikipedia.org/wiki/Bokeh. The 50mm prime and longer telephoto lenses also function to compress the two dimensional image and flatten objects in the frame. In contrast, 35mm and especially wider angle lenses tend to distort the image making objects in the centre of the frame seem closer to the camera than they really are. Of course, there are compromises in lenses as in life. A wider angle of view gives you more of everything but that everything might be distorted. Telephoto lenses magnify and give you less angle of view but compress or flatten the image.
Of course, there are longer telephoto lenses that create larger magnification while reducing the angle of view. These can be anything from an 85mm, 120mm, 200mm, 300mm, 600mm, or even a 800mm. An 800mm lens is a whopper of lens that requires massive effort and heavy duty tripods to use correctly http://www.imaging-resource.com/news/2015/03/31/what-do-telephoto-lenses-really-do. 600mm is 60cm or about the length of an adult person’s arm so 800mm is massive! Telephoto lenses are used for wildlife or sports photography since it may be impossible or dangerous to be very close to the subject. There are specialty lenses as well such as macro, fisheye, or tilt shift lenses, that can be used for close-up photography, special effects, or architectural photography.
A camera is a light-proof box, but it is also a tool. The lens is a tool as well and one of the most important decisions that the photographer as technician or artist must make is which lens to use for which application or desired effect. Landscapes will require wide or super wide angles (such as the 28mm or smaller), while street, documentary, or portrait shooters generally require something in the 35mm-85mm focal length range. After experimentation for street or documentary photography, I have found that 28mm is to wide, 50mm is bit to narrow, and 35mm is just right. Although I oscillate between those three focal lengths for a majority of my work, most of my images are made at the 35mm focal length that is considered a wide angle lens. There is merit in getting familiar with one focal length as you develop the ability to quickly frame a scene a “see” the world in that focal length. I see in 35mm. It just feels right. Experiment and you will find what feels right to you.
Another decision that is required by the photographer is the number of lenses that they purchase and maintain in their arsenal. What lens comes along to a given event, or place? These decisions may be governed or influenced by needs, cost, or travel-related issues. Weather may influence the choice of lens as well since some modern lenses have a weather resistant rating that allows then to be used in virtually all conditions on land.
In addition to the focal lengths, there are prime or zoom lenses. A prime lens is one focal length such as the 50mm or “nifty fifty”, although there are other popular primes such as the 28mm, 35mm, and 85mm. Zoom lenses are adjustable to two or more focal lengths. A popular kit lens that may be purchased with most modern day DSLRs is the 28mm-85mm, for example. Zoom lenses are practice and useful since you effectively get three or four lenses in one. As terrific as this sounds, the disadvantage to these lenses are that they are not as fast as prime lenses. The speed of a lens refers to its maximum aperture. Zoom lenses have relatively fast aperture such as f/2.8. This may be good or good enough for many practical applications, but not great in low light conditions. In low light applications, a faster lens (one that has a bigger aperture or opening with a lower number) will perform better by opening wider and letting more light into the camera to come into contact with the medium (i.e. film or sensor). Prime lenses are simpler in construction, have fewer moving parts, and can therefore be made to have wider apertures. Aperture numbers and sizes such as f/1.8, f/1.4, or even f/1.2 are common on prime lenses. The rule is the smaller the number, the bigger the opening, and higher the price! Leica makes a prime 50mm f/.95 aperture lens that costs over $10,000 US that might be the widest aperture lens made https://en.leica-camera.com/Photography/Leica-M/M-Lenses/Noctilux-M-50mm-f-0.95-ASPH. Some would argue that there is no significant difference between an aperture of 1.4, 1.2, or .95. An aperture of f/1.2 is extremely low and fast enough for 99% of applications. If you are the type of photographer that needs to spend thousands to cover that last 1%, then more power to you! Stops of light are measured in thirds and lenses deliver what they are built to deliver, it’s as simple as that.
To review, basic decisions that the photographer must make regarding lenses are as follows: What subject or subjects will I be shooting? Will I need a longer or shorter lens other than my 50mm? How much money do I have to spend on lenses? Do I get one or more primes, or simply one zoom to cover many focal ranges? Will I need a lens that works in low light conditions? Where will I be travelling with my lens or lenses? Do I need enough lenses to cover the entire focal range such as 10mm to 1000mm or maybe 28mm-200mm will be suitable for the types of photography that I enjoy or plan to do? There are other considerations such as the use of camera systems. Many photographers have multiple brands of camera and most lenses will only work with cameras that match manufacturer. There are adapters for this lens and that body and the possibilities become extremely complex quickly http://www.popphoto.com/how-to/2013/02/lens-adapters-introductory-guide. Further complexity can be achieved when swapping lenses made for film cameras onto digital or modern camera bodies, or visa versa.
Most photographers would agree that the nifty fifty is an essential component of even the most basic of camera systems. If given the stuck on a deserted island scenario with one camera, and one lens, the nifty fifty would likely be a popular choice. As a prime lens, these are usually inexpensive, relatively fast, and a great all-around lens. Zoom lenses that cover the 28mm-85mm range are usually a good buy as well. If you can find one with an aperture number of f/2.8 and weather sealing (bonus), this would be a great lens to use when the shooting situation calls for various focal lengths, but carrying and/or changing lenses I not really an option under certain conditions.
Then comes the dilemma that all serious hobbyist and professional photographers face. If I have a zoom that goes from 28mm-85mm with f/2.8 do I get the 85mm prime portrait lens with f/1.2? Is the f/1.2 redundant and an unnecessary expense? At first, there seems to be little difference between these lenses or at least hardly enough to justify adding the 85mm prime to one’s collection when it comes with a price tag in the neighbourhood of $800 US dollars. Every photographer is different and has different needs. There is sometimes a big gap between want and need. Sometimes the gap is so small or imperceivable that want becomes need and G.A.S consumes even the most frugal of photographers http://jeremyhgreenberg.zenfolio.com/blog2015/7/blog-4. There are those of you out there of the die-hard I’m a one camera and lens photographer philosophy. I for one, am not that kind of photographer. I’m a strong believer in the right tool for the right job approach and for better or for worse, photographers are generally immune to buyers remorse. How many photographers have ever said “I really should not have bought this vintage Nikon DSLR”, or “I really wish that I didn’t buy this 28mm f/2.8 with aspherical elements that do not distort?”. It’s a healthy, albeit expensive, practice to experiment with different cameras, systems, and lenses, at least in the early part of one’s entry into the field of photography, even for amateurs, serious hobbyists, or professionals. Wait! I thought that it’s the photographer that makes the image, not the camera. While that statement is true enough, better tools make for better performance and effect confidence as well as image quality, some might argue.
Is that next lens really worth it? That depends. The answer is that if you want the best, then it probably is. If you are serious about making great images, then you will need to invest in the right tools for the right jobs. Camera bodies come and go and slight improvements are made from year to year. High quality glass, however, lasts for decades. Leica glass can be used reliably for one hundred years, by some estimates. The price is high, but the quality is outstanding. Old Nikon glass is also beautiful. Modern lenses are all really great for the most part. There has never been a better time to be an image maker. Keep your lenses. Save, but don’t compromise. As the old adage goes, If the suit maketh the man, the lens maketh the camera.
The light it always right!