Which Lens Should I Use?
We have another lesson on which camera should I buy but if you buy a DSLR you also need to have a lens so we need to discuss which lens. In addition lenses have unique properties which can impact the photo so understanding those properties we can use them to help us be creative or take action to reduce the impact.
Types of Lenses:
1) Prime Lenses
2) Normal Lenses
3) Zoom Lenses
4) Wide Angle
5) Macro Lenses
This is definitely not a complete list but a good starting list. There are other more specialty lenses which we won’t cover here.
Prime Lenses
Let’s start with a prime lens. These have fixed focal lengths (for an understanding of focal lengths please see class on it). A fixed focal length means you can’t zoom in and out. Typically they are lower in cost as they have less moving parts. While the primes lens may be less versatile it is often optically a better lens delivering better results. Examples would be a 24mm or 50mm lens. I said typically they are lower cost except if you want larger focal lengths with lower F Stops like a 400mm with a F Stop of 2.8. These lenses can be very expensive.
The traditional meaning of primes lens was given to the main lens attached to the camera. Some people add converters or adaptors. So all the above based on a traditional definition are prime. But we are going to refer to those of a fixed focal length or zoom.
Normal Lenses
The next group is normal lenses. These allow you to see through the camera what you see with the eye. They are typically 35mm, 50mm or even 80mm. In the class on focal length we talked about crop factor. APS-c cameras have a crop factor. Full frame cameras do not. So with a full frame if you have a 50mm lens attached you will see basically what the eye sees. Full frame can be compared to the old 35mm film cameras. They will give similar zoom results. Non full frame cameras have a crop factor which means the 50mm must be multiplied by the crop factor to determine actual focal length. My 1D IV has a 1.3 x crop factor. Canon Rebels have a 1.6 x crop factor. So with the 1.6x crop factor the 50mm actual is a 88mm lens. So here you would need a 35mm to come close to the 50mm with a full frame. So the crop factor increases the focal length.
Many recommend you start with Normal lenses or wide prime lenses such as a 24mm lens. They typically give superior performance. The normal lens should give you results basically close to what the eye sees. These lenses typically have low F Stops which makes them great for low light or controlling the depth of field. Normal lenses are excellent for portrait work and their low F Stop (2.8 or less typically) allows for beautiful bokah due to the shallow depth of field. The major negative is the focal length is fixed so you must move to frame the subject rather than playing with the zoom to frame the subject. This lower F Stop is often referred to as being faster. So normal lenses are often classified as “fast” lenses. Why do we call them faster? Because they have a low F Stop means the aperture can open very wide allowing more light in and means you can have very fast shutter speeds.
Wide and Zoom Lenses
When we refer to a zoom lens we are referring to the ability to increase the focal length. They have an assembly of lens elements allowing you to adjust the focal length. As a result they can be very versatile. I personally use these lenses the most. They can break down typically into wide angle zoom lenses and telephoto zoom lenses.
The wide (you can get ultra wide zoom lenses) mean you have a low initial focal length which can be increased. An example of an ultra wide would be my Canon 16-35mm. An example of a wide zoom would be my 40-70mm. These are great lenses. They work great for landscapes (especially the ultra wide). The big negatives when you use them with a full frame include barrel distortions and vignetting. By barrel distortion I refer to the distortions that occur around the edges. If you are shooting people they will appear bigger towards the edges. If you photograph buildings you will notice they start to bend inwards at the edge. Regarding the vignetting increasing the F Stop to at least 8 will help. In addition Photoshop RAW (if you take a RAW format photo) has a tool to help correct this. In addition new tools in Photoshop can help with the barrel effect. Finally, with wide angles chromatic aberrations are more common. Examples of CA include purple fringing. When you have something bright such as a white walled building against something darker like the sky you get a purple fringe. You can also get a blue or magenta fringe. If you shoot in RAW, Photoshop RAW has a great tool to remove this. Generally, the higher quality the lens the less chromatic aberrations you get (but they still happen).
However, wide angle lenses bring many great things to the table. They enable you to photograph more than what the eye can see. This is especially true for full frame cameras. In addition they can have a very wide depth of field even at a low F stop. I find wide angles need a little practice but with practice they can produce incredible photos. One positive which can also be a negative is they distort perspective. Items that are closer will increase in size while those further away appear smaller. So be careful using them to photograph people up close (especially ultra-wide) as their noses and chins will appear larger. But if done right you can use this distortion beautifully. I love using them for example during a first dance. I like to position myself at a low angle or high angle (low angle means putting the camera close to the ground and having it look up at the subject and high angle means lifting the camera high and pointing down at the subject). Because these lenses are wide you can go close at these angles and get a wonderful photograph that to me captures the motion better. Play around with different angles with this lens and see the incredible results you can get. They can allow your creativity to flow!
The telephoto zoom lenses are essential for sports or wide life photography. I also find them great for photos of people. They have a shallow depth of field (please see lesson on focal length to explain this), which results is a great blurring of the background or bokeh. They don’t distort the perspective like wide angle lenses so give a more natural look. Telephoto zoom lenses and super telephoto lenses can allow you to get close to athletes from the sidelines of wide life from a safe distance. However, with zoom lenses the larger the focal length or zoom the shallower the depth of field. Secondly, with super telephoto lenses they usually have a higher F Stop and to get to one with a lower F Stop for low light work costs a lot of money. These zoom lenses allow less light through them and with the higher F Stop you often need to increase the ISO number to get the shutter speed fast enough (for sports ideally you want 1/1000 second). Regarding shutter speeds to avoid blurring caused by your hands moving the shutter speed in normal light should be at least as fast as the focal length. So a 400mm lens needs a minimum speed for being hand held of 1/400 sec. Make sense?
One good general lens is my 70mm to 300mm L 4.5-5.6. The high F Stop means I can use in low light but otherwise this is a great lens. For sports I like at least 400mm so this does not work well for sports. I do find it great for videography as well. It works great for getting intimate shots from a distance. Often when I am shooting weddings you want intimate moments where the couple becomes caught up in themselves. If I am too close I distract them. This lens allows me to get far enough out of their personal space that they forget I am there. The beautiful blurring and natural looking photos are great. My favorite lens for low light is my 70-200mm IS L 2.8. This is a fast lens that is sharp
A good all-purpose lens would be by 35-105mm 4.5-5.6. You can get great landscapes, portraits, macro work and minor zoom work. It is not suitable for low light but very few have low light issues so if you don’t this may work for you.
Macro
Macro photography allows you to get really close to the subject. Each lens has a minimum distance that lens must be from the subject in order for it to focus. Macro lenses typical allow you closer and dedicated macro lens can allow you very close. Getting close can allow for some incredible shots. However, the closer you get the shallower the depth of field. Also, the slightest movement can mean you go out of focus very easy. For extremely close work I recommend a tripod and remote.
On non-dedicated macro lenses they will say macro on the side showing you that they can also be used for macro work.
Types of lenses
Not all lenses are the same. For example with Canon they have their S-EF series, their EF series and their L Series. The E lenses are for NON full frame so they will not work on my cameras (a point to note is make sure the lens you are buying will work on your camera and if you have a full frame double check that it will work on a full frame). I have a few EF lenses but to be honest I need the best performance and that often means I need the top of the line L lenses. A point to note is there are great sites that will review not just different vendors’ comparable lenses but the different lenses the same vendor has. If the significance in a better lens brings no value to you don’t spend the extra money. I will also say that the by staying with Canon every time I buy a new camera or upgrade a camera my older lenses still work. I don’t need to replace a lens unless there has been a clear improvement in performance that brings value to me.
Which Lens?
I personally recommend a good general lens to start with though a lot of literature would recommend a Normal or other prime lens. In determining which lens you need to clearly define the need and potential need. Lenses are not cheap so when we are purchasing a lens we want a business plan for that lens. If you plan to do low light work then pay attention to the F Stop- the lower the better. Low light work includes night time sports, weddings, events, etc. If you want to take family shots then a good general lens will work. If you looking to do landscapes then consider a wide angle.
As I said before there are some great Websites where you can get great reviews on lenses. We plan to begin doing reviews as well comparing different lenses and giving our opinion on lenses (stay tuned).
A Word on Specialty Lenses
As I explained before with ultra wide angles you will see what I refer to as a barrel effect causing subject
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