Friday, October 21, 2011
Which Lens is Best?
Question: Which lens is best?
Answer: The one that allows you to complete the vision you have for your specific subject.
(Photo below taken with: Nikon D-300 w/Nikon 70-300mm lens)
That answer may sound evasive, but it’s true. There are great lenses out there that you may never need because they don’t lend themselves to your type of work. My advice: Figure out what focal lengths you need and get the very best quality lenses you can afford for those specific subjects.
Photographers don’t create images from thin air with our cameras, as an artist does with a paintbrush. Photography is all about the interpretation and recording of existing imagery. Good photographers think about the many ways they have at their disposal to control, compose, influence, record and possibly alter what they see. Camera angle, depth of field and shutter speed are just some of the tools we use to form our images, but none of them are as profound as lens choice.
Lens choice dictates what gets included in the frame, and therefore sets the viewer’s perception and all the manipulations that follow. The photo below is an example of how a wide-angle lens creates large areas of negative space that lead into the human subjects. In this interpretation, the environment is shown as the most important element of the shot. Taken with a Panasonic DMC – FX07 (pocket camera) on the widest setting.
Using the longest focal length available on the same point-and-shoot camera, I did the tighter composition below. The shot is boring. The environment looks gray and colorless. For this situation, the wide-angle does a better job of showing what I pre-visualized.
In the examples below, the subject was taken with the wide, normal and telephoto setting of a zoom lens.
At first glance, the only difference between the shots seems to be the size of the subject, but there’s a lot more at work than that. Each focal length (of the zoom) lens has its own characteristics. Examine the shape of the subject’s face and you’ll see a lot of difference between wide-angle and telephoto.
To simplify the comparison process, let’s divide lenses into three categories: Normal, Wide-angle, and Telephoto. (Zoom lenses are ‘variable focal length lenses’ and they span a range that may include wide, normal and telephoto. We’ll explain that later. )
The normal lens has a focal length equal to the diagonal measurement of the sensor (film) in the camera. For 35mm and full frame digital cameras, this is approximately 50mm. For cameras with smaller sensors, it’s less. The popular APSC/DX size cameras have approximately a 33mm as their normal. Many point-and-shoot cameras have a 15mm as their normal lens.
In the graphic below, the 35mm equivalent focal length runs across the top and the APS-C / DX format lenses are shown below.
This ‘normal view’ relationship between the lens and the sensor size seems normal because it’s similar to the magnification of the human eye. To find the normal focal length of your (DSLR) camera, use one eye to look through your camera and the other to look at the real world in front of you. Rotate your zoom lens until the images from your two eyes are the same size. Refer to focal length scale printed on your lens barrel to see the setting. Voila – that’s the normal lens for your camera sensor.
A WIDE-ANGLE lens takes in a field of view that’s wider than the human eye. The range of wide-angle lenses varies from a fish-eye view to lenses that only see a bit more than normal. The example below shows an apartment building in wide-angle and telephoto views. In the wide view, everything in the shot seems to get smaller. The telephoto view ‘brings in’ parts of the photo.
There’s always some distortion that comes along with a wide-angle lens and it’s most noticeable with closer objects appearing much larger than they would in with a normal view. (Perspective distortion) Tall subjects, like buildings, will appear to get quite narrow at the top, like the photo above. Because the top of the building is farther away from the camera than the bottom, the converging lines of the building make it look like it’s falling backward.
In the case of the photo below, vertical lines (crayons) diverge when the camera is pointed downward. (parilinear distortion) This occurs because the top of the crayons are closer to the camera than the bottom. The subject's head seems larger than the distance from his feet to his waist. That's a giant head! Does this bother you? Do you like this effect? If you can imagine creating photos like this one, maybe wide-angle is for you.
As you’ll see from the example below, the wide-angle view shows much more of the background that any other lens. This is great if you want to show your subject’s surroundings, accentuate the perspective or create a sweeping landscape composition. The shot below was taken with a 18mm lens on a Nikon D70, which would be considered moderate wide angle.
Note that the face of the subject gets distorted in the close up wide-angle view. That’s part of the wide-angle look and it isn’t flattering, but it can be very dramatic.
I love wide-angle lenses and similar to most editorial photographers, I use them all the time. I embrace the distortions as a creative tool. That said, I own the very best wide-angle lenses I can afford to minimize the distortion.
NORMAL LENSES are the least expensive focal length. Although the normal focal length is always included in the range of the kit lens that comes with your camera, many people buy a prime lens in the normal range because they are offered at reasonable prices for the high quality they produce.
A real favorite of many APS-C sized camera owners (Canon Rebel, Nikon D-60 through D-5000) is the 50mm f/1.4 or 1.8 lens. This popular lens is actually a short telephoto (equal to a 75mm lens on a 35mm SLR), but it serves as a very good ‘normal’ lens for portraits and small groups. Due to its impressive light gathering ability, it can be used for shooting inside the house without a flash, or outside after the sun goes down.
We call lenses that gather a lot of light ‘fast lenses.”. In this case, ‘fast’ refers to the ability for a lens to pass a lot of light and therefore stop action in dimly lit environments. A 50mm f/1.8 lens will let in about six times as much light as an f/4 lens. That can make difference between shooting an indoor shot at 1/15 of a second and 1/100th of a second. Eliminating the blur of a moving image can be dramatic.
Reminder: As in the case of all lenses, THE BEST QUALITY IMAGE IS ACHIEVED FROM A NON-ZOOM (PRIME) LENS.
TELEPHOTO LENSES have a narrow field of view and are best for isolating a subject and separating them from the background.
Wildlife shooters depend upon telephoto lenses to magnify the images of animals that are impossible to photograph at close range. (Photo courtesy of Masai Mara National Park, Kenya)
In the photos below, Derek the Musician was the same distance from me in both shots. I used a 12mm in the wide shot and a 200mm in the close up.
Note how different these examples look from the shots that follow (woman pictured against a red church), where the size of the subject’s face is kept consistent in all the views.
The series of photos below show a focal range of 18-175. This comparison clearly demonstrates the change in coverage and character between lenses WHILE STILL KEEPING THE SUBJECT THE SAME SIZE IN THE FRAME. To maintain the consistent face size, the camera had to be moved closer to the subject each time a wider lens was used.
Portrait photographers favor telephoto lenses because they make the nose look smaller, blur the background, allow for a long distance between camera and subject, and portray facial features in an attractive way. Study the following set of shots and the differences between wide-angle and telephoto for portraiture will become very apparent.
The 18mm shot is an editorial perspective because it shows the environment. The 175mm shot is a portrait because it isolates the subject from the background and eliminates the environment. Which result matches your style of shooting? If your answer is “All of them,” then you’ll want a wide angle, normal and a telephoto. If your requirements for sharpness are not critical, you could be satisfied with an 18-200mm ‘super zoom.
Perhaps you don’t want to spend a lot of money, or you like to travel light and want to avoid carrying three or four lenses. Your kit lens is probably in the 18-55 or 18-70 range. I’m a Nikon user and I have both of those kit lenses. My very inexpensive Nikon 18-55 kit lens may feel like a featherweight plastic toy, BUT IT ‘S A TERRIFIC LENS THAT PRODUCES VERY SHARP IMAGES! It has the Vibration Reduction (VR) feature and I’m overjoyed with how well it works.
In this case, the 18mm is wide enough for general-purpose work, so I could conceivably be happy with my kit lens and a 70-300mm telephoto zoom. For less of an investment, I could survive with a 70-200mm telephoto zoom.
Telephoto lenses are available in extremely long focal lengths and wildlife photographers will need at least a 300mm model to capture birds and other critters.
The photo below was done with a Nikon 70-300mm f/4 lens. It’s not a very expensive model, but it’s quite suitable for professional level work.
Because telephoto lenses are easier to design and build than wide-angle lenses, you’ll find it easier to get a sharp result for a reasonable cost. Unlike wide-angle zooms and ‘super zooms’, telephoto lenses that span a range of focal lengths, like 70-300, remain relatively distortion free at all settings.
You need at least one lens in each of the three ranges; wide, normal and telephoto. My recommendation for serious photographers is to stay away from the ‘super zoom’ lenses that span the range of wide-angle all the way to telephoto, like the 18-200mm models. I’ve tried most of them and their quality is not acceptable to me. If you only make 5x7 inch prints, you’ll be satisfied with the super zoom convenience.
For the APS-C (DX format) users, like me, I recommend the following:
- 12-24mm wide angle zoom for architecture, editorial, large groups and landscape.
- 18-55mm for general purpose and vacation shooting
- 50mm f/1.4 (short telephoto) for low light portraits and general purpose.
- 70-300mm for outdoor portraiture, sports and wildlife.
I hope you find this information useful!
Jeffery Jay Luhn and Team Photoflex