Lens Buying Guide for Beginners

How To Pick Out Your Very First Digital Camera Lens: A Total Beginners’ Guide

If you want to get that perfect shot, you need to buy the right camera lens. Your choice of lens determines the quality of the pictures you will take. It is your camera’s most crucial part. You have to invest some serious time and attention to detail to your lens choice because these interchangeable parts can take your photo quality from amateur to pro.

Given the huge amount of lenses available online, it’s too easy to pick the wrong set. Here’s a quick and easy guide that helps you make the right call when you’re buying your very first DSLR lens.

Picking out the very best Camera Lens

Every single photographer has different needs. What works for a friend of yours might not be a good choice for you because you will be taking photos of different things under different settings. Make sure you have a clear idea of what your needs are before you start comparing different lenses using the information below. The bottom line? Select based on how well the lens model fits your needs. Keep the following factors in mind so you can size up different lens models the right way.

Lens Selection Factor #1: LENS MOUNT

This may sound obvious since you need to match lens mount on the camera and lens to use it. However, with camera manufacturers like Canon and Nikon offering multiple formats (DX, Fullframe) and different mounts for DSLR and mirrorless series, it is easy to make the wrong choice.

If you are going for a third party lens brand like Sigma it could be even more confusing since they offer the same lens for different mounts and formats.

Hence make sure that you are getting the lens that is specifically made for your camera lens mount.

Lens Selection Factor #2: FOCAL LENGTH

Focal length measures, in millimeters, the distance between the lens’ center and the camera’s sensor when it is focused on the subject of your shot. Manufacturers like Nikon determine the focal length when the lens is focused on infinity. Low focal length numbers mean you can take wider shots. On the other hand, high focal numbers mean you can zoom in on your subject over a longer distance.

If you’d like to get as much of your subject inside your shot’s frame, look for the following focal lengths optimized for wide-angle shots: 35mm, 28mm, 24mm, 20mm, and 14mm.

If you’re looking for close-up shots, look for a telephoto unit which has a focal length within the range of 50 to 200 millimeters.

The lens that has focal length above 200mm falls under super telephoto lens category. Fancy capturing a beautiful bird sitting far away? This is the lens you need.

Focal Length Full Frame Vs Crop Sensor Vs Micro Four Thirds

Generally, all the photography books and online resources talk about focal lengths in terms of Full frame format or effective focal lengths. This is because a crop sensor camera would effectively multiply the focal length producing a tighter field of view.

In short a 24mm Full frame lens, a 16mm crop sensor lens (1.5 crop factor) and a 12mm micro four-thirds mounted on their respective cameras will produce the same photograph in terms of field of view.
Don’t get confused by all these technical stuff. In order to simplify things, I have compiled a list of approximate focal lengths of each format.

Focal Length/Format Full frame DX Format Micro Four Thirds
Wide Angle 14–35mm 10–24mm 7-18mm
Standard Lens 50–60mm 35mm 25mm
Telephoto Lens 70–200mm 55–200mm 35-150mm
Super Telephoto 300–600mm 200–600mm 100–400mm

Note: In the above chart you might have noticed some overlaps. This is because different lens brands produce a slightly different range of focal lengths and some of which overlaps. For example, Olympus produces 75-150mm telephoto lens while Panasonic has 35-100mm.

Lens Selection Factor #3: APERTURE

Aperture measures the amount of light that can enter your DSLR camera’s lens. Aperture is indicated by ‘f’ and some numbers. These numbers are known as the ‘f-stop’ rating of the lens. Smaller aperture ratings like f1.2 indicate a wider lens opening.

The aperture has two major effects on your photograph. Exposure and depth of field.

Exposure: When you set your aperture to a smaller f-number (eg:f2.8), the shutter will open wider and as a result, a lot more light can come into your camera sensor. Use the lenses with smaller f-number when taking shots in darker or low light conditions.

Depth of Field: A smaller f-number like f1.8 will give you an extremely shallow depth of field. Portrait photographers use this all the time to capture beautiful portraits with blurred background called bokeh.

On the other hand, if you are a landscape photographer, you might want most of your scene to be in focus. Here you must set a higher f-stop like f8 or f16 to get everything in focus.


Prime lenses are fixed focal length lenses.  That means if you want to take a closer shot, you actually need to move closer to the subject you are photographing. On the other hand, a zoom lens is very versatile and gives you the freedom of capturing the shots without you physically moving around a lot. So why should you choose prime lens over zoom lens?

For starters, fixed focal length or prime lenses are very sharp since there are less moving elements inside the lens through which the light has to pass.  Prime lenses often have fast apertures like f1.8 or even f1.2 that makes them ideal for portrait photography. They are smaller and lighter and cheaper when compared to the zooms.

Nevertheless, if you are a travel photographer, nothing can beat the convenience of a good zoom lens.

How do these two types of lenses stack up against each other? Here’s a side-by-side comparison.

Feature Comparison Prime Lens Zoom
Image Quality High quality, well-defined photos even if you shoot in low light conditions. Average quality. Zoom lens’ shot quality is best appreciated by the fact that they help you take shots from long distances
Dimensions and Mass More compact and weighs less than typical zoom lenses Larger and takes up more space
Aperture Speed Very fast aperture movement which makes this lens type an ideal choice for taking shots of subjects that move very fast. Slow aperture. However cameras often overcome this with built-in image stabilization technologies that enable you to slow down your shutter speeds.
How easy is it to transport? Since a prime lens is fixed to a specific focal length, you need to carry several lenses with different focal lengths if you’re going to be shooting from various distances. Since zoom lenses let you zoom in and out, you only need to carry one unit to cover the different focal length ranges you might use.
How adaptable is this lens? You are stuck at the focal length rating of the lens you’re using.
To change your viewing angle, you have to actually move your camera.
You can stay in one location and just zoom in and out to capture different viewing angles.
Pricing Lower cost than zoom because each lens is fixed to a specific focal length. Although zoom lenses cost more, their price is comparable to the price of the number of prime lenses you’d need to buy to match zoom lenses’ shot versatility.

The two lens categories are broken down further into distinct types of lenses depending on their special purpose.

Prime Lens Types:

Basic or Standard Shoots images on a “What you See is What You Get” basis. Focal length range: 35 to 80 mm. Expert photographers usually recommend amateurs interested in this type prime lens to get the Canon EF 50mm f/1.4 USM AF Lens
Telephoto Lenses This lens makes distant subjects look very close without any distortion.
Normal focal length range rating: 75 to 300 millimeters.
Super telephoto Lens You’ll be able to take shots of subjects from a further distance with this lens.
Great for taking shots of birds. Focal length range: 200 to 400 millimeter.
Wide-angle Type These help you take a wider shot of a scene or local.
Great choice for snapping photos of crowds or natural landscapes.
Fish-eye Lens This is a spin-off of the wide-angle prime lens type. You get a hybrid of a round/circular view and a wide panoramic shot.
Fisheye lenses often cover very wide angles.
But the edges are often distorted causing the resulting images to be very interesting.

Types of zoom lens:

Optical zoom Adjusts your lens’ focal length and image size depending on the distance preference you zoom in.
Optical zoom will always produce better images when compared to digital zoom.
Digital zoom Cuts out surrounding space on an image to produce a highly focused area and then resizes this back to fit your frame creating an up-close shot.
Digital zoom is similar to the zoom function that you do on your computer.

Macro Lens

These can be either zoom or prime lenses. Often confused for telephoto lens types, this lens type is used to take snaps of very small items and living things such as food or insects. Macro lens makes very small things look much larger than these subjects’ actual size.


Your DSLR camera’s sensor is the element which records your subject’s image the moment you click on the camera’s shutter. In old-school analog cameras, the recording was done by light hitting the film in your camera. DSLR cameras have larger sensors than those found in point-and-shoot type cameras. This explains why DSLR images tend to look more vivid, realistic, and clearer.

Choose between two types of sensors: Complementary Metal Oxide Semiconductor (CMOS) or Charged-Couple Device (CCD). CCD units are much bigger than CMOS which enables them to catch more light. The greater the light, the more vivid and sharp the image. CMOS sensors tend to take better quality images than CCD type sensors. The main drawback of CMOS units is their size which can impact the overall shape and function of your existing camera. However, you don’t have to worry about the sensor technology since most modern DSLRs offer excellent image quality.

But what you should really look for is the lens that matches your sensor size. Micro Four Thirds has a sensor size of 17.3 x 13mm, whereas an APS-C crop sensor is 23.6 x 15.6mm. The full frame camera which is comparable to the 35mm film has a sensor size of 36 x 24mm.
If you buy a Nikon crop sensor lens and mount it on a Nikon full-frame camera, it will accept the lens since they both share the same mount type. However, your DX lens will not cover the entire full frame sensor area, resulting in a black circle around the image.

Nikon full-frame DSLR cameras can detect a crop sensor lens and it can automatically switch to crop sensor mode. But then the effective focal length would change and the resulting images would have much lower megapixels.
Conversely, a full-frame lens on a crop sensor camera is a waste money and effort unless you are planning to get a full-frame camera in the near future.

Hence please make sure you select lenses which will fit the size, structure, and specifications of your main camera unit.

Lens Selection Factor #6: PRICE

As awesome as some lens and sensor combinations may be, you have to pick a lens that fits your budget. You can still get a great combination of factors 1 to 4 on a tight budget but be prepared to compromise in terms of camera brands and available models.

THE BOTTOM LINE:  Which lens type should you pick?

It all boils down to what you’re shooting and what your expectations are. In other words, your needs must dictate your choice of lens. Lenses directly impact your photos’ quality. Accordingly, pick lenses based on the types of shots you want to take. If you’re into portraits, prime lenses would be right up your alley whereas zooms are preferable for travel photography. If you’d like to capture stunning landscapes, you should go with a wide-angle lens and macro enthusiasts should get a dedicated macro lens.

At the end of the day, your personal circumstances and needs should drive your choice of lens. Ideally, you should experiment with different lenses to see which yield the best results. There’s nothing like getting your hands on the lens and trying it out yourself. Regardless, use the guide above to help you make heads or tails of the often confusing array of lenses on the market.