A guide to purchasing a camera

Need help deciding on the right camera? Say Cheese!

When it comes to buying a stand-alone camera, we often evaluate the most common parameters like resolution, clarity of images, extent of zoom and supported memory. However, there’s more to it than meets the eye. That’s where this book will come in handy – to help you zoom-in on the model that best suits your requirement. Whether or not you are looking at one for personal use or for commercial purposes.

Let’s begin by listing down and discussing the relevant parameters to be considered.


Light enters a camera and falls on its digital image sensor (if it is a digital camera), or on the film (if the camera has a film roll). This light sensitive sensor or film, as its name suggests, is sensitive to light. The ISO rating of a camera is indicative of the sensitivity of the image sensor or film to light. This sensitivity is impacted by the aperture and shutter speed settings. Generally speaking, using cameras with high ISO ratings can help capture good quality images in low light conditions. However, cameras with low ISO ratings also produce stunning results if the shutter speed and aperture are adjusted accordingly to control the light.

High sensitivity can lead to digital noise, whereas low sensitivity can generate smooth images without digital noise. Professional photographers are adept in controlling the aperture and shutter settings to suit the camera’s ISO value. Some cameras which have high ISO ratings: - Canon’s 5D Mark III - Nikon’s D4 With these, you can shoot at ISO 12,800 in significantly low light conditions, and still get performance you usually get at ISO 1000.


Cameras have a diaphragm, called an aperture that opens to allow light to enter. Aperture is denoted by the term ‘f-number’. Larger the aperture, smaller the f-number and more the light that enters, Smaller the aperture, greater the f-number and lesser is the light that enters.


A shutter is a curtain-like mechanism in a camera that opens and shuts either in a matter of milliseconds or longer if so desired. The shutter speed refers to the time that this shutter remains open.

If the aperture is large, more light enters the camera, and hence a high shutter speed (which can last for as little as 1/8000th of a second) would be desirable in order to avoid over exposure of the image. Conversely, if the aperture is small, less light enters the camera and hence a low shutter speed (which can sometimes last up to 30 secs) would be desirable in order to avoid under exposure of the image.

Together - ISO, shutter speed and aperture account for a camera’s exposure.


No matter how much you adjust your camera settings, your camera can’t fetch you the desired picture without a truly sharp lens to filter light through. And if you have one, you will know the real distinction between sharpness and softness in imaging. Such an image shows you a clear separation between edges and colors right down to a pixel level.

The catch here is that there is no easy metric to quantify lens quality. Lens performance varies both with aperture and zoom level. These easy principles will guide you through this.

A.It is important to see what material the camera is made of. Some lenses are built out of real glass with a robust cover on the outside. Example, the Canon’s L series. On the other hand, non-removable lenses in less expensive cameras are made of plastic - both on the inside and outside. Hence, these are less reliable and do not produce superior images. This is not a thumb rule though, as there are some exceptionally good lenses with plastic optics. Generally, the quality and durability of a lens is judged by its weight.

B.It is believed by some that lenses without a zoom function perform better due to their simpler construction. Professionals, however carry with them lenses of the most common focal lengths such as 24mm, 50mm, 80mm, 100mm, and 200mm.


The advantage of using an autofocus camera is that is saves the amateur photographer the ordeal of manually setting its focus and getting it right. However, there are two sides of the same coin, and the flip side is that the photographer may experience a delay between the time he clicks on the shoot button and the image finally appearing on the viewfinder.

This lag, which is often mistaken to be the time taken by the shutter, is actually the time taken by the camera’s fuzzy logic to decide how long it needs the image to be exposed.


Bigger the sensors, better the photos. Full frame and medium format sensors are a professional’s favourite, and beyond the reach of amateurs. Example: The Nikon 1 series, due to its undersized CX sensor, disappointed many. The quality of a picture goes up with the size of the sensor, but so does the price.

That is the reason why most enthusiasts can’t afford medium format and full-frame cameras. Which is also why most popular digital SLRs make a happy compromise by featuring the APS-C format. The price of a camera goes up substantially if you choose one with a larger sensor size. This is a parameter mostly looked-into only by professionals. The rest generally settle for a cost-effective APS-C format.


A megapixel is equal to 1 million pixels. However, what matters is how big you can make the image you captured without having to enlarge it digitally. Enlarging it digitally degrades the image quality.

Megapixel calculation is done by simply multiplying the number of horizontal pixels with the vertical pixels. For example, a 3 megapixel camera will have 2,048 pixels horizontally and 1,536 pixels vertically.


A viewfinder is simply the lens or screen that enables the user to see the current image view and understand what will be included in the photograph. The more expensive a model is, the better is the experience.

Touchscreens too are evolving well, from the tap-to-focus features on the Olympus PEN E-P5 to the completely touch-friendly Canon T4i. They are slowly but steadily becoming favourites.


This is a crucial function in a camera which majority of us ignore, thus leaving majority of indoor images looking yellow. Cameras by themselves won’t account for incandescent lights and try to balance the colors before them based on their presets. That is why the image gets a yellow tint. White balance preset for artificial lighting is found in all modern cameras. The more professional ones however give you granular control over white balance.

Majority of the DSLRs now have the option to calibrate themselves to know that a white object is looking a little different in orange and violet light on a trade show floor.


It was a novelty until a few years ago, but today HD video is a standard and assumed feature. Cameras that lock the focus and zoom when a video recording starts, may achieve unreliable autofocus. It will be good to learn manual focus to avoid focus jumps in videos.

Importantly, cameras with larger sensors make video shooting more challenging but reward those who have a grip on its functions. That is because they are more sensitive, bulkier, and have mechanical zoom and focus. Moreover, the integrated microphone picks up the lens operation noises.

Another advantage you get is a range of cinematic effects that smaller cams can’t achieve (eg Canon 60D).


How close can you get to the subject of shoot without having to physically move closer? Cameras with large zoom functions are hard to handle with steadiness when zoomed in. This may hamper the sharpness of photos - even with the best image stabilisation. Besides, the larger the zoom, the lower the image quality. So lens makers can either give a massive zoom range or a steady image of a fixed focal length.

An additional tip: You may want to avoid a camera with a digital zoom, as it enlarges the picture while reducing its quality, which can be enhanced to some extent with dedicated post-processing software available nowadays.


Lenses with optical Image stabilisation are equipped with a functionality that automatically steadies the image that arrives onto the sensor. A couple of manufacturers have simplified lens designs by building image stabilisation right into the body of their DSLRs.

(Nikon, Canon, Panasonic, Sony, Olympus)


Photographers mostly prefer to buy advanced versions of their cameras from the same manufacturer from which they had bought their earlier lenses. It seems logical to buy a camera that is physically compatible with the lenses they have. However, it's not necessarily the best option as most DSLR bodies change the effective focal length of the lens.

For instance, a 35mm lens designed for imaging onto film has a different structure from an image sensor, and may not produce such good image quality on the DSLR. The 35mm lenses are bulkier than their digital counterparts.

(Eg, Olympus DSLR bodies cannot accept the lenses designed for Olympus film SLR cameras.)


Depending on your current & future requirements and your affinity for gadgets, you can zero-in on a camera that serves the purpose. You certainly don’t need a bulky DSLR if you just want to catch some happy family and friends moments. Look for mirrorless cameras (like the Panasonic GX1) or even point-and-shoots (like the Canon S110). On the other hand, if you want the best and the biggest, you must by a DSLR, which offers more control and more lenses, with a capability of capturing a wider range of photos and video. After all, the best megapixels and lens sensitivity are all useless without the best vision on part of the photographer.