Does the image quality of your picture always elude you? At times it gets confusing why image quality of one camera is better than the other with same mega pixels or may be less. What is it all about?
When we talk about image quality we need to consider a few factors — the camera’s resolution, quality of the lens, size of the sensor and pixel density. Let’s check them one by one.
Does Image Quality Depend On The Megapixels?
In simple language a pixel is a smallest unit, basically the finest dots that make up the picture. Read a pixel as a picture element. Mega pixel means a million pixels. The megapixel number defines the picture resolution only from printing perspective. The more the megapixel value you have, the bigger the print you get. It does not mean bigger pixel value will get you a better quality picture. Why? Consider this. We have a hypothetical sensor of 100 pixels. This value is always a product of the length multiplied by the width. So agile, lets assume that each side is 10 pixels (10×10=100). Now if you have another hypothetical sensor of 15 px of each side, it’s resolution will be 225. You have not doubled the length but the final resolution has doubled. This is a trick manufacturers and salesmen use to boast of megapixels to sell you the cameras. The camera manufacturers implement demosaicing in the camera which is referred to as the bayer interpolation. Check out more about bayer interpolation here. A small change in the length or the width of the sensor boosts the resolution value suggesting better images. Don’t fall for it. Read further to find out.
How Sensor Size Affects The Quality Of An Image?
The size of your camera sensor is one of the most important factor affecting your picture quality. The bigger the size of the sensor, the better the picture quality. That’s the main reason why compact cameras with higher megapixels have low picture quality than a normal DSLR, simply because all DSLRs come with larger sensors than the compact digital cameras. And this is also the reason why full frame cameras have better image quality than crop sensor camera. You can check out other differences between full-frame and crop sensor cameras here.
How Is Pixel Density Related To Image Quality?
Pixel density is a big reason that affects the image quality of cameras. The higher the pixel density, the poorer image quality. Imagine 10 million pixels laid out within a few centimeters. At that amount of area the pixels will be minuscule and light artifacts come into play at such distances comparable to the wavelength of the colors in light. Low pixel density means better image quality given all other factors are equal. More on pixel density here.
See How Quality Of Lens Determines The Picture Quality
The lens quality is another important factor affecting the quality of your picture. Generally, we keep messing with the sensor and number of megapixels. But for a moment forget the importance of the type of lens you use. You can try it out to check for yourself. Telling you from my personal experience, a camera with low megapixel value but with a good lens can give you a better quality picture than a camera with higher megapixel value but with a low quality lens. That’s because not every glass is made equal and not every glass has the same optical properties. Chromatic aberration etc. shall be the topic for another post. Till then, forget the megapixels and go out to shoot some nice colors.
Next time someone pitches you megapixels you know what else to look at. I’m sure these things will help you make a better decision on your next purchase.