Camera Basics #18: More megapixels for better photos? Megapixels explained in detail

Table of contents

Megapixels and the real sharpness on the sensor - The lens dilemma

If you own a camera with 40, 50 or 60 megapixels, you can no longer use your kit lens. That's a harsh statement, but let us explain it to you. Inexpensive lenses usually sacrifice a lot of quality factors that end up making the megapixels of the sensor actually capture the full potential.

Once, it was possible to say that lenses under 1000? do not manage to capture the exposure performance of the cameras. In the past, third-party lenses were also said to have inferior image quality, but this has long been obsolete, as Sigma Art lenses and also Tamron SP lenses were the best way to disprove this.

Nevertheless, many lenses are calibrated and tuned to certain megapixel numbers, so especially cheaper lenses do not reach the demands of 40 or megapixel hungry cameras for sharpness. Of course, this can also be a stylistic device, but you have to ask yourself if you really want to spend that much money for the extra megapixels.

Teleconverters cost megapixels

Using teleconverters costs megapixels because they change the angle of view at which the lens would normally operate. Thus, most lenses are not optimized for this angle and can no longer provide the necessary exposure performance due to the magnification.

Filters can cost image quality

UV filters or "cheap" filters that don't even have real glass, but are made with plastic, cost your image sharpness because they scatter the light that would otherwise fall into the lens and thus not fall properly on the sensor.

Quality factors

1. Glass quality
2. Coating & compensation
3. Number of glass elements

Modern lenses have been produced and calibrated very precisely, there is much more development behind a lens than you might think. More glass, for example, does not mean that the quality is getting better and better, the same is to be understood under the coatings. But it helps to pay attention specifically when describing them.

Advantages & Disadvantages of megapixels

Advantages

• Sharpness of detail
• More cropping flexibility
• Denser pixels

Disadvantages

• Larger files
• Stronger ISO noise
• No detail without proper lenses
• poorer low light autofocus performance
• Faster diffraction blur effect
• The megapixel bolides are more likely to blur

How big can I print?

This question is always difficult to answer in a generalized way. The required megapixels always depend on the selected and desired format, measured by the DPI, the dots per inch. Surely you also know that large prints look pixelated from time to time? This does not depend on the megapixels, but on DPI, if a file is printed with 72 DPI, then this is too low resolution for a two meter print on an advertising space, if the edge length of the image is only 800x400.

For DIN A4 you need about 10 megapixels, a camera doesn't really exist below 20 megapixels anymore, unless they are specialized video cameras like the Sony FX series. With 20-24 megapixels you can still print in A3 format without worrying.

Don't worry, even above that you won't directly see very strong quality loss. Because you always have to think about the viewing distance you have with your picture, if you look at it from 10cm up close, it will surely pixelate a bit, but in an exhibition or on the wall most shots are rather viewed with a distance of 1-3m, except in the photo album where the distance is maybe about 60cm.

How many megapixels do I need for a 4K video?

You will laugh, but if you look at cameras that are only built for videography, then megapixels are not interesting. We have created a list for you:

• HD 1280x720 pixels = 0.92 megapixels
• Full HD resolution 1920x1080 = 2.07 megapixels
• 4K video resolution: 2096x2160 = 8.8 megapixels
• 6K video quality: 4992x3744 = 17.9 megapixels

Important to note in the specifications are the aspect ratios, so the real number of megapixels needed may differ. An open gate video format needs more megapixels than a 16:9 video needs.

How many megapixels did the first digital camera have?

The first digital camera had a resolution of 0.1 megapixels and a format of 4:3, with a CCD sensor in black / white.

Conclusion - Who is this amount of megapixels suitable for?

We think a sweet spot for the vast majority of photographers is something around 24-32MP, because this is where you have room to go for detailed shots. You still have some leeway with the aperture and lens before diffraction blur kicks in. People who need a lot of megapixels are maybe portrait photographers who still want to crop into the depth of the image, architecture & landscape photographers if you use this monster properly, with appropriate filters. Who buys these megapixel-strong cameras should know its usecase, in which case the advantage is in the freer cropping of images.

Sometimes certain functions are tied to the megapixel bolides, which are withheld from the "consumer" cameras, because the megapixels are such a myth and you are quickly considered a professional with 50MP, even if the theory & physics say the opposite.