Mythbusting: Megapixels don’t matter – fewer doesn’t mean better low light performance
If there’s one big giant myth that’s persisted since the dawn of digital photography, it’s that lower resolution means better low light performance. If you need to shoot a lot of low light stuff, get that lower resolution camera and your images will look better, right? That’s been the common narrative for years now and it seems to make sense, although it’s never really been true.
The resolution of a camera has never really been a factor for me when it comes to which body I grab – at least not as far as low light performance goes – but in this video, Chris and Jordan at DPReview TV explain why it’s a myth and why everybody’s been looking at this topic completely wrong for all these years.
The video begins by putting two cameras together from when this myth began, pitting two full-frame cameras against each other – the 12-megapixel Nikon D700 against the 20-megapixel Canon 5D Mark II – and demonstrating that when files from both cameras are viewed at 100%, the D700 images do indeed look cleaner than the 5D Mark II images.
But this is only half the story. When you consider the final intended use of the images – especially when you’re looking at two bodies from the same company of the same generation – there’s virtually no difference between the two at all, as the pair goes on to demonstrate with the 12-megapixel Sony A7S III and 61-megapixel Sony A7R IV.
There are definitely advantages to lower megapixel sensors. Video for one. 12-megapixel sensors (4K) allow for faster capture rates than 61-megapixel sensors. That’s just simple maths. For every 1 frame that a 61-megapixel camera captures, that’s about the same amount of data as five 12-megapixel images. And even you can force those higher resolution sensors to throughput the data fast enough, you can run into overheating issues.
Lower resolution cameras for stills also result in smaller raw files. This means faster buffer clears and faster file transfers, both of which are ideal for sports photographers and photojournalists. That lower noise at 100% can also potentially be a benefit to astrophotographers, too, who don’t want their processing software to mistake noise in the image for stars in the sky.
Newer technology with each new generation of cameras is overcoming some of these challenges, though. Image sensors (regardless of resolution) are producing less noise than the previous generation and image processors in cameras are getting faster. And as we shift to storage formats such as CFexpress and SD Express, memory cards are getting fast enough to handle those larger and faster storage demands for that increased data.
John Aldred is a photographer with over 20 years of experience in the portrait and commercial worlds. He is based in Scotland and has been an early adopter – and occasional beta tester – of almost every digital imaging technology in that time. As well as his creative visual work, John uses 3D printing, electronics and programming to create his own photography and filmmaking tools and consults for a number of brands across the industry.