Wasting Megapixels?

Sony recently dropped a bombshell on the camera industry with the announcement of the Sony A7R Mark IV. The “full frame” sensor has 61 megapixels. Five years ago, that many pixels would only be found on medium format sensors. Naturally, all the camera media, and the denizens of various online groups, are abuzz about the camera.

Some of the buzz I've seen doesn't dwell on the megapixel count so much as on the improvements in auto focus and ergonomics. These are two factors I think are far more important than upping the pixel count from 42MP found in the Sony A7R MkIII. In fact, for most people, and most display applications, 61MP is a big waste. It's not just overkill, it's nuclear warfare overkill.

Huh?

Isn't the axiom in photography that sharper (higher resolution) is always better, and this camera offers the highest resolution of any full frame camera to date?

(Note: discussing resolution verses sharpness is fodder for a different article.)

This axiom is true, sort of: it ultimately depends on how the final image is viewed. The rub is that images are viewed on browsers that don't have the same resolution as the original image. Worse, they are most often viewed online, in browsers that are emphasize fast delivery of content over quality. Then there's the fact that many sites where people upload their photos compress the files.

It's like this:

Ed the Enthusiast Photographer happily shells out $3500 for the A7R Mk3. He downloads his first group of photos (RAW of course) into his computer and opens up his preferred editor. That's where things start to get into the overkill range. Ed has a sweet looking 4K monitor, but it's still only 4096x2160 pixels. That's less than half the 9504x6336 image size the A7R MkIV produces at its highest resolution. Where is all that extra detail going?

No problem for Ed: he just zooms in to 100% to see all the glorious detail his new camera is capturing. (At last he can see just how soft the corners are when he shoots his favorite lens wide open!) Ed completes his editing, saves as a .JPEG (oops, there goes some of the detail as he saves in a compressed format) and uploads it to his online gallery (one designed specifically for photographers so it doesn't compress images). To really show off, he also uploads the images to Facebook and Instagram (which do compress images).

From there, the photos are viewed by people who mostly don't have 4K monitors, and who mostly just view the images in their browsers (which default to a pixel per inch far below what a 61MP sensor produces). Ed's enthusiast friends will zoom in to view the images at 100%, and some may even download the originals to really see how they look. Most people, though, will just look at the images however they are displayed by default, and take Ed's word for it that his new camera is “sharper” than his old camera.

Don't get me wrong: I fully support Ed's desire to buy the latest camera. In the case of the Sony A7R Mk3, there are a lot of other improvements to applaud beyond the megapixel count of the sensor. I'm saying the expectation of such a sensor far exceeds the reality for most people and most display applications.

Angie is a commercial photographer who's been using a Hasselblad 50MP medium format camera for years. She's needed the high resolution because her photos are often used for large displays, such as window banners and even billboards. Those display methods take full advantage of (and may even require) a high pixel count. She reads up on the specs of the A7R Mk3, and the fact that there is a wider selection of lenses available, and trades in her Hasselblad gear on a Sony kit.

Doug is a fine art and landscape photographer who produces exquisitely detailed large prints for sale in galleries and through his website. He tends to produce prints ranging from 30 by 40 inches and larger. He's been happy with the output from his Sony A7RMk3, but he sees he can produce prints with even more detail (or larger prints with the same detail) with the A7RMkIV.

Allie is a nature photographer who uses the Sony A9 for it's ruggedness and auto focus capabilities. She sees many of her preferred features are now in the A7RMkIV, with higher resolution to boot. To her it's a done deal. (I threw this last one in because not everyone will buy the camera simply because of the sensor.)

There are people who can expect an improvement in the images they produce for the way they are displayed. Most people already using full frame cameras, however, won't realize any significant improvement in image quality if they bought the Sony A7RMkIV. Displaying online images with most monitors simply doesn't allow for seeing any increase in resolution. I've talked with many “enthusiasts” who don't even realize this.

This is one reason why I'm in no hurry to switch from the Olympus micro four thirds system I use. Yes, on my monitor, at 100% view in my editing software I would see a notable difference between the images taken with my camera and those taken with any full frame camera, much less the 61MP of the A7RMkIV. However I know most other people wouldn't see any difference when they view the images on the various online platforms (two galleries, Facebook and Instagram) that I use.

I'd say if you want to buy the Sony A7MkIV, do so because of the improvement in auto focus, ergonomics, weather sealing and other small features compared to the A7RMk3. Consider the 61MP sensor a bonus.