Hi-Tech Studio: 4K Vs. 5K

Spend any time in a camera store (or the camera department of a big-box store), and you’ll notice that more and more cameras are touting their ability to capture video in 4K. Where HD video capabilities were a selling point just a few years ago, full-blown 4K has swept the market.

What’s The Big Idea?

Video standards are named according to the number of pixels a device can record or display on the longest dimension. (This is an oversimplification, as video standards are convoluted and confusing, but it works for this discussion.) An HD display is 1080 pixels across, and even the smallest-resolution computer display these days has a higher resolution.

The more pixels a display has available, the more detailed and sharper the images it displays can be. An HD display has two million pixels on the longest side, but a 4K display has 3820 pixels, which means you end up with eight million total pixels for a resolution that’s four times greater than HD.

That’s good for photographers for a number of reasons. The first is that 4K video is astoundingly detailed, which means that videos captured at 4K have a greater level of detail and clarity than even the best HD video. It’s also good because 4K footage is more future-proof than HD, since 4K TV sets will start to become the norm in stores by this holiday season and HD will start to disappear.

4K video capabilities are important to the still photographer, as well, because 4K provides enough resolution to enable photographers to shoot video and then pull an 8-megapixel image from the sensor. While this isn’t the workflow for everyone, it’s a remarkable approach to pulling stills from motion and having the best of both worlds on a shoot.

Even without a 4K workflow, a 4K display will provide the photographer with an image that has more detail and more clarity than even the best HD displays, which makes editing more accurate and more efficient.

The problem is that most photographers today lack the equipment needed to properly display 4K images. HD monitors can display 4K, but it’s either scaled back to work at HD resolution, or resized smaller to have more detail, eliminating some of the benefit of working in 4K to begin with.

Many photographers have upgraded to 4K displays by either purchasing new machines capable of handling the higher-resolution video or by buying new video cards and new monitors. Apple’s Mac Pro, for example, can handle simultaneous streams of 4K on its Thunderbolt ports—simply buy a 4K monitor and you’re in business.

But Apple has a more interesting offering for photographers, an iMac with a Retina 5K display, which leapfrogs over 4K to provide a higher-resolution display. The question is—is it worth it?

iMac On Steroids

The iMac has always been a workhorse machine, offering a nice mix of performance and convenience aimed at the mid-level market. The iMac has been for offices and for enthusiast photographers, but professional shooters have tended to gravitate toward the Mac Pro and a high-end display.

But the iMac with Retina 5K display (we’re going to just call it iMac 5K going forward) radically changes all that with a best-in-class display that shatters all previous performance levels and makes the iMac 5K the perfect machine for the top-end pro.

Not only did Apple manage to combine a groundbreaking display inside the iMac chassis, they somehow managed to produce the complete system at a price that’s the same as the competing 5K display by themselves. The Dell UltraSharp 27", for example, has a street price of around $1,800, just a tad lower than the entry-level iMac 5K.

Pro Vs. Pro

Typically, the iMac lags a bit behind the top-end Mac Pro in performance, and that’s the case with the new iMac, sort of. For a small increase over the base model, the iMac 5K can come with quad-core i7 processors running at 4 GHz. The Mac Pro base model has quad-core Xeon processors running at 3.7 GHz. The Xeon is a slightly older chip, and it’s designed to be more stable than the i7, but it runs just a hair slower.

That means that the iMac is actually faster than the Mac Pro for many of the types of daily tasks that the photographer might face, but not for retouching. And it’s considerably cheaper and has a built-in display, to boot.

Performance Factor

While the iMac is traditionally a bit anemic when compared to the Mac Pro, the iMac 5K is not. You certainly can max out a Mac Pro with more RAM and with faster graphics, but when comparing the base or low-end models of both systems, the iMac 5K is surprisingly fast.

And the display—if you’ve had a chance to work on a computer hooked up to a 4K display, you immediately realize the inadequacy of HD, but once you see Lightroom or Photoshop in 5K, there’s no going back.

Dell UP2715K UHD 5K Monitor


There is an issue with the iMac and a 5K display, however, which is that the graphics processor in the iMac is limited in performance relative to that in the Mac Pro. The GPU is responsible for graphics-heavy tasks in programs that are optimized to use it, instead of using the CPU. Photoshop and Lightroom are using more of the GPU and less of the CPU each revision.

Because of its small size, the iMac uses components designed for laptops and other mobile devices. All models of the Mac Pro come with dual graphics cards while the iMac has the single chip. Even though the GPU of this new-generation processor is equal to a mid-level desktop card, there are still two of those processors in the Mac Pro and one in the iMac.

In fact, it looks like Apple had to jump through a few hoops to make a 5K display work with the graphics processor in the iMac because the GPU it uses was designed "way back" in 2012, when there weren’t yet such things as 5K displays. Apple’s solution was to hack the processor with a custom solution that gets just enough pixels out to drive the display.

Even without a 4K workflow, a 4K display will provide the photographer with an image that has more detail and more clarity than even the best HD displays, which makes editing more accurate and more efficient.

In our tests, the iMac 5K was just powerful enough for most photographic tasks, but bogged down (compared to the mid-level Mac Pro) when performing graphics-intensive retouching and editing in Photoshop and Lightroom. By comparison, the Mac Pro never hiccupped while editing images, even when connected to both a 30" Cinema Display and a Dell 24" 4K monitor at the same time.

So what’s a professional photographer to do?

The iMac 5K is a very, very compelling machine. It’s the first all-in-one with a 5K display, but is also one of the first 5K displays on the market, too. The graphics processor is state-of-the-art for mobile processors (but still lags behind desktop systems) and the performance of the system is excellent.

It’s not a Mac Pro, though, and while it has a very attractive price tag and a very robust set of features, it may not be the best bet for the photographer, at least not yet.

Certainly, enthusiast photographers or those without a high client volume would really do well with the iMac 5K, as has always been the case with the iMac line. With this model, though, they will end up with the extra bonus of one of the best displays on the market.

Very high-end studios might want to pick up the iMac 5K as an additional tool for evaluating and editing images—after all, if you’re just working on one photo at a time on the iMac, you’re unlikely to tax the processors.

In any case, the iMac 5K really ushers in a new era for the digital p
hoto-grapher, one in which the computers targeted at the mid-level consumer can prove to be a better choice than the "professional" tool they would have needed just a few years ago.

You can follow David Schloss on Twitter or Instagram @davidjschloss

How To Go 4K

You want to work in 4K resolution, but you don’t want to ride the bleeding-edge with the new iMac 5K. That’s fine, since a full-on 5K workflow is still a few years away, and you’ll get an enormous boost creatively and production-wise by jumping to a 4K display today.

The first step is to make sure you have a system ready to handle 4K video. If you’re using an all-in-one machine like an iMac, you’ll need to upgrade to the iMac 5K to get a
display that can handle 4K video.

If you have either a Mac or Windows-compatible machine, you’ll need to check the graphics card and be sure you’re on the newest version of operating system for compatibility with the displays and with your applications.

For Windows users with desktop systems, and for Mac users, prior to the current "trashcan" model of the Mac Pro, upgrading to 4K video is just a matter of pulling out an old video card, inserting a new one and making sure the drivers are up to date. 4K-capable video cards start at around $300 and ramp up to around $1,500, depending on the performance of the card.

Since a decent 4K video card comes with a price tag of around $600, many photographers with older video cards would be better off putting that money into a newer computer, and getting the benefits of the faster CPU and RAM that the computers offer along with the newer card.

The new Mac Pro and most new Windows desktop setups come with 4K support already provided by their video cards and OS, so upgrading to 4K is simply a matter of connecting the right display.

While a year ago there were just a few 4K displays, today you can find dozens of models with just a quick search online or in store, and the prices continue to plummet for 4K displays. Entry-level monitors start at around $400 and models from Acer, ASUS and Samsung are common at this price point, and these displays are usually in sizes of up to 26 inches. They make a good secondary display, complementing a larger, main HD display.

Image quality and color accuracy at the $400 level aren’t on par with the top-end 4K displays, such as the 32-inch Samsung U32D970Q (around $1,500) and 24-inch Dell UltraSharp UP2414Q ($1,000). These displays have some of the best color fidelity and sharpness in the field, and can be used for soft proofing.

In 5K computer monitors, there is but one choice (currently). The 27-inch Dell UltraSharp UP2715K HD has a price that’s just a few hundred dollars less than the iMac 5K, but it boasts 99% Adobe RGB coverage (the iMac 5K only hovers around 78%), better than most 4K displays on the market.

Even with the Dell monitor, there are just a few systems that can handle it. The Mac Pro and the MacBook Pro can both power the 5K display, and many Windows systems with high-end graphics cards, as well. Entry-level or even mid-level systems don’t have enough graphics power to use a 5K display.

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