Photographers are obsessed by resolution. Camera makers bombard us with adverts proclaiming how their latest models have more pixels for higher image quality, and lens tests hail ever-increasing levels of sharpness. This is exacerbated by our ability to zoom into our image files and view them at pixel-level detail; it’s like being able to make huge prints of every single picture we take, then look at all the finest detail in close-up. No matter how much detail we can currently record, we still seem to crave more and more.
Traditionally, ultra-high resolution has been the preserve of the medium-format market, and it still just about has the edge. The latest Sony sensor used in cameras like the Pentax 645Z offers 51.4 million pixels, with impressive low-light performance. But this camera costs £7,700 with the basic 55mm f/2.8 lens, and by medium-format standards this counts as affordable.
For enthusiast photographers in the market for a high-resolution camera system, the latest generation of full-frame models offers the most enticing prospect. Not only are the cameras somewhat more realistically priced (although still pretty expensive), but they also attain seriously impressive resolutions. Top of the tree now are three cameras with 36-million-pixel sensors, which capture the highest possible detail by foregoing the optical low-pass filter (OLPF) traditionally used to suppress image artefacts such as aliasing and moiré. These are the new Nikon D810, its predecessor the Nikon D800E and the Sony Alpha 7R.
The D800E is something of an oddity. Rather than having no low-pass filter, its anti-aliasing effect is ‘cancelled’. How this works is explained in more detail on page 47, but in effect, it means that some residual blurring may still occur. In principle, then, the D810 could offer even sharper images.
In this test, I’ll be comparing the three cameras to see what, if any, image-quality differences exist between them. I’ll also be looking at new features in the D810 that should help it produce the sharpest possible pictures, and comparing the very different handling of the Nikon DSLRs against the Sony Alpha 7R compact system camera.
In a way, this isn’t just a camera comparison, but rather a battle between the old and the new. The old guard is represented by Nikon, a company that has been making SLRs for over 50 years. Indeed, the D810 can trace its lineage back to the 1959 Nikon F, using basically the same lens mount and through-the-lens viewing via a mirror and pentaprism. Everything else around the camera has changed, of course, but ultimately the D810 is based on a film-era concept.
In contrast, Sony is the young upstart. It’s an electronics company that never had any interest in film, and only started making cameras with the transition to digital. However, it has now been making cameras for more than 15 years, and has therefore built up plenty of expertise (especially after acquiring Konica Minolta in 2006). And while the Alpha 7R may look superficially like a DSLR, it’s entirely a product of the digital age, with full-time electronic viewing and a strong emphasis on video.
Optical low pass filters
There has been a trend recently for camera manufacturers to remove the optical low-pass filters (OLPFs) from cameras, with Nikon leading the charge. To understand why this is occurring, we need to know what these filters do.
The OLPF slightly blurs the image projected by the lens onto the sensor, to remove any details that are finer than the sensor is capable of recording correctly, otherwise the image will be prone to various artefacts (aliasing and moiré). Aliasing occurs when fine details are interpreted in an incorrect way, often resembling a maze pattern. Moiré refers to the bands of false colour that can occur in images with fine repeating patterns, such as fabrics or brickwork.
However, with increasing pixel counts there comes a point where the benefits of the OLPF diminish. This is because various forms of image blurring, including unavoidable lens optical aberrations, serve much the same purpose. If the lens can’t resolve enough detail to induce these artefacts in the first place, there’s no point in blurring an already imperfect image further.
How they work
An optical low-pass filter consists of a thin layer of lithium niobate, which splits light rays into two according to its polarisation (known as birefringence). The degree of separation of the resulting rays is defined by the thickness of the layer.
In most cameras the light is passed through two layers, one that splits the light rays vertically with the second splitting them again horizontally, to give slight (but controlled) blurring. The stronger the effect, the lower the risk of moiré, but this comes at the expense of image detail.
What about the D800E?
With the D800E, the OLPF is ‘cancelled’. This is because the D800E exploits a strange property of birefringence: light rays that have been split according to polarisation can be almost perfectly recombined using a second filter of the same thickness, but orientated in the opposite direction. On the D800E, the first stage of the OLPF splits the light rays into two, and the second stage puts them back together again.
This has allowed Nikon to produce the D800 and D800E, with the only change between them being the front stage of the OLPF. Nikon could then test whether photographers would accept cameras without OLPFs. As both models have been replaced by the OLPF-free D810, the D800E probably
sold better than expected.
Nikon D810 vs Nikon D800E vs Sony Alpha 7R – Nikon D800E
£2,899 RRP £2,300 street price
Announced in February 2012, the D800E is a variant of the D800 with its OLPF ‘cancelled’
1. Front command dial 2. PC/remote release sockets 3. Fn button 4. Exposure mode button 5. On/off switch 6. Top-plate status LCD 7. Hotshoe mount 8. D-Pad/AF area selector 9. Locking drive mode dial 10. Live view button 11. Rear command dial
With its weather-sealed, magnesium-alloy body, large optical viewfinder and sophisticated autofocus system, the D800E is a big beast. It weighs 1kg without a lens and 1.9kg with a 24-70mm f/2.8. Add telephoto and wideangle zooms and the weight and bulk increase rapidly. Only committed photographers will be happy to carry this much kit around all day.
Nikon has been making SLRs for many years, and the D800E uses much the same basic control layout as the F5 35mm film SLR from 1996. It’s been tweaked and refined over many generations, and almost every key photographic control is at your fingertips and changeable with the camera to your eye.
Autofocus is a phase-detection system with 51 points, which cover a wide area of the frame. It’s fast and accurate, and capable of tracking moving subjects during continuous shooting. But it’s inherently not as accurate as the Alpha 7R’s contrast method.
The D800E uses Nikon’s F mount, and is fully compatible with a vast range of lenses dating back to 1977 (even older lenses can be used with some modifications). The current range of Nikkor lenses is huge, ranging from extreme wideangle to ultra-telephoto focal lengths, and including such exotica as three perspective control (tilt-and-shift) lenses. Overall, it’s rivalled only by Canon’s EF-mount line-up for versatility.
Among that line-up are some standout performers, such as the still-unrivalled 14-24mm f/2.8G ultra-wide zoom and the excellent 70-200mm f/2.8 VR II fast telezoom lenses. Those who want to travel a bit lighter are catered for by a range of premium f/4 image-stabilised zooms. For anyone willing to look beyond Nikon’s own lenses, plenty of third-party options are on offer, including premium manual-focus primes from Zeiss, and Sigma’s stunning recent 35mm f/1.4 and 50mm f/1.4 Art primes.
Nikon also has one of the most comprehensive lighting systems, with a range of flash units with different maximum power outputs (and price tags). One nice feature of both the D800 and D810 is that their built-in flash units can be used as wireless commanders for off-camera flash, which simplifies setting up flashguns for supplementary lighting in the field.
At its base sensitivity of ISO 50, the D800E easily resolves beyond 4000l/ph. This holds up pretty well to ISO 1600, then drops progressively at higher ISOs. Our tests also revealed shutter-induced blurring at speeds from 1/40sec to 1/4sec, which at its worst reduces resolution to about 3400 l/ph in the middle of this range.
Our dynamic range results for the three cameras are also much more similar than different. The D800E shows a very impressive range of 12.9EV at base ISO, which only dips below 12EV at ISO 800. Once the sensitivity is pushed up to ISO 6400, though, the range drops below 8EV, which means shadow regions will get visibly noisy. Beyond this things deteriorate further, and these settings should only be used when necessary.
These grey noise patches continue the same theme as above – there’s just not much difference between the three cameras on test. Low ISOs are incredibly clean, with just a hint of noise creeping in at ISO 1600. Chroma noise becomes progressively more visible as the sensitivity is increased, but it’s still not overly bad at ISO 6400. However, ISOs 12,800 and 25,600 do look noisy, so are best used for small prints or output sizes.
Nikon D810 vs Nikon D800E vs Sony Alpha 7R – Nikon D810
£2,699 RRP £2,600 street price
Nikon’s latest DSLR has evolved from the D800E, with the OLPF removed entirely
1. Bracketing button 2. Customisable movie-record button 3. Metering mode button 4. Drive mode dial locking button 5. Revised AE-L/AF-L button 6. 3.2in, 1.2-million-dot screen 7. ‘i’ button
The D810 is an evolution of the D800 design, and while the main spec is similar and the body design almost identical, it has a number of not-so-obvious changes that should help improve the image quality over that of the D800E. The base ISO is reduced from 100 to 64, which means the sensor can capture more light, with cleaner-looking images with smoother colour gradations the result. In addition, the sensor has no OLPF, whereas the D800E’s is ‘cancelled’, so the D810 has the potential to produce slightly sharper images.
The mirror and shutter mechanism has been refined to reduce vibrations, and therefore minimise any blur induced by the camera’s mechanics. A very noticeable benefit is that the D810’s shutter is much quieter than the D800’s, making it more discreet for shooting in noise-sensitive situations.
This is taken a step further in live view or mirror lock-up mode, with an optional electronic first-curtain shutter. Rather than starting the exposure using the first shutter curtain, it’s instead initiated electronically, eliminating the slight (but sometimes visible) blur that can be induced merely by the shutter opening.
To get the most out of any high-resolution camera sensor, accurate focusing is essential. For landscape and still-life work, this often means using live view on a tripod. The D810 has a much-improved live view magnification compared to the D800E, with a visibly more detailed view that makes accurate focusing easier (as the sensor no longer skips horizontal lines in magnified view).
Another useful feature is the split-screen magnified live view, which allows you to look at two areas of the image simultaneously. This helps with such things as assessing depth of field, or levelling horizons with suitable subjects.
The camera’s control layout has also been refined, with a few noticeable improvements. The AE-lock button is easier to operate (as the metering collar switch that surrounds it on the D800E has been removed), and it’s now possible to assign ISO to the red movie record button, so it is more accessible with the camera to your eye. These don’t improve image quality directly, but make it easier to capture the images you want.
The D810 gives almost exactly the same results as the D800E, but its improved shutter action is much less prone to blurring the image. Again, it offers exceptional resolution of over 4000l/ph at low ISOs, although like the D800E it’s prone to false colour too. At its highest ISO of 51,200, resolution has effectively halved.
The D810 gives overall much the same results as the D800E and Alpha 7R. Base ISO dynamic range is exceptional, which means you’ll be able to recover detail deep into the shadows when shooting raw. The D810’s new highlight metering mode can be employed to make best use of this, by avoiding clipping highlights. As with the D800E the highest ISOs are emergency only, with the top setting of 51,200 very limited indeed.
The D810 behaves very similarly to the D800E and Alpha 7R, and any advantage offered by its newer sensor is really quite small. Here we’re showing how ISO 400 is almost indistinguishable from ISO 100, with ISO 1600 still pretty clean. Of course, higher ISOs show ever-increasing noise patterns, and ISO 51,200 becomes very noisy indeed, with lots of colour blotching. But it’s there if you need it; just don’t expect miracles.
Nikon D810 vs Nikon D800E vs Sony Alpha 7R – Sony Alpha 7R
Sony Alpha 7R
£1,699 RRP £1,600 street price
Sony’s Alpha 7R is a 36.4-million-pixel compact system camera with no OLPF
1. AF assist lamp 2. Front command dial 3. Rear SD card slot opening 4. EVF dioptre control 5. Movie record button 6. Hotshoe mount 7. Rear command dial 8. Exposure compensation dial 9. Playback zoom button 10. Lens release button 11. Quick menu
The Alpha 7R is a small but solidly made camera, with angular lines and a prominent central viewfinder hump. This houses the 2.36-million-dot OLED electronic viewfinder, which gives a view just as large as the D810’s optical viewfinder. It can preview your exposure before you shoot, and display a live histogram to help judge over or underexposure.
The Alpha 7R’s contrast-detection autofocus may not be as fast as the phase detection used by DSLRs, especially in low light, but it is unerringly accurate and the focus point can be placed anywhere in the frame with no loss of reliability. This is important, as even slight misfocusing can negate the advantage of having all those pixels.
The small, sharp-edged body is peppered with buttons and dials. Some of the control positions are awkward to reach and activate, including the movie-record button and top-plate dials for shutter speed and aperture. Overall, the Alpha 7R feels relatively unrefined, as if Sony hasn’t quite yet decided how its cameras are supposed to fit in the hand and work. This isn’t to say that the Alpha 7R is unpleasant to use, though. In fact, once you’ve set up its many configurable controls, it’s a very capable camera. But it’s not as engaging as similar-sized models from Olympus and Fujifilm.
The Alpha 7R uses a new range of FE lenses, currently consisting of a pair of superb Zeiss primes (35mm f/2.8 and 55mm f/1.8), and two image-stabilised zooms (24-70mm f/4 and 70-200mm f/4). All have relatively small maximum apertures, which makes the system more portable than a similar full-frame DSLR set-up.
This limited native range is offset by the Alpha 7R’s adaptability to all kinds of lenses. Sony makes the LA-EA4 adapter for Alpha-mount lenses, and third-party adapters allow the use of a huge range of other optics. If you have a set of old lenses in a long-obsolete mount – Canon FD, Olympus OM, Minolta MD or the like – the Alpha 7R may be just the thing to resurrect them.
The Alpha 7R’s small size makes it less obtrusive when photographing people. Also, the ability to use the tilting screen as a waist-level finder allows you to engage more with your subject. Unfortunately, the camera’s shutter is quite loud, so your subject is always aware that their picture is being taken.
Our test chart reveals that the Alpha 7R’s sensor offers essentially the same resolution as its Nikon counterparts, and drops down in a very similar pattern from over 4000l/ph at ISO 50, through around 3800 l/ph at ISO 1600, to 2800l/ph at ISO 25,600. We don’t see much shutter-related blurring in these tests, either.
All the indications here suggest that Sony is using a very similar sensor to Nikon, and the D800E in particular. At ISO 50 the dynamic range reaches 12.8EV – essentially the same as the Nikons within the limitations of our testing – and it only drops slightly by ISO 800. A range of 9.1EV at ISO 3200 indicates that images should still be quite usable, but beyond this quality will visibly suffer.Again, we’d probably steer clear of the top settings.
Just to emphasise that there’s no clear winner here, the Alpha 7R matches the Nikons in terms of noise performance. Noise is minimal at low ISOs, with luminance noise only starting to creep in at ISO 1600. Even when the sensitivity is increased to ISO 6400, noise isn’t excessively high, and it responds well to noise reduction in post-processing. The higher ISO settings again look distinctly noisy, though.
Nikon D810 vs Nikon D800E vs Sony Alpha 7R – Our verdict
How they compare
The Nikon cameras don’t have built-in Wi-Fi, but an optional WT-5 Wireless Transmitter is available. At around £500, it adds considerably to the overall cost.
The Alpha 7R features built-in Wi-Fi for easy image sharing and remote control from a smartphone or tablet. Quick pairing via NFC is available with many Android phones.
The Nikon DSLRs both use essentially the same 51-point phase-detection AF system. It’s impressively fast and can track moving subjects, but it’s inherently not quite as accurate as the contrast-detection method.
The Alpha 7R employs contrast-detection autofocus using the main image sensor, which makes it exceptionally accurate. The focus area can be placed anywhere in the frame, and face detection is on offer too. Autofocus isn’t especially fast, though.
The Nikon F-mount lens set is huge and comprehensive, with pretty much everything on offer, including micro lenses, fisheyes and professional long telephotos. Lots of third-party F-mount lenses are also available.
The Alpha 7R requires FE lenses for full compatibility, with just four available. Sony E lenses will also fit. It can also use Alpha-mount lenses via the LA-EA4 adapter, and a huge range of other lenses via adapters.
Nikon’s F-mount system is one of the best-established on the market, and almost every imaginable lens or accessory is available, covering practically any eventuality. In contrast, Sony’s full-frame E-mount system is still in its infancy. But the Alpha 7R makes up for this with its adaptability to many other lenses, including the extensive Sony Alpha mount range.
The Alpha 7R is also distinctly more portable than the Nikon SLRs, and includes modern features such as built-in Wi-Fi for connecting to a smartphone. The camera body is much cheaper too, although this is offset by relatively expensive lenses.
Image: All three cameras perform astonishingly well here, and are able to pick out remarkably fine detail in this wideangle view of the London skyline
Image: The D810’s base ISO of 64 should, in principle, give cleaner images. It perhaps shows slightly smoother tones in blue skies, but the difference is very subtle
Image: The Alpha 7R matches the Nikons in the centre of the frame, but its 24-70mm f/4 looks a little less sharp at the edges than the Nikon 24-70mm f/2.8
There’s really not much between the D810, D800E and Alpha 7R in terms of image quality, although the D810 may just have a slight edge overall as it has the most up-to-date sensor. But when making a real-world choice between the cameras, I think the sensors are just about the least important consideration.
There’s no doubt that the D810 is a better camera than the D800E. The refined shutter mechanism and electronic first curtain help keep mechanical shake to a minimum, and for live-view work the D810’s vastly improved magnified view makes critical focusing easier. However, I can’t see any obvious difference in resolution between the cameras under ideal conditions, suggesting that Nikon did a very good job in cancelling the OLPF in the D800E.
Probably the biggest difference between the Sony Alpha 7R and the Nikon DSLRs lies in the respective systems, and the availability of lenses. The longevity of the F mount means that practically every kind of lens can be found for the D810 and D800E. Chances are, though, that only relatively modern designs will be able to deliver all the detail that the 36-million-pixel sensor can record. In contrast, the native lens set for the Alpha 7R is limited, but the 55mm f/1.8 is superb.
The Alpha 7R showcases many of the advantages that mirrorless cameras have over DSLRs. Its electronic viewfinder conveys lots more shooting information, including better manual focusing and exposure aids. Switching between the eye-level viewfinder and the rear screen is seamless, and the latter can be tilted to use as a waist-level finder. The system is also much more compact and portable overall.
Despite all this, I think the D810 edges out the Alpha 7R as the overall winner in this comparison. It’s just a more evolved and refined camera to use, with a more complete system to back it up. The Sony is an amazing camera on paper, but isn’t quite the finished article yet. However, once the rougher edges have been smoothed and a more comprehensive lens range is available, it has the potential to be a very serious contender.