Nikon D3X vs Sony Alpha 850 at a glance

Nikon D3x:  Sony 850:
24.5 million effective pixels 24.6 million effective pixels
Live View on 3in, 920,000-dot LCD screen 3in, 921,600-dot LCD screen
100% viewfinder Approx 98% viewfinder
Street price approximately £4,800 Street price approximately £1,700

Nikon D3X vs Sony Alpha 850

Nikon D3x and Sony Alpha 850 camerasThe old adage so beloved of salesmen – and one that is often used in an attempt to sway you towards buying a more expensive product – is, ‘you get what you pay for’. In most cases this maxim is correct, but it doesn’t take into account the most important factor in a buying decision – the precise needs of the purchaser. After all, there’s no point buying the world’s loudest hi-fi system if you live in a small one-bedroom flat.

The same is true when buying a camera. While I’m sure many readers would love to own the 24.5-million-pixel, full-frame Nikon D3X, it costs around £4,800. Not only is this beyond the budget of most enthusiast photographers, but there’s also the fact that most enthusiasts are unlikely to use
all the features this money buys.

However, there is an alternative. The Sony Alpha 850 has a 24.6-million-pixel, full-frame sensor, yet it has a street price of around £1,700, which is some £3,100 less than the Nikon D3X. In our review, the Sony Alpha 850 scored 81% (AP 9 January), which is 8% less than the 89% we awarded the Nikon D3X (AP 24 January 2009). What is even more intriguing is that the Nikon D3X uses an image sensor, which, although designed by Nikon, is manufactured by Sony. This might lead you to believe that the two sensors share a lot of technology.

The 8% difference in the results of our previous tests show that, on paper, the Nikon D3X is the better of the two cameras. However, are the extra features really worth an extra £3,100 to an enthusiast photographer?

Nikon D3X vs Sony Alpha 850 – Features

The headline feature of these cameras has to be their high-resolution, full-frame sensors. The Nikon D3X has a 24.5-million-effective-pixel CMOS sensor, while the Sony Alpha 850 has a slightly more densely packed 24.6-million-effective-pixel CMOS sensor. Interestingly, the output resolution of both cameras is 6048×4032 pixels, making an identical 24,385,536 total pixel output for both cameras.

Nikon USA has openly stated that the sensor in the D3X was manufactured by Sony, but based on a design Nikon developed specifically for the D3X camera. This has led many to believe that the same sensor is used in the Sony Alpha 850, and while it is safe to assume they have much in common, the architecture surrounding the sensor is different. For example, the microlenses that direct light onto the sensor’s photosites, the low-pass filter above the sensor array, as well as the analogue-to-digital conversion systems may all be different, and each of these individual components will affect the image quality.

Each manufacturer also has its own image-processing engine. In the D3X, Nikon has fitted its Expeed processing system, while Sony has installed its dual Bionz engine in the Alpha 850. How these different image-processing engines process the data passed on from the sensor will affect image quality. So, even though the two cameras share a similar starting point, the images they produce may be very different.

The Sony Alpha 850 is a cut-down version of its big brother, the Alpha 900. One of the main differences between the two Alpha cameras is the continuous shooting rate, which is 5fps with the Alpha 900 and 3fps with the Alpha 850. This is the same as the difference in shooting rate between the Alpha 850 and the Nikon D3X, as the D3X also has a continuous shooting rate of 5fps. Given that neither camera is designed with sports photographers or photojournalists in mind, this shouldn’t concern many photographers. With resolutions in excess of 24 million pixels, both the Alpha 850 and D3X are really designed to capture detail in a studio or landscape environment.

With the Nikon D3X costing £3,100 more than the Sony Alpha 850, you’d think that the D3X would be packed full of features not present in the less expensive camera. However, there is one major feature that the Alpha 850 has that the D3X doesn’t: in-camera sensor-shift image stabilisation, or SteadyShot Inside as Sony has branded it. Nikon uses lens-based image stabilisation in its cameras, with an increasing number of lenses having VR (Vibration Reduction) built in.

Having image stabilisation built directly into the camera has the advantage that it will work with any lens. Nikon’s 24-70mm lens, for example, lacks Vibration Reduction, whereas this isn’t a concern with Sony’s equivalent 24-70mm f/2.8 ZA SSMVario-Sonnar T* lens as the stabilisation is in-camera.

The Alpha 850’s sensor-shift image stabilisation offers another advantage over the Nikon D3X – it can also be used as a sensor-cleaning system by vibrating dust away from the sensor. Nikon omitted a sensor-cleaning system from the D3 and D3X, claiming it would have affected the 100% viewfinder coverage.

One feature noticeably absent from the Sony Alpha 850 is Live View, which is surprising considering that it is now found in most cameras, including the Nikon D3X.

When it comes to the main features of both the Alpha 850 and the D3X, there isn’t a lot to separate them, and certainly not enough to warrant parting with an extra £3,100. In fact, the sensor-shift image stabilisation of the Alpha 850 and the extra 2-4EV exposure time it allows is arguably a more valuable feature than Live View or an extra 2fps continuous shooting rate.

Nikon D3X vs Sony Alpha 850 – Build and Handling

As you would expect from cameras of this type, both the Nikon D3X and Sony Alpha 850 have magnesium-alloy bodies and are sealed to prevent dust and moisture entering the cameras.
Given their similar specifications, there is a big difference in the size and weight of the cameras. At 850g, the Sony Alpha 850 is the lighter of the two, while the Nikon D3X weighs 1,220g. In a studio the weight of either camera shouldn’t be a problem, but I would obviously prefer to carry the lighter Alpha 850 around my neck when out taking landscape images.

Much of the larger body of the Nikon D3X is taken up by the compartment for its EN-EL4a battery. Physically a lot larger than the NP-FM500H battery used in the Sony Alpha 850, the EN-EL4a allows the D3X to capture many more images under CIPA testing guidelines. Sony states that the Alpha 850’s battery can power around 880 images, whereas the D3X’s battery allows it to take a whopping 4,400 shots. This may seem like an advantage for Nikon, but if you find that you need to take 4,400 images, buying another four Sony NP-FM500H batteries will cost a lot less than £3,100.

Anyone familiar with DSLRs should have no trouble getting to grips with either camera, but of the two I find that the Nikon D3X is the quicker to use. Its substantially larger body allows it to have a larger LCD on its top plate than the Alpha 850, but also a secondary LCD below the rear screen. This secondary control display is dedicated to controlling the ISO sensitivity, white balance and image quality, and each of these settings has its own dedicated button.

With a smaller camera body, Sony has kept the buttons on the Alpha 850 to a minimum, but it still has dedicated controls for the white balance, ISO sensitivity and drive mode, as well as a dedicated switch to turn the SteadyShot Inside feature on or off. However, the rear screen of the Alpha 850 displays all the currently used shooting settings. Similarly, by pressing the Fn button on the rear of the camera, all these settings become active on the LCD screen and can be easily changed without having to go directly into the camera’s main menu system.

If you regularly find yourself using the same image and exposure settings, both cameras have the provision to save these settings and recall them quickly. This is quite straightforward on the Alpha 850: with the camera set up as you want it, simply select ‘Memory’ from the main menu and choose one of the three memory banks in which to save the settings. Selecting which to use is even easier as all three can be accessed by turning the mode dial on the top of the camera to the relevant 1, 2 or 3 position.

Nikon has used a similar method on the D3X. Four sets of custom menu settings and four lots of shooting menu settings can be saved. These custom presets may then be selected via the main menu. The D3X also has a My Menu function to allow the menu items you most regularly use to be shown on the same menu screen.

Overall, the Nikon D3X has the more comprehensive custom settings features, although using the Alpha 850’s mode dial to choose which presets are being used is a very clear and fast way of working.

Nikon D3X vs Sony Alpha 850 – Metering

Although centreweighted and spot metering suggest an exposure to achieve a mid-grey tone, what one manufacturer considers mid-grey can be slightly different from another’s. In real-life situations I found that the Nikon D3X and Sony Alpha 850 produced almost identical exposures, and when there was a difference it was generally only around 0.3EV.

However, I found there was more of a difference in how the cameras performed in their evaluative metering modes. Rather than simply having a camera average out the brightness of a scene, modern systems work by evaluating the scene as a whole and then working out the correct exposure.

Of the two evaluative metering modes, the D3X’s 1,005-segment 3D Colour Matrix is the more sophisticated. It uses the colour, brightness and contrast of a scene, as well as focusing information, to compare it to some 20,000 scenes that are kept in an internal database. The D3X then uses all
this information to determine what it thinks is the optimal exposure.

In practice I found that evaluative metered exposures from the two cameras were quite close, being around 1EV apart at most. Generally, it would seem as though the D3X tries to lighten shadow areas a little more than the Alpha 850, while the Alpha 850 tries to maintain highlight detail.

Nikon D3x vs Sony Alpha 850 evaluative metering sample images. How the cameras performed in evaluative metering mode varied from scene to scene. Here I had to reduce the exposure time of the D3X image as it was too light, while I had to lighten the shot from the Alpha 850.

Image: How the cameras performed in evaluative metering mode varied from scene to scene. Here I had to reduce the exposure time of the D3X image as it was too light, while I had to lighten the shot from the Alpha 850

In situations where you wish to tweak the exposure quickly or where a series of images is being captured in the same conditions, the EV compensation button next to the shutter-release button on
both cameras comes in handy.

The Nikon D3X has a few more tricks up its sleeve, though. Whereas the Sony Alpha 850 has exposure bracketing of up to 2EV, the D3X is capable of up to a 9EV spread across a maximum of nine exposures. This is great when trying to make sure the exposure is exactly right, and it also makes it easy to produce HDR images. However, the Nikon D3X doesn’t stop there. Like other professional Nikon DSLR cameras, the D3X features a Fine Tune Optimal Exposure custom option. This allows the user to adjust the metered exposure of each of the centreweighted, spot and evaluative metering modes by as little as 1/6EV. So should you find that the D3X always produces exposures that are a little too dark in spot metering mode, you can adjust the metering to change this.

When the metering systems of both cameras are compared, the Nikon D3X has more options. However in their default settings there is little to separate the exposures of both cameras. There certainly isn’t enough of a difference to justify the extra expense of the D3X.

Nikon D3X vs Sony Alpha 850 – Viewfinder, Live View and LCD

Nikon D3x and Sony Alpha 850 LCD screensSurprisingly, I found that the viewfinder of the Sony Alpha 850 is slightly brighter than that of the Nikon D3X. The Alpha 850 also has a marginally more powerful magnification of 0.74x, compared to 0.7x on the D3X. There is a slight compromise with the Alpha 850 viewfinder as it only offers 98% coverage, compared to the 100% field of view offered by the D3X. I can’t envisage this being an issue except in situations where the utmost precision is required.

In a situation where I require a 100% field of view I would usually switch to Live View, but sadly this feature isn’t included in the Alpha 850. Given that most other manufacturers include Live View as standard, it does strike me as a little odd that Sony has omitted the feature.

Nikon has implemented Live View in the D3X and you can choose between phase-detection autofocus, which briefly interrupts the view to autofocus, or contrast-detection AF. The latter option is found in the Live View menu as ‘Tripod mode’, but as it is quite slow to find the focus point it is really only suitable for still-life subjects.

The rear LCD screens of the two cameras measure 3in. Although the Sony Alpha 850 has a slightly higher resolution of 921,600 dots, compared to the 921,000-dot screen of the Nikon D3X, I suspect they are actually of identical resolution and the manufacturers have rounded the numbers either up or down to get the figures for their specifications.

With such high resolutions and magnification options available, it is possible to see a lot of detail when reviewing images on both the Nikon and Sony screens. This is vital in both cameras to help check accurate focus. Overall, both screens are good, being equal to high-resolution 3in screens available on other DSLRs.

There is one other very useful tool that the D3X has and it is one that will be extremely useful for landscape photographers – a Virtual Horizon level. This can be displayed either through the camera’s main menu or overlaid on the screen when in Live View mode.

Nikon D3X vs Sony Alpha 850 – White Balance and Colour

I imagine that most people using the Nikon D3X or Sony Alpha 850 will shoot the majority of their images as raw files. While it is easy to adjust the white balance of raw images, it is obviously far easier if you don’t have to make the adjustments in the first place.

When in AWB, the D3X uses the same 1005-pixel RGB sensor that is used by the metering system to judge the correct white balance for a given scene. As this system is programmed to recognise particular scenes, such as landscapes, the D3X can recognise a sky and try to adjust the white balance to make it the correct shade of blue.

This is the same system Nikon uses in all its pro-level cameras and it works very well, producing well-balanced colours in almost all situations. I found that under tungsten lighting, midday sunshine and a late afternoon sunset, the automatic white balance produced good results.

The Sony Alpha 850 also produced good results in its AWB mode, although I found that it produced better results when it had to deal with more subtle hues. As Angela Nicholson discovered
when she originally reviewed the Sony Alpha 850, the camera has a tendency to overemphasise particularly strong colours in the scene. For example, in one instance a bright blue midday sky caused the image to have a slight blue hue to it.

Obviously there is a wealth of preset white balance settings on both cameras and it is simple to switch to these, or choose a manual or custom white balance setting should you wish.

However, if you require more refinement, the Nikon D3X has even more options. By selecting white balance in the shooting menu, you can not only choose the white balance setting, but also fine-tune the white balance to adjust the hue of each of the settings slightly.

This level of refinement looks great on a specification sheet. However, I doubt whether too many photographers will ever really get the most out of it or even use this level of control, preferring instead to simply set a custom white balance or adjust raw images.

Nikon D3x vs Sony Alpha 850 evaluative metering. Both cameras metered this scene almost identically, although the AWB of the Nikon D3X produced the more accurate colour rendition.

Image: Both cameras metered this scene almost identically, although the AWB of the Nikon D3X produced the more accurate colour rendition

Nikon D3X vs Sony Alpha 850 – Autofocus

Autofocus is one area where the Nikon D3X really comes into its own. It uses the same 51-point AF system (with 15 of these being cross-type sensors) as the Nikon D3S, D700 and D300S, and it has a huge range of settings and custom options.

First of these is the ability to select the number of AF points being used, with 9, 21 or 51 being selectable.

All 51 points can be used with Nikon’s 3D Matrix tracking system. This uses the same module that is used by the metering and white balance system to track an object around a frame and
adjust the focus accordingly.

With the D3S, the 3D Matrix AF is ideal for documentary, sports and wildlife photographers who want to pan the camera and leave the AF to track the subject. Of course, the slower shooting rate of the D3x limits its usefulness for fast-moving sports photography, but for most wildlife subjects it is still usable, as I found out when photographing deer.

Of course, there is always the option to use just one of the 51 AF points and then to use continuous focus mode, but 3D tracking moves with the subject should it move away from that single AF point.

Fancy modes aside, when set to AF-S mode the D3x is fast and responsive, even in fairly low-light conditions. However, Sony’s Alpha 850 is no slouch when it comes to autofocus. It has only nine AF points, which are set in a diamond shape around the middle of the image frame. There are ten additional AF points, but these aren’t selectable or visible through the viewfinder. They are instead used internally by the camera to help focus with greater accuracy.

At the centre of the diamond layout the centre AF point is a cross sensor, and as such is more sensitive than the surrounding points. Although the Nikon D3x may outnumber the Sony Alpha 850 when it comes to AF points, I found that the 850 quickly locks on to focus, although the centre point is noticeably faster than the surrounding ones.

For the most part I’d recommend that photographers use the Sony Alpha 850 set to the Local Area AF setting. This allows any one of the main nine AF points to be quickly selected via the rear thumb control, which I found fast and easy to use.

I was a little surprised to see that EyeStart AF hasn’t been included in the Sony Alpha 850. EyeStart uses two sensors below the viewfinder to activate the AF as soon as the camera is moved towards your eye. I find it useful on Sony Alpha cameras when taking quick snapshots, but on the whole I can live without it because whenever the viewfinder knocked against me while I was walking, the EyeStart activated the AF and drained the batteries. However, the sensors are still in place on the Alpha 850, but this time they are used to turn the rear LCD off as soon as your eye (or anything else) is placed near the viewfinder, actually saving a little battery life. I just wonder whether Sony couldn’t have left the feature in, but left it turned off by default.

While the Nikon clearly has the better AF system, few photographers will ever really get the most out of it because fast, continuous AF tracking speed is quite low down on the requirements for the studio, landscape or candid photographer. Therefore, it would be difficult for an enthusiast to justify the extra money the Nikon D3X commands over the Sony Alpha 850.

Nikon D3X vs Sony Alpha 850 – Noise, resolution and sensitivity

Nikon D3x vs Sony Alpha 850 sample images, raw performance. Both these raw images were processed in Adobe Camera Raw, with no noise reduction applied, but they were sharpened individually. Both show the same amount of detail, but noise is better controlled in the image taken by the D3X.

Image: Both these raw images were processed in Adobe Camera Raw, with no noise reduction applied, but they were sharpened individually. Both show the same amount of detail, but noise is better controlled in the image taken by the D3X

Image quality should be the ‘meat and potatoes’ of any photographer’s camera-purchasing decision. With more than 24 million pixels, both the Nikon D3x and Sony Alpha 850 are capable of resolving a lot of detail.

At ISO 100, both cameras reach an impressive 30 on our resolution chart.However, as soon as the sensitivity increases, the differences between the processing systems of the two cameras becomes apparent.

Although our noise test shows that the Alpha 850 has a high percentage of noise in the red channel, the green, blue and luminace channels actually show slightly less noise than the D3X.

Both raw and JPEG files from the Nikon D3x are clear at ISO 400 and ISO 800, but chroma noise has started to creep into images produced by the Alpha 850.

The Sony camera also suffers from luminance noise and a speckled effect is present in raw files, while smudging, which is caused by noise reduction, has affected JPEG images.

In contrast, the level of noise is far better controlled in JPEG files produced by the Nikon D3X, and it is easily reduced in raw images.

Images from the D3X at the maximum ISO 6400 sensitivity have a soft, granular texture, whereas the Alpha 850 images have a clumpier, blotchy texture. Nikon has designated the ISO 3200 and ISO 6400 settings as the extended Hi-1 and Hi-2 sensitivities, meaning they are not recommended for regular use but only if and when needed. I would recommend Alpha 850 owners adopt the same approach.

Nikon D3x iSO sample image. In this JPEG image taken at ISO 6400, the Nikon D3X shows little in the way of chroma noise. However, it does take on a rather smudged appearance.

Image: In this JPEG image taken at ISO 6400, the Nikon D3X shows little in the way of chroma noise. However, it does take on a rather smudged appearance

Sony Alpha 850 ISO sample image. The Sony Alpha 850 JPEG image shows patches of coloured chroma noise at ISO 6400.

Image: The Sony Alpha 850 JPEG image shows patches of coloured chroma noise at ISO 6400

Nikon D3X vs Sony Alpha 850 – Dynamic Range

It is no real surprise that both the Nikon D3X and Sony Alpha 850 have the same dynamic range. However, the fact that the dynamic range is 12EV is quite surprising, given that each sensor has more than 24 million photosites. Usually the smaller photosites required to create these densely populated sensors collect less light, which impacts upon the amount of information that can be recorded. This, in turn, will affect the dynamic range, particularly in darker shadow areas.

Both cameras have dynamic range optimisation systems in the form of Active D-Lighting in the D3X and D-R Optimiser in the Alpha 850. The Nikon D3X has the more subtle of the two systems. At its extra-high setting, Sony’s D-R Optimiser creates an effect that looks almost like an HDR image. However, this introduces noise in the shadow areas.

Nikon D3x vs Sony Alpha 850 resolution charts. These images show 72ppi sections of images of a resolution chart, captured using matching 105mm macro lenses. We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera
Image: These images show 72ppi sections of images of a resolution chart, captured using matching 105mm macro lenses. We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately.

The higher the number visible in these images, the better the camera’s detail resolution is at the specified sensitivity setting.

Nikon D3x vs Sony Alpha 850 noise as a percentage of pixels.

Nikon D3x vs Sony Alpha 850 dynamic-range

This graph shows the brightness values recorded by the test camera when it is used to photograph a stepped graduation wedge. The wedge has transmission values in 1⁄2EV steps ranging from 0 to 12EV. The camera’s exposure is set so the 12EV section in the wedge has a brightness value of 255. Software analysis of the image then determines the recorded brightness values of all the other steps and calculates the camera’s dynamic range.

Nikon D3X vs Sony Alpha 850 – Verdict

Let’s get the facts out of the way first: the Nikon D3X is a truly great camera with many advanced features that will impress both the amateur and professional photographer alike. However, the point of testing the D3X and Sony Alpha 850 side by side isn’t to ascertain the superiority of one over the other, but to see whether the Nikon D3X’s ‘better’ features are worthy of the extra £3,100 the camera costs.

Nikon has aimed the D3X squarely at professional photographers and those working for picture agencies, who may already use the Nikon system and will find it easier to justify the cost of the camera. Sony is positioning the Alpha 850 at a different market. By introducing a less sophisticated but far cheaper camera, Sony is trying to tempt new enthusiast photographers to the Alpha system, and in turn take a share of the DSLR market away from Nikon and Canon. In many ways the Alpha 850 is aimed at the same photographers as the similarly priced full-frame Nikon D700 camera, which has just half the number of pixels.

With this in mind, the Sony Alpha 850 is a perfectly acceptable alternative to the Nikon D3X. It may lack the sophisticated AF and custom options, but it is a smaller, lighter camera that in most general situations can match the D3X in terms of performance and image quality.

Instead of asking whether the Nikon D3X is worth an extra £3,100, perhaps another approach would be to ask if the Sony Alpha 850 represents good value for money. And the answer to this question has to be yes. The Alpha 850 offers a high-resolution, full-frame DSLR camera at an affordable price, and it is a great upgrade for users lower down in the Alpha range. Enthusiast photographers using the Alpha 850 for landscapes, studio and travel photography should be more than happy with the image quality the camera offers, without going to the expense of the Nikon D3X.

Nikon D3X vs Sony Alpha 850 Scores

  Nikon D3X Sony Alpha 850
 Tested as: Professional DSLR  Semi-pro DSLR
 Rated: Very good  Very good
 Overall score: 89%  81%
 Features: 8/10  7/10
 Noise/resolution:  28/30  28/30
 Dynamic range:  9/10  9/10
 LCD/video:  9/10  7/10
 Build/handling:  9/10  8/10
 Autofocus:  9/10  7/10
 Metering:  9/10  8/10
AWB/colour:  8/10  7/10