This is a review of the Nikon 24mm f1.4 AF-S G lens, with additional comparison to the Sigma 24mm f1.8 and the Sigma 28mm f1.8.

Following this posts initial publication, it's taken over a year to put the final review together. I have used the Nikon 24mm f1.4 on countless commissions, including nearly 50 weddings, numerous portrait shoots and several commercial assignments.

I will state now, this review was done in such a way as to provide a sound basis for comparison between the lenses and offer some of my real world experiences with the Nikon 24mm f1.4. Be advised though, it certainly isn't a scientifically executed, tightly controlled precision fest; but it will show the clear differences between the lenses (with some surprising results) and how these differences really do manifest themselves in real life shooting.

The test was performed on a Nikon D700, RAW conversion was done in Adobe Photoshop Lightroom with all sliders set to default settings and no output sharpening applied.

If you really want to pixel peep you can view and download the JPEG files here:

Nikon 24mm: http://www.flickr.com/photos/joshuaarcher/sets/72157624230592211

Sigma 24mm: http://www.flickr.com/photos/joshuaarcher/sets/72157624355524736

Sigma 28mm: http://www.flickr.com/photos/joshuaarcher/sets/72157624355721372

BUILD QUALITY AND HANDLING

In this comparison shot (not my finest product shot but the image serves its purpose well enough) you can see that the Nikon is a fair bit larger, and that the lenses have been well used! This extra size belies a noticeable difference in weight too with the Nikon easily weighing more than either Sigma.

For clarity - the Nikon 24mm f1.4 is on the left, the Sigma 24mm f1.8 is in the middle and the Sigma 28mm f1.8 is on the right, without the lens hood. 

Note - Whilst the lens hood on the Nikon may say 'Made in China', the lens itself is made in Japan.

It's not easy to convey it through words but the Nikon is a better built lens. Yes the Sigma's are cheaper, but the Nikon is in a different league. All focusing is internal, unlike the Sigmas whose barrels extend and contract during focusing (but don't rotate) and as a result the Nikon has none of the lens barrel play that the Sigmas do. Equally the Nikon has a rubber seal on the lens mount to aid with weatherproofing and has a superior quality exterior finish.

One significant area to note is the manual focus override. The Nikon enjoys full time manual focus override thanks to the Silent Wave Motor. The Sigma lenses don't incorporate Sigmas version of this, which they dub the Hyper Sonic Motor (HSM), so it is noisier, the focus ring has to be disengaged on the lens AND the mode changed on the camera if you want to make a (not very quick) manual focus adjustment. A very frustrating feature.

Having used all of these lenses in various weather conditions I can definitely say I trust the Nikon to survive far more than the other two. It inspires much more confidence that the Sigmas, it's survived downpours, scorching summers, freezing winters and snow storms without batting an eyelid.

Without question, it is a product that you can put your faith in and it won't let you down on the build quality front.

Score - Nikon 24mm 1 - Sigma 24mm 0 - Sigma 28mm 0

SHARPNESS AND VIGNETTING

As a photographer, it's important to try to surround yourself with ’18% grey' whenever possible. Fortunately for me, the builders of my house were sympathetic to the needs of the photographer and painted most of the outside of it this very same gorgeous colour. They really did! Ok, it's not quite exactly 18% grey, but it very handily shows up the difference between the lenses.

The test was performed on a tripod in 10 second self timer mode. Distance to the wall remained the same for all lenses and was measured to be level and square to the wall as accurately as a £5 B&Q tape measure would allow.

Nikon 24mm f1.4

Series is: f1.4 - f2.8 - f4.0 - f5.6 - f8.0 - f11 - f16

Sigma 24mm f1.8

Unfortunately, it seems a fly/mosquito/GIANT spec of dust landed on the lens on the last two frames in the sequence (which were the first two actually shot). Despite it's apparent hugeness, I didn't spot it. 

Nevertheless, the file is still good enough for these purposes.

Series is: f1.8 - f2.8 - f4.0 - f5.6 - f8.0 - f11 - f16 - f22 

Sigma 28mm f1.8

Series is: f1.8 - f2.8 - f4.0 - f5.6 - f8.0 - f11 - f16 - f22

Something you'll probably notice with this lens; the exposure is different. It seems that for whatever reason, the camera & lens combo conspire to produce images that are more exposed that the other two lenses.

Certainly this has held true in other areas of the test and in normal use to, though not to the extremes shown up by this test. There is no fault with the lens and the aperture blades/contacts are undamaged, but as stated there is a visible difference in the exposure of the lenses.

Summary

Vignetting 

All these lenses vignette wide open, that is to be expected given their focal length and aperture. I was surprised at just how heavy the vignetting was on the Nikon, but equally how quickly it disappeared. It has virtually gone at f2.8 which is useful in the real world whereas the sigma 24mm still vignettes enough to be noticeable until f4.

Sharpness

If you have taken the time to look at the full size files from the gallery, you will notice that all the lenses are sharp in the centre. The Nikon trumps the Sigma glass for corner sharpness however.  Even wide open the Nikon retains an admirable level of detail and sharpness. A very impressive showing.

The Sigma lenses are not far behind but both are noticeably softer, particularly the upper right corner of the frame. 

Score - Nikon 24mm 1 - Sigma 24mm 0 - Sigma 28mm 0

FLARE AND CHROMATIC ABERRATION 

This test was performed handheld at various times. The sun was placed just in and just out of frame to maximise the difficulty placed on the lenses and included high contrast objects that would show up any Chromatic Aberration (CA). There were a few surprises on this test...not least that I wasn't lying about that 18% grey house I have.

Nikon 24mm f1.4

Frankly I am disappointed by this lenses performance in the flare and Chromatic Aberration (CA) arena when the sun is in the frame. As you can clearly see from these files, let alone the full size ones, wide open or stopped down the lens is prone to quite appalling multi-reflective flare/ghosting and large blooms of CA. When out of the frame, things are fine (no point showing here).

Series f1.4 - f1.4 - f2.8 - f2.8 - f8 - f16

Sigma 24mm f1.8

Try as I might, I just couldn't get the lens to flare badly, even wide open. Each frame was similar to the one's below. Having used the lens at several weddings I can testify that it is remarkably good at controlling the nuisance, multi reflected flare that the Nikon failed to control. Sure, any hope of a nice contrasty file is out the window, but the effect is useable. CA is average as you can see on the tree branches.

Series - f1.8 - f1.8

Sigma 28mm f1.8

Pretty much the exact same story here as the Sigma 24mm f1.8. That is to be expected as they share many design features but it really is a good showing from both lenses.

Series f1.8 - f1.8 - f2.8 - f4

Summary

Flare

Quite a big surprise here. Nikon has touted it's new Nano-Crystal coating as some kind of magical elixir guaranteed to wash away all your flare and ghosting troubles. Not so it seems. Equally surprising is just how well the Sigmas perform, sun in or sun out of frame.  

Chromatic Aberration

Again a surprisingly weak performance from the Nikon 24mm f1.4 here. The Sigma 24mm f1.8 and the Sigma 28mm f1.8 do considerably better at controlling CA in the highest contrast areas. They still show fairly large amounts, but the Nikon loses out here again.

Finally, the test circumstances on this occasion were a little extreme, but you will not get much better performance in ordinary shooting.

Score - Nikon 24mm 0 - Sigma 24mm 1 - Sigma 28mm 1

BOKEH

This is a highly subjective quality in any lens but an important one nonetheless. I'll leave it up to you to decide which is your favourite. I already have mine...

Nikon 24mm f1.4

Series f1.4 - f1.8 - f2.8

Sigma 24mm f1.8

Series - f1.8 - f2.8

Sigma 28mm f1.8

Series - f1.8 - f2.8

Summary

 As I said, this is a subjective one, and the files are better viewed large. You'll have to decide for yourself.

Score - Nikon 24mm N/A - Sigma 24mm N/A - Sigma 28mm N/A

DISTORTION

Easy one this - single shot of a brick wall. Classic. All shot at f4 on a tripod, self timer and ISO 200 etc etc etc...I don't think I properly focused the Nikon 24mm f1.4 (and we'll get to focusing in a minute) but that doesn't effect the outcome of the test so the file is valid.

Nikon 24mm f1.4 

Sigma 24mm f1.8

Sigma 28mm f1.8

Summary

Each lens performs extremely well here as expected and distortion is so small as to be unimportant.  Good result all round.

Score - Nikon 24mm 1 - Sigma 24mm 1 - Sigma 28mm 1

NIKON 24mm f1.4 REAL WORLD USE...FOCUSING 

NOTE: I mainly use centre point spot focusing using the ‘back-button’ method (i.e, I don’t use a half press of the shutter release to focus). This method decouples focusing from the activation of the shutter release and offers a bit more flexibility when shooting.

Good Light

NOTE: By good light I mean daylight, well lit interiors/good window light and nothing that requires you to go above ISO 1600 f2.8 1/125 sec.

With a decent amount of light about, or at least a decent amount of contrast on the subject you are focusing on, this lens performs very well. Focusing is actually quite snappy, certainly a shade faster than the 50mm f1.4 AF-S G (though lets be honest, that's not hard) and for the most part it is accurate.

When used outside in 3D tracking mode the lens is quick to react, usually accurate and even at wide apertures returns a high percentage of in focus images. This lens DOES have a back-focusing issue though, particularly in the time of directionless ambient light you might get in the interior of a building. When I say back-focusing I am not talking about a calibration error, I mean it will erroneously select to focus far into the background despite you, the user, focusing on a closer object.

Being a wide-angle lens the issue is obviously exacerbated when you are attempting to focus on a subject that is quite small in the frame, but maybe in the middle distance or at least clearly in front of the background. In these cases it can be very hard to tell exactly where the autofocus sensor is positioned, even allowing for the relatively accurate Nikon focusing system. Add these factors together and the result is a lens that often chooses to focus on something behind the thing you want to focus on.

This can be a real nuisance as these situations can come up fairly often. If you imagine standing at the back of a church, focusing on the Bride and Groom at the end of the aisle and instead the lens focuses on the alter in the background you can see why this would get very tedious, very quickly. Plus, at that distance it s very hard to tell in the viewfinder if you are focused on exactly the right thing, so it's not an insignificant problem.

The only way you can really combat this issue is to know it's likely to occur and keep checking/focusing again and again to make sure you are picking up the exact point you need.

In terms of shooting wide open or stopped down, there really isn't much difference. I ll talk about image quality shortly but in decent light you can happily shoot at f1.4 to your hearts content and still get sharp, properly focused images.

Low Light

NOTE: By low light I really mean dark. I mean the type of light you might get during late evening speeches by candlelight or during a first dance - mostly extremely low levels of light coupled with low contrast and moving subjects.

When your subjects are relatively stationary you shouldn't experience much of a problem focusing with this lens. Even in light that is somewhat difficult to see in with the naked eye, you can achieve accurate focus (baring in mind the back-focus issue described above). During speeches, or a slow moving first dance for instance, it's perfectly possible to focus on the subject, even from some distance, and get a sharp image.

However, capturing fast dancing guests in really low light with this lens can be like trying to sweep fog uphill with a broken toothbrush. Again and again it mis-focuses or reacts so slowly that you miss the shot. But, lets be realistic, all lenses are going to find it near impossible to focus on low contrast, fast moving subjects where the ambient exposure sits at about ISO 6400 f1.4 1/80sec so it s not exactly worse than any other lens in this situation.

It's in these types of situation you should be thinking about manual focus or using flash, both to freeze the action and make use of the auto-focus assist function. In fact, I have had to use this a couple of times, Waldingham School comes to mind, which is dark anyway but the couple decided to have their first dance lit pretty much only by a glitter ball!

When using the auto-focus assist beam it's like focusing in broad daylight, everything speeds up, becomes much more accurate and shot after shot is in focus. I find it undesirable to use this function but when it comes to a choice between getting the shot or not, the choice is an easy one.

Summary

The bottom line is, focusing in this lens is mostly fine, bar a few foibles, and even when you are in a pinch or in an impossible situation like I was at Waldingham School, using the focus assist beam will allow you to get the shot.

The most important thing is to become very familiar with your kit, learn it's limitations and know how to get around them as this lens is certainly no worse than it's competitors.

REAL WORLD QUALITY

I'm not going to publish a load of comparison images, start pixel peeping or begin any other similarly pointless exercise here. If your after that sort of thing, check out any one of hundreds of scientific tests, MTF charts or 10,000% crops out there on the net.

The only thing I am concerned about in terms of real world quality is if the image is of a high enough standard to present to my clients in both electronic AND print form.

Save a number of out of focus shots, I have only ever had to reject a handful of images created using this lens for any defect in sharpness, chromatic aberration or flare. In truth, all of those rejections that were not down to focusing were down to excessive flare and even then we're talking about just few dozen shots from many tens of thousands.

On this basis, the Nikon 24mm f1.4 has been an outstanding lens.

CONCLUSION

Several years ago Nikon spent a great deal of time and invested a great deal of capital into the development of its full frame cameras, the D3, D700 and the subsequent upgrades. These were truly groundbreaking tools that redefined the expectations of the industry in terms of image quality. Similarly, Nikon applied the same ethic to its zoom lenses, systematically updating their fast aperture zoom lenses throughout the 14 - 200mm range and again redefining the expectations of quality and performance. One thing was missing. Primes.

Canon has long held sway over the prime lens market, with such icons as the 50mm f1.2, 85mm f1.2 and the 24mm f1.4 mk2. It seems Nikon has now turned its attention to addressing this area of the market and with the 24mm f1.4, the 35mm f1.4 and the 85mm f1.4 they have entered the arena with guns blazing. The Nikon 24mm f1.4 lens is built like a tank, it's fast, it's accurate, it's silent and it's ergonomically excellent.

Low light Nikon shooters like me have longed for a lens like this for years. This one, whilst it has its problems, doesn't disappoint. Does it redefine expectations like some of Nikon's camera bodies did? No. Canon really do have a set of simply stunning lenses and Nikon was playing catch up, but this new offering is every bit as good as its Canon counterpart.

This lens is not cheap though, at the present time it can be found for upwards of £1900 in the UK. It is a serious investment but if you require the best quality in the best package then look no further than this lens. It outperforms it's third party rivals in most areas, save for its flare problems, and treated well will no doubt last many, many years.

Nikon 24mm f1.4 Pros

• Sharp across the frame, even at wide apertures
• Excellent image quality
• Near silent focus motor with full time manual focus override
• Excellent build quality
• Weather sealed

Nikon 24mm f1.4 Cons

• Susceptible to flare
• Vignettes at wide apertures
• Heavy
• EXPENSIVE!!!

Final score - Nikon 24mm 3 - Sigma 24mm 2 - Sigma 28mm 2