Canon EF 50mm F1.8 II review
Conclusion – Pros
Excellent image quality when stopped down Essentially no lateral chromatic aberration Extremely cheap
Conclusion – Cons
Extremely cheaply built Harsh and distracting bokeh due to pentagonal aperture Vignetting at wide apertures on full frame (which only disappears at F3.5) Inconsistent autofocus in low light (most problematic when using large apertures)
Overall conclusion The Canon EF 50mm F1.8 II may be one of the cheapest lenses currently on the market, but its optics belie its lowly price. As befits a classic standard prime lens, it’s very sharp when stopped down (especially in the centre), shows minimal chromatic aberration, and has relatively low distortion; APS-C users will also benefit from extremely low vignetting. In most regards it comes very close indeed to its much more expensive bigger brother, the EF 50mm F1.4 USM, lagging marginally behind in corner sharpness at any specific aperture. The only real blight in imaging terms is the lens’s bokeh, or rendition of out-of-focus backgrounds, which is anything but smooth with a distinct tendency to render bright highlights as obvious pentagons (it’s a pity Canon didn’t choose to use a diaphragm with 7 or 8 blades instead of 5). Of course getting great optics for relatively little money means that corners have to be cut somewhere along the line, and in this case it’s in the build quality. The 50mm F1.8 II may not be the most flimsily-constructed lens ever made, but I can’t think of another currently on the market which can rival it for a sheer impression of plasticky-ness. This alone will put off some potential purchasers, who will likely gravitate towards the better-made F1.4 lens instead, but in truth it’s just fine for everyday amateur use. Of course the flipside of this is that it’s extremely light, and won’t add much strain on your shoulder carrying it around all day, so it’s a great option to throw in your bag for low-light shooting when travelling. The other slight fly in the ointment is the autofocus; the micro-motor system is a little slow and therefore not an ideal choice for moving subjects. More problematically, focusing can be inconsistent and inaccurate in low light, something that will be most obvious when shooting at large apertures. There’s also no full-time manual focus override for those users who don’t like to trust their camera’s AF system; again these issues are all reason to consider the F1.4 lens instead. Given the price, it seems reasonable to assume that this lens will overwhelmingly be used on APS-C bodies, and in this context it’s worth pointing out that it’s sharper than any of the EF-S lenses we’ve tested so far (the 18-55mm F3.5-5.6 IS, 18-200mm F3.5-5.6 IS or even the 17-85mm F4-5.6 IS USM, which is at its best at 50mm). We suspect full-frame users will on the whole be buying more expensive optics, but to overlook this budget option completely would be a mistake, as it can demonstrably perform very well even on the 21Mp EOS-1Ds Mark III (and therefore also 5D Mark II) at its optimum apertures. That F1.8 maximum aperture lets in more than four times as much light as a typical kit zoom, and so allows shooting in low light while keeping shutter speeds relatively high; this therefore provides a useful alternative to IS when the aim is to keep moving subjects sharp. It also enables the user to experiment with selective focus techniques impossible with slow zooms. So ultimately this is a lens which we’d encourage any Canon DSLR owner currently shooting with ‘kit’ zooms to try. The overall image quality when stopped down a bit is very impressive indeed, and the fast maximum aperture offers creative options which are well worth exploring (while sharpness, particularly in the corners, may not be the best wide open, the point is that you can get to F1.8 at all). It’s a pity about the build quality and harsh bokeh, but ultimately this lens hits a price:performance ratio that’s very difficult to beat.
| Posted in » Tokina AT-X Pro SD 12-24mm F4 (IF) DX review
Conclusion – Pros
Excellent sharpness across almost all of the range, even wide open
Benign distortion characteristics (easy to correct at 12mm, visually neutral from 15mm to 24mm)
High quality build
Well-implemented focus clutch mechanism
Constant F4 maximum aperture
Conclusion – Cons
Relatively narrow wideangle end (12mm vs 10mm of many competitors)
Rather prone to flare when shooting into the light
Complex chromatic aberration behavior
Relatively poor close-range performance
Slightly soft at 24mm
Overall conclusion
The Tokina AT-X Pro SD 12-24mm F4 (IF) DX is a lens that could easily be overlooked by buyers considering a wideangle zoom, simply because of its more limited angle of view compared to most similar lenses on the market. But perhaps because of its more modest aspirations, it comprehensively outperforms the other third party APS-C wideangle zooms we’ve tested recently, i.e. the Sigma 10-20mm F4-5.6 EX DC HSM and the Tamron 10-24mm F3.5-4.5 Di-II. It’s simply a much sharper lens, especially wide open, delivering consistently good results at almost all settings; it also scores well with respect to its distortion and falloff characteristics. These characteristics, coupled with the constant F4 maximum aperture, makes it much better suited to shooting interiors or in low light than similar lenses (with the exception of Tokina’s own 11-16mm F2.8), adding to its overall versatility. This from an extremely solid, well-built lens which feels like it would shrug off knocks capable of breaking less rugged designs, and which also has excellent operational characteristics; the zoom and focus rings are impressively smooth, and the focus clutch system is one of the better-implemented of its kind.
It’s not perfect, of course (no lens ever is), and does have a couple of imaging issues. Its otherwise excellent sharpness characteristics desert it somewhat when shooting at 24mm and apertures larger than F8, however we suspect most users will primarily be buying it for the 12-18mm range anyway. Lateral chromatic aberration can also be problematic – while fringing is really no worse than many other lenses we’ve tested, the concern is that it is difficult to correct in software when desired. Flare can also be a distinct issue, but in this regard we’d expect an improvement from Tokina’s new ‘II’ version of the lens (which owners of entry-level Nikon DSLRs such as the D60 will need to buy anyway, in order to gain functional autofocus). Finally imaging performance at very close focus distances is not particularly good; but again we’d not expect many people to be buying a wideangle zoom to shoot macros.
So overall the choice when considering a third-party lens in this class boils down to either the optical excellence of the Tokina, or the wider angle of view but compromised sharpness of its competitors (or at least those that we’ve tested so far). Now the difference between 12mm and 10mm is indeed significant; those 2mm cost 10 degrees in the diagonal angle of view (99º as opposed to 109º), so the question is whether you’re willing to sacrifice that ultra-wide perspective. But the rewards are, on the whole, worth it; the Tokina 12-24mm F4 simply produces superior images. If sharpness is your goal, it’s an option not to be overlooked.
Nikon D90 Review
Conclusion – Pros
Image quality comparable with its peers
Excellent viewfinder
Superb high resolution LCD monitor
Automatic chromatic aberration correction improves performance from all lenses
Punchy but not un-natural colors (and plenty of control if you want to change them)
Good dynamic range – and Active D-Lighting to help make the most of it
Useful in-camera RAW processing option
Excellent degree of customization (reversible dials and meter ease transition from other systems)
Fast Autofocus with useful control options
High sensitivity performance up there with the best we’ve seen
Sophisticated wireless flash commander built-in
Programmable FUNC button with useful list of functions
Configurable ‘My Menu’ (and option for FUNC button to access the top item on it)
Excellent build quality, tight shut lines, quality materials
Instant power on, very responsive in-use
Auto-focus assist lamp rather than requiring flash to be raised
Control over high sensitivity noise reduction
Customizable automatic sensitivity (ISO)
Easy to use playback / delete combination
Status LCD panel on top of camera (we still like them)
Fast continuous shooting mode
Good SD card throughput and USB 2.0 transfer speed
Extensive retouching features including D-Lighting, Red-eye reduction and distortion correction
Good battery life and precise charge-level indication
Dedicated help button provides in-menu assistance
HD video
Conclusion – Cons
Over-enthusiastic metering a little prone to blown highlights
Very soft (default) JPEG output compared to its peers
We believe more of the captured dynamic range could be incorporated into Jpegs
Menus getting long and complex (though well organized and differentiated)
Bundled software pretty limited
Arbitrary 100-shot limit on continuous shooting
Disappointing automatic white balance performance in incandescent light
In-camera RAW conversion could provide more control
Video capabilities limited in a number of ways
Overall conclusion
We described the D80 as a photographer’s camera and, despite the addition of video, the D90 appears to share that same ethos. On a purely specification level, it’s a highly competitive piece of kit, but it’s the way the features have been chosen and put together that make it the camera that it is.
The D90 viewfinder is amongst the best you’ll find on any APS-C camera and it sits above the highest-resolution screen we’ve yet seen on a camera of this class. The buttons are well chosen and sensibly positioned, and the two-dial interface is a pleasure to use. (Buyers coming from other systems can even reverse the operation of the meter and dials to make everything that bit more familiar).
The image quality, whether at base ISO or the higher settings, is excellent even if it can need a bit of tweaking of the internal settings to tailor the output to specific needs. While it’s understandable that Nikon would want to try to bring the processing settings into line with its more expensive cameras, it’s questionable how well the rather under-sharpened default output will serve the buyers of this camera. A little more contrast and saturation improve things, without any ill effects.
The early talk about the D90 was about its video capability and indeed it does record HD videos – good ones by digital stills camera standards. But don’t let that distract you, this is a camera which lets nothing get in the way of taking photos. Its degree of configurability results in long menus but they’re generally well arranged and color-coded to minimize the likelihood you getting lost in them. There’s also the option to create a menu of your most used settings (or list the most recently used ones, if you don’t want to spend time setting it up), and a status screen that gives fairly fast access to those key parameters that don’t have their own buttons.
Our only real worry about the D90 is the matrix metering, which seems to be so strongly connected to the selected AF point that it allows highlights to clip a bit too often for our liking. There is an option to fine-tune the meter (and assign a different amount of correction to each metering mode), if you find it a consistent problem.
The D80 was a very well respected camera, offering a feature set that seemed perfectly tailored to the enthusiast market – the D90 builds on this by including many of the options from the D300. The automatic Chromatic Aberration correction is just one example – without ever having to think about it, it instantly improves the results of every JPEG, regardless of the lens used. Picking the images apart to find differences between cameras reveals it’s not quite a half-price D300 but that was a camera we described at the time as being best semi-professional digital SLR on the market, setting the bar pretty high. After using and testing the D90 extensively, it’s hard to think of a better enthusiast-level camera.
Max flash sync speed
In previous postings I have mentioned that the specific settings for a photo aren’t often of direct value to us in figuring out the method of exposure. But the one setting that is of huge importance when using flash, is your camera’s maximum flash sync speed.
When the ambient light levels are low, then your shutter speed can vary appropriately, depending on what you want to achieve. But once you work in bright conditions, or have your subject against a bright background, then most often it just makes the best sense to work at maximum flash sync speed, as in that image above.
There is something very sweet happening at that point, and I believe it is imperative for every photographer that use flash, to know what is happening, and why. I would venture as far as saying that this blog posting contains some of the most essential information I can give you about flash photography.
So let’s work through some of the basics …
Let’s work through a hypothetical scenario where our subject is in shade, and our background is much brighter.
For the following tutorial, get your camera and lens out, with a speedlight so that we can go through some of the settings.
Let’s say our background exposure is 1/60th @ f11 @ 200 ISO
Now, it should be obvious that the following are all the same exposures:
* 1/60th @ f11 @ 200 ISO
* 1/125th @ f8 @ 200 ISO
* 1/250th @ f5.6 @ 200 ISO
* 1/500th @ f4.0 @ 200 ISO
* 1/1000th @ f2.8 @ 200 ISO
Manual flash / TTL flash
Manual flash
Firstly, flash could simply be a constant amount of light that is emitted from the flashgun. In the case of manual flash, there is NO control by the flashgun or camera, over the intensity or duration of the pulse of light from the flash unit.
This is manual flash. Photographers can control the output of their flashguns by adjusting the settings in fractions of the maximum possible output, eg, ¼ power, 1/16th power. It should be obvious that the absolute value of ¼ power will vary from flashgun to flash gun, as each model and make of flashgun has a different maximum power. Manual flash exposure is most easily measured by a handheld flashmeter.
With manual flash, four things control the exposure metering of our subject:
– the actual output level from the flashgun, (ie the ratio of the full power),
– distance from our light source to the subject,
– aperture,
– ISO.
Any of these four things can be used to control the amount of light falling on your subject.
TTL flash
The second way to control flash exposure, is as an automatically controlled flash burst. This flash output can either be controlled by the flashgun itself (usually called Auto mode), or by the camera in conjunction with the camera’s metering system (usually called TTL flash). When the flash is controlled by the camera, as then measured as the amount of light coming through the camera’s lens, it is called Through-The-Lens flash metering, (hence, TTL flash.)
For most purposes in understanding the basics of flash exposure with D-SLRs, there is little difference between Auto flash and TTL flash. So, as mentioned earlier, for simplicity’s sake here, we could group Auto flash and TTL flash together. (There are differences with pre-digital cameras and older flashguns, in how Auto flashguns interface with the cameras, and then the explanation is slightly more complex.)
Anyway, with TTL flash, the flash output is varied and controlled by the camera’s metering system. This means that for a certain range, our chosen aperture or ISO, or distance to our subject, does not influence our TTL flash exposure.
This is such a crucial point to understand about TTL flash, that I want to mention it again for emphasis.
With TTL flash, our chosen aperture or ISO (within a certain usable range), doesn’t affect our exposure – and in a sense becomes transparent to our exposure metering. What does affect our exposure, is the reflectivity of our subject, and how large our subject appears within our frame.
This is something that is difficult to comprehend at first, but is easily verifiable with your D-SLR. There, at home, you can photograph any subject in your immediate surroundings using a TTL capable flashgun. You can change your aperture from f4 to f5.6 to f8 … and your exposures should look the same. Similarly if you changed your ISO, your TTL flash exposures should look the same. The reason for this is that your camera and flashgun’s TTL flash metering system takes care of the basic flash exposure … and can do this within a certain range of chosen apertures and ISO settings. Your flashgun will emit more or less light as required for correct exposure, dependent on your settings … but your exposures should appear similar.
So, looking back at the four things which affect manual flash, you’ll notice that none of these, not distance, nor aperure, nor ISO setting, seem to have an effect on our flash exposure. (Within reasonable range of course.)
And it is in this, that the huge difference arises beween approaching metering for manual flash, and TTL flash metering.
The only way to control TTL flash metering, is with flash exposure compensation. You could control manual flash exposure with any of the four variables mentioned earlier on, but with TTL flash, you would have to change your flash exposure compensation.
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In these differences, the individual strengths of using manual flash, or using TTL flash, can be seen. And this will most likely affect which of the two kinds of flash lighting we end up using.
With manual flash, since the flash is a specific level, our subject’s reflectivity or our choice of composition (ie, how we frame our subject) has absolutely no impact on our metering.
This is a hugely important aspect of manual flash. Once we have our lights set up at a specific distance, and determined our aperture and ISO … then the subject’s reflectivity (ie, how much lighter tones or darker tones there are), have NO effect on our flash exposure.
However, with TTL flash, the subject’s reflectivity / tonality, and our choice of composition, WILL affect our flash exposure. And hence, we often need to control our flash exposure with the flash exposure compensation.
