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January 30, 2009
[REVIEW—NIKKOR AF-S 50mm f1.4G lens]
Price: $679
Stunning
The low-down: This is a 50mm Nikkor prime lens with a maximum aperture of f1.4. Auto focussing is by Nikon’s Silent Wave Motor and it works with the Nikon D40/60 range of cameras that are not fitted with in-body focus drives. The lens is chunky and feels reasonably well made, although it is far from luxurious in the feel of its surfaces or the operation of the manual focus ring. The lens is made in China and doesn’t feel quite as smooth as medium priced Nikkors from Thailand. The angle of view is equivalent to that of a 75mm lens on a film camera and that is close to ideal for a portrait lens, giving a pleasing perspective on a face. The wide aperture also makes it easy to shoot with a shallow depth of field and the out-of-focus light spots (called “bokeh” by the Japanese) are soft and attractive.
Like: The sharpness, colour fidelity and contrast of this lens, and the complete absence of distortion, make it a perfect optic for portraits. The closest focus distance is 0.45m, so it is not a macro lens, but the brilliance of the images means they can be cropped and enlarged without loss of detail.
Dislike: The auto focus seems, for want of a better word, languid. It is always accurate and the mechanism is indeed silent, but the lens cruises, rather than snaps, into sharp focus.
Verdict: After shooting hundreds of images, mostly pictures of people, we fell in love with it. It is more expensive than the zoom lenses that come as standard kit with DSLRs, which gives an idea of the relative quality of each lens type. A good prime beats a mediocre zoom any day. The Nikkor only fits Nikon cameras, and we found that the lens mounted on a Nikon D300 is a killer combination. The Sigma 50mm F1.4 EX DG HSM costs $80 more than the Nikkor and is better made, with what are claimed to be some desirable optical innovations. Choices, choices!
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[SURPRISED BY THE NEW]
In the short history of digital photography there haven’t been many innovations in camera design and technology. The compacts are replicas of simple point and shoot 35mm film cameras. The digital single lens reflexes are film cameras with the electronic sensor in the place of film.
The only new type of camera to appear has been the all-in-one superzoom with electronic viewfinder and, usually, a permanently fitted lens with a huge focal length range.
Now Panasonic has come up with a new type of camera that fits somewhere between the SLR and the superzoom. It is called the Lumix G1 and, like an SLR, has interchangeable lenses and, like a superzoom, has an electronic viewfinder.
Panasonic, along with Leica and Olympus, uses a sensor in their DSLRs that is smaller than that used in Nikon/Canon/Pentax alternatives. The Panasonic sensor is designated Four Thirds and its smaller area has meant that lenses can be made smaller. And since its first appearance serious photographers have hankered for a compact camera built around the Four Thirds electronics.
The Panasonic Lumix G1 is not exactly that camera. The new system is being called Micro Four Thirds and is applicable to pseudo SLRs, like the G1, or to smaller compact forms like the mock-up Olympus shown last year.
In appearance the G1 is a miniature DSLR, but it is not a reflex camera. There is no mirror-and-prism viewfinder, instead there is a new type of electronic viewfinder of extraordinarily high resolution.
Doing away with the swinging mirror in the camera body has resulted in reduced body thickness. And without a mirror to get in the way the rear element of the lens can be moved closer to the sensor which leads to a reduction in lens dimensions and weight. The standard 14-45mm lens (28-90 film equivalent) is 35mm shorter than a comparable Canon zoom and is 15mm smaller in diameter while having a wider maximum aperture.
At the moment there are only two lenses for the G1, the kit lens and a 45-200 zoom. Both are image stabilised and focus reasonably quickly with some hunting at the 200mm end of the longer zoom.
The G1 sensor is a 12 megapixel unit. That is a lot of pixels for a small sensor, but the pixel-to-area density is much better than on any superzoom.
The viewfinder is the key to the utility of this camera. Serious photographers won’t give up their mirror/prism optical viewfinders for an electronic gadget that is like looking at the subject through fly wire, but Panasonic has gone some way to dealing with this issue. Their EVF has a notional resolution of 1.44 million dots. That is good, but still no match for the mirror/prism.
With an RRP of $1650 the G1 is up against serious competition. Its selling point is its size and the fact that nothing has been left out in the miniaturisation process. It is beautifully made and a pleasure to use. Image quality is very good. Excellent original thinking from Panasonic.
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January 22, 2009
[REVIEW—CANON 50D DSLR and 18-200mm lens]
Price: $2800 “premium kit”
Fine camera, good lens
The low-down: This is a 15 megapixel single lens reflex, supplied with an 18–200mm lens with effective optical stabilisation. This is the evolutionary replacement for the 40D, with more pixels and a high resolution 75mm LCD to bring it into line with Nikon and Sony competitors. The 15mp sensor is matched to the new Digic4 image processor which Canon claims eliminates any noise problems resulting from increased pixel density. There is automatic dust removal. Construction quality is outstanding but ergonomics are not up to Nikon standards. Auto focus is fast and accurate, even with the supplied lens at its 200mm limit.
Like: Image quality is exceptionally fine, as we expect from this line of cameras. Skin tones are natural and colours are accurate. The long zoom lens works better than expected, focussing smartly at all focal lengths but with some distortion at the extremes. Contrast and sharpness are good.
Dislike: A three exposure auto-bracket for a camera in this price range is inadequate.
Verdict: Some reviewers have been harsh in their criticism of the 50D, generally concluding that its image quality is not as good as the 40D. We tried extreme pixel peeping and there does seem to be some fall-off in sharpness and contrast but we doubt that it will be a problem in the realm of real photography. We certainly wouldn’t recommend that anyone rush out to replace their 40D with the new camera because the difference is not that great. We would like to have seen a rethink of the ergonomics which are not brilliant. But for someone thinking of getting into the Canon DSLR system this is still a great camera. It is rugged, responsive and has a luxurious feel.
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[GOBBLEDEGOOK EXPLAINED – Part Two]
As we were saying… Some of our pals do us the honour of reading this page in Livewire every week, and then they crush the Imaging ego by saying they don’t understand a word of it. Well, here is part two of the digital photography glossary of terms.
RAW is what the word suggests. It is not an acronym, and when you shoot in RAW it doesn’t mean snapping in the altogether. It means recording the raw, unprocessed, uncompressed data from the sensor onto the memory card.
Not all cameras can record in RAW. Most compacts can’t, but all DSLRs can. The alternative to RAW is JPEG, which is an acronym and stands for Joint Photographic Experts Group. The industry group chose a Kodak devised system for compressing image data. The system involves a trade-off between file size and quality and so it is called “lossy”. Even when the camera is set to record JPEGs with minimum compression there is still some loss of detail, which to most people is imperceptible.
JPEGs also have the image processed in-camera, turning the raw data into a colour image. This may also entail some sharpening and noise reduction.
For the fussy RAW is the way to go because the uncompressed, unprocessed (largely) picture file is processed in a converter on the computer, using either the software supplied with the camera or a third party program such as the free Adobe Camera RAW Converter. (www.adobe.com/products/photoshop/cameraraw.html) Adobe keep this excellent program up to date to accommodate the latest cameras, which is necessary because not only are RAW files brand-specific, they are also model-specific.
FOCAL LENGTH of lenses can be confusing, particularly when applied to compact cameras. Because digital single lens reflexes are carry-overs from film antecedents the lenses for these cameras are still specified with focal lengths for 35mm film. But except for a few rarefied models most DSLRs have sensors about two thirds the area of a film frame. The mental arithmetic is simple – a 50mm lens (film terms) on a standard DSLR has the same angle of view as a 75mm lens on a film camera. With the Four Thirds system (Panasonic, Leica, Olympus) just double the number – a 50mm lens has the same angle of view as a 100mm lens on a film camera.
With compacts it is not so simple. These sensors come in a number of different sizes, which means that on one camera a focal length of 6.2mm engraved on the barrel is equal to a 35mm lens in film terms, while on another it is 7.6mm=35mm. All very confusing, so read the specifications on the makers’ web sites.
WHITE BALANCE is something that almost everyone leaves to the camera, which will have settings for Auto, Shade, Tungsten and Fluorescent light. At the very least you should know that these selectable settings are there because Aunty Edna doesn’t have to look jaundiced in the Christmas photos. Select Tungsten or Fluorescent in the white balance settings and she might come out looking in the pink.
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January 15, 2009
[GOBBLEDEGOOK EXPLAINED—Part One]
A CHRISTMAS card comes from a pal: "Happy Christmas," it says. "We read your column in Livewire every week even though we don't understand a word of it." Sadly, this is not the only instance of this ego-boosting-crushing reaction we have had to our immortal words. And we ask plaintively: "What is there not to understand?"
So, as an Ought Nine new year present we hereby provide a digital imaging glossary to be stuck on the fridge door.
PIXELS are the microscopic dots that make up an image. In theory the more pixels you have the more detail you will get in a picture, except that it doesn't quite work like that. Digital newbies think that more pixels must be better, but beyond a certain point more pixels are worse.
The camera sensor is covered with millions of tiny light receptors. With film the light receptors were the grains of silver halide that turned black when exposed to light but in the case of digital cameras each receptor generates a small electrical charge when it is excited by light. These charges are fed to the camera's image processor and turned into a picture made up of red, blue and green dots.
So why is more not better? NOISE, that's why. In this case noise is not what you hear, it is what you see. Even in their quiescent state the photoreceptors are putting out a very small charge which the camera processor interprets as black or randomly coloured dots, a bit like grain in film. With a big fat (relatively speaking) photoreceptor in a digital single lens reflex the true image information is a very strong signal compared with the spurious noise charge — its called signal to noise ratio.
Compact cameras have sensors the size of a little fingernail, crammed with photosites. Their signal-to-noise ratios are appalling, so makers build "noise reduction" into their image processors. But noise reduction blurs fine detail to obscure the grain and that means that desirable detail is also blurred. So putting more pixels on a tiny sensor is self-defeating. Every informed person knows this but the camera companies say that the first question customers ask a salesperson is: "How many pixels has it got?" It's like assessing the health merits of packaged food on the basis of how much sugar has been added — the more the better.
ISO stands for International Organisation for Standardisation. It sets the standards for measuring the light sensitivity of film and digital sensors. With film you were stuck with one sensitivity — typically I SO 100 or 200 for consumer film. With digital cameras the sensitivity of the sensor can be varied anywhere from ISO50 to 6400 depending on the camera. Using a higher ISO results in more noise, but compact cameras usually boast that they have an ISO rating up to 3200. At that speed think Seurat! You will need to stand well back from the photo to make any sense of the muddy mess of dots on the paper.
Coming soon: RAW, focal length and white balance demystified.
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Posted by terry at 11:26 AM | Comments (1) | TrackBack
[REVIEW-TAMRON AF 18-270mm f3.5-6.3 Macro zoom lens]
Price: $969
The longest zoom on the block
The low-down: This is an 18-270mm zoom lens that is image stabilised. Tamron calls it “The Ultimate All-In-One Zoom: Longest, Steadiest Lens On Earth”, which is one of those records made to be broken. It is available in Nikon and Canon mounts. When set to 18mm the overall length is about 10cm and when zoomed to 270mm the lens barrel telescopes and the length is about 19cm. Closest focussing across the entire range is 49cm. The aperture at 270mm is a slow f6.3. Construction quality is average – compared with the Canon 18-200mm it is a little rough.
Like: The sheer versatility of this lens makes you overlook its weaknesses. It is a pleasure to be able to walk around with a lens that replaces a bag full of lesser range zooms and primes. While image quality at the extremes is not wonderful the picture changes in the in-between settings where, from about 30mm to 180mm, image quality is good. Image stabilisation is effective, essential with such a long lens.
Dislike: Auto focus is slow, particularly at the long end of the range. It is not suitable for fast moving subjects. There is noticeable distortion which is just acceptable at wide angle, but the pincushion effect at the long end is so bad that it demands correction in software. Zoom creep is irritating.
Verdict: Assessing a lens like this puts a chap in mind of Dr Johnson who reckoned that when it comes to lady preachers and dogs that walk on their hind legs you don’t ask how well it is done, you are just astonished that it is done at all. Tamron has pushed the zoom range to extremes and that inevitably requires a trade-off in resolution, contrast and sharpness. That they have kept the compromises to a minimum is a credit to their designers. Does the versatility outweigh the limitations? Hmmm!
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January 01, 2009
PANASONIC LUMIX G1
We are currently testing the interesting PANASONIC LUMIX G1.
This is the new camera from Panasonic that looks like a single lens reflex, and is built around the Four Thirds sensor, as used in Panasonic/Leica and Olympus SLRs, but it is not strictly a single lens reflex.
There is no mirror/prism in the camera. The viewfinder is electronic, but a considerable improvement on the EVFs used in superzoom and other cameras. There is no more "looking through flywire" effect because the resolution of the viewfinder screen is extremely high. However it is still no substitute for a good mirror/prism system. There is some image noise in the viewfinder in low contrast light and, as with other EVFs, it is hard to judge tones and focus sharpness.
Eliminating the reflex part of the camera -- the mirror and prism -- means the entire system, lenses and camera body, can be made much smaller than conventional cameras. Put alongside a Canon 50D or a Nikon D300 the Panasonic looks very dainty indeed. However the body design is such that the camera is easy to hold, using the right hand moulded grip.
So far there are only two lenses available -- 14-45mm and 45-200mm [covering a film-equivalent range of 28-400mm]. The lenses are image stabilised. The lenses are sharp, with good contrast, and auto-focus is quick, although not as quick as with a true SLR. Exposure is generally very good.
The LCD screen is articulated, always a good feature on a camera. Ergonomics are fair but the miniaturisation of the system does involve some finicky buttons. The exposure/focus lock is particularly hard to find and use.
Watch this space for a more comprehensive review of this innovative camera.
Panasonic Lumix G1 |
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