Sigma SD1 / SD1 Merrill In-depth Review
Real world RAW advantages
Shooting RAW on the SD1 brings all the usual advantages - you can fine-tune processing individually for each shot, adjusting such things as white balance, brightness, and colour tone. It's therefore the format of choice if you're after the best possible image quality from your camera (and let's face it, there's little point in buying the SD1 if you're not). Perhaps the SD1's greatest strength in RAW is its exposure latitude, with RAW files containing considerably more highlight data than JPEGs.
Highlight recovery - studio scene
The SD1 behaves distinctly differently to most other cameras with regards to its ability to recover highlights from RAW that are blown in the camera's JPEGs. With conventional Bayer-sensor cameras we normally expect to see about a stop of luminance information in the highlights, but with ever-decreasing colour inaccuracy (as individual colour channels clip sequentially). The SD1 behaves somewhat-similarly at ISO 100, but switch to 200 or higher and it surpasses this dramatically, offering an extra stop of full-colour information in its RAW files that's simply not used in the JPEGs. This means that, at ISO200 and higher, the highlight range available in RAW at least matches the best APS-C DSLRs.
In the examples below we show how this looks using our standard studio scene. We've shot in JPEG+RAW firstly with correct exposure, then 1 and 2 stops overexposed. We've then pulled-back the RAW files to compensate, using the Exposure slider in Sigma Photo Pro. We're showing side-by-side crops from the Q60 colour checker chart in the upper right of the scene, comparing the overexposed JPEG and the recovered RAWs at ISO 100 and 200. Note that in the 'correctly-exposed' version of these shots, the lightest tones are approximately 1/2 stop from clipping in JPEG.
ISO 100, JPEG
ISO 100, RAW + SPP
ISO 200, RAW + SPP
|1 stop overexposed||+1 EV / -1 EV in SPP||+1 EV / -1 EV in SPP|
|2 stops overexposed||+2 EV / -2 EV in SPP||+2 EV / -2 EV in SPP|
In this example, at ISO 100 overexposure by a stop results in clipping of the lightest tones in the chart on the camera's JPEGs, but this data can be recovered accurately from the RAW file. However 2 stops overexposure and recovery is a complete no-go; some luminance information can be retrieved, but colour information is lost across much of the chart. In contrast, at ISO 200 and 2 stops overexposure, the results are essentially identical to overexposing ISO 100 by one stop. This means that you'll get maximum latitude for overexposure at ISO 200; we'd estimate you can expect to recover at least 1.3 stops above the JPEG clipping point with full colour accuracy. This in turn means that in bright, contrasty conditions we'd recommend using ISO 200 by default.
Real-world highlight recovery
Here we're showing a couple of examples of how the SD1's RAW highlight recovery can benefit your real-world shooting.
This is all very impressive stuff on the face of it, but it has to be kept in context. The SD1's huge RAW highlight recovery ability stems as much from the relatively-limited JPEG highlight range as anything else - the RAW files don't necessarily contain very much more highlight data than those from competing SLRs. We'd actually prefer to see that data used in the camera's JPEG processing, to give better highlight rendition (and therefore more usable images out-of-camera). This would also offer a more-accurate indication of what's in the RAW file when playing back your images.
RAW files for download
Here we provide RAW files, both from the review and the sample shots we take, to allow you to apply your own workflow techniques and see whether your experiences match ours.
Feb 21, 2013
Jul 6, 2012
Apr 10, 2012
Apr 9, 2015
QuickStories is integrated into the latest version of the GoPro app and automatically creates 'stories' using the video clips you've shot during a day.
Journalists photographing a protest in the US Capitol building claim they were told by Capitol Police to delete photos and videos of arrests.
The Meizu Pro 7 Plus secondary display can be used for music playback, date and weather-related information, or as viewfinder when taking selfies with the rear cameras.
Nikon is marking its 100th anniversary in many ways, including the creation of a new scholarship program for 'future visual creators' in the USA and Canada.
Take one Digital ELPH (or IXUS), rotate it vertically, add a fully articulating LCD and a lens with a camcorder-like focal length, and what do you get? Why, the Canon PowerShot TX1, of course. In this week's Throwback Thursday we revisit Canon's one-of-a-kind hybrid stills/video camera.
Just in case there was any doubt in your mind, here's the definitive video proof that yes, a $50,000 cinema camera beats the pants off a $50 camcorder in a side-by-side test.
Photographers who fly frequently in the US may want to finally invest in that TSA Pre-check status: in standard security lines, cameras and all other electronics larger than a smartphone will need to be placed in a separate bin for screening.
Images have appeared which claim to show Nikon's forthcoming D850 DSLR, the development of which was announced this week. If genuine, the pictures indicate that the D850 will offer illuminated controls and a tilting LCD screen, but no built-in flash.
To celebrate the Daguerreotype Achromat 2.9/64 lens' successful Kickstarter campaign, Lomography has announced a chrome-plated version of the lens in Nikon and Canon DSLR mounts.
Nikon just released four new firmware updates, adding features and fixing bugs in the D600, D610, D750 and the KeyMission 80.
It probably hasn't made your landscape photography bucket list just yet, but there's a good reason to visit Idaho. Here are 9 must-visit locations in this beautiful state.
Oops... Adobe accidentally leaked their unfinished Lightroom-powered cloud-based photo editor 'Project Nimbus' to some Creative Cloud users yesterday.
Storm chaser and award-winning photographer Mike Oblinski just released his latest time-lapse, and it is absolutely stunning.
Looking to level up your video capture capabilities without buying a whole new camera? Blackmagic's Video Assist 4K is well worth considering, despite a few flaws and its lack of 4K/60p support.
We're big fans of Fujifilm's fast-growing GFX system, and the GF 110mm F2 lens is no exception. Positioned as the system's classic portrait lens, its optics are just as impressive with non-human subjects as well.
Nikon turns 100 years old today, and the company is celebrating with a wacky music video, some tributes to its history, and a new vision presented by president Kazuo Ushida.
Phottix just released the Premio Parabolic Umbrellas series, replacing their Para-Pro line with a stronger, deeper and better made set of parabolic umbrellas.
The Moto Z2 is Motorola's first dual-camera smartphone and, compared to its predecessor, comes with a number of improvements and new camera features.
Researchers at Stanford have revealed a new '4D camera system' built for robots. The system is based on the same light field tech that allowed Lytro cameras to refocus images after they were taken.
If you want 'beautiful rendition' from your lenses, follow this simple rule: only buy classic low-element prime lenses with lead glass elements—everything else is junk.
In an interview with CNBC, Leica Chairman Andreas Kaufmann said he dreams of a 'true Leica phone,' and hinted at what's next for the Leica and Huawei partnership.
Wildlife and nature photographer Peter Mather tells the story behind this exceptional shot of a mama grizzly and her cub searching for salmon in Yukon, Canada.
Popular YouTube channel TastyTuts has put together this 33-video Beginner's Guide to Adobe Photoshop—a godsend for anybody who wants to learn Photoshop from scratch.
The long anticipated replacement for the popular Rode VideoMic Pro is almost ready for shipping. The price of the upgraded VideoMic Pro+ will be £290/$300 when it goes on sale in mid-August.
A new iOS app called Explorest wants to help you find new locations to shoot. It's limited to Singapore for now, but the app is packed full of useful location scouting features.
Nikon's D850 development announcement is extremely light on details, so we assembled a wish list of upgrades and features we'd love to see.
Nikon has announced the development of the long-awaited replacement to its full-frame D810: the D850. Nikon says that the D850 will build on the strengths of its predecessor and offer 'new technologies, features and performance enhancements.'
Lens manufacturer Voigtlander has introduced a 65mm F2 macro lens for Sony E-mount that it says "rates as one of the finest in the history of Voigtländer."
The UK released a preview of their upcoming drone safety regulations, and it looks like drone pilots will have to both register their device and pass safety awareness tests.
National Geographic photographer Bob Holmes talks about light, and why you need to learn how to 'see' and not just 'look' at your subject.