Tag: Why shoot raw?

Which camera settings matter when you shoot raw?

Almost all DSLRs come with plenty of options governing aspects of image quality. They almost all affect JPEG output but which of those settings and options matter when you shoot raw? We’ll look at this briefly in this article and in more detail later.

Exposure settings matter, whether you shoot raw or JPEG

The exposure of a given scene will be determined by these settings:

  • Shutter speed
  • Aperture
  • ISO setting

(The ISO setting in digital photography is not entirely straightforward and will perhaps get its own article. For now, we’re keeping things simple.)

As you’d expect, aperture, shutter speed and ISO setting all make a difference to the images that your camera records, whether you shoot raw or JPEG.

Secondary camera settings: do they affect raw files?

A DSLR’s menu system will offer control over other aspects of your image, whether you’ve told it you’re shooting raw or JPEG:

  • Sharpness
  • Contrast
  • Saturation
  • Colour mode (Adobe RGB, sRGB)
  • White balance

Sometimes you’ll see picture controls that change many secondary settings together. For example, your camera might offer an option like “Vivid”, which sets saturation higher and might also affect contrast and/or colour mode. These controls might also change the way colour appears, including small shifts in hue, sometimes emulating certain types of film.

The questions

Which of these secondary settings, if any, affect your raw files? Which of them should you be concerned about when shooting raw? And, again assuming you shoot raw, do they affect any other aspect of your photography.

Before answering them and explaining the answers, let’s categorise everything inside a raw file as being one of two things.

A note about raw files

Simplifying somewhat, everything inside a raw file is either a measurement of the light falling on a part of the sensor or it’s a note about camera settings. You could say that it’s either data (the values for light on the sensor) or metadata.

Let’s say that you take a shot on a current 24-megapixel DSLR. Inside the resulting raw file will be roughly 24 million values representing the light that fell on the sensor during the exposure, one value for each sensor element, or sensel. We can consider all this stuff to be the data that’s eventually turned into an image in your raw converter.

The metadata is a record of things like the shutter speed you used, the aperture, the type of camera, the type of lens you used, the white balance and sharpness settings, which saturation you’d specified and so on. Lots and lots of stuff, only some of it documented publicly by the camera manufacturer.

Some answers

So which of the secondary settings listed above directly affect the data in your raw file?

The answer is: not a single one. Think of there being a note in the raw file that says: this photograph was shot with sharpness set to high and contrast to minimum, noise reduction set to zero and colour space set to Adobe RGB 1998; colour temperature was 5500K and the green-magenta bias was 30% magenta. Most raw converters, including Lightroom and Aperture, read the note and display large parts of your metadata but the only thing they use to influence their initial versions of your images is the white balance information. Everything else—including all the other secondary settings listed above—is ignored. Even the white balance setting is used only for the initial rendering.

Despite the presence of the metadata “note” inside your raw file, none of the 24 million values recorded by your 24-megapixel camera to represent the scene itself were directly affected by those secondary settings.

When you shoot JPEG, things are very different; each and every secondary setting above has a chance to affect each and every pixel of the JPEG. In the case of white balance or contrast, it is almost guaranteed to affect every pixel, often in a way that might limit the changes you can cleanly make later. That doesn’t mean JPEGs are bad or unusable, particularly if you’re in complete control of your light and white balance—it just means that the raw converter inside your camera is making decisions that it might be best to leave for later.

To be continued…

Although the secondary settings have no direct effect on the raw file, they do affect the histograms you see on the back of the camera. As a photographer, you might use those histograms to change the exposure settings (shutter speed, aperture, ISO) that you choose, perhaps as a result of exposure compensation that you dial in. The story isn’t over. We’ll revisit this topic soon.

And speaking of data and metadata…

The metadata

You can get all future articles by e-mail or RSS (both are free) and you can call us on 0333 577 5703 to book your own Lightroom course or to book a support visit. Visit the main blog page here. Have fun shooting!

Stephen Shankland on shooting raw

In a recent article, Cnet’s Stephen Shankland makes some interesting points about raw files vs JPEGs in your photographic workflow. Here’s one that everyone should consider and which we continually emphasise to photographers:

If you’re converting a raw image with software, you not only get more computing horsepower than a camera offers, you get algorithms that are updated.

He’s absolutely right. Put differently: raw files from several years back can look incredibly good when processed using the best of today’s raw converters—much better than they ever did when they were first taken.

JPEGs produced by expensive professional cameras, even recent ones, shot in difficult conditions (low light, mixed lighting, high contrast) are completely outclassed by raw files from the same camera, taken at the same time, processed in today’s best raw converters. When you tell the camera that all you want is a JPEG  file, you have to make decisions that are often better left till later (things like sharpening, contrast, colour space, white balance, noise reduction—none of these settings affect the raw file in any way) or ask the camera to make them for you. In many cases, the decisions you make are difficult or time-consuming to reverse later and have a permanent effect on the quality of your photographs.

Today’s raw converters deal with colour fringing, overexposure, underexposure, sharpness, noise, detail and resolution much better than most cameras’ JPEG engines. Whether you shoot professionally or for pleasure, if you’re serious about image quality, choosing to shoot raw makes sense and costs just a tiny amount of disk space.

Yesterday’s gone but you’ll have gathered the point of this post: the raw images you shoot today are likely to look even better in tomorrow’s raw converters. To start with, all you need to do is tell your camera to shoot raw—and if you don’t know what to do with a raw file yet then set your camera to shoot raw plus JPEG and store the raw files safely away somewhere. They’re your digital equivalent of film negatives and there’ll come a time when you’ll be very pleased that you still have them.

White balance in raw vs JPEG, part 1

A traditional reason given for shooting raw (if you can call any aspect of digital photography “traditional”) is to be able to set white balance in post-production rather than during the shoot.

Claim

The old argument goes like this: when you shoot (particularly events, concerts, weddings…), you have enough to worry about without having to add white balance concerns to the mix. Why rely on auto white balance or set custom white balance using large grey cards for each type of light? You’re better setting it after the fact, taking the occasional shot using a small grey card in it but not having to fiddle with the camera settings. This argument was often advanced by proponents of a raw workflow, who claimed that this approach only worked when you shot raw, not JPEG.

Counter-claim

Others now claim that you can shoot JPEG and take the same approach—set white balance when you’re back at your computer, in a single click, as if you’d shot raw. They say that it’s just as easy and you can even use the same white balance tool.

Facts

Here’s what you need to know.

  1. Just as easy but not as good. Yes, it’s just as easy to use the one-click white balance tool with a JPEG but compare the result with a raw file shot in the same conditions and you’ll see significant differences in colour: the JPEGs can look distinctly unconvincing by comparison.
  2. The more challenging the light, the bigger the differences. If you’re shooting in low light and particularly if that light is tungsten (regular indoor lightbulbs), your results can end up looking a little rough; if you’re shooting JPEG, they’re can get very rough. You’ll know this already if you shoot conferences and events in ambient light and deliver colour results. It’s just as easy to click and change white balance in post-production with a JPEG but it’s much harder to look at the results with anything but disappointment.
  3. Challenging light conditions are not uncommon. Current digital cameras struggle when there’s a strong imbalance between red, green and blue light in scene, particularly if there’s not much light around to start with, overall. For example, if you shoot events in ambient light and deliver colour work, your files have very little blue colour information in them because tungsten light provides mostly orange and yellow. (You won’t see things that way at the time—your own internal white balance routines are much more sophisticated than those of your camera.) When you get the images back to your computer and set white balance, that tiny amount of blue information needs to be amplified to make the images look colour balanced and that process can introduce noise and colour shifts that make the images look a little flat, even with a raw file. With a JPEG, things are worse because of the way the files are compressed. The same thing can apply at dawn or dusk (lots of blue light) or in the mixed light you find at concerts and nightclubs.

Coming soon in part 2, some examples of raw-vs-JPEG white balance corrections—some will be extreme, others less so. You’ll be able to see the differences between raw and JPEG quite clearly.

And a quick update on group training

We visited several potential venues in London last week and we’re working out figures and catering costs. Things are looking very good for January and February, with places (and gift certificates) available later this week. More news to follow shortly—please pass on details of our site to anyone you think might be interested. Meanwhile, we’re still taking bookings for one-on-one training sessions at your studio, office or home. Mail us and we’ll work out a course structure and schedule that suits you: develop@shootraw.co.uk.