Digital Camera Settings: Color Space

There are a number of optional settings in the camera menu that can affect image quality later when you process and make prints. One has to do with the image “profile” in terms of color. In the matter under discussion here profile refers to a certain “color space,” or the type and range of colors that will be captured. 

Your digital camera probably has a number of “default”, or factory settings. One of them is called color space. But like many defaults, there may be optional settings you can make. The two most common color profiles are sRGB and Adobe RGB. The term profile refers to a certain set of characteristics that can be read by the microprocessor and displayed on the monitor.

Simply put, color space defines, in part, how the camera sees and processes a range of colors. The sRGB profile is a bit “tighter” in its color vision, offering rich, saturated colors, yet with a certain clipping of subtle hue differentiation. Adobe RGB is a bit wider in the color gamut it sees and records, and colors tend to be more neutral, and, some would say, more natural in their effect, yet in all Adobe RGB offers more subtle color differentiation.

The general rule is that if you are someone who processes their images in advanced software like Photoshop for prints or reproduction, choose Adobe RGB. This is the color space that simply records more color information, but assumes that you will process the image later. When you load an image into software to process you will have assigned a profile that the program will recognize. It is a pro type of profile and is often the one requested by publications and photo stock agencies for image submission. Some photographers change the default from sRGB to Adobe RGB in their camera menu and leave it there, and then perform any saturation and contrast changes later.

There is nothing inherently wrong with shooting sRGB, and in fact only advanced monitors will show you any difference. But if you want to immerse yourself in advanced shooting techniques and image processing, or your aim is to get images published in books and magazines or offer them for sale, go into the Color Space option in your camera menu and switch to Adobe RGB. If you shoot mainly for the web or sharing of some sort, then sRGB will be fine. Note that most monitors will not show any difference but pro monitors will; in fact, many allow you to split the view with one side being sRGB and the other Adobe RGB, and allow you to easily convert an Adobe RGB to an sRGB profile if you choose the image for web use.

The subtle tonal and color differentiation in this photo requires a color rendering mode that will capture all the various shades and tones it offers. The brighter tones such as the reflective glass and white umbrella should be separate and distinct, and the variations in red hues should be apparent. It is a study in color and tonal values that benefits from choosing Adobe RGB color space.

Settings: Adobe RGB color space: at ISO 200, f/6.3 at 1/200 second, RAW, 16-bit file.

This extreme macro shot relies on subtle differentiation to portray the various tones and shades of color. Since it was shot using RAW format, more saturation can easily be added if desired. Using Adobe RGB helps capture the subtle tones and colors, regardless of how the image might be processed later.

Settings: With a 60mm Macro lens, at ISO 320, f/2 at 1/800 second, Adobe RGB.

Most agencies and publishers will only accept Adobe RGB “profiles” for consideration. This overall view of Heidelberg, Germany, was shot specifically for “stock,” which means it was shot on speculation to be offered through sale through a picture agency. With an Adobe RGB profile the image offers more color differentiation and is the profile “language” that any potential client will seek.

 

Digital Camera Custom User Settings

You may have noticed markings on your mode dial such as C-1, or U-1. These are used to create customized camera menu settings that you can automatically recall and use for specific lighting or scene conditions. These can be as simple or as complex as you might want, and can combine a number of different setting combinations. The dials are best used for scenes and lighting conditions that you often shoot, but they are so easily set up that you can change them from day to day.

For example, you can program a set that would include a specific white balance, metering pattern, exposure compensation and exposure priority. That set might be Cloudy white balance, spot metering, minus 2/3 EV compensation and aperture-priority exposure mode: this might be apt for fall foliage shots.

Or, you could make a set of commands that include autoexposure bracketing with a plus/minus 1 EV spread; this could be used for making exposures for HDR shooting. And you might want to create a set for sports photography in an arena lit by tungsten light, which would include a specific white balance, continuous advance mode and shutter-priority exposure mode.

Each camera has a slightly different route to make these sets. Generally you create the set and then simply turn the dial to, for example, C1. You then confirm this group of settings as a user group on your camera menu using the OK button or similar. This stays in the camera memory and whenever you turn the mode dial to C1 those settings are automatically applied. Some advanced cameras allow you to "name" the group as well.

 Among the mode dial options on this Panasonic DMC-G5 are various exposure modes, Scene modes and Art filters, along with two Custom User setting modes, here indicated as C1 and C2. Once you program these mode settings the camera will automatically set whatever combination of Menu and control options you have assigned to it for the shot.

By programming a combination of settings and assigning them to a Custom User dial you can quickly get all the options you might ordinarily have to set individually for a specific subject or scene. For example, you might want to create a “landscape” User Custom setting that might include aperture-priority exposure mode, Daylight white balance, Center-weighted Averaging metering pattern and Adobe RGB color space. 

Settings: With a 28mm lens, at ISO 100, CWA metering pattern. Daylight white balance, aperture-priority mode at f/11 at 1/125 second.

Nikon D5500 DSLR: Lab Test & Review

The Nikon D5500 is a compact SLR system with an APS-C sized sensor and 24 MP resolution. It has a new and very fast AF system and some enhanced handling options.

The 24MP Nikon D5500 looks familiar: while a bit smaller and lighter than its forerunner, the D5300, the differences are marginal. The D5500 has the same image processor as the D5300 (EXPEED 4), but offers a somewhat higher ISO setting: the D5300 offered ISO 100 to 12,800 with an additional high (push) mode of ISO 25,600, but the D5500 offers ISO 100 to 25,600 as standard. Noise results, however, have improved.

The Nikon D5500 is an entry- or midrange level camera with no status LCD on the top. For image and exposure information the photographer has to use the LCD screen on the back. A mode dial on the right hand side allows for setup of exposure modes and special image effects. The “LV” switch next to the mode wheel activates the live preview on the LCD screen.

The D5500 has an optical SLR viewfinder system with a field of view of 95 percent.  To get a 100 percent field of view you have to use the electronic live preview on the articulating LCD screen. To toggle between optical and electronic view finder the camera has a large “LV” lever next to the mode dial on the top, which can be accessed very easily and comfortably. In addition, the camera has an eye sensor that will deactivate the LCD when the photographer looks through the optical viewfinder.

The Nikon D5500 has a 3.2 inch LCD with a resolution of 1,037,000 RGB dots. An 8-way control field is used for menu navigation.

The smaller body size and the lighter weight might be attributed to a function that was offered with the D5300--an integrated GPS system. Users of the D5500 will have to use Nikon’s optional GPS adapter GP-1/GP-1A in order to access geotagging.

The camera uses Nikon's Multi-CAM 4800DX AF system with 39 focus areas, including 9 cross-type sensors. It worked very quickly in our tests and keeps up with the continuous shooting mode that can deliver a maximum of 5 frames per second. Camera startup time is a little longer than the startup times of professional SLRs, but overall performance of the D5500 is very good.

Comments on Image Quality

Color: The color test chart was reproduced with a saturation of 100.6 percent, which is nearly perfect. The white balance system did a very good job: nearly all gray pattern of the test chart are located in the center although we noted a minor shift into the bluish, cooler color area. Only the brightest test pattern showed a shift into the green direction. As is typical for Nikon cameras, the blue nuances are boosted and over exaggerated (even though the mean saturation is on a lower level). Skin tones are reproduced very realistically and naturally. The differentiation of red colors is very good.

Sharpness: The D5500 showed an excellent performance in our resolution test with 3864 lines per picture height within the nominal resolution of 6000 x 4000. Images look crisp and clear without the artificial look of over sharpening effects. The camera showed some sharpness enhancement effects on contrast lines, but over- and undershot effects are on a very low level. The reproduction of fine details is very clean and crisp without Moiré or aliasing effects.

Noise: The Nikon D5500 showed a very good performance in our noise tests. The luminance noise level keeps way below 1.0 percent in images taken within the ISO 100 to 1600 range. The 1.0 percent line is crossed at ISO 6400, yet even at this speed it still creates very clean looking images. The highest ISO—25600--shows noticeable color noise artifacts and slightly reduced image details that have been reduced and smoothened by the filtering.

The dynamic range results are very good. The camera achieved a maximum of 11.6 f-stops and keeps this very high dynamic range level between ISO 100 and ISO 1600. Beginning at ISO 3200 the dynamic range drops significantly with higher ISO settings. Yet, with 9.62 f-stops at ISO 25,600 it achieves a high level for a camera with an APS-C sized sensor.

Comments on Video Functions

The D5500 is able to record Full HD videos and uses Apple QuickTime as the “container format” for its H.264 videos. It offers high frame rates up to 60 frames per second (50 frames in PAL mode). It also allows the user to shoot in cinema style in 24p mode (23.976 frames per second) and in reduced resolution modes with 1280 x 720 pixels or even VGA-resolution (640 x 424 pixels).

To start recording video, the photographer has to use the “LV” lever on the top to activate the live preview mode and press the additional video recording button. This recording button is located directly behind the photo shutter release button and is easily accessible.

The swivel monitor is very helpful when recording videos: the swivel joint on the left hand side allows rotating the screen even if the camera is mounted on a tripod. 

The camera offers manual exposure setup when recording video, including ISO settings. The camera records stereo sound with its built-in microphones on the top (near the built-in pop-up flash). An additional microphone can be mounted on the accessory shoe.

The D5500 offers a standard 3.5 mm microphone jack; sound level can be controlled by the photographer. The camera offers a special video recording information scheme on its LCD, which marks the 16:9 crop of the image when recording videos and also shows sound level bars. Using manual sound level control and these bars will avoid clipping effects due to over-modulated sound levels.

Comments on Video Quality

The Nikon D5500 showed very good video results. The ISO 12233 chart was reproduced with 797 lines per picture height when recording Full HD video (1080 lines per picture height) which is a good result for an SLR system with a video recording function. Aliasing or Moiré effects are missing, and combined with the AF-S Micro-NIKKOR 60 mm 1:2.8G ED lens, used for this test, the camera created very crisp and clear videos.

The color results are similar to our still photographic reproduction tests. Brighter nuances had a slight shift into the yellowish/greenish area, but most colors are reproduced very naturally. In contrast to photo mode, dark blue nuances show only a little over-saturation and the bright cyan is under-saturated.

Noise results in video mode are very good. At ISO 1600, dark gray areas begin to “flicker” due to image noise, but these effects are acceptable up to ISO 6400 mode (and can be reduced with anti- noise plug-ins in editing software like “Neat Video,” for example). Only the highest ISO speed settings of ISO 12,800 and 25,600 will create very noisy artifacts with unacceptable results. The dynamic range results in video mode are excellent: The Nikon D5500 achieved a maximum of 11.2 f-stops at ISO 400, which is a really high result.

Tests are conducted by Betternet, the TIPA (Technical Image Press Association) testing lab. I serve on the Technical Committee of the association.

Exposure Diagnostics: Check Your LCD Brightness Level

It is important that you ensure that the LCD on your camera reads out correctly. That way, when you review images after exposure you can be sure that they are a true reflection of what you have recorded on your memory card.

Within your camera menu is an item called “LCD Brightness.” You may not have seen it but it’s in there, usually within the Setup menu. Check your instruction book or toggle through the Menu until you find it. You will see a sliding scale of plus and minus. Open an image on the LCD from your memory card. Turn the brightness scale plus or minus using a command or control dial and see what happens. The image gets lighter and darker. If you have Live View you can do this while viewing an image prior to exposure. 

Make sure your brightness setting is right in the middle of the scale. Make a series of test shots at different settings (over- and underexposed, that is) and check them on the LCD. Then download the images onto a computer, and check them on the screen. Make sure the well-exposed image is the one made at the middle setting.

There are some instances when you might want to raise or lower the LCD brightness level. You might want to do this when shooting in extremes of brightness—either in very bright daylight when the monitor might be hard to read or in very low light when you need more illumination to work within the menu. However, you will not want any level of LCD brightness other than being centered on the brightness scale when shooting under normal lighting conditions. Also, be sure to check this scale if you had changed it to adapt to lighting conditions on a previous shoot. Once set the scale stays put unless you change it, even when you turn off the camera.

This is how this image of a set of dock pilings showed up after exposure on the LCD—too bright, right? Lowering exposure is indicated, but in fact doing so resulted in a very underexposed, unusable shot.  This is what can happen if you fail to insure that the LCD monitor brightness is centered. It pays to check this periodically, as it may have shifted without your knowledge or if you forgot to change it when you might have brightened it for viewing reasons on some other occasion. (By the way, the same goes for ISO settings—always check that it’s what you want for the shoot at hand. You may have been working in low light the night before at ISO 1600 and forget to turn it lower for work in daylight the next day.)

Here’s how the playback on the LCD looked with the brightness set correctly. You can imagine what it might have looked like if exposure was less—the subtle shades and colors would be lost. Doing a quick check on your LCD brightness level can make a big difference in how your images turn out and prevent unwanted exposure miscues.

Sensor Dust Problems: Detecting, Preventing, and Curing

Who knew that digital sensors would be magnets for dust? They are, acting like little static electricity machines that attract minute and sometimes grain-sized dust particles that are a pain in the neck. You can “spot” the particles out later (which record as black dots and streaks) using cloning tools and various healing brushes and blur tools, but the frustration of having to spot images is simply not a good use of time, especially when the problem can be eliminated or diminished with a bit of care.

Manufacturers have not denied the problem and many cameras now incorporate dust “cleaning” systems that turn on every time you start up the camera. Generally these “shake” the sensor in the hopes of vibrating the dust off; sometimes this works OK and other times you might have to use more drastic measures. The best bet is to prevent dust from catching on the sensor in the first place.

Dust is pernicious and can work its way inside the camera in more ways than one. Here’s some advice about keeping it to a minimum.

1) Always store the camera in a case or bag. It might look handsome on a bookcase or shelf but you are needlessly exposing it to ambient dust.

2) Never change a lens with the camera turned on. Having a charge across the sensor plane when it is exposed will act as a dust magnet.

3) If possible, change lenses inside a vehicle or changing bag, especially if there is any wind. This is where most dust problems occur. Turning your back on the wind to shield the camera when changing lenses does not seem to help: if you lack a changing bag, shielding it with a coat is better than nothing.

4) If you like to photograph outdoors, when shopping for a camera get one with a dust reduction (shake) system, and one that bills itself as having extra seals to prevent dust.

This shot looks “innocent” enough and seemed fine when  inspected on the LCD after exposure. 

Later, with close inspection, the dust nightmare it contained was revealed. This was at the end of a long day’s shooting with a loaner camera and many of the images were unusable as a result. (Note: enlarge this image on your screen to see the blizzard of dust it contains.)

An experience like this should  teach you a good lesson, as it did me. For some shots the dust had to be meticulously retouched in software. What a waste of time!

Note: If you look through the viewfinder and see dust you might not have dust on the sensor—it might be on the lens itself or in the viewfinder pentaprism ( the optical finder in DSLRs) or on the mirror. Check the lens, and if need be clean the front and rear element. Dust inside the lens cannot be cleaned without sending it to the manufacturer--this can be very expensive. If the pentaprism has the dust it can be bothersome, but that dust will not show up on your pictures. If it's on the mirror clean it very carefully with a commercial kit and remove the lens indoors to get access to the mirror--CAUTION: Be very tender when doing this as too much pressure or force could damage the mirror mechanism.

Mirrorless cameras, have no (optical finder) pentaprism or reflex viewing system. If the dust is not on the lens, any dust marks showing up on images means that there is dust on the sensor. Check and clean the lens itself first, both front and rear elements. Dust on the lens should be quite evident, as minute dust on the lens will usually not show up on the image.

The only way to know if you have a sensor dust problem is to take a picture and inspect it by using the magnifying tool in your playback menu, or download it and enlarge it (though that might be too late for that day’s shoot). It can be tough to see dust on your camera's LCD during playback. If you suspect you have dust, before you go out on your shoot make photo of a blank white sheet of paper and enlarge the image on a monitor.  Move around it and enlarge it  to check—this will make the dust spots quite visible.

If you do have dust on the sensor try restarting the camera (if it has a dust reduction system) a few times to see if you can have the system “shake” it away for you. If your camera has a “clean now”  feature you can use this instead of restarting it. A few cameras have a "dust delete" protocol, which creates a kind of mask to spot out dust from a series of recorded images with the same dust pattern. I find this to be a very hit and miss affair.

Lastly, you can try cleaning the sensor yourself with commercially available kits, although I would CAUTION you to be very, very careful if you go this route as damage can easily occur. You can send the body back to the manufacturer for cleaning if need be, which is perhaps the safest route, or take it to a certified camera clinic.  That’s your call, but if you clean it yourself you need to use the camera’s self-cleaning setup (this is not available on many cameras; if it is instructions will be available on the company's web site or in the instruction book) and be sure to use an AC adapter, because if the power goes out during the process severe damage could result. 

Get in the habit of checking each time before you go on an extended trip. Checking periodically, and especially if you have been photographing in the desert, at the beach or in windy conditions.