Raw or JPEG? File Format Settings for Best Image Quality

You have a number of file format options when making photographs with your digital camera. Each of us has an end use in mind when we photograph: web galleries and blogs, prints, or shares. The following recommendations are for the best image quality overall. Keep in mind that resizing or resampling is an easy matter these days, so why not get the best captured file and then alter it to your specific end use later? In any case, here are my recommendations to get the best image quality your camera can deliver.

Here's the back of a Pentax camera showing the menu for choosing "Image Capture Settings." This is where you choose the file format and compression. When this item is highlighted push the OK button (or in some camera toggle the 4-way controller to the right) and all the options are shown. In this illustrations JPEG "Large" is chosen with the lowest compression ratio.

If you shoot in JPEG format:

1. Choose the largest file size you can get. If you have a choice of various pixel resolutions choose the largest. Cameras give you the ability to choose among a number of JPEG file size images To get the best results choose the largest size as this insures that you'll capture all the information the sensor is able to record. 2
2. Choose the lowest compression ratio. Compression is a way for the system to gather more images on a given capacity memory card, but it tosses away information when it writes to the card and replaces that information with mathematical formulas, not "raw" image data.
3. Don't "tweak" the image processor in the camera with contrast or sharpness settings. These are fine for special effects in the camera, but you can do better with the image information later in the digital darkroom.
4. Don't use digital zoom. This actually crops into the sensor rather than getting optical information through the lens. Even if you use the largest available resolution (Large) and lowest compression you'll lose information.

Here's the back of a Sony alpha camera. Here the size of the image (highlighted in red) and the Image Quality selector are separated. The size here is a large JPEG. Selecting the Quality item will then allow you to choose Raw only, or Raw+JPEG.

If you have a camera that allows you to choose between JPEG and Raw format, do the following:

1. Choose Raw. Raw files allow for the most processing freedom and deliver the best quality image. It’s higher in bit depth (more information) and is not compressed, thus is called “lossless.” The only drawback to Raw is that you have to open and view and change the image file in special software, usually bundled with the camera that has a Raw mode option or a third-party raw processing software, such as Adobe Camera Raw.
2. If you have a choice of pixel resolutions in Raw, choose the highest pixel count. In most cases Raw automatically chooses the highest resolution your camera can deliver, but some cameras now offer a “small Raw” (s-Raw). This is offered to help speed workflow for those who do not need very large files but still want higher bit depth and no compression. For most of us this does not apply, especially when making our own prints.

In ye old days memory cards were expensive and images per card were often limited, both by capacity and budget. These days that’s almost a non-issue, so my best advice is: Shoot RAW+JPEG. That way you have a small and portable JPEG and a file you can use for prints. The camera records both simultaneously and the image will show up in both formats in your browser.  

Although the image resolution or file size is key, that's just part of the equation. Of course, exposure and lens sharpness and how the camera's internal image processor converts the data from the sensor to digitized image information all have a very important role to play as well.

Capture the "Water Flow" Effect

One of the more pleasing uses of shutter speed in landscape photography is recording the flowing motion of water in rivers, steams and even ocean waves. The combination of motion and stillness within the frame is quite intriguing: it "idealizes" the water flow as it opens up the imagination to the complex physics of the world.

There is no set shutter speed that will accomplish this effect for every shot, as the rate of flow will differ in each scene. A good starting point might be 1/15 second. The angle at which you photograph the motion will have a profound effect on the result. Shooting at a right angle (perpendicular to the subject) will enhance the motion; shooting at less than a right angle will require a slower shutter speed to get a similar effect.

copyright George Schaub

To get this flowing water effect I set the camera on a tripod and set the exposure mode at shutter priority at 1/8 second, a guesstimate exposure. I bracketed one stop either way for insurance and got three exposures: the set exposure (1/8 second), 1/4 second and 1/15 second. My guess was right: final exposure: f/22 at 1/8 second. Note that I focused on the foreground rock to insure sharpness throughout the frame (28mm lens).

 The main issue you might run into when going for this effect is too bright a light level. In other words, even if you stop the aperture down to its minimum, working at the desired slow shutter speed may cause overexposure. 

To get around this:

1)    Set the ISO to the lowest number.

2)   Because of the brightness level you might “run out” of aperture to control exposure. In bright light, even at f/16 or f/22, you might only get a reading of, say 1/60 second, which is too fast to attain this effect.

3)   If that occurs you can:

a)   Find a spot where the light level is lower (shoot in the shade) or

b)   Place a light reducing filter over the lens, such as an ND filter (which can help lower light levels by two stops or more, depending on the ND filter strength) or polarizing filter (about 1.5 stops less light.) 

4)   Mount the camera on a tripod or other steadying device. (Of course, if shooting near the edge of the water or even in it make sure the device is rock solid before letting go. I speak from experience.)

5)   Use a cable release or remote shutter release accessory. Lacking same use the short self-timer shutter release mechanism. This helps steady pictures.

6)   Start at 1/15 second and go progressively slower in shutter speed. Use bracketing: set the camera in TV (or S on some cameras: shutter priority mode) and it will bracket with shutter speed settings.

7)   If you are close to the effect you want but are slightly overexposed, shooting in RAW format will give you a 1 to 1.5 stop allowance that you can correct later in processing. Any more overexposure beyond that will usually not be recoverable.

Fisheye Lenses

While an acquired taste, fisheye lenses certainly offer an interesting point of view. Named after the bulbous shape of the eye of a fish, which is how the front glass of the lens protrudes out, these lenses offer radical points of view unmatched by any other optics. The angle of view they offer can go up to nearly 150 degrees (and wider), resulting in extreme distortion at the edges and inclusion of subjects that you could never see in one glance.

There are two types of fisheyes: rectilinear and spherical. As their name suggests, they crop into a rectangular frame or offer a circular view, respectively.

On offer are two classes of lenses, “prime” and “auxiliary,” the former being those that mount directly to your camera body and those that screw over your “normal” lens via the filter threads. Optically there’s no competition, with primes being much sharper, but an auxiliary lens can open the door to fisheye photography in a much more affordable manner. There are also direct mount fisheyes that require you to shoot using manual control (they do not link up with the camera’s autoexposure and focusing systems), which fall in a price range between the two types mentioned above.  

Fisheyes offer incredible depth of field, from inches to infinity at even middling apertures, so focusing is certainly not challenging. The main challenge is figuring out just what to include in the frame; it’s likely that your first encounter with them will get you a bit dizzy!

copyright George Schaub

A trip around Times Square in New York with a circular 6mm fisheye yielded some fascinating points of view. Fisheyes offer, to say the least, a skewed view of the world, but given the right subjects and scene can offer a fun and exciting point of view. You probably are better off trying an auxiliary or affordable prime before you go for a more expensive option, although having a dedicated prime lens makes for much less work in terms of exposure, and delivers overall better image quality.

Settings: At ISO 800, f/5.6 at 1/60 second. Focus is generally not something to worry too much about unless you are shooting very close to a subject. Depth of field with these lenses can stretch from inches to infinity with even middle aperture settings.

copyright George Schaub

This shot was made with an auxiliary fisheye screw-in lens. Although image quality is not near as good as a prime, it can give you a look into what fisheye lenses offer. Note the reflections on the circle around the outside of the image space, a typical issue with this type of lens. This is easy to retouch out later, but flare (internal reflections) is common with auxiliaries.

In-Camera Contrast Control

Photographers have always struggled against high contrast. The main problem was the materials used for recording and their inability to adapt to high-contrast light, where the exposure gap between bright and dark areas was too wide to capture in one exposure. Given that overexposure in digital photography is the worse of two evils, photographers often had to accept that some shadow details (in dark areas of the scene) would be lost to underexposure. There now exist sophisticated in-camera processing algorithms that can save the day.

Known as Active D-Lighting, DRO (Dynamic Range Optimization) and other monikers, it all goes under the general heading of Tone Compensation control. There are two variations on this: one drops the brightness of the highlights slightly and the other opens up, or adds more light to the shadows. The former might be dubbed Highlight Tone Priority (or something to that effect) that acts on the highlights alone with a lesser effect on the shadow areas. Frankly I like my highlights with some sparkle, and have found this tends to dull images somewhat. 

This barn interior was quite dark and is a good test for this “shadow-opening” tool.  A spot reading was made from the brighter areas—the windows in the back—and exposure was locked. This shot was made with no curve compensation. 

The latter, Active D-Lighting (Nikon) or DRO (Sony), etc., actually changes the “curve” or values of the shadow areas and allows you to retain rich highlights while adding more light to darker areas. You can do this in processing later using advanced editing programs, where it’s known as Highlight and Shadow control, or in Photoshop as Recovery and Fill, respectively, or by using advanced curve controls. But if you don’t have access to this or just want to do it in the field, use DRO and I think you’ll be happy with, and amazed, at the results.

A second exposure was made with Dynamic Range Compensation (Sony camera) turned on. This magically brought more light into the dark (shadow) areas without adversely affecting the highlight.

Many cameras have degrees of settings for this control. I encourage you to test to see when this might go overboard and form halos and other false looks to the shadow areas. I generally keep it on Low or Medium: High seems to be excessive and not worth it.

Settings: Both images: At ISO 1600, f/9 at 1/60 second, with and without in-camera curve compensation.