February 22, 2009

Cleaning Your Camera's Lens

Microfiber cloth, blower brush, lens tissue, lens fluid

Keeping your camera's lens free from smudges, fingerprints, water spots and dust makes your images sharp and clear and saves you the time of later trying to remove the flaws they create in the picture. You need only a few simple supplies to manage this: a blower brush, a microfiber cleaning cloth, lens cleaning fluid and lens tissue. You can often buy all four of these in a kit from your local camera store.

Start by using the blower brush to dust off any dirt, sand or other debris on the lens. You don't want any grit on the lens when you use more vigorous cleaning methods or you could make a scratch in the lens coatings.


Then use the microfiber cleaning cloth to polish away any smudges or smears on the lens.
Do not use the cleaning clothes designed for eyeglasses. They may contain solvents that could damage the coatings on your camera's lens. Use light pressure and a circular motion. You can also breathe on the lens to fog it before wiping with the cloth. Check your results by holding the lens at an angle to see if any marks remain.

These two steps are usually sufficient to make your lens clean and sparkling. Occasionally, though, you will end up with a stubborn water spot or a greasy fingerprint on the glass which won't come off easily. Now it's time for the lens cleaning fluid and lens tissue.

First, tear out a piece of lens tissue. Do not use regular facial or bathroom tissue or paper towels; they are too harsh and may scratch your lens. Gently wad up the tissue. Then squeeze a single drop of lens cleaning fluid on to the tissue. Carefully wipe the lens in a circular motion from the center outward, paying attention to the spot you are trying to remove. If necessary, use a second piece of lens tissue to dry off the glass. When you are finished, your lens should be pristine.

Only clean your lens when it needs it. Too much "polishing" can wear away the coatings on your lens over time. Generally, a simple dusting and occasional wipe with the microfiber cloth will be enough to keep the glass clean and shining.

JPEG, GIF or PSD?

Kiery

In my last post I talked about the different picture file formats that digital cameras can create. If you are editing your digital photos with computer software, you may be confused about which file format is best in this situation. Here's the scoop.

First, a recap of the JPEG ("jay-peg") format: it saves your picture in a smaller package (file size) by compressing the image data. Doing so lets your camera save more pictures in the same space on your memory card or hard drive. The draw-back is that this compression actually results in some of the picture information being thrown away. If your photo is compressed too many times, too much information is discarded and your picture quality suffers. For this reason, it's generally not a good idea to use the JPEG format when editing your photos. But JPEG is appropriate for saving pictures in your camera, emailing pictures to friends or posting pictures on a web page.

GIF format (pronounced either "jif" like the peanut butter or "gif" with a "g" like in "goat") is best used for graphics like logos and pie charts. It can use only 256 colors in its files, which makes them nice and small for the internet, but does not generally produce realistic results for photos. (JPEG format uses up to 16.7 million colors.) So GIF format is not commonly used for digital photographs.

PSD (pronounce each letter like "IBM") format is specific to Adobe Photoshop products like Photoshop Elements and the professional version of Photoshop. In order to create, display or print PSD files, you must have a Photoshop program on your computer. If you are editing your images using a Photoshop product, saving a copy of your picture in PSD format before you begin gives you the best quality. PSD format is not compressed, so no information is thrown away during the saving process. PSD format can also use 16.7 million colors, so your photo keeps its realistic appearance. But you will need to save your edited result in a different format (JPEG or TIFF, for example) if you want to share it with someone else who does not have a Photoshop program.


So each of these file formats---JPEG, GIF, PSD---is appropriate in some situations but not in all. Use JPEG files for photos in email and on web pages, PSD files for editing photos with Photoshop products and GIF files for logos and other simple graphics that have few colors.

February 16, 2009

JPEG, TIFF or RAW?

Anacortes Harbor Boats

Digital cameras can save your photos using one of three different file formats. All digital cameras can save photos as JPEG (pronounced "jay-peg") files. This file format is universal. You can view it on a computer screen, email it, add it to a web page, upload it to an online photo lab, or deliver it to your favorite photo store.

JPEG files are "compressed." This means that some color information is eliminated (lost) when the picture is saved in order to create a smaller file. A smaller file size takes up less room on your memory card or hard drive so you can save more photos.

You specify how much information is lost by the quality setting you select in the camera menu. Some cameras use words like Fine, Normal and Standard for quality choices. Others use three, two and one star or other symbol. The best quality is always the least compression, so pick the maximum number of stars or the finest quality.

TIFF (pronounced "tiff") files are not compressed. They contain all the information in the original photo. This means that the file size is much larger than even the best quality JPEG file, usually about three times bigger. You might think that this would mean the picture quality would be three times better, but that's not the case. Most of the time, you can't see the difference between a best quality JPEG version and a TIFF version of the same scene. So you are sacrificing storage space without gaining an improvement in the appearance of your image.

The boat image above when saved as a best quality JPEG file is 4.2 megabytes. The same photo saved as a TIFF file is 18 megabytes, more than four times the size!

I recommend that you don't use TIFF format for saving your digital photos in the camera. You might need to use TIFF format if you are sharing photos with someone who is adding them to a newsletter or other printed publication. But usually a JPEG file will work just as well.

RAW files are completely different from either TIFF or JPEG files. Both TIFF and JPEG pictures have been developed in your camera and are ready to view on your computer or print at a photo lab. RAW files have not been developed; they are "uncooked, unbaked, raw," like take-and-bake pizza. In most cases, you can neither see the RAW file on your computer screen nor print it until you have used special computer software (called a "raw converter") to develop the picture yourself. A RAW file is akin to a roll of undeveloped film which die-hard photographers would process in their own darkrooms. They couldn't see the picture until it had been developed.

So if you are just getting started with your digital camera, I recommend you ignore the TIFF and RAW quality settings and stick with the best quality JPEG file format. You will simplify your life and still get great photos!

February 9, 2009

Get Sharper Photos, Part 2

In my previous post, I told you about a "hidden" feature of your camera's shutter button: the halfway down press and all the way down press. Paying attention to this feature can help you speed up your camera and get a sharp photo.

There's another trick hidden in your shutter button. Have you ever taken a photo in which the background turns out nice and sharp but the subject turns out blurry? You can use the halfway press of the shutter button to prevent this problem.


Focus on background produces a blurry bottle

First, point your camera at the subject you want it to focus on. This positions the subject in the center of the picture. Now press the shutter button halfway down to ask the camera to get ready to shoot. Doing so makes the camera focus on your subject. You can confirm this by looking at the LCD monitor for a green square over your subject.

Once the camera beeps to tell you it is ready, keep your finger on the shutter button while shifting your camera left or right to place the subject on the side of the picture instead of in the middle. Then press the shutter button the rest of the way to take the photo.



Focus lock on bottle creates a sharp subject and blurry background

Congratulations! You've just used a technique called
focus lock. Pressing the shutter button halfway down sets the focus; keeping your finger on the button while you recompose your photo locks the focus at the correct distance. Now your subject is sharp and the background is blurry.

Get Sharper Photos


Many digital photographers tell me they have trouble getting sharp pictures with their new cameras. There are two things that likely contribute to this.

First, because of that alluring LCD monitor on the back of the camera, we now frame our pictures by holding the camera away from our body so we can see the photo in the screen. It's much harder to hold anything steady at arm's length rather than close to our body. So if you have a digital camera with a window or electronic viewfinder (a miniature LCD screen in the eyepiece), try framing your picture by looking through the camera traditionally...with your camera pressed against your face. This will steady the camera and give you sharper photos.


The second likely cause of blurry photos is related to the shutter button. All autofocus cameras (and that includes all digital cameras) have a two-stage shutter button: halfway down and all the way down. When you press the shutter button halfway, you are asking the camera to prepare to take a photo. The camera's computer focuses the lens, adjusts the exposure and color, and maybe even charges up the flash. When the camera is ready to take a photo, it alerts you with a beep. It may also show a steady green or orange light next to the viewfinder (green for no flash, orange for flash) or green squares on the LCD monitor. Then you can press the shutter button the rest of the way down to take the photo.

If you practice this halfway down and all the way down on the shutter button, you will not only get sharper photos. You will also speed up the camera. By preparing the camera before you take the picture, it will be all set to capture the moment when you press the shutter the rest of the way down.

February 2, 2009

High ISO Settings & Noise

Many cameras allow you to adjust the sensor's response to the available light. This setting, called ISO or Sensitivity depending on your camera, lets you get a brighter picture in dim conditions or a sharper picture when you aren't using flash.

Blurry indoor picture without flash at ISO 80

Sharp indoor picture without flash at ISO 1600

But there is a price to pay if you choose too high an ISO setting. You may notice colored speckles in your photo, especially in dark areas or sections without details such as a plain wall or sky. These speckles are visual "static," like the "snow" you see on your television screen when it is tuned to a channel not available in your area. You can see black and white dots on the TV but not the actual image. Noise in your digital photo is like that; it's visible but not actually picture information.

Indoor picture without flash with camera on tripod

The higher the ISO or sensitivity setting, the more likely your picture is to contain noise. Compact cameras generally produce more noise than SLR cameras at the same ISO settings. Compare these sets of images from the still life photo above. Both cameras are from the same manufacturer and both have the same number of megapixels. The images taken at ISO 100 look identical---no noise. But the compact camera photo shows more noise at ISO 1600 than the SLR camera image which is "cleaner" and "smoother" at the same setting.



Noise is hard to eliminate from your pictures after the fact. So use the lowest ISO or sensitivity setting possible to get the best quality photos. If your subject is stationary and you can place your camera on a tripod or other support, use the lowest ISO or sensitivity setting in dim conditions and you will still get a sharp, clear photo. If your subject is moving and a tripod isn't feasible (such as for photos of indoor sports), raise the ISO setting but realize that your picture will have some noise. Still, a sharp photo with some noise is preferable to a blurry one with no noise!