Digital Camera Principles and Tips

Using your Camera

The principles of getting good images with a digital camera are almost entirely the same as those you should apply with a film camera. Quality depends on focus, light level and associated settings, and composition. You need to spend three or four hours with a new camera and its manual trying to learn to manage it and taking pictures witrh different settings. Some things to keep in mind:

• Use the highest quality setting for your camera that is still JPEG for most work. This will give you flexibilty in your choices for using the images. You may have some achival work where you need an uncompresed raw or TIFF mode, but this is usually the rare exception. You'll need to figure out how to have your camera power-up in high resolution JPEG. (This is not easy on some cameras, like the Olympus ones on campus.) Try not to ever use the lower resolution JPEG modes.
• Hold the camera to your eye for composing and shooting with your arms close to your body. Do not use the viewscreen on the camera back unless you have no other choice (like shooting over an obstruction). Professional grade cameras wont allow the viewscreen to be used for previewing. Camera shake is the most important cause for poor focus. Holding a camera away from your body is a recipe for a poor image. If you must do it, take several (5 or more) and hope at least one is acceptable. Use a tripod if you can.
• Learn to adjust the ISO setting of your camera. This is like being able to switch between 100, 200, 400, etc., speed films at a moment's notice. The higher the number, the less light is required to create the image. But, the higher the number, the grainier the image. Try to keep it low, but if your speed drops below 1/30th and/or the lens is shooting wide open producing little depth of field), you'll need to raise the ISO setting. SO, for daytime work, try ISO 100 and use 400 at night as a general guideline and adjust.
• In bright light, shade the lense. Otherwise you'll get odd circular shapes on the image.
• Don't always use the autoexposure settings of your camera. Figure out what is the main subject in an image. IF it is lighter than the rest of the image, underexpose (go to -1 stops or so.) If your main subject is darker than the background, overexpose (use +1 or so).
• If you use a "Smartcard," and the camera has trouble with it, try rubbing the gold surface lightly with a clean pencil erasure.
• Take lots and lots of pictures.

Downloading images

The techniques for downloading depend a lot on your particular gear. Ask IT for help if you have a new setup. Use a picture management program, such as Adobe Album in Windows or iPhoto on Macs. Set up your computer so that attaching the camera automatically loads your management program. See the above linked pages for more detail. Set up your program so that there is an easy way to pop an image into Photoshop. Both Album and iPhoto allow you to connect to a service bureau to order prints. The quality you'll get is very good.

Photoshop Image Improvement Techniques -- Stuff you should do to every image

Photoshop is amazing. It has so many wonderful tools, filters, and other capabilities that you could study it for a year and still not know all of it. But there are a few techniques that you should always (well, almost always) start with. Generally, start with the following steps:

1. Do an initial Save As so you're not actually changing your original.

2. Crop the image to what you want. Close-ups are culturally popular now. Be creative. Don't just center the main subject. If a person is looking right, have them left of center so you dfon't suggest something's missing. Try not to have the horizon vetically centerred. Try different crops. Use the rectangular selection tool if you intend to print using the final image size set for your final output. This is actually a tricky little detail. We often want to print images, but sometimes we want a 4"x6", and other times we want 5"x7" or 8"x10" etc. The ratios of these dimensions are all different. You'll often start with pulling down inder Image to Image Size and adjusting resolution to 300 dpi for prints and adjusting width and height up or down to create enough pixels for the crop. After finishing the sizing, sedlect the rectangular selection tool and adjust the fixed size settings. Then do your selection and click the check box in the menu. If you wish to e-mail or web post your image, the techniqeus are a bit different. See the discussion below.

3. Try the normal image adjustments. Use Image -> Adjustments -> Auto Contrast. Similarly, try Auto Levels and Auto Colors. Each can be undone. Manually adjust Levels if needed. Levels is often easier to work with than Brightness/Contrast.

4. Sharpen the Image with an Unsharp Mask. To do this, Select Filter -> Sharpen -> Unsharp Mask. In the dialog window that opens, you will need to set 3 settings. A good normal starting point is to set LEvel at 80%, Radius at 2 Pixels, and Threshhold at 2. If you set the level too high, the image will appear grainy.

5. Save your image before printing.

Preparing Images for e-Mailing in Photoshop
(Both iPhoto and Album can e-mail from inside the management program.)

If you wish to e-mail images, follow the steps above in Photoshop, with the following variations:

• In step 2 above, when in the Image Size dialog, set the resolution to 72 dpi. Set the width and height using whatever aspect ration you want. Do your cropping in whatever sizing you want. Just remember, the larger the image, the longer it will take to send and receive.
• When saving, choose File -> Save For Web ... In this dialog, save as a JPEG. Adjust the quality slider to balance file size and quality. Remember where you save your stuff so you can attach the file in your e-mail program

Preparing Images for the Web in Photoshop
(Both iPhoto and Album can e-mail from inside the management program.)

Preparing images for the web is very similar to preparing them to e-mail. You should follow the instructions for Photoshop Image Improvement with the following variations:

• In step 2 above, when in the Image Size dialog, set the resolution to 72 dpi. Set the width and height using whatver aspect ration you want. Do your cropping in whatever sizing you want. Just remember, the larger the image, the longer it will take to download.
• When saving, choose File -> Save For Web ... In this dialog, save as a JPEG. Adjust the quality slider to balance file size and quality. Make sure you save your work directly into your web authoring folder. This must be done before you place the file on a web page inside Dreamweaver.
• NEVER resize an image in Dreamweaver. Web authoring programs do not resize as well as Photoshop, and the person viewing your site will still have to wait for the entire original to flow to them before the resizing happens.

More info to come. This page is a work in progress!

Author: Bob Fry

June 28 2004