Have a question about digital photography? Send it to me. I reply to as many as I can--though given the quantity of e-mails that I get, I can't promise a personal reply to each one. I round up the most interesting questions about once a month here in Digital Focus. For more frequently asked questions, read my newsletters from November, December, and January.
Demystifying Crop Sizes
I've used a film SLR in the past, and so I recall that when shooting a photo, you need to leave extra room around the subject if you want to print it as an 8 by 10 since the negative is a different shape. Now that I have a Nikon D90, I have heard that what you see on the screen is even more drastically different from what you can print out as an 8 by 10. So do I need to allow even more space when framing my subject?
--Pamela Deegan, Oshkosh, Wisconsin
It's true, Pamela, that the proportions of a standard digital photo, a 35mm negative, and typical print sizes are all different. The easiest way to show the variations in sizes is with a picture, so take a look at the composite photo linked here.
The full image is an 8-megapixel photo from my Nikon D200. Before I resized it for this article, it measured 3872 by 2592 pixels; by a happy coincidence, that is almost exactly the same proportion as a 4-by-6-inch print. If that's the size you're shooting for, you have to do virtually no cropping or correction. Almost all digital cameras use this aspect ratio. Notice that the green outline is somewhat shorter: That's the same photo cropped to 5 by 7. And 8-by-10 images are cropped even harder, as you can see from the red outline. So keep in mind that if you do plan to print photos at 8 by 10 inches, you will lose a lot of the original image in the process.
What Are These Mysterious Spots?
I occasionally see large spots or reflections, such as in this photo. Can you tell me what causes them?
--Dan Wright, Mt. Pleasant, South Carolina
What you're seeing is called lens flare, Dan. It's caused by a bright light source--usually the sun, but it can also be bright indoor lights--shining into your lens.
There are a few ways to minimize lens flare. You should avoid shooting directly towards a bright light source--keep it at least 90 degrees away from the direction your lens is pointing. If your lens came with a hood, use it. A lens hood keeps stray light from shining into the lens from the side.
Inexpensive point-and-shoot cameras are more susceptible to lens flare than digital SLRs. Higher-quality lenses have specially designed optics, including lens coatings, to minimize flare.
Oddball File Formats
I saved some old photos in the .mix format and my new program, Adobe Photoshop Elements, won't import them. Can you change a photo saved in .mix to .jpg?
--Barbara Heelan, Detroit, Michigan
The .mix format was used by the old (and no longer sold) Microsoft Picture It photo editor. Unfortunately, this format is pretty obscure. I had to search the Web to figure out what it was, and I was unable to find any major photo editing program that could read this format.
Your best bet, Barbara, is to track down an old copy of Picture It (assuming you no longer have one) and use it to save your images as .jpg files. You can probably find the program on eBay quite inexpensively, for example. This is a good reminder to be wary of proprietary file formats; some people are even reluctant to use their digital camera's RAW format for this very reason.
Is there a way to assign tags to images in the PNG format?
--Pat W, Newark, New Jersey
Yes and no, Pat. Don't you love it when I give you such a precise answer?
Technically, the PNG format has no provision for tags or keywords in the metadata region of the file. But some photo organizers let you add tags that are stored externally, in some sort of database. My favorite free photo organizer, Windows Live Photo Gallery works like this. You can tag any kind of image, from JPEG to PNG to TIFF to RAW. Photo Gallery stores the tags in the JPEG files, while it manages the tags in other files, like PNG and RAW, in its own database. For the most part, it all works seamlessly, and you'd never know the difference. The only time it'll be obvious that something funky is going on is if you try to search by tags outside of Photo Gallery, such as in Windows Explorer. That's when you'll find the PNGs can't be searched by tags.
I have often wondered if it's possible to remotely trigger the shutter the way I used to do with my 35mm camera using a flex cable. I'm currently considering the purchase of a SLR, and this will affect my decision.
--Zeon, San Diego
Sure thing, Zeon. Most digital SLRs, including models from Nikon, Canon, and Olympus, have a port for connecting a remote trigger. In addition, some cameras come with--or offer as an option--an infrared remote control so you can take pictures wirelessly. You can find a lot of information by using your Web browser to search on "[camera name] remote trigger."
Hot Pic of the Week
Get published, get famous! Each week, we select our favorite reader-submitted photo based on creativity, originality, and technique.
Here's how to enter: Send us your photograph in JPEG format, at a resolution no higher than 640 by 480 pixels. Entries at higher resolutions will be immediately disqualified. If necessary, use an image editing program to reduce the file size of your image before e-mailing it to us. Include the title of your photo along with a short description and how you photographed it. Don't forget to send your name, e-mail address, and postal address. Before entering, please read the full description of the contest rules and regulations.
This Week's Hot Pic: "America's Pride," by Ron Todd, Amissville, Virginia
Ron writes: "The Marine Corps Memorial in Arlington is a beautiful and serene place. It was even more so on this windy and cold evening with a full moon and the lights of Washington, D.C. reflecting from the clouds. The textures and setting were worth the battle with rush-hour traffic. I had to set my D80 to ISO 1600 since the scene is too big for flash of any kind."
This Week's Runner-Up: "Red Sun," by Katherine Forkner, Crescent City, California
Katherine captured this photo on California's North Coast with a Canon Digital Rebel XT and a wide-angle lens.
See all the Hot Pic of the Week photos online. Have a digital photo question? Send me[mailto:firstname.lastname@example.org] your comments, questions, and suggestions about the newsletter itself. And be sure to sign up to have the Digital Focus Newsletter e-mailed to you each week.
This story, "Frequently Asked Photo Questions for February" was originally published by PCWorld.