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 August, September, and October.
I want to print high-quality 8-by-10-inch color pictures. What are the correct camera settings and printer specifications to achieve this output?
--George Bauer, Denver
Here is the quick answer, George: You need at least 3 megapixels to print a good 8 by 10, so pretty much any camera manufactured in this century is up to the task. Likewise, any inkjet billed as a photo printer can make a decent print for you.
There's a longer answer too, of course. Most inkjets print between 200 and 300 dots per inch, so that's where the 3-megapixel number comes from (1600 pixels x 2000 pixels = 3.2 million pixels). Since most cameras qualify for those basic specs, you should read reviews (like the ones here at PC World) to differentiate cameras based on image quality.
Beware USB 1.1
I have an old computer that works fine, but I've run out of room to store photos. If I get an external hard drive, will it work on a USB 1.1 port or do I need USB 2.0?
--Ernie Tevebaugh, Lakewood, New Jersey
I have some bad news for you, Ernie. While some external hard drives support slow USB 1.1 connections (you'll need to read the system requirements carefully), most require USB 2.0. And for good reason: If you do add a USB 1.1-compatible hard drive to your aging PC, transferring your photos will be so slow that it would probably be more efficient to store the files by writing their 1s and 0s down on a piece of paper by hand. I definitely don't recommend a USB 1.1 hard drive.
Mysterious Photo Sizes
Whenever I e-mail pictures to my local newspaper, they reply that the size is too small--I need to send it at the original size. I never change the size, so I am confused as to what to do. I use Gmail. Should I use a different program?
--Gene St Clair, Pelham, Massachusetts
This is tricky, Gene. Gmail does not automatically resize photos, so I am guessing that your original photos really are too small to begin with.
Here's one way to find out: Open your My Pictures folder, right-click a photo you want to e-mail and choose Properties. On the Details tab, look for Dimensions. If you see a number like 2592 by 3872, that's 10 megapixels--plenty big. If the number is very small, like 1024 by 768, that's less than a megapixel and won't be big enough to satisfy your newspaper.
As I explained when answering George's printer question, you can multiply the two photo dimensions to find the number of megapixels. You should ask the newspaper how big submissions need to be, but I'm guessing they want at least 3 megapixels.
If you want to eliminate Gmail as a possible culprit, you could try using another free e-mail client, like Windows Live Mail.
AD/AF Lock vs. Shutter Button
I'm new to digital SLRs, and would like advice on why I would want to use the AE/AF lock. I have gotten used to setting focus and exposure with a half press of the shutter button on my old point-and-shoot camera, so I don't see the value of this button.
--Arnold Victor, Lincoln, California
It turns out, Arnold, that a half-press of the shutter does not lock exposure on many digital SLRs. Instead, it locks the focus only. You'll want to check your SLR's user guide to see how yours behaves, but I bet that's the case. If you want to lock both exposure and focus at the same time, you'll use the AE/AF button. Just want to lock focus, so you can recompose the scene? Use the shutter button.
I should point out that some digital SLRs let you customize how both of those buttons work--explore the camera's setup menu to see if you can adjust them to your liking.
If you look at the following photo, you can see some fuzzy pixels around the faces of people. What did I do wrong?
--Donna M. Smith, Amsterdam, New York
Digital photos--at least those saved in the JPEG format--are affected by a quality setting when the image is saved. Lower quality settings make for smaller file sizes (so you fit more photos on a disc or memory card, for example) but decrease the visual quality of the image. At the extreme, image quality can be absolutely atrocious, as in the image that you sent me, Donna. There are two ways this loss in quality can happen.
Your digital camera could be configured to save the photos you take at high, medium, or low quality. I highly recommend digging out the manual and figuring out how to set the camera to its highest level, and then leave it there.
Also, if you open a photo in an editing program and then save the changed file, the program will again use a quality setting to save the photo. Every time you resave the photo, you are reapplying the quality setting, which is like making a photocopy of a photocopy. Even at the highest image quality, you're lowering the visual quality of the image a little every time. I suggest you set the quality level in your photo editor as high as possible and minimize the number of times you edit and resave your photos.
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: "Agnes James," by James Lewis, Nashville
James writes: "This was a candid I took of my teacher while I was staying in Dresden, Germany. The shot was a little underexposed and the color balance was off, so I worked on it in Photoshop. In addition to some basic editing, I added some Diffuse Glow in a layer with partial opacity and let the original eyes shine through. I used Canon EOS 300D Digital Rebel."
This Week's Runner-Up: "Corn Stalks," by Margaret David, Jamestown, New York
Margaret says that she took this photo in her backyard as the sun set over the corn field. She used a Nikon CoolPix 885, and she used a flash to illuminate the stalks in the waning light.
This story, "Frequently Asked Photo Questions for November" was originally published by PCWorld.