Auto ISO, Making Stills From Video, and More Reader Q&A

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 April, May, and June.

When to Use Auto ISO or Change It Yourself

My camera lets me set the ISO on automatic. If I use a fixed ISO, are all of the other settings automated, or is everything fixed as well? When is it desirable to use the Auto ISO setting?
--Hugh Wright, Somerset, Massachusetts

As you might know, Hugh, the ISO setting controls how sensitive the camera is to light. The higher the ISO, the easier it is to take photos in low light situations, but the "noisier" your pictures will look. It's like the "grain" you might have seen in film photos.

When you set the camera on Auto ISO, the camera will try to automatically increase the ISO when you take pictures in low light. The other exposure settings depend upon whatever mode the camera is in. If you set the camera on Auto or Program mode, for example, you won't have to worry about setting the shutter speed and aperture, either. (For more information on controlling exposure in Program and Auto mode, read "Master the Hidden Power of Your Digital Camera's Program Mode.")

The Auto ISO mode is convenient for times when you are taking snapshots and don't want to worry about messing with camera settings. But if you are trying to be creative and want to dial in a particular shutter speed or aperture, an ISO that changes on its own can be annoying (and counterproductive). Finally, don't forget about that digital noise--if you want the sharpest, clearest photos possible, dial in the lowest ISO and leave it there.

Shooting the Moon

What setting should I use to get good photos of the moon?
--Emily Jackson, Baltimore, Maryland

As a rule of thumb, you'll get good photos of the full moon by using what's called the Sunny 16 Rule. To use the Sunny 16 Rule, put your camera in Manual exposure mode and set the aperture to f/16 (hence the "16" in the name of the rule). Then set the ISO to 100 and dial in a shutter speed around 1/100 second. If your camera's ISO doesn't go any lower than 200, use that setting and try a shutter speed around 1/200 second.

Making Stills From Video

I accidentally took some shots in my camera's movie mode. They were supposed to be some landscape photos of trees and snow, so there's very little movement. Is it possible to turn them into stills?
--Margot Brunbauer, Jefferson, Georgia

Yes, you can definitely pull stills out of video, Margot. Almost any video editing program should have a command that lets you save a single frame of video as a JPEG photo. If you don't already have a video editing program, you can download the free Windows Live Movie Maker. Launch Movie Maker, open the video clip, position the cursor over the part of the video you want, open the ribbon's Home tab, and click Snapshot.

Keep in mind, though, that a still taken from video will never be quite as sharp as a photo. The still will be limited to the video's resolution, which (even if your camera shoots HD video) will be far, far less than the resolution of the camera's photo mode.

What is the Alpha NEX-5?

I'm thinking about buying a Sony Nex5 camera. Can you tell me what the difference is between this camera and a DSLR? They are not calling it a DSLR. So confusing!
--Rose Keller, Claire City, South Dakota

You're right, Rose--this is a bit confusing. There's a new kind of camera in town, and it's neither a point-and-shoot nor a digital SLR. Instead, it has elements of both.

First, a little background: A digital SLR is so named for its single-lens reflex mechanism. There's a mirror that directs light through the lens to the viewfinder until you press the shutter release. At that moment, the mirror swings out of the way so the light can hit the sensor and expose the photo.

The Sony Alpha NEX-5, like a handful of similar models from other companies, has interchangeable lenses like an SLR, but is a mirrorless camera like a smaller point-and-shoot. Compact, interchangeable-lens mirrorless cameras are a new innovation in digital photography, and as of right now there are only a handful of examples available for sale. You can read a full review of the NEX-5 right here at PCWorld. Spoiler alert: It got a very positive four stars.

Choosing the Right Format for Scanning Photos

I scanned a photo and then tried to improve it using Adobe Photoshop Elements. Then I noticed that the file was named Lily.pdf, and Elements would not recognize it. What did I do wrong?
--D.C. Nelson, Tampa, Florida

It sounds like you might have chosen a setting in your scanner software that indicated you were trying to scan a document, rather than a photo. If your scanner lets you indicate what kind of image you are scanning, be sure to choose "Photograph" (or something similar) from the document type options, or to save the scanned photo as a JPEG image when you are done.

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 800 by 600 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: "New Tulip," by Nichole Bengtson, Markesan, Wisconsin

Nichole says that she took this photo with her Nikon D40 just as the sun was setting.

This week's runner-up: "Jungle Sunset," by Aitijhya Mallick, West Bengal, India

Aitijhya used a Fuji FinePix S2000HD to take this photo in West Bengal, India.

To see last month's winners, visit our June Hot Pics slide show. Visit the Hot Pics Flickr gallery to browse past winners.

Have a digital photo question? E-mail me your comments, questions, and suggestions about the newsletter itself. And be sure to sign up to have Digital Focus e-mailed to you each week.

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