July/August 2006 HelpLine

Be Sure Of Your Backup

    * 50 Ways To Lose Your Data
    * Stuck On Auto
    * From Film To Video

50 Ways To Lose Your Data

Before I answer your questions, I want to touch on a topic I’ve mentioned before—but one whose importance I can’t stress enough: backup! Image file sizes are getting bigger, storage mediums are carrying more data, and all of this leads to the potential of catastrophic failures.

A good friend of mine recently had the hard drive on his laptop fail. No amount of cajoling could revive it. This was his main image-editing computer. Although he had been following my advice of regular backups, there’s one thing that was still missing: he assumed his backup process was working properly. He didn’t test to make sure that if something went wrong with his online data, he could readily access his offline backup.

It turns out that his regular backup routine was only backing up some of his files. He ended up having to contract with a data recovery company to restore his files. In this case, it was to the tune of more than $1,000, and even then, several critical files were gone.

For some people, there’s the thought that “It won’t happen to me!”, but in reality, I think it’s a matter of when it will happen, not if it will happen.

I’ve mentioned a little envisioning exercise before: next time you sit down at your computer, close your eyes, wait a few seconds, then open them and imagine that your hard drive has been completely wiped out. What would you do? What did you lose? How important is that data?

Then, check to see if your backup is working properly. Try to recall important files, open them up in your image editor and verify that they haven’t been corrupted. Bottom line: if you value your images, you should evaluate your backup system.
Stuck On Auto

Q)  I’ve been enjoying my new digital camera. I’ve learned about histograms, flash and focus, and even a bit about composition, but I struggle with shooting modes. When it comes down to taking pictures, I fall into automatic mode all of the time. There are two settings that I’m trying to learn: aperture priority and shutter priority. When should I be using them?

Trish D.
Toronto, Canada


A)  It’s great that you’re reading the manual and trying, and the fact that you understand histograms will help you even more (the histogram sometimes can be more difficult for people to understand than aperture priority).

First, let’s review the basics so we can understand what these settings do. You control the amount of light reaching the image sensor through two basic adjustments: aperture and shutter speed. Aperture controls a diaphragm in the lens that’s similar to the iris in your eye. By opening and closing this diaphragm, you restrict the amount of light hitting the image sensor. The bigger the opening, the more light is let in. Aperture is measured in ƒ-stops, which represent a fraction, so the larger the ƒ-stop number, the smaller the opening.

The shutter is a mechanism for controlling how long the light passing through the aperture is allowed to land on the image sensor. The longer the shutter is open, the more light that lands on the sensor. Shutter timing is shutter speed and is measured in fractions of a second (or seconds for long exposures). These two settings are calibrated in cameras to allow you to easily control your exposure. For example, if you want to increase your shutter speed by one step, you’d need to decrease your ƒ-stop by one step.

When you’re using aperture or shutter priority, you’re using your camera’s auto exposure mode; however, you’re telling the camera that you want to pick one of the exposure settings and let the camera, in combination with the light meter, choose the setting for the other parameter. For example, you might set the camera to shutter priority (Tv or S) and choose a shutter speed of 1?125 sec. In this case, the camera will always take the picture at 1?125 sec., but the aperture will vary, depending on how the light meter reads the scene. Conversely, if you choose aperture priority (Av or A) and set the camera at ƒ/8, the camera will adjust the shutter speed to the proper setting as guided by the meter.

Why pick one over the other? Because aperture and shutter speed don’t control just exposure; they also control the look of the image. If you choose a fast shutter speed like 1?500 sec., you’ll stop action in your scene. So if you’re shooting sporting events, you might want to set your camera to shutter priority, use a fast shutter speed and freeze all of the motion in your photos. Or you might want the action blurred, so you’d force the camera to stay at 1?60 sec. (or longer). If you choose this mode when shooting water scenes and set the speed to a 1?2 sec. or longer, you’ll get that “smooth, blurred water” look.

Choose aperture priority when you want to affect depth of field. Depth of field is the range of distance from foreground to background where the image is in focus. If you set the aperture to a small opening, like ƒ/4, the range of objects that appear to be in focus will be shallow, with the subject and little else in focus. If you close down the iris to ƒ/11, the range of sharpness will increase to include much more than your subject.

Aperture priority, then, helps to control the depth of field. If you’re shooting someone outside with a busy background, you might want to have a shallow depth of field so that the background goes out of focus and becomes less distracting. Conversely, you might be taking nature photographs where you want both foreground objects and the mountains in the background to be in focus. In that case, you’d want a large depth of field. Since you probably wouldn’t be too concerned about shutter speed, the Av setting would work well.

In short, aperture and shutter priority really allow you to take more control of your camera’s auto-exposure capability.



From Film To Video

Q)  Years ago, I converted old 8mm movies to 8mm videotape by projecting to a converter box and taping with a video camera. I’d like to convert the film again with better quality by scanning the film digitally. Does anyone make a scanner that converts 8mm movie film to a digital video file?

Joe Cuomo
Monkton, Maryland


A)  There isn’t an 8mm scanner available, unfortunately-or at least one that would be available on a retail basis. If you think about the differences in size between a 35mm negative and an 8mm motion picture frame, you can see that 8mm is just a fraction of the still image size. Size difference aside, think of how long it takes to scan one 35mm transparency. Now imagine scanning multiple frames—maybe as many as 18 frames per second—and you can see how the requirements of an 8mm scanner would be a tall order.

Now, one could argue that with 8mm, you wouldn’t need the resolution requirements of a 35mm scanner. Since you’d probably output to traditional video devices, their pixel count is 720 x 486 for NTSC (the North American television standard) or 720 x 576 for PAL. (If you’re used to thinking in terms of dpi or ppi, think “less than 100 ppi.”)

There’s one more piece to the equation, however: each frame that was placed in the scanner would have to match the exact position of the previous frame. If any frames aren’t positioned properly, there would be a very distracting “film weave” as each frame of film jumps around when displayed in sequence. This isn’t a feature of current transparency scanners.

If you have the money, there are professional film scanners called telecines that are used for motion-picture transfers. They’re expensive (well over $100,000), however, and many don’t have an 8mm “gate” for transferring that size film.

Another option is to call a film transfer company to see if its telecine has an 8mm gate. In my experience, the charge for transfer would be several hundred dollars per hour.

There are many small labs that advertise the transfer of film to video, however. Check out what’s available in your area and give one a test to see what they can do.

If you have any questions, please send them to HelpLine, PCPhoto Magazine, 12121 Wilshire Blvd., Ste. 1200, Los Angeles, CA 90025 or helpline@pcphotomag.com.

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