What Can You Do

Photography Masterclass

Photography Masterclass Online Course

Get Instant Access

Pay attention: If you're having problems, the first thing you should do is stop using that memory card. Don't take any more pictures. Don't do anything with the card until you've figured out what's wrong. Your second line of defense (your first line is to be sufficiently careful with your cards that you avoid problems in the first place) is to do no harm that hasn't already been done. Read the rest of this section and then, if necessary, decide on a course of action (such as using a data recovery service or software described later) before you risk damaging the data on your card further.

Now that you've calmed down, the first thing to check is whether you've actually inserted a card in the camera. If you've set the camera in the Shooting menu so that Shoot w/o card has been turned on, it's entirely possible (although not particularly plausible) that you've been snapping away with no memory card to store the pictures to, which can lead to massive disappointment later on. Of course, the No CF card message appears on the LCD when the camera is powered up, and it is superimposed on the review image after every shot, but maybe you're inattentive, aren't using picture review, or have purchased one of those LCD fold-up hoods mentioned earlier in this chapter. You can avoid all this by turning the Shoot w/o card feature off and leaving it off.

Things get more exciting when the card itself is put in jeopardy. If you lose a card, there's not a lot you can do other than take a picture of a similar card and print up some Have You Seen This Lost Flash Memory? flyers to post on utility poles all around town.

If all you care about is reusing the card, and have resigned yourself to losing the pictures, try reformatting the card in your camera. You may find that reformatting removes the corrupted data and restores your card to health. Sometimes I've had success reformatting a card in my computer using a memory card reader (this is normally a no-no because your operating system doesn't understand the needs of your 40D), and then reformatting again in the camera.

If your Compact Flash card is not behaving properly, and you do want to recover your images, things get a little more complicated. If your pictures are very valuable, either to you or to others (for example, a wedding), you can always turn to professional data recovery firms. Be prepared to pay hundreds of dollars to get your pictures back, but these pros often do an amazing job. You wouldn't want them working on your memory card on behalf of the police if you'd tried to erase some incriminating pictures. There are many firms of this type, and I've never used them myself, so I can't offer a recommendation. Use a Google search to turn up a ton of them.


I recently purchased an 8GB Kingston memory card that was furnished with some nifty OnTrack data recovery software. The first thing I did was format the card to make sure it was OK. Then I hunted around for the free software, only to discover it was preloaded onto the memory card. I was supposed to copy the software to my computer before using the memory card for the first time.

Fortunately, I had the OnTrack software that would reverse my dumb move, so I could retrieve the software. No, wait. I didn't have the software I needed to recover the software I erased. I'd reformatted it to oblivion. Chalk this one up as either the ultimate irony or Stupid Author Trick #523.

A more reasonable approach is to try special data recovery software you can install on your computer and use to attempt to resurrect your "lost" images yourself. They may not actually be gone completely. Perhaps your CF card's "table of contents" is jumbled, or only a few pictures are damaged in such a way that your camera and computer can't read some or any of the pictures on the card. Some of the available software was written specifically to reconstruct lost pictures, while other utilities are more general-purpose applications that can be used with any media, including floppy disks and hard disk drives. They have names like OnTrack, Photo Rescue 2, Digital Image Recovery, MediaRecover, Image Recall, and the aptly named Recover My Photos. You'll find a comprehensive list and links, as well as some picture-recovery tips at www.ultimateslr.com/memory-card-recovery.php.


Usually, once you've recovered any images on a Compact Flash card, reformatted it, and returned it to service, it will function reliably for the rest of its useful life. However, if you find a particular card going bad more than once, you'll almost certainly want to stop using it forever. See if you can get it replaced by the manufacturer, if you can, but, in the case of CF card failures, the third time is never the charm.

Replacing Your Clock Battery

In addition to the large rechargeable lithium ion battery that provides most of the power for your Canon EOS 40D, a second battery nestles in the same compartment to provide enough power to retain your current settings and preferences, as well as the local date and time. This coin-sized clock battery is a long-lived C2016 3-volt lithium manganese dioxide cell, located in a slide-out carrier near the hinge of the battery door, shown in Figure 9.4.

Figure 9.4

Your clock battery is located in the main battery compartment.

Figure 9.4

Your clock battery is located in the main battery compartment.

Canon 4225 Door Sensor Location

You may never notice this battery at all, as it may last several years without needing replacement. Your first clue will be when you switch on your 40D and a message on your LCD asks you to input the date and time. That's your cue to trot down to the electronics store and buy a new one.

To install it, just slide out the plastic carrier and remove the old battery. There is a pair of plastic tabs holding it in tight, and you may have to pry one up to free the dead cell. Then slide the new one in and return the carrier to your camera. When you turn the power on, you'll need to enter the current date and time. Don't forget to choose OK when finished; if you simply exit the settings screen by pressing the Menu button, your time setting will not be entered. You'll also have to reenter other camera and user settings that the EOS 40D normally "remembers."

Clean Your Sensor

There's no avoiding dust. No matter how careful you are, some of it is going to settle on your camera and on the mounts of your lenses, eventually making its way inside your camera to settle in the mirror chamber. As you take photos, the mirror flipping up and down causes the dust to become airborne and eventually make its way past the shutter curtain to come to rest on the anti-aliasing filter atop your sensor. There, dust and particles can show up in every single picture you take at a small enough aperture to bring the foreign matter into sharp focus. No matter how careful you are and how cleanly you work, eventually you will get some of this dust on your camera's sensor. Some say that CMOS sensors, like the one found in the EOS 40D, "attract" less dust than CCD sensors found in cameras from other vendors. But even the cleanest-working photographers using Canon cameras are far from immune.

Fortunately, one of the EOS 40D's most useful new features is the automatic sensor cleaning system that reduces or eliminates the need to clean your camera's sensor manually. As I mentioned in Chapter 3, Canon has applied anti-static coatings to the sensor and other portions of the camera body interior to counter charge build-ups that attract dust. A separate filter over the sensor vibrates ultrasonically each time the 40D is powered on or off, shaking loose any dust.

Although the automatic sensor cleaning feature operates when you power the camera up or turn it off, you can activate it at any time. Choose Sensor Cleaning from the Set-up 2 menu, and select Clean now. If you'd rather turn the feature on or off, choose Auto cleaning instead, and then choose either Enable or Disable with the Quick Control Dial. Press Set, then press the Menu button to return to the Set-up 2 menu. (See Figure 9.5.)

You can activate automatic sensor cleaning immediately or enable/disable the feature.

Sensor cleaning

Auto cleaning


Clean now jZh

Clean manually

You can activate automatic sensor cleaning immediately or enable/disable the feature.

If some dust does collect on your sensor, you can often map it out of your images (making it invisible) using software techniques with the Dust Delete Data feature in the Shooting Menu 2. Operation of this feature is described in Chapter 3. Of course, even with the EOS 40D's automatic sensor cleaning/dust resistance features, you may still be required to manually clean your sensor from time to time. This section explains the phenomenon and provides some tips on minimizing dust and eliminating it when it begins to affect your shots. I also cover this subject in my book, Digital SLR Pro Secrets, with complete instructions for constructing your own sensor cleaning tools. However, I'll provide a condensed version here of some of the information in that book, because sensor dust and sensor cleaning are two of the most contentious subjects Canon EOS 40D owners have to deal with.

Was this article helpful?

0 0
Digital Camera and Digital Photography

Digital Camera and Digital Photography

Compared to film cameras, digital cameras are easy to use, fun and extremely versatile. Every day there’s more features being designed. Whether you have the cheapest model or a high end model, digital cameras can do an endless number of things. Let’s look at how to get the most out of your digital camera.

Get My Free Ebook

Post a comment