Using a Card Reader and Software

You can also use a Compact Flash memory card reader and software to transfer photos, and automate the process using the EOS Utility, Photoshop Elements 5.0's Photo Downloader, or the downloading program supplied with some other third-party applications. This method is more frugal in its use of your XTi's battery, and it can be faster if you have a speedy USB 2.0 or FireWire card reader attached to an appropriate port. The installed software automatically remains in memory as you work and...

Other Lighting Accessories

Once you start working with light, you'll find there are plenty of useful accessories that can help you. Here are some of the most popular that you might want to consider. Soft boxes are large square or rectangular devices that may resemble a square umbrella with a front cover, and produce a similar lighting effect. They can extend from a few feet square to massive boxes that stand five or six feet tall vir-tually a wall of light. With a flash unit or two inside a soft box, you have a very...

What Can Go Wrong

Lots of things can go wrong with your memory card, but the ones that aren't caused by human stupidity are statistically very rare. Yes, a Compact Flash card's internal bit bin or controller can suddenly fail due to a manufacturing error or some inexplicable event caused by old age. However, if your CF card works for the first week or two that you own it, it should work forever. There's really not a lot that can wear out. The typical Compact Flash card is rated for a Mean Time Between Failures...

Continuous Lighting Basics

While continuous lighting and its effects are generally much easier to visualize and use than electronic flash, there are some factors you need to take into account, particularly the color temperature of the light. (Color temperature concerns aren't exclusive to continuous light sources, of course, but the variations tend to be more extreme and less predictable than those of electronic flash.) Color temperature, in practical terms, is how bluish or how reddish the light appears to be to the...

Your First Lens

Some Canon dSLRs are almost always purchased with a lens. The Digital Rebel, Digital Rebel XT, and Digital Rebel XTi, for example, are often bought as entry-level cameras, frequently by first-time SLR or dSLR owners who find the Canon EF-S 18-55mm f 3.5-5.6 autofocus lens an irresistible bargain at about 100 over the cost of the camera body alone. Other, more advanced, Canon models, including the EOS-1D Mark III, EOS-1Ds Mark II, and EOS 5D, are generally purchased without a lens by veteran...

Zoom BrowserImage Browser

ZoomBrowser is an image viewing and editing application for Windows PCs (the equivalent program for Macs is called ImageBrowser). You can organize, sort, classify, and rename files, and convert JPEG files in batches. This utility is especially useful for printing index sheets of groups of images (see Figure 8.1). It can also prepare images for e-mailing. It works with RAW Image Task for converting CR2 files to some other format, and it can be used to select images for merging using PhotoStitch....

Macro Focusing

Some telephotos and telephoto zooms available for the Digital Rebel XTi have particularly close focusing capabilities, making them macro lenses. Of course, the object is not necessarily to get close (get too close and you'll find it difficult to light your subject). What you're really looking for in a macro lens is to magnify the apparent size of the subject in the final image. Camera-to-subject distance is most important when you want to back up farther from your subject (say, to avoid...

Telephoto Extenders

Telephoto extenders (often called teleconverters outside the Canon world), multiply the actual focal length of your lens, giving you a longer telephoto for much less than the price of a lens with that actual focal length. These extenders fit between the lens and your camera, and they contain optical elements that magnify the image produced by the lens. Available in 1.4X and 2.0X configurations from Canon, an extender transforms, say, a 200mm lens into a 280mm or 400mm optic, respectively. Given...

Avoiding Potential Wide Angle Problems

Wide-angle lenses have a few quirks that you'll want to keep in mind when shooting, so you can avoid falling into some common traps. Here's a checklist of tips for avoiding common problems Symptom converging lines. Unless you want to use wildly diverging lines as a creative effect, it's a good idea to keep horizontal and vertical lines in landscapes, architecture, and other subjects carefully aligned with the sides, top, and bottom of the frame. That will help you avoid undesired perspective...

Cancel

One of the Rebel XTi's best new features is the automatic sensor cleaning system that reduces or eliminates the need to clean your camera's sensor manually using brushes, swabs, or bulb blowers (you'll find instructions on how to do that in Chapter 9). 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 XTi is powered on or off,...

Incandescent Tungsten Light

The term incandescent or tungsten illumination is usually applied to the direct descendents of Thomas Edison's original electric lamp. Such lights consist of a glass bulb that contains a vacuum, or is filled with a halogen gas, and contains a tungsten filament that is heated by an electrical current, producing photons and heat. Tungsten-halogen lamps are a variation on the basic lightbulb, using a more rugged (and longer-lasting) filament that can be heated to a higher temperature, housed in a...

TiD

Canon EOS Digital Rebel XTi 400D Guide to Digital SLR Photography Professional Technical Reference 2008 Thomson Course Technology, a division of Thomson Learning Inc. All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system without written permission from Thomson Course Technology PTR, except for the inclusion of brief quotations in a...

Turn the power switch to after cleaning

Figure 9.13 While the mirror is up, this message appears on the LCD. Your first attempts at cleaning your sensor should always involve gentle blasts of air. Many times, you'll be able to dislodge dust spots, which will fall off the sensor and, with luck, out of the mirror box. Attempt one of the other methods only when you've already tried air cleaning and it didn't remove all the dust. In all cases, work in a clean environment, preferably with a high intensity light that allows you to view the...

Image Stabilization

Canon has a burgeoning line of more than a dozen lenses with built-in image stabilization (IS) capabilities. This feature uses lens elements that are shifted internally in response to the motion of the lens during handheld photography, countering the shakiness that the camera and photographer produce and which telephoto lenses magnify. However, IS is not limited to long lenses the feature works like a champ at the 17mm zoom position of Canon's EF-S 17-85mm f 45.6 IS USM and EF-S 17-55mm f 2.8...

What Lenses Can You

The previous section helped you sort out what lens you need to buy with your XTi (assuming you already didn't own any Canon lenses). Now, you're probably wondering what lenses can be added to your growing collection. (Trust me, it will grow.) You need to know which lenses are suitable and, most importantly, which lenses are fully compatible with your Digital Rebel XTi. With the Rebel XTi, the compatibility issue is a simple one it accepts any lens with the EF or EF-S designation, with full...

Shooting Your First Digital Rebel XTi Picture

Mode Dial Canon

If you're like me, the first time you laid your hands on your Canon EOS Digital Rebel XTi, you couldn't wait to use it. I would have taken some shots on the way home from the camera store if I'd remembered to bring a Compact Flash card along with me. It's likely the battery didn't have much juice in it, but I would have tried anyway. The XTi is quite tempting right out of the box, especially if you've previously used either of its predecessors, the original Digital Rebel or the Digital Rebel...

Update Your Firmware

As I said, the firmware in your Digital Rebel XTi is the camera's operating system, which handles everything from menu display (including fonts, colors, and the actual entries themselves), what languages are available, and even support for specific devices and features. Upgrading the firmware to a new version makes it possible to add new features while fixing some of the bugs that sneak in. For example, updates to the XTi's firmware eliminated a condition that prevented the camera from using...

Lens Hoods

Lens hoods are an important accessory for all lenses, but they're especially valuable with telephotos. As I mentioned earlier, lens hoods do a good job of preserving image contrast by keeping bright light sources outside the field of view from striking the lens and, potentially, bouncing around inside that long tube to generate flare that, when coupled with atmospheric haze, can rob your image of detail and snap. In addition, lens hoods serve as valuable protection for that large, vulnerable,...

Automatic Exposure Bracketing

The first entry on the Shooting 2 menu is AEB, or automatic exposure bracketing. Bracketing using the XTi's AEB feature is a way to shoot several consecutive exposures using different settings, to improve the odds that one will be exactly right. Select this menu choice, then use the left right cross keys to spread or contract the three green dots on the -2 +1 scale until you've defined the range you want the bracket to cover, shown as one-stop jumps in Figure 3.8. When AEB is activated, the...

Working with Long Exposures

Because the Rebel XTi produces such good images at longer exposures, and there are so many creative things you can do with long-exposure techniques, you'll want to do some experimenting. Get yourself a tripod or another firm support, and take some test shots with long exposure noise reduction both enabled and disabled (to see whether you prefer low noise or high detail) and get started. Here are some things to try Make people invisible. One very cool thing about long exposures is that objects...

But First a Word from Our Sensor

One pervasive consideration that will trip us up in this chapter (and throughout this book) is the omnipresent lens crop factor. If the sensor is smaller than the standard 35mm film frame (24mm X 36mm), then any given lens will produce a field of view that's cropped from that full frame. To express the real field of view in 35mm terms, you must multiply a lens's focal length by the crop factor, which in the case of the XTi is 1.6X. Canon also sells dSLRs with 1.3X and 1X (full frame) sensors,...

Ingredients of Canons Alphanumeric Soup

The actual product names of individual Canon lenses are fairly easy to decipher they'll include either the EF or EF-S designation, the focal length or focal length range of the lens, its maximum aperture, and some other information. Additional data may be engraved on the barrel or ring surrounding the front element of the lens, as shown in Figure 6.4. Here's a decoding of what the individual designations mean EF EF-S. If the lens is marked EF, it can safely be used on any Canon EOS camera, film...

Using FE Lock and Flash Exposure Compensation

If you want to lock flash exposure for a subject that is not centered in the frame, you can use the FE Lock button (*) to lock in a specific flash exposure. Just depress and hold the shutter button halfway to lock in focus, then center the viewfinder on the subject you want to correctly expose and press the * button. The preflash fires and calculates exposure, displaying the FEL (flash exposure lock) message in the viewfinder. Then, recompose your photo and press the shutter down the rest of...

What Lenses Can Do for

A saner approach to expanding your lens collection is to consider what each of your options can do for you, and then choose the type of lens that will really boost your creative opportunities. Here's a general guide to the sort of capabilities you can gain by adding a lens to your repertoire. Wider perspective. Your 18-55mm f 3.5-5.6 or 17-85mm f 4-5.6 lens has served you well for moderate wide-angle shots. Now you find your back is up against a wall and you can't take a step backward to take...

Image Editors

Image editors are general-purpose photo editing applications that can do color correction, tonal modifications, retouching, combining of several images into one, and usually include tools for working with RAW files and reducing noise. So, you'll find programs like those listed here good for all-around image manipulation. The leading programs are Adobe Photoshop CS3 Photoshop Elements 5.0. Photoshop CS3 Standard and Extended versions are the serious photographer's number one choice for image...

Transferring Your Photos

While it's rewarding to capture some great images and have them ensconced in your camera, eventually you'll be transferring them to your laptop or PC, whether you're using a Windows or Macintosh machine. You have three options for image transfer direct transfer over a USB cable, automated transfer using a card reader and transfer software such as the EOS Utility or Adobe Photoshop Elements Photo Downloader, or manual transfer using drag and drop from a memory card inserted in a card reader.

Aeb

Flash exp comp WB SHIFT BKT Custom WB Color space Picture Style Dust Delete Data 5. As the shots are taken, three indicators will appear on the exposure scale in the viewfinder, with one of them flashing for each bracketed photo, showing when the base exposure, underexposure, and overexposure are taken. 6. Bracketing remains in effect when the set is taken so you can continue shooting bracketed exposures until you use the electronic flash, or return to the menu to cancel bracketing. Figure 4.12...

Speedlite EX

This flagship of the Canon accessory flash line is the most powerful unit the company offers, with a GN of 190, and a manual automatic zoom flash head that covers the full frame of lenses from 24mm wide angle to 105mm tele-photo. (There's a flip-down wide-angle diffuser that spreads the flash to cover a 14mm lens's field of view, too.) All angle specifications given by Canon refer to full-frame sensors, but this flash unit automatically converts its field of view coverage to accommodate the...

Canon Digital Rebel XTi Troubleshooting and Prevention

One of the nice things about modern electronic cameras like the Canon Digital Rebel XTi is that they have fewer mechanical moving parts to fail, so they are less likely to wear out. No film transport mechanism, no wind lever or motor drive, no complicated mechanical linkages from camera to lens to physically stop down the lens aperture. Instead, tiny, reliable motors are built into each lens (and you lose the use of only that lens should something fail), and one of the few major moving parts in...

Glossary

Here are some terms you might encounter while reading this book or working with your Canon Digital Rebel XTi. additive primary colors The red, green, and blue hues that are used alone or in combinations to create all other colors that you capture with a digital camera, view on a computer monitor, or work with in an image-editing program, such as Photoshop. See also CMYK color model. A-DEP A Creative Zone mode that analyzes your scene and attempts to choose an f stop and focus distance that will...

Setting Up Your Canon EOS Digital Rebel XTi

Menus, set-up, playback, and shooting options are what enable your Canon EOS Digital Rebel XTi to perform in ways that better suit the needs of a particular shooting session. The options available customize how your camera behaves, shoots photos, and displays the images you've taken, transforming it from a limited single-purpose tool into a versatile, do (almost) everything machine. As I've mentioned before, this book isn't intended to replace the manual you received with your Digital Rebel...

Self Timer

The Rebel XTi has a built-in self-timer with a semi-fixed 10-second delay. Activate the timer by pressing the Drive mode selection button continually until the self-timer icon appears on the LCD status panel. Press the shutter-release button halfway to lock in focus on your subjects (if you're taking a self-portrait, focus on an object at a similar distance). When you're ready to take the photo, continue pressing the shutter release the rest of the way. The lamp on the front of the camera will...

Adjusting White Balance and ISO

If you like, you can custom-tailor your white balance (color balance) and ISO sensitivity settings. To start out, it's best to set white balance (WB) to Auto, and ISO to ISO 100 or ISO 200 for daylight photos, and ISO 400 for pictures in dimmer light. You'll find complete recommendations for both of these settings in Chapter 4. Set the white balance by pressing the White Balance button (the down cross key), and choosing a white balance from the menu of choices that appears on the color LCD with...

Direct Transfer

Canon Eos Xti

There are some advantages to transferring photos directly from your Digital Rebel XTi to a computer. The destination computer doesn't need to have a card reader all it requires is a USB port. So, if you have the USB cable that came with your camera, you can transfer photos to any computer that has the Canon utility software (discussed later) installed. However, direct transfer uses your XTi's internal battery power (whereas removing the card and transferring the photos with a card reader...

Adjusting White Balance

I showed you how to adjust white balance in Chapter 3, using the XTi's built-in presets, white balance shift capabilities, and white balance bracketing (there's more on bracketing in Chapter 4, too). In most cases, however, the Digital Rebel XTi will do a good job of calculating white balance for you, so Auto can be used as your choice most of the time. Use the preset values or set a custom white balance that matches the current shooting conditions when you need to. The only really problematic...

Sensor Cleaning

Those new to the concept of sensor dust actually hesitate before deciding to clean their camera themselves. Isn't it a better idea to pack up your XTi and send it to a Canon service center so that their crack technical staff can do the job for you Or, at the very least, shouldn't you let the friendly folks at your local camera store do it Of course, if you choose to let someone else clean your sensor, they will be using methods that are more or less identical to the techniques you would use...

Using Wide Angle and Wide Zoom Lenses

To use wide-angle prime lenses and wide zooms, you need to understand how they affect your photography. Here's a quick summary of the things you need to know. More depth-of-field. Practically speaking, wide-angle lenses offer more depth-of-field at a particular subject distance and aperture. (But see the next sidebar for an important note.) You'll find that helpful when you want to maximize sharpness of a large zone, but not very useful when you'd rather isolate your subject using selective...

Red Eye Reduction

Your Digital Rebel XTi has a fairly effective Red-Eye Reduction flash mode. Unfortunately, your camera is unable, on its own, to eliminate the red-eye effects that occur when an electronic flash (or, rarely, illumination from other sources) bounces off the retinas of the eye and into the camera lens. Animals seem to suffer from yellow or green glowing pupils, instead the effect is equally undesirable. The effect is worst under low-light conditions (exactly when you might be using a flash) as...

Advanced Shooting with Your Canon EOS Digital Rebel XTi

Now that you have a good understanding of exposure under your belt, you'll want to master some of the other techniques that can contribute to great images. In this chapter, I'm going to show you how to work with some additional exposure options, use the automatic and manual focusing controls available with the Canon EOS Digital Rebel XTi, and explain some of the many ways you can fine-tune your images with optimized white balance, sharpening, tonal values, and color. In Chapter 4, you learned...

Adding Circles of Confusion

But there are other factors in play, as well. You know that increased depth-of-field brings more of your subject into focus. But more DOF also makes autofocusing (or manual focusing) more difficult because the contrast is lower between objects at different distances. So, autofocus with a 200mm lens (or zoom setting) may be easier than at a 28mm focal length (or zoom setting) because the longer lens has less apparent depth-of-field. By the same token, a lens with a maximum aperture of f 1.8 will...

Fill Flash

Who says that electronic flash can't be used in full daylight Even when there is plenty of illumination to make an exposure, you still can benefit from adding a little more with electronic flash. A perfect example can be found in contrasty daylight situations in which bright sunlight forms deep shadows that could use a bit of brightening. Indoors, you might have enough light to take a photo, but still be plagued by dark shadows that ruin your shot. In either case, your Rebel XTi's built-in...

Using Telephoto and Tele Zoom Lenses

Telephoto lenses also can have a dramatic effect on your photography, and Canon is especially strong in the long-lens arena, with lots of choices in many focal lengths and zoom ranges. You should be able to find an affordable telephoto or tele-zoom to enhance your photography in several different ways. Here are the most important things you need to know about. In the next section, I'll concentrate on telephoto considerations that can be problematic and how to avoid those problems. Selective...

Customizing White Balance

Back in the film days, color films were standardized, or balanced, for a particular color of light. Digital cameras like the Rebel XTi use a particular white balance matched to the color of light used to expose your photograph. The right white balance is measured using a scale called color temperature. Color temperatures were assigned by heating a mythical black body radiator and recording the spectrum of light it emitted at a given temperature in degrees Kelvin. So, daylight at noon has a...

Using the Self Timer

If you want to set a short delay before your picture is taken, you can use the self-timer. Press the Drive button (located to the right of the LCD and marked by three icons representing continuous shooting, a self-timer, and remote control), and press the left right cross keys or rotate the Main Dial until the self-timer icon appears on the Drive mode screen. Canon supplies a rubber eyepiece cover, which attaches to your camera strap and can be slid over the eyepiece in place of the rubber...

Setting AF Point

You can change which of the nine focus points the Canon Digital Rebel XTi uses to calculate correct focus, or allow the camera to select the point for you. As I mentioned in Chapter 1, in A-DEP, or any of the Basic Zone shooting modes, the focus point is always selected automatically by the camera. In the other Creative Zone modes, you can allow the camera to select the focus point automatically, or you can specify which focus point should be used. To set the focus point manually, look through...

Color Space

Canon Digital Rebel Color Space Option

You can select one of two color gamuts (the range of colors available to represent an image) using this menu entry, shown in Figure 3.11. Adobe RGB is an expanded color space useful for commercial and professional printing, and can reproduce a wider range of colors. Canon recommends against using this color space if your images will be displayed primarily on your computer screen or output by your personal printer. The sRGB setting is recommended for images that will be output locally on the...

Your Autofocus Mode Options

One Shot Canon

Choosing the right autofocus mode when using Creative Zone modes, and the way in which focus points are selected is your key to success. Using the wrong mode for a particular type of photography can lead to a series of pictures that are all sharply focused on the wrong subject. When I first started shooting sports with an autofocus SLR (back in the film camera days), I covered one game alternating between shots of base runners and outfielders with pictures of a promising young pitcher, all from...

Electronic Flash Basics

Until you delve into the situation deeply enough, it might appear that serious photographers have a love hate relationship with electronic flash. You'll often hear that flash photography is less natural looking, and that the built-in flash in most cameras should never be used as the primary source of illumination because it provides a harsh, garish look. Indeed, most pro cameras like the Canon EOS 1D Mark II N and IDs Mark II don't have a built-in flash at all. Available (continuous) lighting...

Quality Settings

You can choose the image quality settings used by the XTi to store its files. You have three choices to make Resolution. The number of pixels captured determines the absolute resolution of the photos you shoot with your Digital Rebel XTi. Your choices range from 10 megapixels Large, or L , measuring 3888 X 2592 pixels 5.3 megapixels Medium, or M , measuring 2816 X 1880 pixels to 2.5 megapixels Small, or S , measuring 1936 X 1288 pixels. JPEG compression. To reduce the size of your image files...

Getting the Right Exposure

Zone Canon Evaluative Metering Image

The Canon EOS Digital Rebel XTi gives you complete control over many of the basic functions of the camera. These include exposure, sensitivity ISO settings , color balance, focus, and image parameters like sharpness and contrast. You can choose to let the camera set any or all of these for you automatically. Or, you can opt to fine-tune how the XTi applies its automatic settings. If you want absolute creative control over any of these functions, you can set them manually, too. That's why the...

Canon EOS Digital Rebel XTi Roadmap

Cannon Rebel Xti Camera Settings

It's time for you to get to know your Canon EOS Digital Rebel XTi up close. Unfortunately, there are so many buttons and dials and knobs on this camera that many new owners especially those coming to the XTi from point-and-shoot models find the array of controls bewildering. What you really need is a roadmap, showing you where everything is and how it's used. Unfortunately, the diagrams provided in the XTi's manual have more resemblance to a world globe than a roadmap everything is there in...

Fluorescent Light Other Light Sources

Fluorescent light has some advantages in terms of illumination, but some disadvantages from a photographic standpoint. This type of lamp generates light through an electro-chemical reaction that emits most of its energy as visible light, rather than heat, which is why the bulbs don't become as hot. The type of light produced varies depending on the phosphor coatings and type of gas in the tube. So, the illumination that fluorescent bulbs produce can vary widely in its characteristics. That's...

Telephotos and Bokeh

Nonagonal Bokeh

Bokeh describes the aesthetic qualities of the out-of-focus parts of an image, and whether out-of-focus points of light circles of confusion are rendered as distracting fuzzy discs, or whether they smoothly fade into the background. Boke is a Japanese word for blur, and the h was added to keep English speakers from rendering it monosyllabically to rhyme with broke. Although bokeh is visible in blurry portions of any image, it's of particular concern with telephoto lenses, which, thanks to the...

What Can You Do

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 so 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...

Custom White Balance

If automatic white balance or one of the six preset settings available Daylight, Shade, Cloudy Twilight Sunset, Tungsten, White Fluorescent, or Flash aren't suitable, you can set a custom white balance using this menu option. The custom setting you establish will then be applied whenever you select Custom using the White Balance menu entry described earlier. To set the white balance to an appropriate color temperature under the current ambient lighting conditions, focus manually with the lens...

Flash Exposure Compensation

Use this menu choice to adjust the amount of additional or reduced exposure to be applied to images taken with electronic flash. You'll find a complete discussion of flash exposure in Chapter 7. When you've chosen this menu entry, use the left right cross keys to select the desired amount, as shown in Figure 3.9. Moving the indicator to the left reduces flash exposure to the right increases it. Press Set to lock in your exposure. Return to this menu to cancel flash exposure compensation when...

Photoshop CS

The latest version of Photoshop includes a built-in RAW plug-in that is compatible with the proprietary formats of a growing number of digital cameras, both new and old. This plug-in also works with Photoshop Elements 5.0. To open a RAW image in Photoshop CS3, just follow these steps Elements 5.0 users can use much the same workflow, although fewer settings are available 1. Transfer the RAW images from your camera to your computer's hard drive. 2. In Photoshop, choose Open from the File menu,...

Using Multiple Light Sources

Studio Amrela 400d

Once you gain control over the qualities and effects you get with a single light source, you'll want to graduate to using multiple light sources. Using several lights allows you to shape and mold the illumination of your subjects to provide a variety of effects, from backlighting to side lighting to more formal portrait lighting. You can start simply with several incandescent light sources, bounced off umbrellas or reflectors that you construct. Or you can use more flexible multiple electronic...

Continuous Shooting

Canon Continuous Shot Icon

The Canon Digital Rebel XTi has a single continuous shooting mode that grabs shots at a speedy three frames per second rate. This capability reminds me how far digital photography has brought us. The first accessory I purchased when I worked as a sports photographer some years ago was a motor drive for my film SLR. It enabled me to snap off a series of shots in rapid succession, which came in very handy when a fullback broke through the line and headed for the end zone. Even a seasoned action...

Upgrading Your Firmware

If you're computer savvy, you might wonder how your Digital Rebel XTi is able to overwrite its own operating system that is, how can the existing firmware be used to load the new version on top of itself It's a little like lifting yourself by reaching down and pulling up on your bootstraps. Not ironically, that's almost exactly what happens at your command when you start the upgrade process , the XTi shifts into a special mode in which it is no longer operating from its firmware but, rather,...

How Electronic Flash Works

Flash Curtain Sync

The bursts of light we call electronic flash are produced by a flash of photons generated by an electrical charge that is accumulated in a component called a capacitor and then directed through a glass tube containing xenon gas, which absorbs the energy and emits the brief flash. For the pop-up flash built into the Digital Rebel XTi, the full burst of light lasts about 1 1000th second and provides enough illumination to shoot a subject 10 feet away at f 4 using the ISO 100 setting. In a more...

Replacing Your Clock Battery

Dslr Canon Clock Battery

In addition to the large rechargeable lithium ion battery that provides most of the power for your Canon Digital Rebel XTi, 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 9.7. You may never notice this battery at...

White Balance Shift and Bracketing

Amber Blue Magenta Green

White balance bracketing can be performed in any JPEG-only mode you can't use RAW or RAW JPEG . This form of bracketing is similar to exposure bracketing, but with the added dimension of hue. When you select WB SHIFT BKT, a screen like the one shown in Figure 3.10 appears. First, you turn the Main Dial to set the range of the shift in either the Green-Magenta dimension turn the dial to the left to change the separation of the three dots representing the separate exposures , or in the...

Troubleshooting Memory Cards

Sometimes good photographers can treat their memory cards badly. It's possible that a memory card that works fine in one camera won't be recognized when inserted into another. In the worst case, you can have a card full of important photos and find that the card seems to be corrupted and you can't access any of them. Don't panic If these scenarios sound horrific to you, there are lots of things you can do to prevent them from happening, and a variety of...

Shoot Without Card

The last entry in the Set-Up 1 menu gives you the ability to snap off pictures without a Compact Flash card installed or to lock up the camera if that is the case. It is sometimes called Play mode, because you can experiment with your camera's features or even hand your XTi to a friend to let them fool around, without any danger of pictures actually being taken. Back in our film days, we'd sometimes finish a roll, rewind the film back into its cassette surreptitiously, and then hand the camera...

Clean Your Sensor

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...