Metering for ambient lighting conditions and flash metering has totally different requirement. The metering for ambient lighting condition is done before the shutter of the camera is opened. In the Canon EOS camera, ambient light metering is done when you press the shutter button halfway down. Flash Pulse metering however is done when the shutter button is press fully down. There are two ways to meter for flash pulse automatically. One way is by measuring the flash pulse as it is being released. The other way is to do a pre-flash test. This is achieved by a low powered test pulse of a calculated brightness before the shutter opens.

Canon uses both these two methods for the metering of the flash pulse. The first way is called the "Through The Lens" (TTL) system. It was first used by Canon in their T90 model during it debut in the 1980s. Later the TTL system became a standard facet of the EOS range of Cameras. In fact the T90 became the only Non EOS camera to ever use the TTL flash metering system.

The TTL system works by measuring the light which bounces of the subject matter and entering the camera lens after the flash light pulse has been emitted. In essence, the TTL system, measure the actual light which is reflected off from the film in real-time. This is done by using a OTF (Off The Film) sensor. When enough light has entered the sensor, to get a proper exposure level, the light from the flash will be extinguished. Because Digital Camera does not use film, the Canon Digital EOS cameras do not support TTL.

The progression of the TTL flash metering system is as follows:

1. When the shutter button is depressed halfway the ambient light metering operation runs its course. The shutter speed and aperture is set by the camera or the user depending on what mode is used. For example; P mode, AV mode or M Mode.

2. Only when the shutter button is depressed all the way, the internal mirror is turn up and exposes the film. Power is then sent to the flash unit which will emit a flash light to illuminate the scene. The length of the flash pulse is determined by the OTF sensor in the camera which is metered for normal operational conditions. If the picture is taken under bright lighting conditions, the auto fill reduction will take effect and reduce the illumination of the Flash.

3. When the foreground is sufficiently illuminated, the power supply to the flash unit is terminated which in turn extinguishes the flash light. The shutter is opened during the entire duration of its speed run. After that, the shutter then closes and the mirror flips back to it original position. For those cameras which have a warning light to confirm the success of the flash exposure operation, the warning light will then glow to indicate the success of the flash metering operation.

It is also important to note that as the OTF sensor reflects the amount of light of the film, the composition of the film itself will also affect the amount that is reflected off. But as all camera are calibrated to work with normal film this will not become an issues except with special films like slide films which has different level of tolerances.

You have decided to buy yourself a camera. A brand new compact digital camera. Reviews are available all over, and you will use the information to make a good choice. But many reviews are created simply for the sake of selling a product, many of those even on the company website. How do you as a regular internet user discern fake from real, and ultimately, who can you trust?

The obvious choice would be to steer clear of any reviews done by, or connected to, the manufacturer. Any manufacturer would obviously sing its own praises, because they have to believe in what they offer. You will find, in such cases, that the "review" is actually a very well presented sales letter.....

This does not mean you should leave any website with a link to a sales page. But you should be careful if all links point to one single manufacturer. Anyone spending all the time and money involved to set up a professional website is entitled to make money off it, but be careful of biased reviews. If a manufacturer is directly involved, the negative points are likely to be withheld.

But you need to find credible compact digital camera reviews. Where do you go? Go out in search of photographic journals, and comparison sites. You could even go buy a computer, or photographic magazine. Here you will find reviews done by professional photographers, people who have proven their credibility. They have standard procedures for conducting evaluations, ensuring objective reviews.

A "real" review does not hold back. It does not minimize the disadvantages, or shortcomings of the product. A real review will employ a standard checklist to compare performance and features, being brutally honest about each point. Unless the camera reviewed is something out of this world (probably costing a fortune), there will probably be room for improvement. You will find out about any problems, and all the limitations of the product.

Eventually, you are the one who lays out the money. There is a load of choices out there, as well as a multitude of "compact digital camera reviews" that are simply junk, trying to get you to buy a specific camera. You In order to be able to make an educated choice, you have to separate fact from fiction. When you eventually decide what you want, you do not have to walk into another sales pitch at your local photographic store: Your homework is done.

The popularity of Photoshop among professional designers easily makes it the digital imaging industry standard. The idea that it is, in essence, a brand name that has crossed grammatical barriers makes it a true cultural phenomenon. However, don't let all this grandeur get in your way if you are an amateur photographers. Photoshop is a powerful tool for anyone who simply wants to make their personal photo collection look better.

Opening Photos with Photoshop I recommend opening Photoshop and becoming familiar with the desktop environment before trying to figure out how to get your photo in there. If your photos are already in a digital format (i.e. taken with a digital camera), you can transfer them to your computer using the USB lead that came with your camera. If your photos are actual prints you can still edit them with Photoshop! To get them into your computer you will need to use a scanner to scan the photos onto your desktop. When you finally have your photos in your computer, I recommend grouping them in a folder. To make it easy to find later call the folder something simple like "Original Photos" and place it on your desktop. If you click on the closed folder and press your CTRL button and drag you will make a copy of the folder; it is important to work with a copy of your pictures. You can right click on the new folder and rename it "Edited Photos." Working with duplicate photos enables you to always have an original copy of your photo to go back to, just in case you make an editing mistake. To add your photo to Photoshop you will first need to open your Photoshop program by double-clicking on the icon. Next click on the File menu and select open. Navigate to your "Edited Photos" folder and double click on a photo. Now you're ready to begin!

Adjust Levels in Your Photos Before you begin editing it's always a good idea to check a photo's levels. When photos are backlit, lit poorly, or overexposed, the colors tend to not look quite right. At times this is obvious, however at other times it's hard to tell, so you always want to check your photo's levels. Doing this first will help you make the colors in your photos look their best. To change the levels in your picture click on Edit in the menu bar. Move your mouse to Adjustments > in the drop-down menu and leave the cursor there for a second. In the sub-menu that pops up, choose on Auto Levels.

Save your work by hitting Apple + S in Mac OS X or CTRL + S in Windows. Alternatively, you can press Shift + Apple + L on a Mac or CTRL + L on a PC to use the Auto Levels function. You should notice a change in the appearance of your photo. If you don't see a noticeable difference, it's okay. It just means your photo looked good right from the start.

Reduce Red Eye in Your Photos Everyone has fallen victim to the curse of Red Eye in our photos. Red eye has ruined more photos than silly expressions, closed eyes, and blurred photos combined. With Photoshop getting rid of red eye is a snap. With your image open in Photoshop you will want to make sure your Layers Palette is visible. Usually you can find the Layers Palette in the lower right hand corner of the window when you open Photoshop. If you do not see the Layers Palette, simply click on the Windows option in the menu bar, scroll to Layers, and make sure Layers has a check mark next to it. If it doesn't, click it once and the Layers palette will appear. In the Layers palette you will find the adjustment layer button. You can find this button at the bottom of the window. It has a half-black, half-white circle and when you move your mouse over it should have a pop-up box that says "Create new fill or adjustment layer". To activate it, click on the adjustment layer button. A menu should come up, select Channel Mixer. A window with the header Channel Mixer should open. To fix the red eye you will want to set the Red slider to 0%, and the Blue and Green sliders to 50%. Click OK. Don't be alarmed if the people in the photos look like bluish-gray-skinned phantoms. Don't worry, you haven't messed anything up, they're supposed to! You will soon fix this so they look like their regular selves again. At the bottom of the toolbar set the foreground color to black. In the toolbar, click on the brush tool. If the red eyes are too difficult to see because of their size you can go to the toolbar and select the zoom tool (magnifying glass with a +). Clicking on the eyes with your mouse will zoom in on them. When you have zoomed in to where you feel you can work on the eyes you will need to select the brush tool again. Return to the Layers palette. You should see a Background layer and a layer called Channel Mixer 1. Make sure the layer Channel Mixer 1 is selected by clicking it once. Use the brush tool to paint the parts of the eyes that looked red. They should turn red again. At the top of your screen click on the Image menu. Just like we did earlier you will want to move your mouse over Adjustments in the drop down menu. Click Invert in the sub-menu that comes up on the right. Tada we fixed the red eye! After all that hard work you definitely want to save your work by hitting Apple + S in Mac OS X or CTRL + S in Windows. You may still see a red ring around the newly-fixed eyes; don't worry, we can fix that too. You first want to make sure the Channel Mixer 1 layer is selected (click it once). In the main toolbar, make sure the foreground color is set to white. Since it was set to black a second ago, you will have to change it. Again, using the the paintbrush tool from the toolbar, carefully paint the red ring. As you paint you should see the color change to the correct eye color. At the top of the screen, in the menu bar, click Layer. Click on Flatten Image at the bottom of the menu. Save your work by hitting Apple + S in Mac OS X or CTRL + S in Windows.

You've probably been dreaming about your wedding day for years. You want everything to be perfect on your special day, especially the photography! It's important to make sure you pick the right photographer for your wedding, since it can have a big effect on your wedding day memories.

If you don't have a great photographer at your wedding, you may end up with only a memory instead of with great pictures. So, although great photographers are not necessarily going to be cheap, you can find a great deal if you know what to look for.

You want to be sure that the whole day is perfect, including your wedding pictures. Here are a few tips to help you ensure that's a possibility when you pick your wedding photographer.

First, take a look at the price you'll be paying for your photographer. Find out if you'll be charged only an hourly fee, or if there'll be a base fee in addition. This could be an important factor in your decision to go with one photographer or another.

You'll also want to find out how many hours the photographer will spend at your wedding. Usually after a certain amount of hours, the photographer will charge overtime, so you need to know this ahead of time.

Remember to read the contract carefully when you make a decision. Closely reading the contract before you sign paperwork will allow you to know what you're getting when you choose a photographer.

Find out how long it will take in order to get your proofs back, as well as the prints. No doubt you want them as soon as possible. Of course the faster you want them back, the more you'll probably pay.

Remember to stop and think about the photography style you prefer when choosing your photographer. Take a look at a potential photographer's personal style to see if you like it.

Choose a photographer whose personality is compatible with yours. It doesn't matter if the person you hire takes excellent photos if you can't get along with them. To avoid strife on your big day, meet with your photographer in advance and decide how well you like him or her.

References are a good idea, too. Check out the references you've been given to see how other people felt about using this photographer. Your friends or family might have hired the photographer in the past - ask them how it went.

Hiring the right wedding photographer for your big day is an important choice. Make sure you plan ahead and keep these tips in mind when you decide on your photographer.

It can be challenging to make sure you get the perfect wedding photography, and it's one thing you don't want to mess up. While it can take a little bit of extra effort, in the end you'll find that it's worth it to carefully plan your photography.

The first thing that you will want to do when you are planning out the photography for your wedding is to decide what exactly you want. How many pictures do you want to have taken? Where will the pictures be taken? Who do you want in the pictures?

These questions can lead you into the next step - deciding where to get married. The space, ambiance, and lighting should be taken into consideration if you want great photos. This way you are sure that your photographer will have everything he needs to take great pictures.

Once you're sure about the setting, you'll start your quest for a good photographer. There are a few things to take into consideration for this, including the photographer's pricing, experience, and ability. Make sure that you clear the date with the photographer well in advance to be sure he or she is available.

While photographic appeal isn't the only thing to consider when booking your venue, it should be something you think about. A good wedding venue will be easy to take pictures in. After all, no one wants an unattractive backdrop in the photos of their special day.

After you know more about the wedding venue, take that information to your photographer. Show them the ambiance, size and the location of your chosen venue. Then you can discuss more about scenery and specific pictures you want to have taken.

Take some time to come up with a written plan for your wedding photography. Make sure that everyone is expecting the same thing, and that you and your photographer both know one another's plans. That way, when the big day comes, you'll have no trouble getting your photos taken perfectly.

If you are not sure what specific photographs you want taken at your wedding, take a look at some bridal magazines. Tear out pictures that you love and want done at your wedding. You can also look through the wedding photos of friends and of the photographer for more ideas as well.

Although you'll be paying the photographer to take pictures of your wedding, you won't choose the photos you want until later. Once you get the proofs, you'll be able to decide how many of each shot you want and in what size. Unless the photos are part of a package, you'll pay for them separately - something to remember when you work out your wedding budget.

Since your wedding might be one of the most important days in your life, take your time to plan it with care. That way, you'll be sure to get great photography that you can treasure for years to come.

Macro photography is when you photograph your subject close-up. Macro photography allows you to get in close and photograph small details on your subject. Usually macro lenses are 1:1 ("life size"). That means the size of your subject in the frame is generally the same size in real life. Here you will find macro photography tips.

1. The first thing you have to think about is equipment. You can use a close-up lens, attach a close-up filter to the lens you are already using, use a bellows attachment, or a telephoto extender. If you are just starting out, you may just want to invest in the macro filter.

2. In macro photography, it is important to know that the depth of field is different. Choose a high f-stop number such as an F16 or F22 (small aperture). Most of what is in the background will not be in focus.

3. Be careful when focusing your subject, because if you are not, the part you want to be in focus will end up blurry. Except under bright lighting conditions, you will probably use a slow shutter speed.

4. It is critical to properly light your subject. You lens will be very close to your subject, so it's important to have light in between your camera and the subject. Many photographers will use a ring flash.

5. High film speeds will allow you to increase your shutter speed, since you will be using a slow shutter speed. It is recommended to stay at ISO200 or lower.

6. Experiment with a number of different subjects. Play with shape and texture. Do not forget about composition, and color in your background. Additional things you may want to try: experiment with light balance, use a tripod, or use a diffuser. Take your time with macro photography and always have fun. Great subjects are flowers and bugs.

Additional things you may want to try: experiment with light balance, use a tripod, or use a diffuser. Take your time with macro photography and always have fun. Great subjects are flowers and bugs.

While taking photographs in color is often a common choice, black and white photography often affords interesting results. The following points are quick tips for black and white photography.

1. There are many different sizes of film, and different formats: 35mm (1" x 1"), medium format- 120 (2" x 2 "), and large format (4" x 5"). Typically, people will start off using a 35mm SLR (single-lens reflex) camera. With an SLR, you can focus and view the subject directly through the lens.

2. There are different film speeds for different situations; film speeds are rated by an ASA (American Standards Association) number. For brightly lit subjects, a slow film such as 32 ASA is used; slow film produces fine grain negatives. Outdoor photographers will typically use a medium film speed such as 125 ASA, and that produces medium grain negatives. A fast film speed, such as 400 ASA is best for indoor use, and produces coarse grain negatives.

3. The aperture is adjusted to control the amount of light entering the lens. F-stop is a measurement of the size of the lens opening. A smaller F-stop number is a bigger opening and allows more light to reach the film. A larger F-stop number decreases the amount of light that reaches the film. The following is a typical F-stop range: 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22.

4. Lens size is measured in mm and is referred to as focal length. A narrow angle of view is a result of a longer focal length. Conversely, a wider angle of view is a result of a shorter focal length. Lens types and focal length: normal (50mm), wide angle (21-35mm), and telephoto (105-300mm).

5. Shutter speed refers to the length of time the film is exposed to light. A fast shutter speed means the length of exposure time is short. A slow shutter speed means the length of exposure time is long. Shutter speeds: B, T, 2, 4, 8, 15, 30, 60, 125, 250, 500, 1000. Shutter speed time can be better understood if you place a 1 over the number to turn it into a fraction. When you place a 1 over the 2, that means the shutter speed is a second.

6. Regarding shutter speed, the B means bulb, and the T means time. When using bulb, you just hold the button down for the desired amount of time. When using time, the second time you press down the button is when the shutter closes.

The effects you can achieve today with editing software are beyond what professional photographers years ago thought possible. Now is a time when there are no limitations on editing images- everything is possible and creativity is the only requirement to make outstanding pictures. There are thousands of programs that help us improve the photographs we take, but none have the respect of the professional and amateur community as Adobe Photoshop. The software is so closely linked with altering images that the term 'to Photoshop' has come to mean 'to enhance pictures'.

It is possible to 'Photoshop' images to give fantasy the illusion of reality. You can alter images so that figures and objects appear in the image that could never be seen together. Whether it's a party with past presidents, Frankenstein and the Easter Bunny, or a picture of you and a celebrity you've never met, you can make anything appear completely realistic.

Photoshop is also useful for taking things out of the picture that you don't want. Glaring physical flaws like skin blemishes can be removed to improve the image, and it is even possible to remove entire objects or figures that you want out of the image. Photoshop is so refined that it will be impossible to tell if your images have been enhanced at all.

Photoshop is essential for anyone interested in photography in today's digital world. The software is just as important and wide-spread as Microsoft Word and PowerPoint in the media industry. You may feel pressure to learn how to use the software, but the resources are easily available to anyone due to the popularity of the program. A lot of people know how to use Photoshop, so if you know anyone in college or high school, ask them if they could teach you.

The birth of Photoshop was in 1989 by the Knoll brothers. The software was being developed for their own use at the time, but the sophistication of the software made it clear that there was a market for Photoshop. They soon founded Adobe and began selling the program in 1990.

Adobe is a great success story of the internet. Adobe's presence dominates the internet, and there are few computers that do not have some form of Adobe software for example. The free Adobe Reader is as common as Microsoft Word or PowerPoint. Everyone is aware of these programs, and the PDF reader is yet another instance in which Adobe has taken over a section of the online industry.

To gain experience with Photoshop you should find a copy you can experiment with. Perhaps a friend or relative has one. Go over and explore the program, browsing all the features and adding effects to images. Once you get a feel for how the software operates, ask your friend to show you the more advanced features. Then you'll see why Photoshop has its first-rate reputation. Within no time, you will be addicted to Photoshop.

Eventually you'll want to get a copy for your own use. You can get a trial version that will give you a lot of the features, but for full access you have to get the licensed version. Photoshop is everywhere, so buying a copy will save you a lot of hassle. Now that you have your own copy you'll probably play around with it for hours trying out all the cool features. While you will learn this way, there is something to be said for taking a class in Photoshop. These will be streamlined to give you the information you need to improve your skills. Once you've covered the fundamentals, experimenting will expand your horizon, but without the basics, you will not be as effective at enhancing images as you could be.

When you master the software, there is no limit to what you can do. Just imagine any concept and you will be able to translate it into an image in no time. Keep experimenting, and remember to have fun!

If you are planning on doing some night photography I have a few planning tips you will need to keep in mind prior to taking your evening shots:

You first want to choose a good viewpoint;

And second, you need either a tripod or a solid base to place your camera on. The viewpoint - this depends a little on the type of shot you are after. My preference is for somewhere that is above the ground (a set of steps, for example), but not always. Sometimes the best shots can be had at ground level.

I recommend a tripod or solid base simply due to the fact that your camera's shutter will be open for several seconds and you definitely want to make sure that your camera is absolutely still during that time.

Then, if you have a tripod, secure your camera upon it. If you don't, find a solid surface to rest your camera on; propping it up with something like a bag or jumper.

Once your camera is in place, make sure your shutter speed is set to a good few seconds. Start with about 15 seconds.

If your camera doesn't let you control the shutter speed, set it to "night" mode.

You are ready to take your pictures once you have everything arranged (camera on a solid surface and self timer primed).

The first thing you want to do is observe your scene. Does it contain everything that you wanted to be in it? If you are hoping to get streaking car headlights do you notice any traffic around?

Once you are happy with things, press the shutter button.

The self timer should begin to count down. Please note that if you are waiting for something to appear in your scene you need to remember that your shutter speed will have to count down first - time for this.

When you hear the shutter click it is actually opening up so you want to wait. And wait, and wait . . . until it closes again. Remember, depending on the length of time you set it for, that this could take a few seconds.

Don't worry if you must wait some more. Due to the long exposure typical digital cameras take longer than usual to process the photo, so the preview on your LCD screen may take a while to show up.

If you are wanting to try out night photography but don't have any idea where to start here are a few ideas on what to photograph:

Neon lights Streaks of car headlights and tail lights Available light There is some advance planning that you need to do for these ideas. Whatever you choose for you subject you want to find an area where you can photograph safely.

The first thing you do is find your solid spot, or put your camera onto a tripod, and then take a few test shots. If you choose neon lights be aware that they flash so you will want to keep the shutter open for a while in order to catch all the flashes.

For photographing streaks of car headlights and tail lights you will obviously want to find a spot that has a good bit of traffic, but again, be safe in your choice of locations.

A tip is to try and get something in the background as well, usually streaks of light on their own can be somewhat boring!

Then take your shot.

One thing to remember is that the longer you keep your shutter open, the more streaks you will capture. Obviously the more traffic you have the more streaks you will have!

The available light also has a part to play in making a good night photography shot.

You will find that there are times when a scene looks its best when you set it amongst inky-black skies. By playing around you will also find that there are times when a little light works best, so photos just prior to dark really sets in are worth a try too.

Try both, and see what captures the effect you are after best.

You also will want to play around with your shutter speed since there are times you will find that a 10 second exposure gets the look you are after. Sometimes you may need up to a minute.

Practice, and you will soon get a feel for what you will need for any given situation.

Selecting Colors From An Image Quickly Press I to activate the Eyedropper Tool and then click on any color in your image to turn that color into the foreground color. Press the ALT Key and click on any color in your image to turn that color into the background color.

Change Brush Tip Sizes Quickly With any brush selected you can press the Right Bracket Key "]" to increase the size of the brush tip, or Press the Left Bracket Key "[" to decrease the size of the brush tip.

The Move Tool & The Arrow Keys Get in the habit of calling up the Move Tool with the keyboard shortcut, which is the letter V. Also, once the Move Tool is active you can use your Keyboard Arrow Keys to nudge a layer or selection in 1 pixel increments. To speed things up, Press Shift along with an arrow key to nudge in 10 pixel increments.

Hide Your Palettes Press Tab once to hide all your palettes. Press Tab again to bring them back. Press Shift+Tab to hide all your palettes except the toolbar.

Zooming In & Zooming Out To zoom in Press Command and the plus sign "+" (PC: Control and the plus sign). To zoom out Press Command and the minus sign "-" (PC: Control and the minus sign).

Navigating In Magnified Images If you are magnifying your image using the zoom tool and lose your bearings you can jump quickly to specific views using the following shortcuts: To change the view to the top left hand corner of your screen or image press the Home Key. You will want to press the End Key to set the view to the bottom right hand corner of your image. To move the view down one full screen view press the Page Down Key. Press CTRL+Page Down (Mac: Command +Page Down) to move the screen view one full screen to the right. Press CTRL+Page Up (Mac: Command +Page Up) to move the screen view one full screen to the left.

Selecting Just the Pixels in A Layer One very easy way to select an object that is on a transparent layer is to press the Control Key (Mac: Command key) and click on the layer that contains the object in the Layers Palette. Doing this ensures that only the visible pixels will be highlighted.

Tile Images for Better Visibility When you simultaneously open a bunch of files in Photoshop they automatically cascade, and it can be difficult to select individual windows within all the overlapping files. To eliminate this problem choose Window> Arrange> Tile and all of your open files will rearrange themselves to be visible all at once. When you're ready to close the windows you don't have to spend time closing them individually, instead use the Close All shortcut Control+Option+W (Mac: Command+Alt+W).

Getting Rid Of The Welcome Screen - And Bringing It Back When first launching Photoshop CS you'll see a Welcome Screen that has links to some Tutorials, some Tips and Tricks, and a set of Color Management Help Files. After a while you might want to get rid of this screen. There's a check box at the bottom you can select to hide the screen at startup. If you change your mind later and decide you'd like to investigate the tutorials and other goodies, you can temporarily bring the screen back by going under the Help menu and choosing Welcome Screen.

Cycle through All of Your Open Documents At some point you may want to find one of your open documents that are hidden on your toolbar. You can easily press Control-Tab repeatedly (MAC and PC) to cycle through all of your open documents and switch between them.