Saturday, April 18, 2009

A Guide to Exposure Metering Modes

A Guide to Exposure
Metering Modes


 

While you may understand how to utilize the simpler features on your digital camera such as the flash and zoom, or maybe even more complex features such as exposure modes, one feature that often remains a mystery to many casual photographers is the metering mode.

The metering mode selected on a digital camera decides how the camera’s exposure sensor will react when a photo is taken. Different metering modes determine how much light is needed and how long the shutter remains open.

Don’t worry if you’re confused - this article will help to explain the difference between the three metering modes available on digital cameras and how to choose between them to take better photos.
 

1. Center-Weighted Metering Mode

The Center-Weighted metering mode is without a doubt the most imprecise of the three metering modes we will be looking at in this article. Being more suited towards casual photographers who want to take everyday snapshots, this metering mode takes more consideration into the amount of light located in the center of the scene so that objects centered in the photograph are properly exposed.

Although you do not need to avoid this metering mode altogether, using the Center-Weighted metering mode may give you more impressive results with many of your photographs.
 

2. Matrix / Multi-segment Metering Mode

While the Center-Weighted metering mode uses a simple and sometimes inaccurate method of measuring the light in you photographs, the Matrix or Multi-segment metering mode takes a more detailed approach. By splitting the scene into many segments and then measuring the exposure data based on the position of each segment, the Matrix / Multi-segment metering mode manages to deliver exceptional quality photos in various lighting conditions and levels of contrast.

Although it is not perfect for every situation, this metering mode is an excellent choice for photography in most conditions. However, when you require better exposure for very high contrast scenes, think about taking a look at the next metering mode.
 

3. Spot Metering Mode

Maybe you’ve tried taking a photo using the standard Center-Weighted or Matrix / Multi-segment metering modes and neither provide satisfying results. Don’t give up yet, because turning to the Spot metering mode may give you that extra helping hand that you need.

This metering mode can provide excellent results for high-contrast scenes, and it achieves them by measuring light in the center of the scene alone – anywhere between 1 and 10 percent depending on your digital camera – and exposing the photo with the subject in mind.

So the next time you are trying to take a high-contrast shot, think about trying out the Spot metering mode – so long as your subject is in the center of the scene then this metering mode should avoid over or underexposure in almost any situation.
 

Conclusion

As you can see, the Matrix / Multi-segment metering mode is the best choice out of the three to use for most forms of photography. Choosing this mode over the standard Center-weighted metering mode will be sure to give you more impressive results, but when this mode doesn’t quite cut it, then the Spot metering mode is more than likely to offer better quality photographs in high-contrast lighting conditions.

That's all then! Hopefully this article has helped you to better understand the different metering modes available to use on digital cameras, and which modes are better suited towards various kinds of scenes.

Learn About the EXIF Metadata in Your Digital Photos

Learn About the

EXIF Metadata in Your Digital Photos

In this article we present a simple guide to the EXIF metadata for your digital photos.

Metadata refers to information that describes the your digital photos—information such as the exposure, shutter and other settings that you used when you took the picture.

The topic can prove to be confusing to the uninitiated. So read on, find out more, and soon you'll be handling EXIF like the experts!


The EXIF information from a digital photo
 

EXIF (Exchangeable Image File Format) metadata is pretty much the standard format in use for most digital photos. Metadata is not information that you can 'see' in the same way that you see pixels in your digital photo. Rather, you’ll need an EXIF viewer or an EXIF launcher to see it. You’ll benefit greatly from knowing how to interpret this data.

1. What is EXIF?


EXIF, as stated, is the standard format for metadata in your digital photos, a standard invented and made popular Japan Electronics and Information Technologies Industries Association (JEITA).


All digital cameras and major image processing programs nowadays work with EXIF. Your digital camera remembers the settings you used to take your picture, such as exposure and focal length, and then stores it into EXIF format and saves it to your memory stick with your image file.


You can imagine the usefulness of this feature for a variety of situations where you tweak your photos in-camera. Imagine, for example, that you crop a picture you’ve taken using the camera’s crop feature. Your camera stores the information that defines the new cropped image in-camera, so when you print from the memory stick, it prints the cropped image and not the original unaltered image.


Metadata make this possible. Likewise, image processing programs like Adobe Photoshop are designed to work with EXIF metadata as well to properly reflect any picture adjustments that were made in camera.

 


2. EXIF Viewers


To interpret this EXIF data, you will need an EXIF viewer. There are many ways to go about this. Your image processing program should provide that functionality within the program.


Most image processing programs will store the EXIF metadata as properties of the image. Access your photo’s properties, and you should see a tabbed interface, with one tab indicating metadata. Here you’ll see information such as the Focal Length, Resolution, White Balance and so forth. Check your image processing program’s help for information about where your program stores its metadata.


You may be surprised to discover that EXIF metadata isn’t reported the same way between various cameras and image processing programs. One program may show that your White Balance is set to 'Auto', for example, while another program will show some number that you don’t think properly reflects the original settings. Or these programs will report varying figures depending on the camera you use.


Field tests have shown this to be true, but we trust in your case you will stick with one camera and one program. That should eliminate the headaches.

 


3. Make Sense of EXIF Information


If, however, you have more than one camera, you may want to take some steps to make some sense about different EXIF information reported by your program. The first thing you should understand is that your EXIF metadata is in read-only format.


The creators of EXIF saw no reason for you to overwrite the information, so it’s stored in the header of your image file where you won’t be able to touch it. (Unless you want to hack into it, something we don’t recommend)


Ok, so let’s suppose you have two cameras, and with both you took pictures with an Auto Focus setting. You open up your image editing program and examine the photo’s metadata for Camera #1. It reads, correctly, 'Auto'. You then plug in Camera #2, and it reads '1'. You know that both cameras were set to Auto, so you have to remind yourself that in Camera #2, 1 means Auto. We recommend that you create a cheat sheet to keep track of how numbers from one program translate into another program.

 


4. Image Editing Programs and EXIF


You have only two other alternatives to create some consistency between different EXIF information for your two cameras. First, find an image editing program that actually lets you change the metadata. We don’t know of many major programs that will let you do this, but it’s worth a try. The second option is to use software that will extract EXIF information to text files. You might be able to do this, on a per shot basis, with your existing image editing application.


There are some better applications to use if you want to extract EXIF information from a whole batch of images all at once. ImageMagick is one such program, although it’s probably not user-friendly since it’s a command line utility. Breeze System’s Downloader Pro is an easier-to-use Windows program that performs the same function. The extracted EXIF information in the text file is easier to read, and if you want to tweak it to achieve consistency in values between your two cameras, it’s certainly easy to do.

 


5. Advanced EXIF Analysis


You can take additional steps to create consistent values from your EXIF information. For example, you may notice that equivalent focal lengths for digital cameras and film cameras are noted using different numbers. This may be a bit disorienting at times if you are trying to relate your digital camera settings with what you know from the film world.


You can use your EXIF information to create a lookup, or a database of some sort, to perform the conversion—if you think it’s worth the effort. It’s up to you. Additionally, realize that if you get photos from a scanner as opposed to a digital camera, you will not have the same kind of EXIF information encoded in the final output. The only metadata stored will be about the scanner, perhaps a date and time stamp, but little else. A cataloguing program such as Extensis Portfolio 7 will allow you to alter the EXIF information stored in the images.

 


Conclusion


We hope this brief guide to EXIF has opened your eyes to the world of metadata, and shown how useful this can be for you. Whether you use an independent EXIF viewer or EXIF launcher, this kind of information serves a number of important purposes.


The digital camera stores all of your photo settings in the header portion of each image you take. Likewise, image editing programs then interpret this information so as to accurately reproduce the picture on your computer in its original dimensions. Finally, you can examine EXIF information and use it to better analyze and catalogue your pictures.

A Guide to the Various Camera Modes

A Guide to the
Various Camera Modes

If you've bought a camera that offers custom exposure settings and scene modes, you may be confused by all the options available.

We're talking about the different camera modes you find on your new toy.

While the standard Program, Aperture priority and Shutter priority modes are will be familiar to many, the latest digital camera models have many other scene modes which are bewildering to the uninitiated.

Which is then the purpose of this article - to help you understand the most common scene modes available in the digital cameras today.



The camera mode dial on a Nikon D70 camera

Auto Mode

This is the automatic mode found in all cameras. It is used by beginners and professionals who just want to take a quick snap without worrying about exposure settings. In the automatic mode, you will usually not be able to adjust ISO or white balance settings.

Shutter Priority Mode

The Shutter Priority Mode is best used when you're taking fast action photos and is usually found in entvhusiast or advanced digital cameras. Here, you select the shutter speed and the camera chooses the best aperture. Some examples would include sports or wildlife photography, where you’ll need a high shutter speed.


Aperture Priority Mode

The Aperture Priority mode is found in many enthusiast level cameras, such as the Kodak EasyShare DX7590, Panasonic Lumix DMC-FZ20 or the Canon PowerShot G6. Essentially, what happens here is that you select the aperture, thereby locking your depth of field. The camera then automatically sets the best shutter speed to match the conditions. When do you use the the Aperture Priority mode? Well, its very suitable when you're shooting a stationary subject when you want to control your depth of field and aren’t too concerned about shutter speed.

Manual Mode

In this camera mode, anything goes. You can set the shutter speed and aperture, with options to change white balance, ISO, flash and even focus on some cameras. Choose this mode if you know what you're doing and want maximum flexibility for experimenting with the photo.


Landscape Mode

As the name implies, the Landscape mode allows you to shoot pictures of landscapes like mountains, Your camera will select the smallest aperture possible under the conditions to maximize depth of field in the image.

Note that the Landscape mode may not always work. Playing with my Panasonic Lumix DMC-FZ20, I found that the camera attempts to deliver sharpness from the foreground to the background - but it really depneds on the lighting conditions and the lens used.


Portrait Mode

If you want to shoot close-ups of people or faces, the Portrait Mode is the mode to choose. When you choose Portrait mode, the camera will select a wide aperture setting, minimizing your depth of field for a soft background effect, and also may adjust your zoom. In addition, the flash setting will try to switch to red-eye reduction.


Macro Mode

If you take pictures of flowers a lot (I do), this mode is invaluable. The Macro Mode allows you to focus on objects at amazingly small distances - sometimes just centimeters from the lens. Use the Macro mode when you need to capture the smallest little details on your subject. When activating this mode, I usually use a tripod for best results.


Sports Mode

If you want to capture fast action, then you'll need the fast shutter speed setting offered by the Sports Mode. When you switch to this mode, your camera will automatically choose the fastest shutter speed possible given the situation. Some cameras will also activate continuous shooting (instead of single frame), enable the evaluative metering mode (if any) and also disable the flash.

Beach & Snow Mode

If you shoot pictures on the beach or the snow, the bright and reflective surfaces will confuse the camera. The Beach & Snow Modes serve to compensate for the abundant ambient and reflected light by slightly overexposing based on the meter reading.



Conclusion

Hopefully, this article has taught you a thing or two about the various scene modes available in your digital camera. Learn how to use the correct scene mode in a given photo situation - and you'll start to achieve better exposures. Happy shooting!

How to Buy Digital Camera Lenses

How to Buy
Digital Camera Lenses

Do you get confused by the different types of lenses in the world of digital photography? I know I was when I started out in this field.

We all need to learn about digital camera lenses because they are fundamental to good photography.

However, how do you distinguish between the different kinds of lenses? Wide-angle or telephoto? What focal length and what speed? What brand of lens do you buy?

There are so many different lenses with varying specifications available that it can be quite overwhelming to find exactly what it is that you require from a lens, but that is where we step in to help.



Some digital camera lenses available to the consumer

This article acts as a guide to explain the jargon and to allow you make a better-informed purchase the next time you are shopping for a new digital camera lens.

Choosing a Suitable Focal Length

Focal length is probably the most important factor that should be considered when choosing a lens, and for good reason: focal lengths determine the field-of-view of the photos you will be able to take successfully with your camera.

The two main types of focal length are telephoto and wide-angle, and while telephoto lenses have a narrow field-of-view and are best suited for close-up shots and portraits, wide-angle lenses have a wider field-of-view which is perfect for indoor photography and landscapes.

Keep in mind that the performance of lenses can differ from camera to camera, with the magnification power behind a lens generally being greater on a digital camera than on a 35mm film-based camera.

The Need For Speed …

When you hear about fast and slow lenses, reference is being made to a lens's maximum aperture, which is the maximum amount of light that a lens can let in. A simple rule of thumb is that a fast lens lets in a lot of light, while a slow lens lets in less light, which defines how your photos will look.

Maximum apertures are measured in f/stop numbers, which are actually a ratio of the size of the lens aperture and focal length. The smaller the f/stop number, the more light is let in. An increment in the f/stop number doubles the amount of light let in, so f/1.4 lets more light than f/2.0.

This may seem quite confusing at first, so the easiest way to make sense of it is to remember the following: fast lenses are best suited towards successful photography in darker lighting conditions, and slow lenses are targeted towards photography in lighter conditions.

The Ins and Outs of a Zoom Lens

Unlike a fixed-focal-length lens, a zoom lens often gives you the diversity of a range of focal lengths all rolled into a single adjustable lens. This can be great if you often have to switch between various lenses for different shots, but it is important to remember that not all zoom lenses have a constant maximum aperture, and those that do are often larger and more expensive.

Although the maximum aperture may be reduced as you zoom in using a lens with a variable maximum aperture, this may not be as important to some photographers as the reduced cost and size of such lenses. Keep this in mind when purchasing a zoom lens.

Add-on Lenses

Add-on or accessory lenses are targeted towards compact digital cameras, and allow owners of such models to significantly lengthen or reduce the camera's built-in focal length while at the same time being able to automate camera functions including f/stop settings and focusing.

These lenses can be an excellent low-cost add-on to your digital camera, with telephoto add-on lenses being able to increase focal lengths by up to 300%, and wide-angle versions allowing for reduction in focal lengths of up to 30%.

Final Considerations

There are several other terms to take into consideration when buying a digital camera lens to make sure you are making the best purchase. If your lens utilizes aspheric lens elements, then you can rest happily with the knowledge that your lens will help produce sharper photographs and help keep lens weight to a minimum.

Lenses using internal and automatic focusing also keep lens weight down thanks to less moving parts, and of course allow for faster focusing. Low-dispersion glass leaves photos looking less hazy or fuzzy, while stabilization systems help to keep images sharp when taken using slow shutter speeds.

Conclusion

Hopefully this article has helped you to better understand what to look for in a digital camera lens. There are a lot of terms to remember here - so before shopping for your new lens it may be a good idea to take the time to make a list of what you want to do with your camera. Then you can double check your requirements against the features of different lenses. If you are still unsure if a lens will cater for your needs then by all means try to test it so that you can see some results before you buy!

The Adobe Photoshop CS Book for Digital Photographers

The Adobe Photoshop CS Book for Digital Photographers




Do you have a problem editing your digital photos? Maybe you’ve taken a ton of during your last vacation, but are not sure how to clean them up.

Or perhaps you’re a traditional film photographer who needs help in the realm of digital photography.

There are many digital photography books out there, but many of them fall short of delivering the correct mix of content.

Well, look no further, because the Adobe Photoshop CS Book for Digital Photographers is the book for you. This book shows the exact techniques used by digital photographers in cleaning up their images.


The Adobe Photoshop CS Book for Digital Photographers


It’s written by Scott Kelby, who is President of the National Association of Photoshop Professionals (NAPP). This is a trade organization for Adobe Photoshop users, with thousands of members in the US and 63 countries. Scott is also the editor of various Photoshop magazines and is a leading Photoshop trainer.

The book itself is not meant to be an exhaustive reference on Adobe Photoshop CS. What it does, and does extremely well, is to show you the inside tricks that experienced photographers use. You’ll learn how the pros correct, edit, sharpen, retouch and present their photos to their clients.


File Browser Basics

In Chapters 1 and 2 of the book, you’ll learn about the file browser within Adobe Photoshop CS. Scott shows you have to perform basic navigation tasks and the layout of the menus and commands. There’s a nice tutorial on digital contact sheets which allow you to print an inventory of the pictures on a CD. This makes looking for a photo much easier.


Basic Photo Editing Techniques

Chapters 3, 4 and 5 expose you to basic image editing techniques in Adobe Photoshop CS. You’ll learn stuff like cropping, resizing and color correction. If you have a lot of underexposed pictures, the book shows you how the professionals fix these. I also particularly like the trick on taking small photos and blowing them up to poster size, with minimal loss in quality.


Other Techniques

There are many other techniques illustrated in the book. Throughout Chapters 6, 7 and 8, you learn techniques like masking, retouching and sculpting.

Have dark circles around the subject’s eyes? No problem. The book shows you clearly how to remove those ugly patches.

Want to change the color of the sky or the background? It’s simple to do by extracting the subject from the background.

You’ll also learn about the different types of sharpening available in Adobe Photoshop CS, how to stitch panoramic scenes and watermarking. Watermarking is important for stamping your photos with your personal signature.

Scott also shows you how to package your pictures. From creating a website, to burning a picture CD, the book shows you how using illustrative step-by-step examples.


Shortcomings

I thought one of the shortcomings of the book is the fact that it is slightly biased towards portrait photography. Many of the examples are geared towards portraits. I’d like to have seen more examples of other genres of photography, like action shots or landscape photos. In any case, this is a minor flaw.


Conclusion

In summary, the Adobe Photoshop CS Book for Digital Photographers is a fun to read and extremely informative guidebook. You’ll learn the tricks of the trade and how the pros editing and retouch their digital photos. What’s more, it’s written by one of the leading trainers on Adobe Photoshop, and should be an essential tome on any digital photographer’s bookshelf.

6 Tips To Prevent Your Digital Photos From Fading

6 Tips To Prevent Your Digital Photos From Fading



Do you take a lot of photos and find that after some time, the prints start to fade out? Well, you're not alone. This is a very common problem amongst photographers.

To prevent your photos from fading, you need to have a combination of a good printer, good paper, as well as good ink.

This article delves into the specifics of preventing digital photo fade - so read on and find out more.

1. Get A Good Printer

The first thing you can do to ensure your digital photos last a long time is to print them using a good quality printer. HP, Canon and Epson produce good printers and one model that comes to mind is the Epson Stylus Photo 2000P. Although a little expensive, it is touted as one of the best printers for preserving digital photo quality upon printing and preventing fade out.

Another model you can consider is the Canon S800 BubbleJet Pro printer - cheaper than the Epson Stylus Photo 2000P but it produces reasonably good prints. If you need to do some more shopping, check out this site for comparing printer prices.

2. Select Good Paper

The other piece of the puzzle with regards to preventing digital photo fade is the printer paper. Try to choose paper that goes well with your printer. For example, Canon printers will usually have Canon paper to go with their printers. Selecting paper suited to the printer you use will help to ensure the best quality prints and prevent photo fade.

3. Store Prints In An Album

One important tip for preserving printed digital photos is to store them in an album. Storing them in such a way helps to preserve them and make them less susceptible to fading. Avoid those albums with plastic covers to hold each photo though.



Store prints in album to preserve them longer

4. Display In Frames Under Glass

If you display your printed photos, its good to display them in frames under glass. Try to go for anti-UV glass and also, don't expose the photos to open air. This helps to preserve the photos for a long time.

5. Keep Photos Out Of Sunlight and Humid Areas

Printed digital photos, if kept exposed to sunlight and humid air, will necessarily fade out due to chemical reactions. Keep those photos away from the attic and heater areas and you'll be safe.

6. Make Sure Prints Are Dry Before Stacking

After you print out digital photos, make sure you allow them to dry before stacking the photos together. When you stack photos which are not completely dry, chances are you'll cause damage to one or more of the photos concerned.

Conclusion

I hope this article has given you some good ideas on how to preserve and prevent your digital photos from fading out. Digital photos contain good memories of your family and friends, so don't let those memories get washed away! I've to run now ... until next time, have fun taking pictures.

5 Basic Digital Camera Terms

5 Basic Digital Camera
Terms You Need to Know



Being familiar with the terminology used in any subject of interest in is always useful, and digital cameras are no exception.

Although most digital cameras available on the market allow you to simply point your camera and quickly snap a picture with the touch of a button, there is often a lot more going on behind the scenes than you may have realized.

All sorts of things happen in the camera once the shutter button is pressed.

Put simply, understanding the most important terms about digital cameras will allow you to make a better-informed purchase of a new digital camera, let you have more control over your digital camera’s features, and help you to take the best quality photos possible.


1. Megapixel

When we use the term megapixel, we are referring to the maximum resolution at which a digital camera can take photos in millions of pixels. This means that a camera with a range of 4 megapixels can take photos which each contain a maximum of 4 million pixels.

But what does this mean to the consumer? One word: quality. A higher megapixel count means better quality photos, and considering the price of digital camera getting lower all the time; you should try to stick with a digital camera that has a 3 megapixel range or above, especially if you intend of making prints of your photos.


2. Focal Length

Focal length is a term overlooked far too often in amateur photography, and refers to how much the lens of a camera can magnify a shot. Focal lengths are generally split into two categories, these being wide-angle and telephoto, which are better for spacious and narrow fields of view respectively.

Due to the ease of manufacturing telephoto lenses, digital camera manufacturers seem to provide wide-angle lenses in a lot less cameras, even though these lenses are better suited towards the type of photos that most people commonly take, including groups of friends and wide landscapes. To sum up, a wide-angle focal length is the better choice in most cases, with the 20mm and 35mm varieties catering to most people’s needs.


3. Digital Zoom

Unlike the focal length, digital zoom is a term that seems to be given a lot more attention than it deserves. Unlike optical zoom, which uses the physical lenses inside the camera to enlarge a scene, digital zoom electronically enlarges the pixels in the center area of a photo, meaning that any time you use the digital zoom function on your camera you are actually sacrificing the quality of your photos. It is a good idea to disable the digital zoom function all together to stop this from happening.


4. ISO

The term ISO stands for the International Standards Organization, but what does this have to do with your digital camera? The organization sets standards for photography, and the ISO range of a camera refers to how sensitive the camera is to light.

For instance, a low ISO number (100 or under) is not very sensitive to light, and is best for shots in good lighting conditions. A higher ISO range means that the camera will be suitable for photography in darker conditions, so it is best to look for a camera that has an adjustable range; ISO 100 to 400 should be adequate for most people’s needs.


5. Shutter Lag

Shutter lag refers to the time between pressing the button to take a photograph and the time when the picture actually gets taken. This may not seem a very important factor when buying a camera, but think of it this way: if you have to wait a second or longer for a photo to be taken, like with many older and inexpensive digital cameras, then chances are that you won’t end up with the photo you desired. Many camera manufacturers do not list the shutter lag time for their cameras, so the best way to find this out is by testing a camera before you buy.


Conclusion

Hopefully this article has helped you to better understand some of the most important terms used when referring to digital cameras, and in turn will help you to choose the digital camera that best suits your needs. I think that testing a digital camera before you make a purchase can help greatly when it comes to making a final decision, and it makes sense to do so; you may be using the camera you choose to capture your memories for years to come!