The Heart of a Digital SLR: The Sensor

The sensor is an important part of your camera. And while it should never be the “be all and end all” when making a camera purchase, you should put thought and consideration into the type and size.

The CCD (charged-coupled device) is the most common type of sensor in a digital SLR. Every manufacturer offers at least one model with a CCD. They offer the highest image quality, hands down, but they are of course, the most expensive and use a lot of power.

CMOS (complementary metal-oxide semiconductor) strip away extra circuits on the chip to increase a pixel's light-collecting area while reducing costs and using less power than a CCD. The only con is they are bigger and therefore, the cameras are bigger.

What about sensor size? There are three standard sizes. The first is called Four Thirds, found on Olympus and Panasonic cameras. It's a standard size that was created by Olympus and Kodak, measuring 17.3mm by 13mm. Most other DSLRs use an APS sized sensor, the second standard size. It is a fairly loose term for a sensor the size of an APS-C or APS-H film format. Finally, we have the 35mm-film format, also called a full-frame because it is the size of a standard frame on a roll of 35mm film. These sensors are big and expensive to build. You'll find them on the Canon EOS 5D and the Nikon D3.

We can thank large sensors for giving us better photos with less noise, a greater dynamic range, and better performance at high ISO settings.  

Battle of the Cameras: DSLR vs. Interchangeable-Lens Camera

Last week we saw a digital SLR do battle with a high-end point-and-shoot—today the DSLR faces its hybrid challenger, the interchangeable-lens camera. The main difference between these two cameras is that the latter does not have a mirror to bounce the image to the viewfinder.

The major difference between these two cameras lends itself to the main advantage of a DSLR over an ILC. The viewfinder on a DSLR is superior and ensures there is no update lag. The mirror allows the photographer to see what is currently happening in the viewfinder, while an ILC can only show you what has already happened. The advantage to the EVF, however, is that it accurately displays exposure and white balance. Some optical viewfinders on DSLRs can do this, but it comes at a greater cost.

While there are certainly plenty of digital camera lenses to choose from for ILCs, the selection is still larger for digital SLRs. DSLRs also have the ability to use older film-camera lenses without an adapter. But with better technology and bulky lenses, DSLRs tend to be bigger and heavier than ILCs (though there are compact DSLRs, as well as large ILCs on the market).

The bottom line is that the ILC is a good stepping stone for consumers who want a step above their point-and-shoot but without the bulk and the high cost.  

Battle of the Cameras: DSLR vs. High-End Point-and-Shoot

As an effort to keep consumers purchasing the standard point-and-shoot, we have seen a great insurgence of more high-end digital cameras. These are a great option for photographers looking to increase the quality of their photos without breaking their budget. But can they really compete with the quality of a DSLR? Let's find out in this head-to-head battle.

An SLR offers superb lens versatility. Most manufacturers offer at least 40 digital camera lenses, allowing you to accurately target and compose your shot. The disadvantage? The pentraprism we talked about last week isn't light as a feather. SLRs are much bulkier, and so are many of their accessories. However, most entry-level models are lighter than their more expensive counterparts.

One cannot doubt the increased image quality of an SLR. 10 megapixels on an SLR is better than 10 megapixels on a digicam. It's even more apparent at higher light sensitivities. With better quality, though, comes more complexity. For some, it's a welcomed lesson, while for others it's a confusing chore.

The performance of an SLR cannot be beat. They have a faster autofocus, shorter shutter delay, continuous shooting, and more memory. And all that comes at a higher price. But cheaper SLRs are now about the same price as high-end point-and-shoots.

The digital SLR doesn't just come with great lens choices, they also have a host of accessories to improve quality, including external flashes, wireless transmitters, remote triggering, and more. With an SLR, more is, well, more! If more sounds good to you, then opt for the SLR.  

The Leap to Digital SLR Cameras

Over the next few weeks I'd like to devote some time to amateur photographers. As of late, there has been an increased interest in the purchase of SLR cameras. A decade or so ago they were used solely by professionals, students, and serious hobbyists. But today, we all know someone with little-to-no photography knowledge desiring the quality of a digital SLR. We may as well give them some advice before they purchase and we sincerely hope that the occasional photographer turns into a more serious hobbyist!

So what the heck is an SLR? It stands for digital single lens reflex because these cameras use a mirror behind the lens to direct light towards the viewfinder. As the shutter is released, the mirror moves out of the way, allowing light to travel to the sensor and briefly blacking out the viewfinder. A prism inside the viewfinder flips the image right side up and bounces it onto the screen.

All SLR cameras are not created equal, however. There are several types and you should know the difference before investing. The one most people are referring to when speaking of one is a full system digital SLR with an interchangeable lens. Users can remove the lens and replace it with another. Almost all SLRs today are this type.

A fixed-lens digital SLR is one in which the lens cannot be removed. Most use a semitransparent, non-moving mirror to bounce some of the light to the viewfinder, while the rest of the light goes through the main sensor. This translates to using the LCD to compose the shot.

An SLR-like, or SLR-style, is actually a standard digicam that uses an electronic viewfinder (EVF) instead of the standard pentaprism. They're technically not an SLR because they don't use a mirror and the image quality does not compare.

And lastly, we have the interchangeable lens camera, also known as a hybrid camera. They use the technology of a point-and-shoot with the ability to change digital camera lenses. However, they too use an EVF and lack a mirror in the viewfinder.