DSLR News - October 2008 I recently realized that there is no longer one true "type" of digital SLR camera. There used to be, but as time an technology have marched on, the digital SLR camera has "evolved" into several distinct camera sub-types. Today, there are five types of digital SLR cameras you can lay hands on, and I'll begin with the most common one. 1) Cropped Sensor SLRs The vast majority of the digital SLRs of old and the modern ones of today fall into this category. They are cameras where the sensor is not the same size as a frame of 35mm film - it's smaller. When you use lenses originally intended for film SLR cameras on a cropped sensor SLR, parts of the image captured by the lens are left out. This leads to a common effect called "crop factor" or "focal length multiplier". 2) Full Frame SLRs I discussed full-frame SLR cameras in more detail in last month's newsletter, so I'll be brief about this type of camera. Simply put: a full-frame SLR has a sensor that's the same size as 35mm film. Forget about crop factor and focal length multiplication: they don't apply with a full-frame SLR camera. Today, full-frame cameras are significantly more expensive than their cropped frame counterparts, but I expect this to change as more full-frame cameras are released and competition in this category increases. 3) 4/3 SLRs The 4/3rds format was originally conceived to allow consumers to swap lenses between cameras made by different manufacturers. The 4/3 format was adopted by both Olympus and Panasonic, but since Panasonic hadn't developed any lenses on their own, this really only meant that you could use an Olympus lens on a Panasonic SLR. This format does have an impact on the aspect ratio of your photos - something to be aware of if you want to make large-scale prints. 4) Micro 4/3 SLRs This new format - which I'll discuss in more detail later in this newsletter - creates a brand new category of camera that ultimately could be immensely appealing to a huge number of compact digital camera users. It does away with one main feature of an SLR - the optical viewfinder - but retains the ability to change lenses. Micro 4/3rds cameras will be tiny compared to other SLRs but should still offer the increased speed and image quality that you're used to getting from an SLR. 5) Video SLRs A few short months ago there wasn't a single SLR camera available that could take both stills and video - now there are two (the Nikon D90 and Canon 5D Mark II) - with plenty more rumored for early 2009. The video captured by these SLRs isn't designed to be played back on your computer or shared via YouTube - instead, the video is optimized for display on widescreen flat-panel television sets. So there you have it - the five main types of SLR cameras currently available. Only time will tell which ones catch one and which ones fall flat. Either way, there's a lot going on in the world of digital SLR cameras and the Digital SLR Guide (and this newsletter) will continue to keep you updated about the latest and greatest cameras available.

In This Issue SLR Types EF vs. EF-S Lenses Exposure Compensation Do You Need a Small SLR? Micro 4/3 Photo Links Latest SLR Guides Nikon D60 Canon Rebel XSi Pentax K20D Canon 40D Olympus E-510 Nikon D80 Canon Rebel xTi Nikon D40 Digital SLR Terms Megapixels Stabilization ISO / Image Noise Sensor Dust Crop Factor RAW vs. JPG Continuous Photos Autofocus Points Aspect Ratio Lens Terms Focal Length Prime vs. Zoom Maximum Aperture First vs. Third Party SLR Lens Features Canon Lens Glossary Nikon Lens Glossary

Digital SLR Q & A

Question: What's the difference between Canon EF and EF-S lenses?

Answer

It's good that I opened this newsletter by talking about different camera types - it will make answering this question a whole lot easier.

Canon EF lenses are designed to work with film SLR cameras and full-frame digital SLRs, while EF-S lenses are only compatible with cropped sensor SLRs.

EF-S lenses are optimized to project an image onto a sensor that's smaller than 35mm film. The theory here is that EF-S lenses will capture sharper images when used with a standard digital SLR than EF lenses which aren't optimized for the digital format.

The only potential drawback of investing in a slew of EF-S lenses today is that if you decide to get a full-frame SLR in the future, the lenses won't be compatible with that camera. If you only purchase EF lenses, then you can rest assured that they'll work with both cropped sensor and full-frame SLRs.

Having said that, cropped sensor SLRs are definitely here to stay and won't become obsolete any time soon.

Full-frame SLRs are becoming more common, but they are currently aimed at the professional photographer market, and are priced well out of the range of the average consumer budget.

So, if you've used my 6-step guide to finding the right digital SLR lens and have determined that an EF-S lens is the best match, don't fret too much about compatibility unless you're 100% sure that you'll be upgrading to a full-frame SLR within a few years.

See all of Canon's latest EF-S lenses

DSLR Cheat Sheet

This month's cheat sheet tackles a fairly universal problem with all digital SLR cameras: How to Take Pictures in Shade.

At first, this sounds extremely straightforward. I mean, why would taking pictures in the shade be any different from taking pictures in sunlight or using a flash?

Here's the problem: virtually all digital SLRs left on AUTO mode will under expose every photo you take in the shade.

This is a sample image taken in the shade in AUTO mode with no further adjustment on my part:

I can honestly say that I have no idea why shade creates such a problem for the exposure sensors inside digital SLR cameras. Regardless of the cause, every digital SLR I have ever used exhibits this behavior.

You can tell that it's a widespread problem, because the new Canon 50D has a feature specifically designed to correct this problem: it's called "Auto Lighting Optimizer".

Auto Lighting Optimizer just boosts the exposure a bit when you're taking photos in the shade - this is something that you can do manually, and I'll explain just how in the steps that follow.

1. Set your camera to Program, Shutter Priority or Aperture Priority mode
This first step is important, because in these three modes, you'll have access to another setting called "exposure compensation" (which is unavailable in the AUTO and program modes).

2. Point the camera at a subject in the shade and press down halfway on the shutter release
This will take a reading of the available light in the scene, and will set the aperture and shutter speed accordingly. You'll notice a scale inside the viewfinder (this is the light meter) and the reading should be at zero (meaning the camera thinks the photo is correctly exposed).

3. Take a picture
You should notice that this first image - like the one I've included above - looks a bit dark and muddy on the LCD screen

4. Find the Exposure Compensation setting on your camera
Exposure compensation is really just a fancy name that indicates that you are in control of exposure, not the camera. With exposure compensation, you can tell the camera to ignore its light meter, and intentionally over or under expose every photo you take.

5. Intentionally over expose
Exposure compensation lets you shift exposure in small increments until the photo looks right. Since you are taking a picture in the shade, you're going to need to change the exposure compensation setting so that the camera thinks the photo is over exposed.

Since the camera is "accidentally" under exposing, forcing it to over expose actually brings things into balance, creating a photo in the shade that's much more vivid and bright than it would be if you took the shot in AUTO mode.

Here's my second pass at the image above:

Special Note: if you do fiddle around with exposure compensation, just make sure you set it back to zero before you take pictures in sunlight. In sunlight, the camera's light meter should take an accurate reading and if you leave exposure compensation set you're going to get a lot of pictures that are WAY too bright.

What Do You Need?

The question for this month is: Do you need a small-sized SLR camera?

Not all digital SLRs are created equal when it comes to functionality and the same is also true when it comes to size and weight.

More "professional" models tend to be much larger and heavier than their consumer or "entry-level" alternatives, since pros have come to expect a certain feeling of durability in the cameras that they use.

However, with advancements made in materials, you can now get a camera that's quite durable and can withstand some pretty good bumps without having to carry around a lead weight all the time.

The biggest advantage of small-sized digital SLR cameras is their portability: whether you're into travel photography and want a camera to go with you, or you enjoy snapping photos on the streets, having a small camera will ensure that the camera is with you more often rather than back at the hotel in its bag.

On the flip side, there is a drawback to the new crop of tiny and lightweight digital SLRs: they aren't easy to hold, especially if you have long fingers.

The larger cameras like the Canon 40D, Nikon D90, Olympus E-3, Pentax K20D and Sony DSLR-A350 have very large hand grips which makes them easy to hold - you don't ever feel like the camera might slip out of your hand.

Smaller cameras like the Canon XS, Nikon D60 and the Olympus E-520 require some people to curl their fingers in order to get a good grip on the camera.

If you're thinking of buying one of the small-sized digital SLRs, the best advice that I can provide is to try one first. Go to your local camera store and hold some of the demo models in your hand.

Ergonomics can play a surprisingly large role in how comfortable you feel using a camera and hence how often you want to use it. A camera that "feels good" in your hand will be a joy to use which means that you'll have it with you when those important photo opportunities come by.

New Digital SLRs: Micro 4/3

A new breed of digital SLR camera has recently emerged, and it's fitting to talk about it right after the previous section on camera size and weight.

Part of the name gives it away: Micro 4/3rds cameras are almost the size of a compact digital camera, yet they still allow you to use interchangeable lenses (Micro 4/3rds press release).

How do they get away with this? They do away with a part of a "true" SLR camera: the optical viewfinder.

Traditional digital SLRs work like this:

1. Light passes through the camera lens
2. Light strikes a mirror that's in front of the digital sensor
3. The mirror reflects the light up to a group of reflective surfaces that turn the light 90 degrees
4. The light emerges through the camera viewfinder

The upshot of all this light getting bounced around is that when you look through the viewfinder of a digital SLR camera, you see exactly what the lens sees. Even if you whip the camera in a circle to track a moving subject, the image that you see in the viewfinder is equivalent to watching the subject with your eyes.

Micro 4/3rds cameras eliminate this reflective system entirely and opt instead for an electronic viewfinder (also called an EVF). When you look through the viewfinder, what you're seeing is a video projection of the image that's passing through the lens and striking the camera's sensor.

It's equivalent to using the live view option on many modern digital SLRs, except that the LCD screen inside the viewfinder is tiny.

The upshot of using an electronic viewfinder instead of an optical one is that the camera body can be dramatically thinner: about 1/2 the thickness of a more traditional SLR.

So what you now have is a camera that is virtually the same size and weight as a compact digital camera with one massive difference: you can change the lens whenever you like.

Rather than having to settle for the one lens the manufacturer attached, you can swap lenses out to take landscapes, portraits, wildlife and macro shots.

The companies that developed this new format - Panasonic and Olympus - are hoping that the small size, low weight and electronic viewfinder are the keys that help some owners of compact cameras finally make the transition to an SLR.

The first camera to market that leverages the Micro 4/3rds format is the upcoming Panasonic DMC-G1.

Photo Links

In Conclusion

Wow - what an incredibly busy month this has been!

I don't often try to tackle two cameras guides at the same time but it has been interesting - and informative - to be simultaneously using both the Nikon D60 and the D90.

Having both cameras at my disposal really allows me to compare and contrast how the "feel" and performance of each camera is different - something that can be just as important as the features packed inside.

In my Nikon D60 guide, I mention the fact that the camera is a great option for beginning digital SLR users - while this is not the case with the D90 (reading some of the manual made me go cross-eyed) the D90 excels in areas where the D60 does not.

I'm hard at work on that Nikon D90 guide even as you read this, so look for that to be published in the very near future.

Until then, happy picture-taking!

--Chris Roberts, Your Digital SLR Guide

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