Full-frame SLRs drop in price

Camera manufacturers are churning out more and more digital SLRs with full-frame sensors, which are the size of one frame of 35mm film and significantly larger than sensors found in point-and-shoot digital cameras. While not cheap, these new SLRs are less expensive than in the past: The three most recently announced, Canon's 21-megapixel EOS 5D Mark II (Click on image at right for a closer look), Nikon's 12-megapixel D700, and Sony's 24-megapixel Alpha A900, all cost around $3,000. (Images of the Nikon and Sony SLRs are below.) In the past, most cost from $5,000 to $8,000.

But, you may be wondering, just what are the benefits of SLRs with full-frame sensors? There are at least two: They can handle a wider variety of lighting situations more accurately, and they limit the amount of visual noise that can distort and degrade an image.

To appreciate them, it's useful to look at the smaller sensors that point-and-shoots use. For example, consider the Sony Cyber-shot DSC-W300, one of the models in our recent Ratings of digital cameras. (Model information and Ratings are available to subscribers only.) It's a 14-megapixel subcompact point-and-shoot digital camera. That's two more megapixels than the Nikon D700.

So, what gives?

For starters, the number of megapixels has very little to do with a camera's sensor size. It only refers to the number of pixels on the sensor, or the camera's resolution. It determines how large you can print your image, but not how sensitive the sensor is. And it certainly is no indication of image quality. (If you're shopping for the best digital camera for your needs, find out what features you need to really focus on by reading our free "How to choose: Digital cameras" advice and watching our Digital Camera Buying Guide video.)

In fact, the Sony sensor is about 5 to 6 times smaller than Nikon's. So, each pixel on the Nikon D700 (Click on the image at right for a closer look) is larger than pixels in the Sony subcompact. And it's what allows each pixel to be much more sensitive to light, in turn, making the whole sensor more sensitive.

This is especially noticeable in very brightly lighted situations as well as low light. So, for example, when shooting a portrait on a sunny day, the Sony may not be able to capture the details in someone's hair if the sun is shining too brightly. With the D700, you're much more likely to see all the details in this highlighted area.

Cameras with small sensors also fall short in low-light situations. Details in a shadow area will often be swallowed up by dark tones. They'll also introduce something we refer to as visual noise, or unwanted "grain" or spots of color, that will further degrade image quality.

For example, if you use the Sony to take a group portrait at an evening event, in low light, faces may be mottled with specks of reddish or purplish spots. With the D700, that's far less likely to happen. In fact, with the D700, you can crank up the ISO setting (up to ISO 6400) to capture the shot, letting you increase the SLR's sensitivity to capture an image in low light.

If you crank up the ISO to its maximum setting of ISO 3200 on the Sony DSC-W300, you'll start to have problems. The image would most likely be tainted with specks of false color. It's why we suggest that you raise it no higher than 200 ISO, according to the "Max. ISO with best quality" column in our Ratings of digital cameras. This score recommends the highest ISO setting at which a camera can produce a good image. Better models should excel in low light.

For the D700, you'll likely be able set the ISO much higher-probably 800 or 1600 ISO, if not higher. (At the moment, we haven't included the D700 or any other full-frame SLRs models in our Ratings of digital SLRs, which is why we don't have an exact number for our "Max. ISO with best quality" test.)

SLRs with full-frame sensors have other benefits as well. Since they are the same size as a 35mm frame of film, they generally eliminate what we refer to as a lens magnification factor. A basic SLR like the Nikon D60 has a magnification factor of 1.5x, which means if you attach a 50mm lens, it will have a focal length of 75mm. This factor is important because it boosts a zoom lens's telephoto capabilities, while reducing its wide-angle. On full-frame SLRs, a 50mm lens remains a 50mm lens. For more on lens magnification factors, check out the "Sensor Size and Lens Magnification Factor" section of my first impressions of the Canon EOS 40D Digital SLR.

Shortly, our labs will be checking out the performance of this full-frame sensor technology and comparing it with conventional SLRs.

For more on the SLRs mentioned in this post, check out the Nikon D700, Canon EOS 5D Mark II or Sony Alpha A900 (Click on the last image at right for a closer look).

—Terry Sullivan

Comments

[Frank Symbula]

I have shot film for many years and was always frustrated that my wide,17mm-35mm, f/2.8, would no longer serve it's purpose as a great true wide angle lens. Canon has had a good selection of full sensor products and being a Nikon enthusiast I was pleased by my purchase of a D700 and that all of my fast and wide lenses performed as designed. This along with the quality, low noise and large reproduction capabilities make any full sensor camera well worth a look for any serious photographer at any skill level if theirquest is a superior image and the ability to handle tricky lighting situations

[Frederick Dunn]

It's wonderful to be able to come to CR for objective camera spec and performance reviews.

As you have not yet posted CR Ratings on the full frame SLR's and I'm sure you will be thorough as always... Consider lens type differences and how they make use of, or fail to make use of the full sensor size.

The DX compared with the FX lenses, the effect on sensor vignetting with the incorrect lens. I use both the D300 (DX) and the D700 (FX) as lenses are a big part of the investment for photographers and advanced hobbyists, this is an important consideration. Put a DX lens on a FX camera the the sensor drops, those expensive DX lenses will fail to fully exploit the D700's large sensor. It's preferred to have the FX lens with the Nikon full frame line...

Very much looking forward to your future articles on the subject.

[Mel Dorin]

If you are a landscape photographer, you will probably want to do at least two things-- print large and photograph in low light conditions. Because of this, I have been limited to large format film cameras to get the quality I need for fine-art work. If the digital small format SLR full frame equipment can solve the technical problems of high resolution and low light imaging with no noise, then that would basically revolutionize the market for large format photographers and put quality lightweight tools finally in our hands. I hope that Canon and Nikon, at least, can do this with the full frame next generation equipment to come. Please do a careful job of evaluating these cameras. You are an oasis of unbiased opinion in an otherwise overhyped product area.

[Armin Helisch]

I am looking forward to your test report on full frame cameras! I love the D700 (superb handling, responsiveness, virtual horizon, ability to fully use old lenses without chips, image quality at low light, ...) and have been able to try it for almost 2 months, thanks to Crutchfields very generous return policy. I finally returned it, because now, finally, digital SLRs with video mode are coming out and as a tango dancer I have been craving for this. The combination of full frame with video mode (Canon 5D Mark II) sounds like a dream come true...hopefully Nikon will follow soon! It remains to be seen whether Canon sacrificed low light image quality by sqeezing 21 megapixels on their 5D Mark II sensor, but the images on their website on on a DP Review preview look promising...