DSLR cameras are typically equipped with either an APS-C size sensor or a larger, full-frame sensor. Full-frame cameras are generally bulkier, more expensive and require larger, full-frame lenses. If you’ve been wondering what advantages a full-frame dSLR offers and whether the benefits justify the bulk and expense, this article will explore the strong points of full-frame sensors.
Nearly all 35mm film cameras were designed for a frame size of 24x36mm. There were a few quirky SLRs that used a different film size, and medium format SLR cameras used much larger 120mm film. Overall, however, the typical film SLR standardized on a frame size of 24x36mm.
Full Frame DSLR Camera
The first dSLRs created a dilemma for camera-makers. It was difficult to build a sensor the size of a 35mm film frame. Availability of larger sensors was limited, and the quality of some early 35mm size frame sensors was questionable.
For this reason, dSLR makers adopted a sensor the size of the APS-C film frame, which measures 15.7×23.6mm. APS size sensors were simpler to make and while smaller, offered sufficient quality for most users.
By the time digital technology evolved to where it became practical to build reasonably priced full-frame cameras, APS dSLRs had become the standard. While the majority of dSLRs still use the APS size-sensor, full-frame cameras appeal to photographers for several reasons:
Image quality
Since an APS image will require more enlargement than a full-frame image to obtain a specific size, prints from a full-frame image will almost always be superior. For small photos, the difference is marginal, but 8×10 and larger prints are noticeably superior from a full-frame camera.
Improved Dynamic Range
Dynamic range refers to the ability of a camera to capture detail in both the shadows and the highlights. Manufacturers use different methods of processing images inside the camera, so it is difficult to compare dynamic range between brands. Overall, however, smaller sensors capture less dynamic range. This means prints from the full-frame dSLR have better tonal range.
Less Image Noise
Many photographers assume a manufacturer can cram any number of pixels into a sensor, so sensor-size is irrelevant to pixel count. In reality, sensor dimensions determine the size of the individual pixels. For a sensor of any given pixel depth (megapixel rating) full-frame sensors will contain larger photo-sites (pixels). Larger pixels collect more light, so there is less need to amplify the signal. Amplification translates into heat, which increases image noise. When you compare sensors of the same pixel count, a full-frame sensor will generally control image noise better than its APS cousin.
Availability of Wide Angle Optics
Cameras with an APS-C sensor are often referred to as “crop” cameras, because the smaller sensor captures a reduced portion of the image compared to a full frame sensor. In other words, an APS size sensor crops the image that a full-frame camera would deliver.
This magnifies the effective focal length of the lens. A 200mm lens on an APS-C camera will capture an image roughly equal to a 300mm telephoto on a full-frame dSLR.
At first this might seem to be a big advantage, and many wildlife and sports shooters choose crop cameras for this very reason. They get a longer focal length without the need to invest in super-telephoto optics.
Of course the focal length magnification applies to all lenses, so it becomes difficult to find suitable wide-angle lenses for an APS sensor camera. They can be had, but they are rare and expensive. Fast wide-angle primes are particularly hard to come by. So those who shoot landscapes, interiors or other wide-angle subjects will find a full-frame dSLR offers a major advantage.
Greater Selective Focus Options
Selective focus, the ability to isolate subjects from the background, is closely coupled to shallow depth of field. Although a number of elements affect overall DOF, selective focus increases as you get closer to your subject. Because the smaller sensor magnifies the image when compared to a full-frame camera, you have to move farther away to get the same composition.
The result of this is that for any given focal length, you will see less selective focus with an APS-C sensor, because you need to shoot from farther away to achieve the same image crop. Long telephoto lenses are capable of delivering nice selective-focus effects on an APS-C camera, but on the whole, you will achieve greater, more pleasing selective-focus with a full frame camera, particularly with shorter focal-lengths.
Ability to use lenses at their designed focal length
On a 35mm camera, a focal length of 35mm is considered a wide angle, while a “normal” lens has a focal length of 50-60mm. Telephotos start at around 85mm.
Because of the crop factor, a normal lens on a APS camera would have a focal length of 35mm, while a 50mm lens is equivalent to a 75mm lens. An extreme full-frame wide-angle of 16mm would only offer the view of a 24mm lens when coupled to the APS-C camera.
This might seem to be an exercise in semantics, but many photographers have favorite lenses, and are distressed that they cannot use them as they could on a film camera. This problem is compounded because they may not be able to find a suitable lens to give them the same effects on an APS-C camera. High-speed 50mm lens are quite common, but it is difficult to find a 35mm f/1.4 optic. In other words, very fast “normal” lenses are practically nonexistent for APS-C cameras.
Whether any of these factors are relevant to you will depend on your subject, your final application and your style of shooting. For many photographers, the APS-C sensor will provide all the quality and composition ability they need. For others, however, full-frame sensors offer superior images and special effects that cannot be duplicated with a smaller sensor.
About the Author
Do you want to improve your photographs? Take better pictures with the help of the Photography Basics resource at Alphatracks.com. You’ll find free, easy to understand information about cameras, lenses, lighting and basic photography techniques.
Tom Bonner is the author of the Sony Alpha DSLR – A300/A350 Digital Field Guide, published by Wiley Publishing.
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If you read Tom Bonner and Michael you have the full picture – not easy to get, you normally have to read a lot of sites to get that – THANKS TO BOTH
Michael: I am from Europe, so I need to be sure, when you use inches;);):
Do you say, that printing u n d e r 18 x 27 inches (that should be about 45 x 68 cm ) is SO good with the Nikon D7000/Pentax K5 at iso 100 up to iso 1600 as the 24MP camera ??
I’m glad that they make both cropped sensor and full frame sensor. We own and use both regularly. The coolest thing about this is that it effectively adds “new lens” selections to your arsenal. Have a 50mm lens? With both cameras you now have an 80mm lens if you want it.
Plus, with Canon’s crop sensor cameras, you’ve got the ability to use the EF-S line of lenses plus the EF lenses. The EF-S lenses tend to be lighter and less expensive, which is definitely a plus.
I like both full and crop sensors – neither is “better”. They just both have different purposes.
I like the article as it is. Its not complete but it says the right things in short.
@michael: Your right too. But I think, that the author of article had not the intention to deliver a complete comparison with all the pros and cons to FF and APS-C or similar formats. It seems to be just some kind of a short information.
Most of your points I do agree with. But you compare the absolutely latest gizmos in APS-C cam-tech with the current available FF products on the market. Cams in APS-C Format are produced in much bigger numbers than FF cams and the innovation in that field renews itself much faster than in FF format. This is because APS-C cams are meant for a wider mass of customers. FF cams are mostly designed for pros and a pro is not interested in spending every year new money in the latest tech-gimmicks available on the market. Pros have to rely in a perfect product that lasts at least 2-4 years of operation time in their hands. Most FF cam brands refresh the product line in such a cycle. And always the steps in the next generation makes them ahead of the most APS-C cams. One can say, that for the manufacturers the APS-C format is something like the live field test center for new tech later used in FF cams.
I for myself use both formats as a pro and for private purposes too. Every format has its advantage for some reasons. And i like the possibility to chose what I need for what I want do do.
While most of your points are valid, this article tells less than half the story. I’ll admit that the current high end full frame cameras will produce better poster sized prints, for what most of us will hang on our walls the difference, if any, is too small to bother with.
Disadvantages of a Full Frame Camera
Cost. The least expensive full frame camera is the Sony A850 at $2000. The next least expensive full frame is another 400-500$ and these are the low end full frame cameras from Nikon and Canon. Those and the Sony all have areas where they compare less than favorably with the newest APS models. Also lenses for full frame cameras are often more than the crop sensor equivalent. You need to step up to the next level of full frame models to really have an across the board advantage. $5000 for a camera body? No thanks.
Weight. Full frame cameras weigh significantly more than APS sensor models. Since their lenses have to be larger, the lenses add to the weight. This is a major reason why I gave up on FF models.
ISO. While it’s true that Nikon and Canon Full frame cameras beat crop sensor cameras for low light use, the Sony full frame cameras are actually worse at high ISO than the latest crop of APS cameras. And the difference even for the Nikons is only a stop.
Dynamic Range – Looking at the DXO Labs ratings on the new Nikon D7000 and Pentax K-5, it turns out that the widest dynamic range currently comes from the Sony APS-C sensor they use.
Depth field. While it’s true that for shallow depth of field, FF cameras have a stop advantage, for wide depth of field, APS cameras have the equivalent step up. Give with one hand, take with the other.
Telephoto. For wide angle shots FF cameras have an advantage. For telephoto work a lens a third shorter brings the same results. Think less money and weight. So for sports, wildlife or any distant shots, the APS camera has a decided edge. This also means lighter and less expensive lenses have the same reach. And if you have trouble multiplying by 1.5 you have my sympathy.
Processing speed. The flip side of having the larger files of a full frame camera also means that they take more of a speed hit when using the files in Photoshop. That is unless you are using the Nikon 12 MP full frame cameras with have the same or lower resolution than current APS cameras.
Storage space. Convert your FF files to 16 bit tiffs for printing and you have huge files. That difference in fils size quickly adds up.
Finally, for print size, you should really look at the new Pentax K-5 images (probably the Nikon D7000), too). I compared them to the same scene shot with a Sony A900 and below 18×27 I can’t tell the difference until 1600 ISO and above where the K-5 has a decided advantage.
I fully agree with you on the advantages of a full-frame verses a cropped camera, and I don’t even own a full frame –the quality is simply there when viewing images made with such cameras.
However, I’m confused about the magnifying power you mention for a cropped camera. I also thought that a 50mm continues to behave as one, simply with less field of view. There is no REAL magnification, is there? I’ve done some comparison looking through a 50mm on my 1970s Pentax verses my D200 on the Nikon 50mm and the visual effect seems the same, but I am simply seeing less within the frame on my D200 because of the limited field of view verses a full frame. Am I wrong?
Anyhow, less or more, I really wish I could afford a full frame. I feel owning one is an element that can take one’s images to another level. It doesn’t make you a better photographer, but the quality, tonal range, and so forth are all big pluses when you have a given vision in mind. For example, I suffer when it comes to low-light photography, even with faster lenses on my Nikon D200; the grain at 800 ISO is terrible at night.