What is a full frame?
By Eugene Struthers
This is the term used to describe a camera with a sensor the same size as a 35mm film negative, measuring 36X24mm. Most DSLRs have a sensor which measures approximately 24X16mm. Digital camera's with a smaller type of sensor are classified as APS-C, which is relative to the size of a APS-C film fomat from which they get their name. When digital technology was just beginning, all digital cameras had a sensor at about this size (24X16mm). The APS-C sensor produces an image with a narrower angle of view as a result of capturing a smaller area of the image than a full frame digital camera with a 35mm size sensor. So if you don't want large parts of your image cut off, then use a full-frame digital SLR camera. A Full frame digital SLR cameras have image sensors which are the same size as a 35mm film. This means that they have no crop factor or focal length multiplier. A point to remember: A digital SLR sensor is smaller than a standard frame of a 35mm film.Which basically means a full frame camera has zero crop factor or a focal length multiplier of one. A 35mm lens on a full-frame digital SLR camera captures an image just like a 35mm lens on a film SLR camera. But a 20mm lens on a APS-C camera sensor with a crop factor of about 1.6x will not be wide angle lens anymore. If the lens has a fixed focal length of 20mm. Once we consider the crop factor of 1.6X. It will probably capture images more like a 32mm lens (20mm X 1.6X = 32mm). So it will not be considered wide anymore. A 35mm lens on a full frame camera will still deliver images of a 35mm lens.
Which basically means a full frame camera has zero crop factor or a focal length multiplier of one. A 35mm lens on a full-frame digital SLR camera captures an image just like a 35mm lens on a film SLR camera.
But a 20mm lens on a APS-C camera sensor with a crop factor of about 1.6x will not be wide angle lens anymore. If the lens has a fixed focal length of 20mm. Once we consider the crop factor of 1.6X. It will probably capture images more like a 32mm lens (20mm X 1.6X = 32mm). So it will not be considered wide anymore.
A 35mm lens on a full frame camera will still deliver images of a 35mm lens.
Okay! lets look at it this way.
To fully understand the concept. Imagine you are standing on the beach photographing a lighthouse far off in the distance. You take the image using a standard roll of film. The entire lighthouse fills the whole frame of your image. Now without moving your position on the beach. You pick up your digital SLR camera, we know that our digital camera's sensor is smaller than that of the 35mm film. You take an image using the Digital camera and compare images. Do you see the difference? Large sections around the top and sides of our image are missing, almost creating an artificial zoom effect. Our APS-C digital SLR camera has captured less of the scene with the lighthouse than the film SLR did. This is termed the crop factor as the sensor in the APS-C digital camera has cropped the view. To correct the crop, we will need to step back wards a few steps to include the cropped area's back into our image.
Example: 100mm lens
You decide to attach a 100mm lens to a digital SLR camera with a 2.0 crop factor. You will discover that the camera will capture images more like a 200mm lens on a film SLR (100mm X 2.0 =200mm).
Camera manufacturer / Crop factor
Crop factor Focal length New Focal length
1.5 28mm 42mm
1.6 28mm 45mm
2.0 28mm 56mm
What are the benefits of a Full Frame camera.
Full frame digital SLR sensors can use standard wide angle lenses to capture dramatic buildings and landscapes.As the full frame sensor is larger than the APS-C digital SLR camera sensor, it can capture larger, higher quality images in low light situations.
Type Dimensions Description
Compact 8.8 x 6.6mm This is the type of sensor that's used in many compact digital cameras.
Micro 4/3rds 17.3 x 13mm This sensor is used in mirrorless digital SLRs made by Panasonic and Olympus.
4/3rds 18 x 13.5mm All Olympus digital SLR cameras include this size sensor.
APS-C 23.7 x 15.7mm This is the most common sensor size in digital SLR cameras, and is also used in some mirrorless DSLRs.
Full Frame 36 x 24mm Used in high-end digital SLRs, this sensor is the same size as a frame of 35mm film.
The comparison above gives an accurate indication on the relative sizes of different sensors. In order to compact the amount of photosites (Individual light sensitive element in a digital image sensor / One colour pixel in a CCD or CMOS sensor) onto the APS-C digital SLR camera sensor. Each photosite must be smaller in order to fit into the reduced suface area of the camera.
When the photosite surface area decreases it is less effective at capturing extended dynamic range (Highlights, midtones, Shadows) and it produces more noise at a higher ISO setting. So to compensate for this. The manufacturers pack the sensor with more megapixels thus reducing the size of each photosite. Which results in two benefits for the consumer. The first one being when you print out your images at a larger size, you won't lose any data detail. Secondly, you can crop out huge sections of the image and still print it at a very large size.
Advantages of a cropped sensor
• Lower cost compared to full frame cameras
• Smaller and lighter camera bodies compared to full frame cameras
• Telephoto lenses have more capabilities because of their narrower field of view compared to a full frame camera - 1.5 or 1.6 times narrower field of view
• Lenses designed for cropped sensor camera bodies are cheaper, lighter and more compact than their full frame counterparts • Lenses designed for full frame camera bodies can also be used on cropped sensor camera bodies
• When using full frame lenses it uses the “sweet spot” or best performing part of the lens optics (the centre region)
Disadvantages of a cropped sensor
• For a wide field of view you need a much wider lens than on a full frame camera
• A cropped sensor with the same or similar pixel count will not perform as well in low light as a full frame sensor
• If you want a shallow depth of field then the greater depth of field provided by a cropped sensor camera may be an issue (e.g. portrait photographers)
Advantages of a full frame sensor
• Better overall image quality compared to a cropped sensor
• Capable of producing shallower depth of field compared to a cropped sensor with the same lens and subject distance
• Wide angle lenses give a wider field of view compared to cropped sensor camera body with the same lens
• Low light performance is enhanced due to the larger size of individual pixel elements compared to a similar pixel count cropped sensor
• Lower noise at higher ISO's
• Advanced features also put into these camera bodies (suitable for professional work)
• Greater Selective focus options: More greater, pleasing selective points particularly with shorter focal lengths.
Disadvantages of a full frame sensor
• Higher cost of the camera body• Generally found with a larger and heavier camera body
• Higher cost of some full frame camera lenses
• Telephoto lenses don’t have the same “reach” compared to a cropped sensor camera body. This “reach” refers to the wider field of view that a full frame camera has with a given lens – see Cropped Sensor for more information
• Can’t use all the same lenses that a cropped sensor camera body - for example: Canon EF-S lenses cannot be used on full frame Canon camera bodies