Full format, APS-C, micro 4/3 … How to find yourself between the different types of photographic sensors

Some examples of cameras and smartphones:

Full-format cameras, APS-C, 4/3… Understand the size of the sensors

MAJ 04/14/2022 – Essential for image quality, the size of the photo sensors is constantly returning to tests and comparisons. But faced with the multitude of existing formats, sometimes difficult to navigate. That means the terms full format, APS-C and others ? What is the impact of the sensor size in the photos ? We explain to you.

Posted on 02/03/2010 at 5:17 PM | Updated on 04/14/2022

Article updated on 04/14/2022 – We updated the information of this guide who needed a little facelift and added product suggestions to always advise you in your searches of equipment.

In the era of silver, everything was simpler. The majority of amateur photographers used the famous 35 mm dandruff, and then that’s it. But digital has passed by and turned everything upside down. Since the appearance of the first digital sensors, which replace our dear dandruff, the models have multiplied and with them, the formats.

If today, CMOS technology has largely taken precedence over the others, the sensor sizes, they can vary considerably. Whether for reasons of cost or miniaturization of the devices, the latter also tended to shrink, transforming the 24 × 36 mm format (or full format/full frame), the equivalent in size of 35 mm dandruff, In one of the largest formats on the market even though it was considered small in the era of silver. This did not fail to create confusion with the Middle Format which, contrary to what its name inherited from the argentic indicates, is even greater.

As you will see, the size of the sensor has different consequences on your photos, especially on their image quality, but not only. This is one of the key criteria to take into account before the purchase of a device. Before you explain it all, here is a comparative scheme of the main formats of sensor available on the market. It is not on a scale, but the proportions are respected.

How does a photo sensor work ?

In general, it is said that the greater the photo sensor, the better the image quality will be. But how is a big sensor better ? Without going too much into technical details, the principle of a photo sensor is to receive light and convert it into electric current. These are then interpreted by an electronic circuit in order to form an image.

Logically, the greater the amount of light received by the sensor, the more intense the electric current. The intensity of the current also stems directly from the sensor surface: there is a minimum threshold below which the current cannot be measured. It must then be amplified, an amplification source of digital noise that degrades image quality, this is what happens when you increase the ISO sensitivity of the camera.

A sensor is made of several million cells sensitive to light, called photosites. Thus, a sensor of a definition of ten million pixels (the points that make up the image) has 10 million photosites. For the same image definition, the photosites of a large sensor “Full format” (with a size of 24 x 36 mm therefore) will be logically larger than those of a smaller sensor in APS-C format for example, and they will be larger than the photosites of a 4/3 sensor (Thirds oven ), etc…

The advantages of a large sensor

However, photosites need space to capture light as well as possible. Due to their larger surface, large photosites are more sensitive and more reactive to small amounts of light, therefore more precise, and more effective in low light conditions (attention, lack of light arrives very quickly, and not only the night). They better support the increase in ISO sensitivity, this allows full -format devices to go up to ISO 12800 for example, while retaining an acceptable noise level and good image quality. Besides, their sensitivity range is generally more extensive than that of smaller sensors.

The Nikon Z6 hybrid, with a full -format sensor

These elements shed our fiercely anti -anti position “Megapixel race” that manufacturers engage in, especially smartphones, even if these devices can count on techniques such as pixel binning (grouping of several pixels in one to capture more light) or very powerful image processing (and more in more advanced) to correct the problems of too small photosites. Fortunately this race seems to have calmed down in manufacturers of cameras.

Other advantages

But large sensors also offer other advantages (they also have drawbacks, including their high price). Among their strengths, there is the fact that they allow much lower field depths to be obtained than with small sensors. The depth of field, it is the sharpness area of ​​the image. Thus, a shallow depth of field will make it possible to obtain a very pronounced background blur and particularly aesthetic when you make a portrait, for example.

In addition, it will be more difficult for you to have a short focal length and therefore a wide angle of view with a small sensor, not terrible for landscape lovers … A 50mm lens on a full format will give a 50mm focal length, But mounted on a device with a smaller 4/3 sensor, it will actually give a 100 mm focal length. In a word, there will be like a zoom. To avoid confusion, manufacturers often indicate equivalence in 24 × 36 mm format (full format) in the technical sheets of their objectives. On the Fujifilm website, you can read about the Focal of the SQ20 Instax: 33.4 mm (equivalent in 24 × 36 format).

As you can see, the focal distance is doubled with a 50mm lens mounted on a 4/3 sensor device, it is therefore said that this type of sensor has a conversion coefficient of 2. Here are the coefficients for the most common sensors:

From SLR to smartphones

Still in order to get a more precise idea of ​​the order of magnitude which separates the different types of photo sensors, here are the main formats available, accompanied by their size in mm on width and height:

Some examples of cameras and smartphones:

• Full format: Sony A7 III, Nikon Z6, Canon 5D IV, Panasonic Lumix S1
• APS-C: Sony A6400, Nikon D500, Nikon D7500
• APS-C (Canon): Canon Eos M50, Canon Eos 4000D
• 4/3: Panasonic Lumix G9, Panasonic Lumix LX 100 II, Olympus OM-D E-M1 Mark II
• 1 ″: Sony RX100 VII, Canon G5 X, Panasonic LX15
• 1/1.7 ″: Huawei P30 Pro
• 1/2 ″: Xiaomi Redmi Note 7 Pro, Honor View 20
• 1/2.3 ″: Nikon P1000, Gopro Hero 7 Black, Silver and White
• 1/2.5 ″: iPhone XS

Here are two cameras that we highly recommend you. One with a full-format sensor, the other with an APS-C, the two most interesting formats in our sense:

Here are also two very good photophones:

Our selections of cameras

After theory, make way for practice. Fruit of expert compact tests, reflex and other hybrids that we carry out on CNET, we strive to identify the “Best” devices on each of these categories. Before drawing the credit card, remember to take a look at it.

• The best hybrids
• The best SLRs
• The best expert compacts
• The best smartphones for the photo

Karyl-Aka published on 02/03/2010 at 5:17 PM | Updated on 04/14/2022

• Hybrid cameras
• Compact
• Objective – Photo optics
• Photo
• Reflex

Full format, APS-C, micro 4/3 … How to find yourself between the different types of photographic sensors ?

We can differentiate and group the photographic boxes according to The size of their sensor. Indeed, the larger the sensor, the more sensitive it is to light and can therefore reveal unsuspected details, even by the human eye.

We often talk about full and medium format but also of APS-C sensors, four-thirds microphone etc … Discover the different types of sensors and what differentiates them.

The medium format sensor

The medium format is the largest sensor that exists on the market these days. But contrary to what one might think, full format is not the biggest. With maximum dimensions of 40.4 x 53.7 mm (it depends on the models), the means format is used mainly on very specific cases used in professional photography and in the world of cinema.

The full -format sensor

Known to be the High -end sensor, The full format is the darling of professional photographers. More expensive than others, it gives a Restable to a silver film 24 x 36 mm. If you do not understand the concept of 24 x 36 equivalence, we advise you to read the dedicated page to the subject.

Take a case capable of deliver photos of 24 megapixels. The photo having a definition of 6000 x 4000 pixels will deliver a better rendering than a smaller sensor because all of the pixels will be spread over a larger area.

The APS-C sensor

The more affordable APS-C is very often used in hybrid housings. Less expensive to manufacture than his big brothers, he still delivers very high resolution clichés. Its dimensions ranging from 14.9 x 22.3 mm to 15.7 x 23.7 mm (APS-C Canon for the first dimensions and the rest of the APS-C for the other brands), it is one of the two most widespread sensors with the four -thirds microphone.

The micro four -thirds sensor (4/3 microphone)

More frequently called Micro Four Thirds in English, it is a widespread sensor on hybrid cameras and is four times smaller than full format. Particularly represented on Panasonic and Olympus devices, its dimensions are 13 x 17.3 mm.

1 inch and smaller sensors

There are also smaller sensors in Sony RX100 Type RX100 devices which are very good compromise to start the photo while enjoying very high quality images. Its dimensions are 13.2 x 8.8 mm.

Finally, we find smaller sensors in smartphones (for example ⅓ ”) which have the following dimensions: 4.8 x 3.6 mm.

Which sensor to choose ?

The first question to ask if you are looking for a camera is why do you want to use it. Then, you will have to make a choice between the different types of cameras: SLR, hybrids etc ..

Depending on the use (daily, for travel, for your professional activity), you will choose the sensor and its case that enter your budget and above all allow you to issue photos and videos at the level of quality you are waiting for.

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