What is Crop Factor? What does it do?

Hello fotografmania followers. The subject of this article will be about the crop factor. We will examine topics such as what is Crop Factor, what is a crop machine, what is a crop factor for, what are its advantages and disadvantages, what is a full frame camera and a crop sensor, and the difference between full-frame and cropping.

If you are reading this article, it means that you are already interested in photography. The crop factor is a phenomenon that directly affects the construction of cameras and lenses that have to be used in photography. I felt the need to explain this value from the very beginning below so that we can know the starting point.

Before digital, there were 35mm films in the analog era. It was taken in rolls of 24 or 36 pieces, in the form of rectangular films, carefully inserted into the machine and photographed. The horizontal length of each 35mm film was 36mm and the vertical length was 24mm.

Of course, not only 35mm films and machines were used at that time. Films in the size of 6cm x 6cm, which we call medium format or large format, were also used. Or even smaller, it was used very rarely. But these users were too few to exceed the fingers of one hand. And therefore, the 35mm film size has become a generally accepted value and has become a habit. For example, when it comes to photography taken with a 35mm lens, the angle of view of the lens was clear. It was very easy to visualize.

Contemporary and Crop Factor Relationship

Now let’s come to the present. Films began to disappear when the first digital cameras were introduced in the early 2000s. It was replaced by digital sensors. Cameras no longer needed film, photos could be taken and printed much faster than analogues.

But these professional machines that were put on the market proved to be very, very expensive. It was certain that it found a response in the consumer and it had to enter every house. Therefore, it was necessary to reduce the cost. The shortest way to cut costs was to reduce the size of the most expensive part, the sensor. This is how the emergence of the crop factor began.

Sony a7 is ff camera. the crop factor is 1x

To sum up, the analog film size was the same as the sensor size of the first cameras. In other words, there were sensors that we call 35mm in dslr machines and they called this format full frame, that is, full frame format. The sensor size of full-frame cameras is approximately 36mm x 24mm. Sizes made other than this size were called crop sensor machines. The crop factor of full-square machines was counted as 1. Those with a smaller sensor had a larger number than 1, and those with a larger sensor had a smaller crop factor factor of 1.

Fujifilm xt5 is not ff camera. the crop factor is 1.5x

To put it briefly, the crop factor is the coefficients that show the size (or smallness) amount of sensors of different sizes compared to 35mm, that is, full-frame sensors.

The work does not end with machines alone. There are also lenses produced for these. When the camera was cropped, lenses started to be produced with a crop factor to avoid cost. At the same time, the crop factor had a side effect, such as reducing cost, as well as increasing portability or reducing size. The sizes of the cameras and lenses produced have shrunk.

Mathematical Calculation of Crop Factor:

Let’s explain the mathematical calculation of what the crop or cut factor does on an example:

Let’s take Nikon’s full-frame camera with a crop factor. Let our crop factor camera be the d7500 and the full frame d800. Have a 50mm f1.8 lens that can be used on both cameras as a lens.

Full frame of crop factor

If we attach this 50mm lens to the d800e, we can use it with a 50mm angle of view. But if we attach it to the d7500, we can use it with a 75mm angle of view due to the crop factor. The crop factor changes the angle of view of the focal length on the lens. Focal length, on the other hand, is a technical conceptual issue and the crop factor does not change the focal length of the lens, it only changes the angle of view.

What Brand Camera’s Crop Factor?

Brands used their own unique sensor size when producing cameras. The most well-known and focal factors of these are as follows.

Nikon crop factor           1.5x
Canon crop factor          1.6x
Sony crop factor             1.5x
Fujifilm crop factor       1.5 x
Pentax crop factor         1.5x
Samsung crop factor     1.54x
Olympus crop factor      2x
Panasonic crop factor   2x
Sigma crop factor          1.7x

It’s worth mentioning right away. The crop multipliers we mentioned are valid for professional machines. We wrote down the multiplier coefficients valid for DSLR or mirrorless cameras. Otherwise, for example, Nikon has produced amateur compact machines and there are many model machines with coefficients such as 4x, 5x, 7x.

Nikon, Canon and Sony from the brands we listed above produced both full frame and crop factor cameras. Others preferred to produce only crop sensor machines.

Some manufacturers with 2x factor such as Olympus and Panasonic decided to use the same lens mouth by uniting and they called it m43, micro four thirds system. Thus, they have increased their potential to be widespread.While a Sony lens cannot be used on Canon cameras, Panasonic lenses on the m43 system became usable on Olympus cameras.

Advantages and Disadvantages of the Crop Factor

1. As we just mentioned, the most important advantage of the crop factor was to reduce costs and increase portability. The dimensions have shrunk, the cameras have become fit in the arm bag.

2. Another advantage is that it can use lenses made for full frame. In other words, a lens produced for a full-frame camera can be used with the same performance in the same brand camera with a crop factor. But the opposite is not the case. For example, a 35mm lens made for crop cameras cannot be used on full-frame cameras. More precisely, it can be attached to the machine, but it can be used by making blackening in the corners.

3. Another advantage was experienced especially in the use of tele lenses. The crop factor turned the already tele lens into much more tele than the multiplier factor. With the same light transmittance. For example, it has become possible to use a 70-300mm lens as 100-450mm on a camera with a 1.5x crop multiplier and 140-600mm on a camera with a 2x multiplier. The distances could be photographed even closer.

4.. Especially when 1:1 macro lenses are taken into account, this ratio will be higher in crop factor cameras and therefore they will be able to enlarge the object even more. Focus multiplier cameras can magnify the subject at a multiplier ratio, or for a 1:1 ratio it can allow shooting from a farther distance than 35mm cameras.

These systems gave birth to a disadvantage. First of all, the smaller sensors affected the photo quality. In particular, the ISO performances have decreased noticeably. There are definitely differences in iso performance between a full frame camera and a crop machine, no matter how software-related it is. Of course, full-frame cameras get much more light, so their ISO performance will be good.

Another disadvantage emerged in getting the finer details from the photo. In texture-sensitive photos, details were not as prominent as full-frame cameras. As the sensor size gets smaller, the capacity to give details, which is especially important for professional users, has decreased. Professional users therefore prefer to work with a full-frame camera, although it is still expensive. Even medium format…

Effect of Crop Factor on Aperture and Depth of Field

With the crop factor, not only the focal length of the lenses changes. The diaphragm effect was also changing. We have explained the effects of the diaphragm on photography in detail in our article here. The crop factor directly affects the depth of field, not the light transmittance of the diaphragm. The bokeh power of a full-frame camera will never be the same as that of a crop factor camera, even with the same lens. Within the framework of physics rules, cameras with the lowest crop factor have the highest bokeh power. Therefore, the full frame camera provides more bokeh than other crop factor cameras.

The mathematical explanation for this is as follows. If a 50mm f2 lens is attached to a camera with a 1.5x crop, the focal length will be 50 x 1.5 = 75mm, while the bokeh effect will be 2f x 1.5 = 2.4f.

The most important issue to note here is that the aperture values do not increase arithmetically, that is, straight. In the above example, it means dimming the diaphragm 1.5 times, and it creates a bokeh effect in the form of f2.4, which is the half stop between f2 and the other stop, f2.8.

Let’s not forget that the crop factor has no effect on the light reception power. In other words, if a 50mm f2 aperture lens gives 1/200 shutter speed in the same light conditions on a full frame camera, it will also give 1/200 shutter speed on a crop factor camera.

Similarly, let’s open a paragraph to the stacking effect. The clutter effect or perspective effect is directly related to the focal length. For example, the stacking effect of a 200mm lens is very strong. Since the crop factor doesn’t change the focal length (it just changes the viewpoint), it won’t change the clutter or perspective either.

Much More Crop Factors…

Samsung nx mini crop factor is 2.7x

The features we mentioned above are valid for professional machines. There are also cameras with a much smaller sensor whose lens cannot be removed, which is an amateur. Sensor sizes are different in such machines. But there are so many crop factors that we don’t know which one to write. Therefore, you will need to learn the factor multipliers of amateur machines from the user manuals, not here. Thank you for your understanding.

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