Crop vs. Full Frame

07 Jan

Crop vs. Full Frame

There are several sizes of sensors. From tiny sensors of small cameras to medium format sensors. I will focus on the two sensors that produce the most arguments and quarrels about their pros and cons, and I will try to show you the differences between them, and my personal opinion of both. I of course talk about the sensors:
Full Frame sensor-the BIG sensor vs. APS-C sensor-the SMALL sensor.

Nikon D800E. Zeiss Milvus 35mm f/2. @f/14 @1/160 @ISO-400

So why size determines?

Let's take for example a 24-megapixel crop sensor compared to a 24-megapixel full Frame sensor. In both cases we will have the same resolution. But the question arises how? If you plug in a 24 megapixel big frame sensor, how can we put the same amount of pixels into a smaller space? (crop) in Nikon, for example, a crop sensor is 1.5 times smaller than the full Frame sensor, which means there is significantly less room for the same amount of pixels. The way for manufacturers to solve this problem is to reduce the size of the pixel. Each pixel is actually a photoelectric cell. Which collect photons (light particles) and convert them into electrical signals, and in the crop sensor the size of the photoelectric cell is smaller. This way you can insert exactly the same amount of pixels into space
smaller. But this means that each pixel in the crop sensor absorbs 1.5 times less light than a pixel in the full Frame sensor, which means less sensitivity to light.


So why should a sensor with less sensitivity to light bother me?
Because this means that with a crop sensor I have to work with a higher ratio than the full Frame sensor, when the shutter speed and light conditions are the same. The result of this will be more noise. How much more noise / which higher? The answer is 1.5 times, which is precisely why professional photographers prefer to work with full Frame bodies because it is important for them to get cleaner images for work purposes. The client eventually does not understand nor need to understand photography. He does not know if the picture looks grainy because of poor printing, an unskilled photographer, or photographer's photographic equipment, but he understands very well whether the picture looks good or not. Every professional and amateur photographer knows that work at a higher level always looks less good. Although it is possible to work with a crop sensor on the same low as the full sensor
Frame, but it means a lower shutter speed, and may be smearing of the photographed object

Is there really a problem with lenses?
Crop has their own lenses. The reason is that full Frame lenses are designed for shooting on a larger surface, and the smaller cropped sensor sees only part of the image that the full Frame lens conveys.


Note that in the photo the light diameter that the lens conveys is larger than the size of the sensor, and this is because the sensor is rectangular while the lens itself is round.
Another disadvantage of working on crop bodies is that the lenses designed for the crop sensor do not give the same angle of vision that full Frame lenses will give to the full Frame body. In other words, a 20mm focal length crop lens will give a smaller angle of vision than a 20 mm lens to the full Frame body. In addition, there are almost no crop lenses in the market that are as good as those of the Foley bodies. In other words, the crop lenses will be much less sharp and certainly at the edges of the image, will suffer more mechanical problems, and will have more plastic parts than Polycarbonate lenses. The reason for this is that
Manufacturers are aware that professional photographers work with polyphere bodies, and for professionals, the quality of the lenses is more important, partly because they understand problems of sharpness, etc. more than hobbyists

At the same time, it is important to know that you can work with Polycarbonate lenses on the body of crop, and then you can work with the best lenses in the world, such as Zeiss lenses, but you will get a smaller angle because the smaller sensor sees a small part of the lens. In the case of Nikon the sensor is 1.5 times smaller and the Canon body is 1.6 times smaller, which means that this is the part you can see from what the lens provides to the body.

You can take this problem to a better place and take advantage of it. A good example is the new crop body of Nikon D500. It is a crop body, but it has introduced all the technology of the most advanced Nikon's full Frame body (as of 2017). The reason is that this body is designed for animal photography and is designed to take advantage of the doubling of sensor size. So you can work with a prime 500mm lens, and it will become a 750 mm lens, because each lens is multiplied by 1.5 times its focal length. Although the amount of incoming light is 1.5 times smaller, but this body allows work at a very high level, and even if we shoot with an amazing 18,000, we will still get a clean and usable image



Notice that these two images were taken with the same body in the same lens. In the first picture in the full Frame sensor and in the second image I activated the function of selecting a crop sensor (which is possible in this body). The technical data are:
Nikon D800E, Zeiss Apo Sonnar 135mm f / 2. @ F / 4 @ 1/125 @ ISO-100
Note that not only has the object increased by 1.5, and in fact the crop sensor has become a type of magnifying glass, but the amount of light is 1.5 times smaller.
The images of course did not undergo image processing of any kind.

Another problem arises when you want to enlarge images for printing. crop bodies are limited to smaller prints because of the resolution, which falls on prints of two meters or more. In order to obtain the highest quality printing, it is necessary to print according to the size of the sensor of the camera. You can find the ideal size for a completely clean print at the highest level by simple calculation, when calculated according to the demands of the printing press to the highest size -
300PPI = Pixels Per Inch

And for the sake of example we will take a 12 megapixel sensor that produces an image size of 4256 on 2832
The best resolution image size will be 14.2 by 9.4 inches. And this according to the following calculation
4256/300 = 14.2 & 2832/300 = 9.4

Of course, we can print a larger picture but print quality (even with existing technology) will be less qualitative as print size increases. Now you can also understand why sensors of 36 megapixels (which produces a file size 7360 on 4912) and a 50 megapixel sensor (which produces a file of 8688 on 5792) suddenly appear on the market.

And if you asked what was the problem with crop picture? (And there is no student of mine that I do not bother them about), so here's the answer. The print quality is decreasing, and the more we print, the more it will stand out. In fact, when you print on a size of 70 by 100 cm you will see the difference so that the next time you do a cropping on your picture, you will think about the size of the print you are taking, so I always tell my students that it is best to redirect the camera to the correct angle crop.


To summarize a few words
Krupp has an advantage. An advantage I have not touched until now, and that's their low cost. The bodies will always be cheaper and so will the lenses. Another advantage is the lower weight of the body and lenses naturally. There is no doubt that anyone who goes on a trip and looks for light photographic equipment that will be comfortable to hang out with, crop's body is the right solution for him. So does the amateur photographer who uploads his photos to the social networks or prints small photo albums, and nothing more, a crop body can do. Even if you need to print a photo size of 70 * 100 cm a new crop body with a perfectly good lens can provide a good result.

But, but it is very important that a person who shoots a lot at a high level, because he takes pictures at dark parties or closed halls, or sports photography that is not in the best lighting conditions, it is recommended to think about buying a full Frame body. In the full Frame body it will be possible to work at a lower level, because more light is coming in, and in most polycrystalline bodies the higher iso will look cleaner than crop's. Even for those who print in large formats, and it is important to have high resolution even in prints of two meters or more, it is recommended to work in poly frame. Another thing to keep in mind is that the full Frame has higher quality lenses and a larger variety, and any photographer even if an amateur who is not at the beginning of the road will be able to distinguish the difference in lens quality.


For further questions or comments, you can write in comments at the bottom of the article. I'd love to answer


Nikon D800E. Zeiss Milvus 18mm f/2.8. @f/16 @8" @ISO-100


Nikon D610. Zeiss Milvus 35mm f/2. @f/6.3 @1/100 @ISO-4000

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