Matrix size matters.

One of the most important and basic parameters of any photographic equipment is value of the photosensitive camera sensor. And this is not about about megapixels, but about the real physical area of ​​the photosensitive element.

What is crop factor

What is crop factor

Previously, most photographers shot on film cameras that used the so-called 35mm film (film standard from the distant 1930s). Those were quite old times, and somewhere since 2000, digital-SLR cameras (DSC) became very popular, the principle of operation of which remained the same as in film cameras, but instead of the DSC film, they began to use an electronic photosensitive matrix, which forms the image ...

That's just the price of making such a matrix hundreds of times more expensive than ordinary film. Due to the huge price of manufacturing an analogue of 35mm film and the general complexity of manufacturing a huge matrix with millions of transistors, a number of manufacturers began to produce sprinkled cameras... Concept 'cropped matrix 'meansthat we are talking about a smaller matrix for a standard size of 35mm film.

Crop factor (Crop - from English "cut") Is an indicator for cropped matrices, it measures the ratio of the diagonal of a standard 35mm film frame to the diagonal of the cropped matrix. The most popular crop factors among CPCs are K = 1.3, 1.5, 1.6, 2.0. For example, K = 1.6 means that the diagonal of the camera sensor is 1.6 times smaller for the diagonal of a full-frame sensor or for a 35mm film diagonal.

In fact, not all central control centers are equipped with a cropped matrix, now there are a lot of cameras in which the matrix size is equal to the size of a 35 mm film, and K = 1.0. Cameras in which there is a matrix the size of a classic 35mm film, are called full-frame digital SLR cameras.

Cropped cameras are usually APS-C cameras with K = 1.5-1.6, or APS-H cameras with K = 1.3. Full-frame cameras are commonly called Full Frame. For example, Nikon's cropped APS-C cameras are called Nikon DX, while full-frame cameras are called Nikon FX.

DX (cropped camera, APS-C type, K = 1.5) has a matrix with dimensions of approximately 23.6 to 15.8 mm, the area of ​​such a matrix is ​​equal to 372,88 sq. Mm.

FX (full-frame camera, K = 1.0) has a matrix with dimensions of approximately 36 to 23.9 mm, the area of ​​such a matrix is ​​equal to 860,4 sq. Mm

Now we divide the area of ​​the matrices and we find that the DX matrix is ​​smaller than the full-frame matrix in 2,25 times. To quickly calculate the real difference in the physical dimensions of a full-frame and a cropped camera, it is enough to square the crop factor. So, DX cameras use crop factor K = 1.5, we get that the areas of DX and FX cameras differ by 1.5 * 1.5 = 2.25 times.

If we install a standard (for example) lens with a focal length of 50mm per cropped camera and look into the viewfinder, we will see that the viewing angle is narrower than with the same lens on a full-frame camera. Do not worry, everything is in order with the lens, simply because the matrix of the cropped camera is smaller, it “cuts out” only the central region of the frame, as shown in the example below.

The difference between cropped and full-frame cameras

The difference between a cropped and full-frame camera. The first picture was taken on a full-frame camera and a 50mm lens, the second picture was taken on a cropped camera and the same lens. The viewing angle on the cropped camera has become smaller.

At the same time, many people have the opinion that the focal length of the lens is changing - but this is just an illusion. In fact, the angle of view that a person observes in the viewfinder is changing, the focal length of the lens does not change. Focal length is the physical size of the lens and will remain the same on any camera. But because of this illusion, it is convenient to say that on a cropped camera, the visible picture is similar to a 75mm lens (50mm * 1,5 = 75mm) when used on a full-frame sensor. That is, if we take two tripods and two cameras - one full-frame, the other cropped and screw a lens with a focal length of 75mm on a full-frame one, and on a cropped one with a focal length of 50mm - then in the end we will see an identical picture, since they have will be the same.

The recalculated focal length is called Equivalent Focal Lengthabbreviated EGF. EGF recalculated even for cropped lenses like Nikon DX and canon Ef-s.

Full-frame shot

Full-frame shot in full-frame mode

And an example of the same picture taken from the same distance, without changing the settings, but only in cropped mode:

Crop

Full-frame shot in DX mode. The difference in viewing angle is visible. DX mode, or DX camera as if cut from the original image, which gives the lens, only the central area.

In fact, when using lenses from Full frame cameras on cropped cameras, we get some significant advantages:

  1. Reduced viewing anglemaking a telephoto from a standard lens, and a super telephoto from a telephoto. So using a 300mm telephoto, we get a viewing angle the same as in a 450mm lens on a 35mm film. This is a pretty great opportunity to buy a cheap zoom telephoto for less money and due to the crop factor, get a large EGF.
  2. Due to the fact that full-frame lenses work only in the central area on cropped cameras, you can get rid of such image defects like vignetting, a drop in resolution at the edges of the frame, part of the distortion. Usually in the central region of the frame, image quality is maximum.

Also, using lenses from cropped matrices, we get lenses cheaper. Although there are downsides. Lenses from cropped cameras need to cover a smaller area of ​​the photosensitive element, which means you can use less expensive glass, make less weight, etc. At the same time, when buying lenses for cropped matrices and with the subsequent transition to full frame, you will have to additionally buy new lenses for a full frame. I advise you to read the related article - Nikon lens differences, and - Features of cropped cameras and lenses

Conclusions:

Cropped cameras (cropped matrices) are simply smaller matrices, and in order to understand the amount of matrix reduction, the concept of crop factor is used. The crop factor is convenient to use to obtain EGF lenses when using them on cropped cameras. To obtain EGF of any lens, when using it on a cropped camera, it is enough to multiply the value of the focal length of this lens by the crop factor of the camera.

More information in the sections

Material prepared Arkady Shapoval... Look for me on Youtube | Facebook | Instagram | Twitter | Telegram.

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Comments: 234, on the topic: Matrix size matters.

  • Ilya.

    Arkady, hello. Do I understand the essence of the issue correctly.
    1. There is Nikon D7000 and Nikkor 17-55 DX lens. Since the camera is cropped, the EGF of this lens is 25-82.
    I planned to buy a Nikkor 24-70 FX. His EGF on the D7000 will be 36-105, respectively. Therefore, the range of EGF of the first lens will block the EGF of the second within 36-82 (67%). In this case, the purchase of 24-70 FX does not justify itself. The transition to a full-matrix camera will be, but not soon.
    Before your article, I had different arithmetic. 17-55 for a crop is 17-55. And 24-70 on the crop is 36-105. The overlap is not big, you can take it!
    2. And the second question. Whatever portrait-fix you recommend for the D7000. Within the allowable range 800 ye.
    If I loaded it too much, I apologize.
    Sincerely.
    Ilya.

    • Arkady Shapoval

      1. Due to the fact that the focal length is a physical parameter, it is necessary to recalculate the EGF for cropped lenses.
      2. From portraits for such money you can find 85 1.8G

  • Ilya.

    Thank you!
    You have confirmed my plans for the 85 1.8G. And 24-70 helped save money. After all, it would turn out that I changed the awl for soap.
    Another question in the recommendations of the online store. It is relevant for many. Advise.

    • Arkady Shapoval

      I don’t get involved in these questions about stores, I observe neutrality so as not to give rise to unnecessary thoughts.

  • Ilya

    I only have shopping experience in the Photoshop and Chaco. It seems they did not disappoint.

  • Alexander

    Arkady, good afternoon.
    I apologize in advance for the question repeated here repeatedly. I can not fully understand one thing. Let's touch the Canon lineup.
    1. For example, let's take a camera with a full-frame matrix and a Canon EF 17-40mm f / 4 L USM lens - here FR and EGF correspond to 17-40mm.
    2. Take a camera with an APS-C format sensor (crop factor 1.6) and a Canon EF-S 18-55mm f / 3.5-5.6 IS II lens - the FR corresponds to 18-55mm, but there is no EGF (it is recalculated and = 28-88mm )? If FR is true (as I suppose), then please answer the next. question?!
    3. Why on cameras with crop matrix and a lens that is designed for such cameras (ie EF-S) does EFR still recount anyway? More precisely, one can even ask a different question: why do manufacturers produce 2 directions of EF and EF-S lenses, if visually, whatever the lens (EF / EF-S), the picture taken on a camera with crop matrix looks the same? Could be limited to the EF line.
    Or is it not so and I misunderstand a lot of things ?! Enlighten me please, because until today I had hoped and believed that the Canon EF-S 18-55mm f / 3.5-5.6 IS II on the crop would be exactly 18-55mm, and not 28-88mm. Or is it still 18-55mm that only the viewing angle remains (due to crop), or what?
    Thank you very much for your prompt reply. I hope the question is clear.

    • Arkady Shapoval

      It is recalculated for all lenses, since the focal length is a physical quantity. If you set 18-55 to a full frame (this is possible on Nikon), then it will give real 18-55 there, but with black corners, and on the crop it will be something narrower :)

    • Paul

      For cropped lenses (EF-S, DX), the size of the projected image is designed specifically for the cropped matrix, that is, smaller in size. This was done in order to reduce the size of the lens, its weight, cost.

      • anonym

        Thanks to Pavel. Clear answer

    • Paul

      With cropped lenses (EF-S, DX), the size of the image projected onto the sensor is designed specifically for the cropped matrix, that is, it is smaller. Accordingly, it became possible to reduce the size of lenses for such matrices, their weight and price.

  • Tadik

    The author writes: ... And if you have an ordinary digital compact with a small matrix, then even with a high-aperture lens you will not be able to achieve good background blur ...
    I disagree - even an ordinary digital compact with a small matrix copes with this perfectly, its shortcomings are completely different ...

    • Arkady Shapoval

      The question is what counts as “fine”. Compact cameras can only afford good blur at best when shooting macro.

      • Tadik

        I totally agree with you, but just in macro, a good blur makes sense. And in the real world, very often only a slightly distinguishable background or foreground sometimes has a significant meaning and this is an indisputable fact. How many times have encountered this. As for the advantages of full-frame DSLRs and their capabilities, everything is clear - here you are right.

  • Vladislav

    Thanks for your reviews. As for cropped sensors, I personally like them very much, I don't understand this fuss about 35-24mm full-frame sensors at all. In the 80s, we only shot full frame. Any of the simplest cameras was full-frame. I don't see any actual difference. Yes, the viewfinder is wider, and the field of view is wider, but taking pictures in full frame FX and then shooting DX (taking into account the angles of the field of view) I got ABSOLUTELY THE SAME !!! pictures. Hence the conclusion, why pay 700-65 thousand rubles for the D70. when all the same can be depicted on the D3100 16 thousand rubles. choose only the lens you need. In Soviet times, along with 35-24mm, there were 45-60mm 60-60mm etc. medium format devices, but they were abandoned due to their bulkiness. I think that basically FX is just show-off. Maybe I'm wrong, but I know people who shoot on the phone, they shoot, if not masterpieces, then something about that, and there is a 4-9mm matrix ... Sincerely, Vladislav Chernyavsky SPb

    • NE

      Not everyone was filmed in full frame then. There were FED-micron, Kiev-30. Medium format is also not as simple as you write. Different tasks, different techniques. If you have been photographing, remember magnifiers, and also understand that different magnifications are required to print the same size from 35mm or medium format negatives. And the grain size on a film with the same sensitivity is generally the same for both 35mm film and SF film. Accordingly, the more we increase, the worse the quality. Therefore, if you take a photo 10 * 15 - you probably need a soap dish.

  • Vadim

    Great article, Arkady! Many thanks.
    Everything is extremely simple and clear.

    I'm hopelessly in love with photography, I shoot with the Nikon D80 and, like all amateurs, dreamed of a full-frame camera. To fully understand what kind of Full Frame it is and what it is eaten with, I bought a Nikon F80 film for ridiculous money. Dreams come true :) Figures and terms cannot explain this difference :) Photos are equally good. DX / FX, digital / tape ... The biggest difference in the final result depends on the person who presses the button.
    Arkady, I wish you inspiration and more free time to write new articles and reviews.

    • Arkady Shapoval

      Thank you :)

  • Vasja

    Good day. I want to ask you the following: in the NIKON D3100 I want to add my own Nikkor DX 35mm f / 1.8G AF-S or Nikon AF-S 50mm f / 1.8G. Yak Vi would have pleased. I want to know children, love, expensive, enjoy the outdoors.

  • Andrey_SPb

    Thank you, Arkady for your disinterested educational work. And for the ability to talk simply about the complex.

    I want to add a small comment that will help to more clearly understand the difference between full-frame and cropped cameras.
    Quote first:
    “If you take ... two cameras - one full-frame, the other cropped and screw on a full-frame lens with a focal length of 75mm, and on a cropped one with a focal length of 50mm - then in the end we will see an identical picture, since they will have the same viewing angles”

    It seems to me that another example is even more important, visual, and most importantly - vital:
    If we take the same lens and put it first on a cropped camera, and then on a full-frame one, then to get an identical picture (that is, the frame that we want to shoot!) We will have to come 1.5 times closer to the subject (t .e. to shoot an object from a closer distance). This will obviously affect the resolution and quality of the picture!
    But that's not all! A full-frame camera has a larger physical matrix size and, as a rule, a larger number of pixels. Which will also positively affect the quality of the photo!

    These are the main reasons that provide the benefits of full-frame cameras in picture quality.

  • Yeri

    Hello Arkady! I liked your site - interesting and definitely useful! I have a question for you: I am a wedding photographer, I am currently shooting on a Canon 60d camera with Sigma AF 17-50mm F2.8 OS HSM lenses (for Canon) and a fifty-fifty Canon EF 50mm f / 1.4 USM lenses;
    In the near future I want to buy a full-frame Nikon d600, but I still don’t have a precise definition with the lens, or I want to buy the 1st option) Nikkor AF-S 17-35 2.8D IF-ED (a little expensive) or the 2nd) Sigma AF 24-70mm F2.8 IF EX DG HSM for Nikon, since the Nikkor AF-S 24-70mm f / 2.8G lacks a budget. What do you advise? Actually, taking into account the image quality, the 1st option is more acceptable, but at weddings this lens has a small zoom. And the 2nd option is just convenient for wedding shots, but I think that the quality of the photo will be lower than the 1st option. And what do you think? or are they almost equal in quality? please help me figure this out, I will be very grateful. Thanks! I wish you good health and creative success!

  • willow

    Good day! please tell me how 35mm elka with kenon d7 will work

  • Alexander

    Hello Arkady and dear site visitors! I did not read the entire correspondence, but I would like to note the following. All photographers dream of a full-frame camera, but when choosing a camera, it is most reasonable to proceed from specific needs. Based on your review, the advantages of full frame over crop are more control over depth of field at open apertures, better performance at high ISOs, and naturally a wider angle of view. My question is: will there be a significant difference in image quality at a closed aperture (well, f8 for example) in studio conditions with the same optics, frame composition and other identical conditions, respectively, between crop and full frame? In principle, from the review, I conclude that if there is sharpness throughout the frame and when it is not necessary to “wash” the background, a full-frame camera has no advantage.

    • Arkady Shapoval

      Crop usually has a lower diffraction threshold, which means that starting from a certain large F-number, it makes no sense to close the diaphragm. Lots of thoughts about crop here (including grip) - https://radojuva.com.ua/2013/05/the-crop-identity/

      • Alexander

        Yes, I understand that most crop lenses show maximum sharpness somewhere at f / 5.6. In general, the point is that a full-frame camera is simply a convenient and practical thing that a commercial photographer needs in his work. I wrote the previous post, because I noticed that many amateur photographers, roughly speaking, drool over stamps and elks, but they do not delve into the essence of the problem, into banal physical parameters, and that a price increase is not always equivalent to an increase in quality: sometimes for what -or the slightest advantages have to pay a lot.

        You have a wonderful site, Arkady, thank you very much for taking the time for a photographic educational program :) Creative success!

        • Arkady Shapoval

          Yes, sometimes there comes a moment in photography, in which you have to pay a lot of money for small details.

  • Natalia

    Very cool article! And at first glance it seemed that I didn't need it ...
    It seems that for 200 percent now I know my camera better))
    Thanks to the author!

    Sincerely,
    Natalia S.

  • Pauline

    Arkady, please tell me which optimal lens can be used to obtain a wide viewing angle. Camera Nikon D 7000. Thought to get a fix of 20 mm, but after reading the article. great thought that a wide viewing angle and will not work. I would like to choose the optimal price.

  • Albert

    dear Arkady! Thank you very much for a selection of excellent articles. Please write if possible or give a source about the best lenses for crop cameras. Recently I became the proud owner of a Nikon d7100 with a 18-105 mm whale, I bought a nikkor 55-300 VR and 1,8 f50 mm flashlight 700 according to the advice from your articles, and I would like you to recommend me some good portrait lens or "fifty kopeck piece" is it good yet ?! I plan to take photos of both families and nature, macro and animals. Thank you in advance for your response.

  • Ilya

    Dear Arkady. Like many others, I express my gratitude and appreciation for such detailed and, most importantly, articles that are easy to understand for a simple person (novice photographer).
    I got a digital mirror for the occasion. What can I say - the difference in the quality and color of the pictures, in comparison with the “soap box” (albeit significantly expensive at the time of purchase), which was used to shoot a family photo, etc., is very noticeable. Photographs are pleasing to the eye (not always ... practice is needed ..), arouse enthusiasm and a desire to experiment.
    I shoot with "whale" 18-55 mm f3.5-5.6 and Soviet "fixes". I constantly read your articles in order to improve education. Thanks again.
    I wish you prosperity.

  • Basil

    If on crop and FF the physical dimensions of the central part of the image are the same, then the "advantages" of a crop in 1.5 times (I mean the focal length) is just digital zoom when displayed on the monitor?

    • Arkady Shapoval

      To simplify a lot, something is similar to what you wrote.

  • Sergei

    Dear Arkady, I’m interested in the question that was already asked but there was no answer, please tell me, I have a 3200 Nikon, I want to buy a wide-angle lens to get similar photos http://i1.r24.me/ARW5rj.jpg Do not tell me with which lens it is possible to implement with my camera? thank you in advance.

  • Vladimir

    I wish you good health, Arkady, and please us further with such articles, in which everything is remembered from one time, where there are no these exhausting operations, very few understandable terms. I am surprised at your tolerance, to answer the same question several times in one article ... Thank you. Now I will ask you. (if I'm wrong, correct me, please). If you shoot with, say, the Sigma AF 50mm f / 1.4 DG lens on a full-frame camera, and on the Sigma AF 35mm f / 1.4 DG on cropped, then the pictures should be the same?! Or not? And one more thing, I have Jupiter 21M 4/200 and Helios 44m 2/58 (film heritage). Should their FRs also need to be multiplied by 1.5 (I have a Nikon D5200)? And what will the true FRs be: 200 and 58, or 300 and 87 ? And also, tell me, from the Nikon, Sigma, Samyang lines, which lenses, in terms of parameters, are closest to my Jupiter and Helios?

    • samovarchik.info

      1) at the edges of the frame, the images from 35 on crop and 50 on FF will be close (not exactly the same), but the space will look different, there is a different bulge - because shirik space crumples up, i.e. seals, then, say, the face is 35mm more crumpled than 50mm and even more so by 85/105 / 135mm. And between 35mm and 50mm it is less noticeable than 50mm and 85mm in comparison.

      2) yes, with Soviet lenses, you also need to multiply the focal length by 1,5 in order to understand what the viewing angle will be - for a 200mm lens, the angle will become like 300mm, but the space density will remain as for 200mm, for 58mm, the angle will be 87mm, but the space will look the same as 58mm.
      those. it’s the same as taking a 58mm shot, and then trimming the edges, leaving only the central part.

  • Alexey

    Hello Arkady! Tell me please! Recommendations for landscape photography aperture f / 8 - is it a recommendation for a full frame or not? As I understand it, on the crop you need to set the aperture (f / 8) /1.5=5.3333. According to the increase of about f / 5.6? Nikor 50mm1.8G lens. Nikon d3100 camera. Many thanks in advance!

  • Jeka

    Vladimir, I don’t remember that Sigma had such a "thirty-five", otherwise Nikon would have gone broke. Pictures will be almost the same. About. And it will also be approximately equal to DOF. Why multiply FR by 1,5? Why do you need to understand how it will look in FF if you shoot with Crop? True focal points are the same and will remain there and there. It's just that on the FF you see a house, and on the crop there is only a window with shutters, but of the same size.

  • Jeka

    I'm sorry - Sigma has such a wonderful lens, objectively speaking.

  • Ivan Kharkovsky

    Arkady, thank you. Everything is competent and intelligible :-) Finally, I managed to understand why they count the number of aperture together with the focal length, if the number of transmitted light when reducing the matrix can not be less.

  • Sergei

    For many years he was engaged in animalistic shooting on film with a Sigma 170-500 lens. Currently I have a Nikon D3200 camera, I plan to buy a Nikon 80-400mm f / 4.5-5.6G ED VR AF-S NIKKOR lens. How much will the focal length of this lens increase and how will such a combination (camera lens) affect quality?

  • anonym

    everything about me

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