What's different is that although the image of the object is the same size, on a crop sensor that same-size image fills more of the frame.ĭoes a 90mm lens on a crop sensor give you the magnification that a 135mm lens gives you on a full frame sensor, For any lens at given length and given distance to subject the magnification is the same. Magnification is the ratio of the size of the image of an object on the sensor to the size of the real object. To be more clear, I was referring to the magnification you receive.Īctually you are being less clear. So "zoom" doesn't mean only a type of lens but when it comes to lens types there's only that dichotomy: primes that have fixed focal lengths or lenses that have variable focal lengths and can zoom - which are called zoom lenses. To zoom in photography means to alter the focal length of a lens by moving some of its elements and doing that alters the angle of view and (from the same position) field of view. But the part you can see would look identical in both lenses. except that it would be missing all of the would look like a tunnel effect with huge vignetting. Put another way, the full frame camera could use the 100mm APS-C lens and it would look EXACTLY THE SAME as the full frame 100mm lens. ![]() This means the lens can be smaller because it doesn't have to focus the light to as big of an area. The only difference between a full frame lens and a APS-C sized lens, is that the smaller sensor lenses only focuses the light down to the 20x14mm area, instead of the full frame 36x24 area. If you took the full frame result and cropped it, you would have the same result as the APS_C smaller sensor.įurthermore if you took the APS-C sensor camera and changed to a 66mm full frame lens, it would look exactly the same as the full frame with the 100mm lens. The picture will look like it is "zoomed in further", but in reality it is just cropped. In othter words the sensor can only take say 20x14mm or whatever and the rest is wasted. If you took the picture with both cameras at some fixed distance, you can imagine that the sides of the picture would be cropped off with the smaller sensor. Which is the size of the full frame sensor. The lens takes all the light and focuses it down to a 36mm by 24mm box. Imagine a full frame 100mm lens, the same one on two different cameras. So that isn't the term you likely want to use. So a 5x zoom lens could be a 10-50mm or a 100-500mm. Note the definition of "zoom" is the ratio of furthest reach divided by shortest. I am not understanding your question exactly. It's also the same image as with the same focal length, but cropped, without the resolution issues of actually cropping the wider image.ĮDIT: I see, based on Leonard's reply, that I too have mixed up on the "magnification" term, using my intuitive definition (the relative size of the subject in the frame, final image), so I'm sorry if I misled anyone. You get the same magnification, the same angle of view, with "equivalent" focal lengths-no differences between these two. The two things you mentioned here are exactly the same. Does a 90mm lens on a crop sensor give you the magnification that a 135mm lens gives you on a full frame sensor, or does it give you the same magnification a 90mm lens will give you on a full-frame sensor just that the image will be cropped. ![]() ![]() To be more clear, I was referring to the magnification you receive. Well, you are actually the one who is mistaking. The word "zoom" is not solely dedicated to differentiate between the two types of lenses you know. Yes, I understand that it's a prime and not a zoom lens. The FL of a lens is a physical property that doesn't change when the sensor size changes. ![]() If you separate these two operations, your mind will be clear. Changing the sensor size is like "cropping" not "zooming". What I don't understand is if the 90mm will give me the same "zoom" as will the full-frame 135mm, or will it give me the zoom of a full-frame 90mm, just with an angle of view of the full-frame 135 (meaning - same zoom as a full-frame 90mm, just that the image will be cropped as compared with a full-frame 90mm). I do understand that this means that in terms of angle of view, the 90mm lens will give me the same angle of view as a 135mm lens on a full frame sensor. If, for example, I'm using a 90mm lens on a crop sensor which you need to multiply by 1.5 to get the equivalent of a full frame sensor, then the equivalent focal length of the lens is 135mm. Sorry if this is a stupid question, it's just something that I don't fully understand.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |