15

When I started photography, this one took me ages to figure out, because people tend to explain it with a lot of math, or in a way that makes sense once you already grasp the principle but not before. How does crop factor affect perspective? It doesn't. Not at all, in the slightest. The only way you change perspective is to move the camera. Changing ...


13

From the "Recommended For" tab of the Tamron web page for that lens: Tamron Di-II lenses are engineered expressly for digital SLR cameras with image sensors commonly referred to as APS-C, measuring approximately 24mm x 16mm. This means the image circle is sized for the smaller APS-C sensor, and is too small for a full-frame camera like the 6D. This is ...


13

Crop factor has nothing to do with T-stop. T-stop is strictly about light transmission which affects exposure. If a lens could be 100% transmissive the T-stop and f-number of the lens would be the same number, but they would still be measures of different things. T-stop measures how much light is passed through the lens, f-stop measures the size of the ...


12

The difference between the EF 50mm f/1.8 II and the EF-S 18-135mm f/3.5-5.6 IS is not in terms of focal length or angle of view provided by each lens when both are used on an APS-C body. What makes the EF-S lens different is that the image circle projected by that lens is smaller than the image circle projected by the EF lens. The EF lens must project a ...


11

It's quite simple: A lens projects what is called an "image circle" onto the sensor. A DX-only lens is designed to project an image circle just big enough to cover that sensor. An FX lens is designed to project an image circle big enough to cover a FX frame. Therefore an FX lens will work on a DX sensor properly. (But it will have an effective "crop ...


10

Here are a couple of different common paths you could go that are sub-$1000. But as everyone is telling you, usage is the easiest way to narrow down your choices to something you actually need, rather than something you just want. The easiest way to really start considering an "upgrade" from the kit lens is to consider in what ways the kit lens frustrates ...


10

Perspective is determined by one thing and one thing only: Subject distance. Period. If you took an image using a rectilinear wide angle lens such as 17mm, which yields a diagonal angle of view of 104° on a full frame/35mm camera and cropped the resulting image so that only the center 3.08333° is in view, you would have the exact same perspective as if you ...


10

No. You should set your zoom to 85mm to see what an 85mm lens looks like on your camera. The focal length of a lens is a physical property that does not change no matter what size sensor you put behind it. The distinction between a crop (DX) and full frame (FX) lens is how big an image circle it projects. A crop lens can only cover an APS-C sized sensor, ...


9

Here's the short answer: a wide angle lens on a crop sensor skews the image exactly in the way it does in the center of the frame on a full-frame sensor. In turn, this means that using a wide angle lens (small focal length) on a crop sensor gives the same perspective distortion as using a narrower lens (larger focal length) on a full frame sensor, with the ...


9

The amount of light passed through the lens stays the same, the lens will still be a F/2.8 lens. Since the smaller sensor only crops out a different area from the illuminated circle, the exposure related properties of the image taking process will stay the same, regardless of the crop-factor.


9

In general cameras do use darker materials to construct light boxes and the interior surfaces of lenses. Many also use materials, such as the flocking material found on the inner surface of higher end lens hoods or plastic that is molded with a textured surface, that scatter what little light is reflected. Even when using a camera with a full frame sensor a ...


8

You will crop away the outer edge of the image and this will cause you to lose the highly distorted edges of the photo. this is particularly obvious when you are dealing with a very very wide angle where normally a circular image would be seen but due to the crop you see a square image. This review of the Canon 8-15mm fisheye contains a picture how the ...


8

You can get more lens flare using a full frame lens on a smaller sensor when shooting close to the sun or other lightsources. The reason for this is simply the APS-C lens has a narrower field of view and so a lightsource just out of frame has no physical path through the lens. If you're using a full frame lens with the same composition then there is a path ...


8

The same light will pass through the lens regardless of the type of camera to which it is attached. Less of that total amount of light will land on the smaller sensor. But exposure, when discussed in terms of varying sensor/film sizes, is not about the total amount of light falling on the sensor. It is about field density, or the amount of light falling on ...


8

You can't. What we refer to as equivalence is only an approximation. You can't put a different lens on a crop sensor camera and get the same shot with the same field of view from the same shooting position with the same depth of field using the same ISO and the same shutter time as you can get with a full frame camera. The converse is also just as true. You ...


8

Lens produces circular image (image circle), which projected on rectangular matrix. So question is not only about full frame lens on a crop sensor. AFAIK black box (mirror box) is specifically covered in material that absorbs light well. I remeber that in older cameras (my film Nikon F90) this space is covered in fuzzy (furry?) material so that light ...


7

Your logic is sound. If your assumptions were right, then your conclusion would be right. Let me turn one of your questions around. You ask: Why does crop factor apply with APS-C-lenses, while it sounds like the image circle is compressed onto the APS-C-sensor (thus making a wider FOV)? In fact, the image circle isn't compressed, and does not make a ...


7

The Canon extenders will not physically mount to an EF-S lens. Even if you defeat the keying the front part of the EF 2X (any of the three successive versions) would extend into the rear of the EF-S 55-250mm and almost surely contact and damage the rear lens element or the front element of the extender or both, at least at certain focal length and focus ...


7

If you take a photo of a FF camera and 75mm DX lens and compare that image with another shot of same subject made by a cropped camera and a 50mm lens what you will see ? But to be able to see the "same subject size" in the pictures, the longer lens must stand back further. So that is a difference in what the lens will see there, at that new location. So ...


7

The "equivalent" focal length draws from history, namely how it relates to a 35mm film camera, and there should come a time (and I think it is past) when we move on. The focal length IS the focal length. Having a smaller sensor may crop a portion of the field of view, but the focal length is a real and meaningful number. Anyone who is interested in the ...


6

Focal length does not change with sensor sizes - what actually changes is the field of view: FOV [°] = 2 * arctan ( d [mm] / (2 * f [mm]) ) FOV is our field of view in degrees, d is one of the dimensions of the sensor (for diagonal, it is d = √(h² + w²) ) and f is the focal length in millimeters. In very simple terms, a smaller sensors sees a smaller ...


6

There are many various film and digital sensor sizes and formats. 135 film (also known as "full-frame") became the most used film in the 60s and the most common format was 3/2, meaning 36mm x 24mm frame size. The camera determined the format/ratio but was always 24mm high. There were even half frame cameras that used this film but would result in ...


6

You said you own an 18-55mm zoom lens. You can just set that one to 35mm and 50mm (there is a scale on the barrel that tells you what focal length your current zoom position corresponds to). That way, you can see the field of view each focal length gives you for yourself. Even though the same focal length will give you a different field of view on ...


6

The only guarantee is that a DX lens will throw an image circle approximately large enough to cover a DX sensor. Some throw them a bit larger, but the only way you'll know if a given lens does that or not will be to try it. Carrying your math a bit further, the DX diagonal is 0.12mm smaller than that of the AX100. The pixels on that sensor have a diagonal ...


6

Short answer no - it will be approximately equivalent to the 50mm lens on a full frame camera. What you are referring to are issues of perspective. The perspective is not a property of the lens but is due to the position of the camera relative to the subject. If you are at the same distance from the subject you will get the same perspective no matter what ...


6

Just about any wide angle (WA) or ultra wide angle (UWA) lens used with an interchangeable lens camera will use a retrofocus design. That does mean larger, heavier, and more complex than a non-retrofocus design. But that doesn't mean all retrofocus lenses must be equally large and heavy (and expensive). A wide angle lens that uses a retrofocus design is ...


6

Let's start with some Nikon terminology. Nikon refers to their full frame cameras and lenses as “FX” and their cropped frame cameras and lenses as “DX”. The crop factor for Nikon cameras is approximately 1.5x. Identifying an FX camera is extremely easy. Face the lens and look in the bottom right corner of the camera. If you see a yellow box with the letters ...


6

The f-stop is a simple ratio. It is the focal length divided by the working diameter. We use this value to compare the image brightness of one lens vs. another. The f-stop is often in error because it does not take into account light loss due to reflections from the polished surfaces and the lack of perfect transparency of the glass. The "T" -top is ...


6

Not correct. Perspective (referring to the size and spacing of background objects relative to subject) is determined by only the distance of camera to subject. This is the geometry drawn from the camera position, regardless of any camera details. Another focal length or another camera crop size (and subsequent enlargement to equivalent size) can "magnify ...


6

Well, sort of. There's no such thing as absolute equivalence. In terms of angle of view a 55mm lens will give the same AoV with a 1.5X APS-C sensor as an 85mm lens on a 36x24mm FF camera. In terms of exposure you'd need a 55mm f/1.8 to get the same AoV and exposure in the same light as an 85mm f/1.8 on a FF. In terms of depth of field (DoF), you'd need a ...


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