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60

It's an extra two-thirds of an f-stop, with all that comes with it: Narrower depth of field (perhaps marginal in comparison to the f/1,8) Brighter viewfinder; great in low-light situations Might be the difference between getting the shot or not, also in low-light situations Lenses tend to get sharper when stopped down. At f/1,8 the f/1,4 lens is stopped ...


57

An f-stop is kind of a combination of two terms. First off, f/N is generally the notation used to indicate the size of the diaphragm opening, or aperture, in a camera. Let me give a little detail about how that notation came about, before I go on to explain the meaning of a stop. Aperture Values and f/Stops Aperture openings are measured as fractions of ...


53

TL;DR answer In general, Canon DSLRs require a maximum aperture of at least f/5.6 to autofocus. Depending on the camera model, and with some exceptions, a maximum aperture of at least f/2.8 or f/4 enables cross-type and/or high-precision focusing. EOS-1 series cameras, the EOS 5D Mark III (with the latest firmware), and the EOS 7D Mark II can autofocus at ...


43

There have been some very good answers, however there are a couple details that have not been mentioned. First, diffraction always happens, at every aperture, as light bends around the edges of the diaphragm and creates an "Airy Disk". The size of the airy disk, and the proportion of the disk that comprises the outer rings, and the amplitude of each wave in ...


35

It's likely the sum of a few factors. Firstly, although you state "the same f-stop", it's important to realise that the manufacturer stated focal length and aperture values are often rounded, and not always in the way you'd expect. It might be the case that the Samyang is f/1.45 in reality, not f/1.4. The next factor is vignetting, wide aperture lenses are ...


30

The aperture range on your lens only shows the maximum aperture for your lens at the extremes of the zoom range; i.e. f/3.5 at 18mm and f/5.6 at 55mm. There is nothing to stop you using a narrower aperture; remember a larger number is a smaller hole (the f number is the diameter of the hole as a fraction of the focal length).


30

Firstly the iPhone 5 lens has to be f/2.2, due to the small pixel size, the effects of diffraction which start to creep in at f/11 on a DSLR, start to creep in at f/1.45 on a 5.6mm (diagonal) sensor! I though that in order to have a big aperture such as f/2.2 a big amount of light should be able to enter to the sensor and in order to do it, a big lens ...


27

Aperture simply means "opening", and in photography we use the term to refer to the diameter of the opening in a special adjustable diaphragm within each lens. When this diaphragm is constricted, there's less physical space for light to get in, so naturally the exposure is darker, and a more-open aperture allows more light and results in a lighter exposure. ...


26

Depth of field depends not only on aperture but also on distance to the subject. Depth of field increases as the subject gets farther away. If the wave and boats were all relatively far from the camera, but not terribly far from each other, then it's not surprising that they were all reasonably sharp. You can use DOFMaster to run the numbers yourself. Some ...


25

Noise is better than blur (and much less of a problem than you might think from reading the internet), so don't hesitate to vigorously boost ISO. Underexposing won't help; it's basically the same as increasing ISO w.r.t. noise. The only time to do this is when you've already maxed out the ISO adjustment. Consider a "fast fifty" - you can get a 50mm f/1.4 ...


25

Broadly speaking wide aperture lenses are easier to design the longer the focal length. The reason that you don't see any 400mm f/1.4 lenses is due to manufacturing difficulties, e.g. keeping dispersion low while producing elements of the size required for such apertures. It's worth restating that the designation f/1.4 means that the size of the aperture ...


24

Get a flash! Seriously, even the small external flashes make a huge difference. You can also (at least on my Nikon SB-400) direct the flash at the ceiling, which both annoys people less and also nearly always eliminates red-eye.


24

First of all, it was an issue on film. If Bryan Peterson wasn't aware of it at the time, it just shows what he didn't know, not that it actually wasn't a problem. There were differences though. First of all, we didn't have EXIF data, and most people didn't keep careful enough notes to really know why shot X came out quite a bit sharper than shot Y. Even for ...


24

Why the wide aperture blurs the background more Let me start with Wikipedia figure: Above we have a wide open aperture. Only point 2 is in focus. Points 1 and 3 are out of focus. Due to wide aperture, the rays coming from them through different parts of the lens intersect the screen 5 (a film or a digital sensor) in different points. We may also tell ...


23

I was recently trying to figure this out myself, and found this question. I didn't feel the accepted answer was quite complete, so here's my shot (no pun intended!): The first thing to understand is that the light that reflects off any one point on a surface isn't one beam of light, but many, coming in at many different angles and reflected off at many ...


22

It's now more common to control aperture through the camera. The mechanical aperture ring adds cost, mechanical complexity which can lead to equipment breaking, and it can be confusing to users (if it's set to something other than the smallest aperture many cameras will give a confusing error on a lot of modes). It also prevents Nikon from putting a seal ...


22

F-stops are purely geometrical, the ratio of aperture to focal length, regardless of actual light transmitted. But all lenses absorb a part of the light passing through them, and the amount being absorbed varies lens to lens. So, in situations where even the slightest change of lights being transmitted affect the output, i.e cinematography, where many images ...


21

The aperture affects not only the amount of time required to take a photo, but also the depth of field within it. With a wide aperture (so a low number, like f/1.8) gives a shallow depth of field - sometimes less than a millimetre with a macro lens. Because a lot of light is reaching the sensor (be it film or digital), this allows for fast shutter speeds ...


21

Yes, there are several reasons for this. Larger apertures allow for a smaller depth of field, and generally better bokeh. Faster/more accurate auto focus, because more light is available to the focus system. Much more versatility, because more light falls on the sensor at a wide aperture, which opens up your options in lower-light settings. Better image ...


21

This is called the "program line". Imagine a grid labeled aperture in one direction and shutter speed the other way, as in the "exposure rectangle" in the middle of this answer. There are many different combinations which could produce the same exposure, and the program line is literally the line drawn on the graph to represent what a given program actually ...


21

This is normally referred to as something like "dual control dials", and you're right, it's a very desirable feature. Very few entry-level cameras have this, but it's common on mid-tier "prosumer" DSLRs, and universal on higher-end models. You can find a list of models with this feature on a camera review / database site like Neocamera; try this search: ...


20

F-stops deal with doubling/halving the amount of light hitting the sensor. Everything revolves around twos. With the shutter speed, it's easy to understand, as you say. Every shutter f-stop is (roughly) half/double the amount of time as the previous one. Personally, I don't even bother paying attention to the numerator ("1/") part of the shutter speed; I've ...


19

I'm not sure about with Nikon, but one of the biggest differences I see mentioned between the Canon 50mm 1.8 and 1.4 lenses is the build quality - plastic vs metal among other things. This is probably what accounts for most of the price difference.


19

f1.4 will always be 2/3rds stops faster than f1.8. The diameter has nothing to do with whether or not part of the sensor is hidden. That is a separate measurement referred to as vignetting, and not the image circle's light level. The image circle's light level/brightness is directly affected by the aperture of the lens design. FF lens simply means the ...


19

Although the relative aperture numbers — the ƒ stops — are the same regardless of format, the actual focal lengths of the lenses on small cameras are quite low: 5mm or 6mm at the wide end. That in turn means that the real aperture is small, which is why the diffraction limit kicks in sooner. The smaller format also means that depth of field is hugely ...


19

The wider a maximum aperture, the more prevalent optical aberrations will tend to be (given a "simple" lens.) Wide aperture lenses become increasingly difficult to manufacture at reasonable cost, as you have to put more effort into correcting those optical aberrations. Additional lens elements are necessary to mitigate chromatic aberration (which can become ...


19

Well, one way of remembering the f-stop scale is to remember that every other value is a multiplication by two, or in more photographic terms...every four-fold jump in light availability is twice the f-stop number. As an example: Double-stops starting at the beginning: 1, 2, 4, 8, 16, 32, 64 Double-stops starting skipping the first stop: 1.4, 2.8, 5.6, 11.2 ...


19

Sigma 28-300mm F3.5-6.3 DG Macro? You are going to get a $7,000 camera with that piece of glass? Or even any of those Tamron's. I highly doubt anyone in the market for the 1DX even has these in a backup kit. How important is it? Not important at all.


18

Here's the Thom Hogan review: http://bythom.com/Nikkor50AF-Slensreview.htm His take is: yes, the f/1.4 is somewhat better, but not by a whole lot, so save your money unless you really do need the extra 2/3 stop. Consider boosting the ISO by a stop instead (and you should be ignoring the pixel-peepers and their 100% crop noise tests anyway). Also note that ...


18

The sweet spot of a lens is probably just as dependent upon the type of image capturing surface used as the lens itself. Both film and digital sensors have a limit of detail they can resolve (although large-format film has the tendency to capture FAR more detail than 35mm or digital sensors at much tighter apertures, around f/22.) Assuming you have a lens ...



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