19

It's widely believed that a lens with a faster aperture will perform better stopped down compared to a slower lens wide open. Whilst this is often the case it's not a hard and fast rule. With DSLRs the lens is wide open until you take the shot (at which point the iris quickly closes). Having a faster lens therefore means you get a brighter viewfinder image. ...


18

Many many reasons exist to buy lenses slower than f/2.8. Price Size Specialty lenses No need for a wide aperture Versatility Compromise over above factors As you suggested not all types of photography require wide apertures. Landscape photographers oogle over the Canon TS-E 24mm f/3.5 L II Tilt-Shift Lens for example. It is f/3.5, costs around $2,000USD, ...


15

When used at the same aperture and focal length, a faster lens will have less vignetting than a slower lens. For example if you choose to shoot at 35mm f/4.0, then a 24-70mm f/4.0 lens will have the most vignetting, a 24-70mm f/2.8 lens will have less, and a 35mm f/1.4 prime will have the least vignetting. The reason this happens is because of tradeoffs in ...


14

Those are almost certainly reflections from the UV filter. I recommend taking it off. This is a topic of much debate, but the fact is filters do cause artifacts visible in your photos — you've got the evidence right there. You can get better results from a more expensive filter, but then it'll cost almost as much as your lens. Lenses aren't as fragile as ...


11

This is called axial chromatic aberration (or longitudal chromatic aberration) and it's fairly common with large aperture lenses. It appears as a purple halo around objects that are closer than the plane of focus and as a greenish one around objects that are further, regardless of where they're located in the frame. It often shows up around highlights, ...


11

A faster lens (= low F-stop) allows easier manual focus and better auto-focus, given the camera has AF sensors which can exploit faster lenses. For landscape however, there is usually enough time that there is not much to gain from this. Faster lenses often surpass slower lenses when stopped down to the same F-Stop (eg. f/8). The reason is not that a faster ...


10

Canon's 70-200 f/4 L lens is a perfect example of a lens slower than f/2.8 that has a niche even when an f/2.8 equivalent is available. Comparing the f/4 lens(s) to their corresponding f/2.8 cousins, the f/4 lenses are around half the weight (not to mention half the cost), which makes a real difference to some people if they're carrying the lens around all ...


9

No matter what the maximum aperture of the lens, the plane of absolute focus is the same. That is, if you shoot with a 50mm f1.4 or a 50mm f2.8 at, say, 10 feet out, it is focused on the exact same specific point of your subject. The difference is that at f1.4 a thin slice appears to be in focus and at f2.8 a thicker slice appears to be in focus. So, let's ...


8

When I was doing online photography course, the photographer who wrote it was specialised in food photography. At some point he admitted moving from lens with f2.8 to f4 explaining it by the change of his style of shooting. Before he liked food having very shallow DOF, and now he wanted to show more details. I am shooting food for stock and almost never use ...


8

Before you get any other lens, get the 50mm f/1.8. Its a must-have lens for anyone even remotely interested in portrait photography. You just can't go wrong with it. Actually I never used the 18-55 after I got my fifty prime. For your zoom needs, you would be better off with a third party lens like the the Tamron 17-50 f/2.8 (non-VC). At INR 21,000 ($440) ...


8

However, someone has told me that if in both lenses I will use f/1.8 aperture, still the latter lens will have more light. It sounds illogical because it's wrong. At f/1.8, both lenses will let in (approximately) the same amount of light. I say "approximately" because the f number is derived only from the ratio of the focal length to the size of the ...


7

The UV filter likely explains this. As I've explained in this answer, any filter will degrade image quality, but some do so more than others. Tiffen filters do not have anti-reflective coatings and are thus prone to flare. You should either remove the filter or use a high-quality one from a brand like B+W or Hoya.


7

Some have told me the f/2.8 lens requires more glass to achieve f/2.8 and therefore it lets in more light and can shoot at a faster shutter speed at the same aperture - but I really don't think that makes sense. Basically incorrect. The entrance pupil for 300mm at f/8 will be 37.5mm in diameter, regardless of the diameter of the lens' front element. So you ...


7

Consider low light conditions. If you can use a low F-stop, you can use a lower ISO. You'll then have less noise and higher dynamic range. Even with a tripod, you'll have more options if you only need an exposure time of, say, 0.3 seconds instead of 2 seconds. In very windy conditions the tripod may shake, but even in alight breeze tree branches may move a ...


6

There is more than just lens quality, depth of field control and low light shooting ability to consider. For some applications size and weight are important or perhaps a convenient zoom range in one package. As @Itai said "buy what you need". My kit consists of several fast primes but I also have a 24-120 f4 zoom. I have that lens because I wanted ...


6

Lens design is always a matter of choosing the right balance between a number of factors. Maximum aperture is one, of course, but others are size, weight, distortion, micro-contrast, evenness of field, zoom range, curvature of focal plane, chromatic aberration, spherical aberration, and more — including, of course, price. Pushing a lens to a fast aperture ...


6

Your two requirements are orthogonally opposed to one another. To get more detail and resolution requires more sensor pixels (assuming the lens is not more limited than the sensor). More sensor pixels require more processing, which increases the time needed to process each frame. This reduces the maximum number of images that can be taken in a specified ...


5

With the parents permission, you are going to get the best results by putting a remotely triggered flash unit on her balcony. Then you expose for the ambient and adjust flash power to light her properly -- at dusk this could be a really cool shot. This is much cheaper than a 300mm f/2.8 and will greatly expand your capabilities as a photographer. Pick up a ...


5

I only have odd numbered 5Ds, but the pixel pitch is very similar between the 5DmkII and 5D mkIII so the results ought to hold up. Here's the same scene shot using a tripod under the same lighting, 1/8s exposure ISO 100, f/1.2 (using the Canon 85L). RAW, converted with ACR with the same settings (everything on zero with a linear tonecurve). I shot pairs of ...


5

Some times we have a f2.8 or two already and don't need all lenses f2.8. Because of weight. size and cost. I'm using a 5Dmk3 and currently use a 40mm f2.8, 100 f2.8L and 70-300L so I really don't need a 24-70 f2.8L unless I was a full time Professional and I'm not. Only studying less then 3 years Photography full time. Yes f2.8 and faster lenses are easier ...


5

The big difference between the two lenses will not be when the picture is taken. At that point both lenses will allow the same amount of light through within the limits of the accuracy of their aperture settings and transmission ratios. The big difference will be when the lenses are focused prior to stopping down. The wider aperture lens will allow more ...


5

I don’t have a dedicated camera. Just using an iPad, not good enough though. Distant shots are grainy, and fast-paced mages get blurred. You have arrived at what you think is a solution to your problem (high pixel count, long distance shooting) and have asked about that. Instead, I'd encourage you to take your solution, shelve it, and instead ask the meta-...


4

If you are going to use a fast lens in manual focus mode, do yourself a favour and replace the matte screen in your camera. The mattes that cameras are delivered with these days are optimized for slow zoom lenses (the f/3.5-5.6 kind of thing), this has been achieved at the expense of focus accuracy. Such a matte is physically unable to show accurate depth of ...


4

I agree with everything you said except low light. f/2.8 is still not good enough for many situation, the difference between f/3.5 and f/2.8 is very little and can almost be ignored. f/5.6 and f/2.8 is only two stops so you are looking at 1/10 turns into 1/40. If you have the impression that f/2.8 is amazingly good for low light, it is not. 15-85 is more ...


4

What matters for distinction between fast and regular lenses is relative position of maximum aperture in regard to general availability of lenses for same format and focal length. For any given lens, if one can't easily (ignoring price) buy a lens of similar focal length for same image circle size with maximum aperture more than a stop wider, it's a fast ...


4

Faster lenses give you almost always better image quality than slower lenses at the same f-stop. This is true for vignetting, resolution and contrast, distortion and color. A faster lens also gives you a brighter look through your viewfinder or less noise on your live view display. Anyone who has tried to focus on a star at night knows how annoying a noisy ...


4

A prime lens has a much simpler design, so for the same price, and weight, you can get larger lens elements and therefore a higher aperture. However, there are some other factors to what you're asking. In the case of a 18-55 zoom lens, the lens has to have a retrofocal design, because at the wide end you are going down to much smaller effective focal ...


4

Depends what sort of AP you're talking about. And whether you're using a standard photo tripod or a proper astronomical tracking mount. For a standard tripod, you're limited in exposure by star trailing; as the earth rotates, the stars appear to move across the sky. Unless you're intentionally after star trails, with a fixed tripod the length of time you ...


3

Lifting the relevant section from another answer of mine: Basically, the larger the aperture is, the larger the angle of light rays on the outside of the lens has to change: Look at the image and imagine that D increases while f stays the same - it should be clear that the light rays then need to "bend" more. And making optics that refract light rays at ...


3

Yes, absolutely! 1.4 is fast which means it has a very narrow depth of field. Check out this image: This is a crop of a shot I made. It was taken with a Canon 50mm f1.8 on a Canon crop body. I was also fairly close to the subject. Notice how part of her hair is in focus. But the wisps that stick out towards me are not and as the forehead recedes the hair ...


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