What's the name / specification for a camera lens which gives fast shutter speed in low light conditions?

Question

I know the bigger the aperture the faster the shutter speed, but is there a technical name for such a lens? I want to get one that I can use in dim lighting conditions but don't know what exactly to ask for.

Not a tripod or remote shutter release, got those already!

I've seen some lenses that are really fat looking, almost like miniature astro-telescopes, are these the ones with really wide aperture settings?

Answer 1

You're simply looking for a "fast" lens.
That would be one with a f/1.2 or f/1.4 aperture.
The f/1.2 being the fastest.
By the way, there are lenses called "ultra-fast" with openings as wide as f/1.0...about the "fastest" lens you can get.

The word "fast" in this context, does NOT necessarily relate to the shutter speed, but instead the ability of the lens to capture light quickly (fast) because of the wider aperture (lens opening) which allows for more light to reach the film at a "faster" rate than a smaller or "slower" aperture such as, for example, a lens with only an aperture of f/2.0
On the other hand, some say the designation "fast" DOES relate to the shutter speed, in that you can use the fastest shutter speed possible due to the fact that you are able to "open" the lens wider to allow more of the light in to the camera.

If you had a lens, and the aperture at it's widest opening is, say f/2.8...this would be considered a relatively "slow" lens (compared to one with a f/1/2 opening).
You can always tell just how "fast" a lens is by looking at the front of the lens (around the rim of the glass itself) and it should tell you what the widest lens opening is for that lens, e.g. f/1.2, etc.

If you walked into a Camera store, walked up to the counter, and
told the salesman you are looking for a "fast" lens for your Nikon (for example), he would know exactly the kind of lens to show you.
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Additional Info:
The type of lens you're describing could be one of the telescopic variety (like a 400mm) used for taking shots at long-distance.

A fast lens can just look like a "normal" camera lens and still be fast because of it's wide f/stop.
Although the glass or lens itself can be of a larger diameter to allow for capturing the light faster. But, this should not be confused with a "Wide-Angle" lens (28mm or 35mm for example), which are much larger than the "Normal" lens (50mm or 58mm for example)
Here, for example, is a picture of a f1.4 fast lens for a Nikon:
http://www.moosepeterson.com/gear/images/50f14.jpg
(notice where it says f/1.4 on the aperture ring)
The lens you're describing (minature astro-telescope)...
is probably like this one:
http://www.the-digital-picture.com/Images/Other/Canon-Super-Telephoto-Lenses.jpg
which is classified as a "Super-Telephoto" lens.

So, if you're looking for a fast lens that can take pictures in low-light situations, it won't necessarily be the big, bulky kind that you are describing.

Answer 2

Gene gave you one of the best answers I've seen in this category in weeks.
Here's just a few additional bits of info:
* For zoom lenses, a constant f/2.8 is the fastest you'll find. Perhaps these are the chubby lenses you're thinking of. My 17-55mm f/2.8 fits that description - it has a 77mm filter thread.
* Fixed focal length lenses can be much faster than zooms. A 50mm or 85mm f/1.4 is two stops faster than f/2.8 lenses, which makes them 4x faster. (Every stop doubles the sensitivity).
* Every little bit of extra sensitivity will cost you dearly.
A Canon and Nikon 50mm f/1.8 can be had for under $100 retail.
A Canon and Nikon 50mm f/1.4 will cost you $360 and $260 retail.
Canon's new 50mm f/1.2 will cost $1600. Nikon's discontinued f/1.2 'Noct' goes for around $1400 on eBay.
* Image stabilisation is great for stationary subjects, but it's not going to do jack for moving subjects. IS works as a substitute tripod - it lets you keep the shutter open *longer*.
If you're currently using a slow zoom lens (something like f/3.5-5.6) , your cheapest option is to add a used 50mm f/1.8. That focal range can be used for quite a few things, and for just a few bucks, you'll be able to cut your shutter time down to around 25%.

Answer 3

Gene L had a great answer, I'll add that you can also get IS- Image Stabilized lenses, also called VR for Vibration Reduction.

These lenses contain an electromechanical system that effective makes the lens up to three f-stops "faster"

Answer 4

You need a 'FAST' lens, A fast standard lens 50-55mm focal length would be one greater than f1.8, say f1.4 or even f1.2. but this figure reduces as the focal length increases. Most manufactuers used to offer at least 2 lenses in each length.

Answer 5

high speed lenses and yes they have bigger diameter than the ones with lower aperture you need a monopod for the these lenses especially for the tele with more than 135 mm focal cause they are quite heavy

Answer 6

shutter speed is for movement if you want piccy's in low light need a low lux lens the lower the lux rating the better the picture quality in low light.

Answer 7

Infra red, low-light - can't see what else you mean that you've not already said.