Aperture is the opening in the diaphragm of a camera lens.
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Is there a noticeable difference between 1.8 and 1.4 prime lens?
I have been shopping around for a prime lens for my Nikon d50. I noticed that the 1.8 is hundreds of dollars cheaper than the 1.4 AF-S. What will I gain for that cost difference? Is it really ...
38
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2answers
12k views
What does f-stop mean?
What does f-stop mean? Is it the same thing when people say "2 stops" for example?
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6answers
3k views
What is a “diffraction limit”?
I've seen the term used, but what is a "diffraction limit", when should I worry about it, and what undesirable effects are a result of it ?
31
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10answers
1k views
What are some tips for shooting in low light?
I own a Canon 450D with just the standard lens kit that comes with it (poor so won't be buy a new lens for a while) and one thing I tend to struggle with is shotting in lower light conditions, indoors ...
31
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3answers
6k views
What apertures are required to enable autofocus, including cross-type or high-precision focusing, on Canon DSLR cameras?
This is a follow-up to Why does Canon and Nikon limit or disable autofocus beyond certain f-numbers? I'm doing this to separate the AF aperture requirements from the linked question above. My goal ...
29
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7answers
6k views
What is aperture, and how does it affect my photographs?
How does aperture affect my photographs?
Why should I care about the aperture with which a photo was taken?
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5answers
4k views
How do constant aperture lenses work?
Cheaper zoom lenses usually are faster at the wide end and slower at the long end (for example, the $150 Canon EF-S 18-55mm f/3.5-5.6). More expensive constant-aperture zoom lenses have the same ...
26
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4answers
1k views
How does aperture work without “cropping” the image hitting the sensor?
I've been teaching myself the various settings in cameras and now have a much fuller understanding of how to use my camera effectively, but one thing is still bugging me.
When the aperture size is ...
25
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7answers
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When to use shutter priority instead of aperture priority?
Under what circumstances would you use aperture priority vs. shutter priority and vice-versa?
I typically don’t use shutter priority (ever) and favor aperture priority to try to get a max aperture ...
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5answers
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What is special about lenses with f-number < 1?
Talking about fast lenses, Wikipedia mentions
Nikon TV-Nikkor 35mm f/0.9-Fastest Nikon lens ever made
Why don't, for example, f/0.5 lenses exist?
Is there some special construction that comes ...
19
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2answers
1k views
Why use a small aperture when trying to see sensor dust?
Here and there I read of people who set their lens to a small aperture while testing their sensor cleanness, supposedly to get the best image of dust speckles. However, the image of the on-sensor dust ...
18
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8answers
1k views
What's the benefit of a tiny aperture?
In this answer to another question Rob Clement wrote:
Think background first. What story do you want to tell? Epic background, big mountains. Looking to deliver a sense of grandeur with your ...
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4answers
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Why do compact digital cameras not have the aperture range of DSLRs?
Why is it that on compact digital cameras the aperture never seems to go any smaller than about F8 ? Even on high-end compacts such as the Cannon G10 or Panasonic LX5. Is there some practical or ...
17
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4answers
2k views
How do you find out the “sweet spot” of a lens?
I've tried googling this, but have never found a satisfactory answer.
I've heard the term "sweet spot" thrown around by some photographers to mean the f-stop of a lens which results in the highest ...
17
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3answers
928 views
Do smaller apertures provide more depth of field past the diffraction limit, even if peak sharpness suffers?
In Understanding Exposure (3rd edition, on page 48), Bryan Peterson has what might be called a rant against modern on-line conventional wisdom about diffraction limits. Answers on this web site are ...
17
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0answers
2k views
Why does a larger aperture cause more blur of the background? [duplicate]
Possible Duplicate:
Technically, why is the out of focus area blurred more when using a bigger aperture?
Why is it that a larger lens aperture produces a shorter depth of field, causing the ...
15
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7answers
830 views
Why isn't my variable-aperture photo more interesting?
I took a photo where I changed the aperture of the lens during the exposure. I was hoping to get a cool or unusual effect, but I didn't. Why not, and is there any really interesting effect that I ...
15
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8answers
685 views
Would a prime be redundant with a fast zoom?
Now that I am finally getting a fast zoom (Tamron 17-50mm 2.8) I've been considering a fast prime to go with it, specifically a Sigma 50mm 1.4. Despite its shortcomings, it still does really nice ...
15
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2answers
532 views
Do rounded edges on aperture blades improve image sharpness, and how?
In the description for the XF lenses for its new X-Pro system, Fujifilm crows:
The [XF lenses] all offer precise control over depth-of-field and deliver excellent out-of-focus bokeh thanks to the ...
15
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2answers
398 views
Does a specific f number across all lenses denote same amount of light?
When we say a light source emits 1500 lumens of light, it does not really matter if the light source is incandescent, CFL, diode etc. Similarly, when I say f/1.8 can I assume that all lenses pass the ...
15
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5answers
696 views
How do I find the aperture that produces the highest-quality images for a given lens?
I'm not talking about large aperture (f/1.8, f/2.8...), rather, about small apertures (f/18, f/20, f/23...). I read somewhere (actually I think it was on this site, but I don't exactly remember which ...
15
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4answers
2k views
Why is the depth-of-field preview in the optical viewfinder of my Canon 500D inaccurate?
I have noticed that in my Canon 500D, the depth-of-field preview in the optical viewfinder is inaccurate with large aperture settings.
If I press the DoF preview button, there is very little ...
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4answers
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Why is the aperture ring removed from new Nikon lenses?
Maybe I'm wrong, but I notice that Nikon's newer lenses don't have an aperture ring. For example, an older AF 35 mm f/2D is now replaced by AF-S DX 35 mm f/1.8G, or AF 50 mm f/1.8D is replaced by a ...
14
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5answers
6k views
What is an easy way to remember the full stop scale?
If you were teaching someone new to photography the full stop scales, is there a better way then flat out memorizing these values? Does anyone have an easy way that they remember the scale? Would it ...
13
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6answers
1k views
Can a smaller sensor's “crop factor” be used to calculate the exact increase in depth of field?
If APS-C and similar crop-sensor digital cameras have a focal length multiplying effect such that a 50mm lens has an apparent focal length closer to the field of view of an 80mm on a full frame ...
13
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3answers
1k views
Does a bigger aperture create better photos?
I have observed that the wider the aperture, the more expensive the lenses are. However, I would like to know whether it really makes a difference in your photos or not?
13
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2answers
509 views
DSLRs with separate controls for aperture and shutter?
I just bought a Nikon D3200 DSLR and I'm going to return it. It's fine if you always want to use in fully automatic mode, but in Manual mode, it's much less convenient. You have to set the shutter ...
13
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3answers
302 views
How to test what aperture is actually used?
It seems odd to me that Canon EF 100-400mm f/4.5-5.6L does away with a front element of only about 63 mm, as reported by @jrista - which would be enough for only f/6.3 at 400mm, missing the spec by ...
12
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6answers
523 views
Why are only certain shutter speeds or apertures available?
For the exposure control function DSLRs there are specific shutter speeds available. For example there are 1/4, 1/100, 1/500. Why, even in high end DSLRs, is there no option to use a custom shutter ...
12
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6answers
461 views
Does lens speed still increase meaningfully when the physical aperture is larger than the sensor size?
This question came to me this morning, thinking about 50mm lenses. I have the Pentax 50mm f/1.7 (manual) and it's a very nice lens, but would be considered (relatively) slow on 35mm film, and many ...
12
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2answers
1k views
Why do wide angle prime lenses have relatively small apertures?
I've noticed that many of the wide angle prime lenses (at least for Canon) have somewhat smaller apertures than their normal or telephoto counterparts. E.g. the regular Canon 24mm prime is f/2.8 while ...
12
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3answers
965 views
Do the same camera settings lead to the same exposure across different sensor sizes?
Let's say I have a micro-4/3rd camera and a full frame camera, both set to 1/60 at f/2.8, taking a picture of the same scene in the same lighting. Will the exposure be the same across both cameras ...
11
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5answers
910 views
How can aperture be f/11 on a lens with an aperture range designation of 3.5-5.5?
I made a series of outdoor shots with Nikon D5000, with the 18-55mm 1:3.5-5.6G VR kit lens.
On some shots, I see in the EXIF info f/11, and in another shot, f/9.
How can that be, that the f-number ...
11
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5answers
2k views
What is the meaning of “stopped down”?
Was reading this answer (emphasis mine):
It also tells us that the lens was stopped down, as if it were wide open there would be no corners to cause diffraction, regardless of the number of ...
11
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4answers
2k views
What is a “fast” lens?
I've been reading lots of camera reviews lately and have ran across several references to "fast" lenses.
What exactly is a fast lens and what are its advantages compared to other lenses?
11
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2answers
1k views
What is T-number / T-stop?
Usually, when discussing aperture of a lens, F-stop and F-number are used for quantifying. But some photographers, and especially videographers, also mention T-stop. The concept and numbering used ...
11
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4answers
275 views
Why aren't lenses designed with extra large apertures for autofocus beyond what's used for imaging?
Historically, designing large-aperture lenses has been difficult because correcting the optical aberrations that arise from large apertures requires complex designs and very large amounts of glass. ...
11
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3answers
2k views
What settings should I use to photograph aurora borealis with a wide angle f/4 lens?
I've tried my first night photography of the stars last week. Most articles I've seen were recommending a fast lens, fully opened, @ ISO 800 and about 20 - 30s exposure, etc. Unfortunately, my only ...
11
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4answers
758 views
Is overall light gathering of a lens only dependant on aperture?
My impression is that the aperture value of a lens determines its light gathering ability, but I'm not sure I understand how it works...
When considering light gathering in telescopes, it is ...
11
votes
4answers
421 views
Is there a noticable difference in sharpness between a 1.8 lens and a 2.8 of similar design?
I recently bought a second-hand Carl Zeiss Jena PANCOLAR MC 1.8/50mm Lens off eBay (still waiting for it to arrive though) and am going to mount it to my Canon 7D via a M42 adaptor. I primarily shoot ...
10
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8answers
2k views
Will using a lens at max aperture (“wide open”) result in poor images?
I’m looking to add a second lens to my kit lens I got with my Nikon d7000.
I have read several reviews on both the 35 and 50 mm lenses made by Nikon in particular that said using either lens at the ...
10
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2answers
3k views
Why does Canon and Nikon limit or disable autofocus beyond certain f-numbers?
One thing that I've noticed with Canon DSLR camera is they will disable or limit autofocus when the lens is below certain aperture values, which are specified in my answer to What are the aperture ...
10
votes
4answers
433 views
Focusing on moving target with large aperature?
I have read about difficulties getting focusing right when using a large aperature (because of depth-of-field issues).
If I am using a fast prime wide open (say F1.4 or F1.8) to shoot a target in ...
10
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2answers
473 views
How to stop a high F number from appearing blurry?
I have been out taking some evening photos (just after sunset) and I have noticed that in a number of instances the higher f numbers ( 14+ ) are appearing more blurred than the lower f numbers ( < ...
10
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3answers
272 views
ND filter vs stopping down for long exposures?
To achieve long exposures in daylight, one might need to stop down, or use an ND filter. By stopping down, the depth of field increases, but at some point the image quality/sharpness will suffer, due ...
10
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2answers
288 views
Max aperture on zoom lenses - stepwise or linear?
When zooming with lenses without a fixed max aperture, the change in aperture* that the camera displays is stepwise, usually in steps of thirds. But, is the max aperture really the same all the way as ...
10
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1answer
226 views
What are the limits of extension tubes?
Given lighting is not a problem, can you hit a limit where you have too much extension tubes (a very long tube) and the quality of the image will suffer? For example a diffraction limit will be hit ...
10
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1answer
517 views
Does focal length affect diffraction, in addition to aperture?
The reason I ask is that f/18 on a 24mm lens = 1.5mm, and f/18 on a 180mm lens = 10mm. I thought diffraction is due to the small physical size of the aperture, rather than the f-ratio, yet I only ever ...
9
votes
4answers
398 views
Why do filter sizes vary for lenses of the same focal length?
I have a Nikkor 18-55 kit lens that has a 52mm filter, and recently I was looking that the 17-55 lens has a 77mm filter.
Is it because the latter is a better quality lens? I assume a bigger circle ...
9
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3answers
724 views
Small Aperture difference - A big difference?
I had a second a second thought about asking this question because I have already asked a very similar question here but then I decided to proceed and make this one as different as possible.
I ...
