Open

by damned truths

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

A photographic lens is used to focus the light onto film or a digital sensor. Many cameras have interchangeable lens systems, allowing the photographer to choose the type of lens to use.

learn more… | top users | synonyms (1)

123
votes
3answers
43k views

What do all those cryptic number and letter codes in a lens name mean?

Then looking at a lens name there is a lot of acronyms in the name describing it's features (often specific to the manufacturer). Examples, Nikon: Nikon AF-S DX 16-85mm VR f/3.5-5.6G IF-ED Nikon ...
66
votes
10answers
4k views

How much do lens lineups vary across DSLR platforms?

I was reading this question and recalled how often I hear the advice "choose your lenses and then choose the body that matches" in the context of deciding on a camera platform ...
66
votes
12answers
4k views

Why are lenses always round in shape?

Why are lenses round in shape although the image sensor is not? Why they can not be square or something matching the shape of image sensor?
60
votes
11answers
24k views

Is there a noticeable difference between 1.8 and 1.4 prime lenses?

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 ...
56
votes
10answers
5k views

Are there any downsides to using a good-quality UV filter?

Are there any real downsides to using a UV filter? I know that a poor quality UV filter can effect image quality ... but, assuming I use a good quality UV filter, will that actually be an issue? Is ...
53
votes
8answers
3k views

Why do some lenses cost 10 times as much when the specs are very close?

For example, a Canon 50mm f/1.8 lens is about US$110, while another Canon 50mm f/1.2 lens is about 14 times as expensive, at about $1450. Is the 1.8 or 1.2 the main reason for the price difference? ...
52
votes
6answers
8k views

Why are wide-angle lenses so much more expensive?

What is it about wide-angle lenses that makes them so much more expensive than an equivalent-quality tele or prime lens? Take the Canon EF-S 10-22mm USM, for example. RRP is nearly £1,000! Are they ...
51
votes
5answers
1k views

Is there development in the world of lenses?

Now, I'm not an expert, so if this post makes you laugh, you're welcome. Still, as far as I know there are basically two components that determine the potential quality of a camera's photos: Sensor ...
47
votes
10answers
3k views

Is it lenses which make your photographs, not camera bodies?

I read somewhere on this site itself that you should spend more on your lenses and less on your camera bodies. Is it a myth or a fact that mostly it is the lenses which make your photographs not the ...
47
votes
5answers
11k views

What is “angle of view” in photography?

I read on the Lens Buying Guide @ neocamera: Focal-length determines the angle-of-view seen through a lens for a given sensor-size. With a full-frame sensor a lens gives the same angle-of-view ...
42
votes
6answers
24k views

Why do pro photographers use huge lenses to take portrait shots?

Every time I see a photoshoot video on youtube, the photographers have the biggest lenses I have ever seen in my life to shoot portraits or full-body shots. For example, the Nikon 70-200 f/2.8 ...or ...
41
votes
9answers
3k views

What is the best way to clean lenses and filters?

After removing dust with an air pomp and a brush, what are you using to remove stains from the lens and filters? So far I'm using the liquid from a Giotto's CL 1002 cleaning kit for the lens, but I'm ...
40
votes
9answers
89k views

What can be done using a 18-55mm lens?

I have a Canon EOS 1000D with 18-55mm kit lens (entry level, as many say). Whenever I go out for a shoot, I always end up feeling handicapped because of the limited zoom range. Most of my friends ...
40
votes
11answers
4k views

Should I keep Image Stabilization (IS) off when I do not actually need it?

I own a Canon 7D and a EF-S 15-85 IS lens and I keep the image stabilization turned on all the time. Recently, an experienced photographer told me that this is a huge mistake because it reduces image ...
38
votes
8answers
6k views

Why is the 50mm prime lens the most standard?

Seems that most photographers choose the 50mm as their prime lens (at least from what I've read). I'm looking at getting a prime lens for my Nikon D3000 and the cost difference between the 35mm 1.8 ...
36
votes
4answers
2k views

Should I get DX for my APS-C camera, or FX lenses in case I upgrade to full-frame in the future?

I recently bought a Nikon D90 camera body, which has a "DX" APS-C-sized sensor.. Within the same budget, should I go with DX lenses or should I get full frame lenses in case I upgrade to a full frame ...
35
votes
5answers
94k views

How do I convert lens focal length (mm) to x-times optical zoom?

What is the rule to convert the 'mm' notation to the 'optical zoom' notation? I searched a bit and found this one: optical zoom = maximum focal length / minimum focal length For example a 18-55mm ...
34
votes
9answers
7k views

Why do people recommend 50mm or other prime lenses as starting lenses for learning photography?

I've seen quite a few people recommend the 50mm prime lenses, in particular the sub-$100 50mm/f1.8, as a starting lens for photographers (especially because they're likely to be using cameras with ...
34
votes
8answers
5k views

What are the dangers of removing a lens while the camera is on?

The manual warns that you should turn the camera off to remove the lens, but it doesn't say why. I suspect this may have to do with dust, but I could imagine there are lots of other reasons. I'm ...
34
votes
5answers
6k views

What should one look for when buying a used lens?

When buying a used lens, what should the buyer check? Other than looking for obvious physical damage on the outside of the lens, what else should be inspected to identify the condition or quality of ...
33
votes
10answers
9k views

Which focal-length lens is usually used for portrait photography, and why?

What focal length or range of focal lengths are usually used for portraits? What is used by professionals? Why would one select a certain focal length? What are the advantages and disadvantages of ...
33
votes
2answers
2k views

How do I interpret an MTF Chart?

As part of how Canon (and other lens makers) give technical information about their lenses, they supply an MTF (Modulation Transfer Function) chart. How do I read and interpret what the chart is ...
32
votes
8answers
4k views

Do I really need a fast 50mm lens?

Everyone I speak to says that a 50mm lens is the best and beats them all as an all-rounder. I was wondering whether to get myself a decent, fast 50mm as well. However I'm still not 100% sure whether I ...
31
votes
7answers
14k views

What can a fisheye lens be useful for?

I have a variety of lenses in my camera kit. One that I do not have, and has me curious, is a fisheye lens. I mostly understand what it does: it captures an image with distortion similar to what you ...
31
votes
7answers
1k views

Do good lenses really last a lifetime?

I’ve heard people say “a good lens will last a lifetime” many times. Is this actually true of modern lenses? More specifically, will a good lens be usable for a lifetime? With an inexpensive adapter, ...
31
votes
5answers
5k 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 ...
30
votes
4answers
5k views

Do professionals really never use a 24-70 lens?

I was reading lens reviews on the Rockwell site — mostly because it came up as first result in Google search — and he was saying professionals don't need and don't use mid-range zoom lenses like 24-70 ...
30
votes
6answers
18k views

Is it worth to upgrade from Canon 50mm f/1.8 to Canon 50mm f/1.4 on 550d?

I'm a newbie in the world of DSLR photography, having played around with my Canon 550d for few months. After posting my first question here and getting some superb advices I decided to buy Canon 50mm ...
30
votes
3answers
13k views

What does the number of elements and groups in a lens mean?

All lens specifications include a statement of how many elements the lens contains, and in how many groups, for example: Nikon AF-S VR Zoom-NIKKOR 70-300 mm 1:4,5-5,6G: 17 elements in 12 groups (two ...
29
votes
4answers
44k views

What is back-focusing?

What is back-focusing? Is it something I need to be worried about, or can I just live with it? How can I tell if my camera/lens is sufferring from it?
28
votes
12answers
8k views

Should I buy a camera with kit lens, or body plus lens separately?

I am planning to buy a DSLR soon. Before I zero in on the model, I want to know whether it is advisable to buy a kit (body + 18-55 lens) or not? OR should I go for the camera-body and the lens ...
28
votes
2answers
2k views

Why no zoom lenses below f/2.8?

I can understand that a zoom below f/2.8 would be difficult and costly, but it seems like something pros would kill for. Surely it can't be more expensive (if its possible) than some of the $10k+ ...
27
votes
3answers
2k views

What does a hexagonal sun tell us about the camera lens/sensor?

In this picture, we see that the sun comes out as a hexagon. I am sure it is not arbitrary. What does the hexagon tell us about the instrument that captured the image?
27
votes
6answers
2k views

What is the definition of a “prime lens”?

There are many discussions of differences between prime, zoom and macro lenses. I have not heard about prime lenses until recently. Could someone explain what exactly a prime lens is? Is it ...
27
votes
4answers
11k views

What is a macro lens?

I've read a few threads on here that mention some elementary descriptions of macro lenses and found some marketing fluff in the box for my Canon about them as well, but being a complete novice I was ...
27
votes
3answers
3k views

How can I test a new lens to make sure it is operating correctly?

How can I test a new lens to make sure it is operating correctly? I found two similar questions with answers specific to things such as sharpness and focus, but I want to cover any and all possible ...
27
votes
2answers
3k views

What is a pancake lens?

I've read about a "pancake lens" but don't really understand what that means. What the pros and cons of having a pancake vs. another type of lens? I'm thinking of getting a Panasonic Lumix DMC-GF1 ...
26
votes
11answers
2k views

Will a tilt-shift lens solve my 'leaning building' shots?

I shoot primarily with a Nikon D300, and that's not likely to change soon. The camera does everything I need it to do, but this. I also use a 17-55 lens, which I know that Thom castigates as being ...
26
votes
5answers
10k views

What is the effect of a scratched lens?

I have a lens with a small but significant looking scratch near the center. But I don't see any difference in the photos. Where does the imperfection show up? How important is it to get the piece of ...
26
votes
10answers
1k views

Are Sigma lenses comparable to Canon lenses for a Canon camera?

I always feel that I should buy a Canon lens for my Canon camera, and Sigma would just be a cheap knock-off. Is that the case?
26
votes
7answers
1k views

Is it ok to breathe on the front glass element of a lens to fog it and clean it?

Nikon specifically recommends not breathing on the glass elements to clean them as harmful acids in the breath can damage the coatings on the glass. However, I've read on many other websites that it ...
26
votes
6answers
4k views

Can I damage the focus system by turning the focus ring when the lens isn't mounted?

I have a couple lenses that don't have an internal focusing system, and whenever I want to put them back in my bag, I turn the focus ring to make the lens shorter. I noticed that when the lens is set ...
25
votes
2answers
5k views

How do I properly position a lens hood?

I understand the basic idea of a lens hood, but after looking at mine and contemplating how to use it, I get stuck on the same question every time: Does the orientation of the hood on the lens ...
25
votes
4answers
4k 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 ...
25
votes
3answers
2k views

When you zoom in with a lens on an SLR why does the lens go in then out?

I guess this is more a question of optics than photography but I just got an SLR with a basic 18-55 lens. I noticed that when going from 18 to 55 or 55 to 18 the lens physically comes back in and ...
24
votes
15answers
14k views

What lenses would best comprise a travel photography kit?

On a crop sensor camera, e.g. Canon EOS 7D, what would be the best kit to travel with around Europe for a few weeks? My shooting style will focus on landscape, architecture, and general travel shots ...
24
votes
5answers
2k views

What are the most notable differences between Canon and Nikon lenses?

I'm currently considering to buy one of the next generation enthusiast DSLRs. Either a Canon EOS 60D or the slightly more expensive Nikon D7000. I'm quite new to the SLR discussion but I know there ...
23
votes
2answers
2k views

What characteristics make a lens good or bad?

When reading lens reviews on the Internet, I often find subjective statements about the image quality that a lens produces, such as "good contrast" or "sharp". The problem is that I don't think I am ...
22
votes
5answers
5k views

How to capture the scene exactly as my eyes can see?

What settings of my DSLR camera will emulate the scene exactly as I can see through my naked eyes? I think it's not possible to get the contrast and colors exactly as my eyes can see, and it may vary ...
22
votes
7answers
2k views

Why do some lenses cost so much?

Something that confuses me is why there is some lenses that cost so much. For example the only difference that I see between the two lenses is the aperture: f/2.8 vs f/4. Canon EF 70-200mm f/2.8L II ...