Tagged Questions
0
votes
0answers
7 views
Digital video cameras optical zoom vs lenses [migrated]
If you read at digital video cameras specifications, you will probably read that camera has 20x optical zoom or even greater.
If you compare this camera with my Nikor 18-200 lens, the lens itself is ...
6
votes
3answers
290 views
Why are Zeiss lenses heavier and larger for Canon EF than Nikon F mounts?
We recently acquired specifications for all DSLR lenses by Carl Zeiss and almost always the Canon EF-mount version is larger and heavier than the Nikon F-mount version. The difference ranges from ...
5
votes
1answer
213 views
Why are so many kit-lenses parfocal if it's an expensive feature?
According to this answer, parfocal lenses (lenses that can zoom in/out without losing focus) are relatively rare and more expensive.
However, the original poster's kit-lens is parfocal. ...
2
votes
2answers
130 views
Why are large aperture lenses so expensive? [duplicate]
Why are lenses with very large apertures so expensive?
For example, generally speaking, there is a significant price difference between a f/1.8, f/1.4 and f/1.2 lens of the same focal length.
Doesn't ...
5
votes
0answers
46 views
How does lens design affect the richness of color reproduction? [duplicate]
Comparing a kit zoom lens to a faster, 20-year-old prime it seems like the old lens produces richer, warmer color. I've noticed the same kind of comparisons elsewhere. What is the lens actually doing? ...
3
votes
2answers
108 views
What's the difference between real and effective aperture?
I understand that the simple idea that f-stop is focal length divided by aperture really applies to a simple single-glass lens, not the compound lens systems used to provide good image quality in ...
10
votes
6answers
658 views
Do lenses lose sharpness when they age?
I was reading this answer where it mentions, "..it's a lens that can lose sharpness as it ages.." and was wondering if this is true and if yes, true for all lenses. Reasons as to why this happens and ...
1
vote
1answer
116 views
Is the size of the rear opening of a lens related to image quality?
I purchased a Sony NEX F3, and it came with a 16mm lens and a 18-55mm lens. It seems to me that the 18-55mm lens produces better picture.
Does the bigger lens opening in the 18-55mm lens produce ...
2
votes
3answers
214 views
What are the difficulties with making a 10mm-300mm zoom lens?
I'd like to have a comprehensive explanation why such a lens doesn't make 'sense', whether economically, technically, ergonomically, etc. Please support each reason with some details so I can learn ...
18
votes
3answers
619 views
Is it physically possible to build a long zoom (17-300 mm for example) at an aperture value of around 1.4 or 1.2?
I'm curious if the physics allow a company to build such a lens of course with good IQ, minimal color aberration, maximum sharpness, and little to none lens vignetting or edge softness
4
votes
2answers
328 views
Are all DSLR lenses made of glass?
This question is about lenses to "big" DSLRs, not system or compact cameras with interchangeable lens.
Are all lenses made of glass in DSLR? And if not, is there a notable difference between:
kit ...
3
votes
2answers
753 views
What does “Flat Field Focus” mean?
Looking at lenses, specifically sigma macro lenses, I noticed that it had a ""Flat Field" front lens element". What does this mean? And how is it different to the norm?
1
vote
1answer
431 views
What are screw drive lenses?
Are lenses known as screw drivers actually available?If so what are their features and why are they called so.Name some of the lens and their manufactures.
9
votes
3answers
385 views
Why are 50mm Lenses Cheaper?
There is no doubt that 50mm lenses, if all other variables are held equal, will beat any other lens when it comes to value for price (lower f/number). I want to know why.
Possible theories I have ...
3
votes
1answer
113 views
What is meant by 'centering quality'?
I'm reading lens reviews and I have encountered the term 'centering quality' a few times (e.g. http://www.photozone.de/sony_nex/720-sony50f18nex?start=1).
What does this term mean? What are the ...
12
votes
1answer
411 views
How does a macro lens focus so close?
How does a macro lens focus so closely and how is the system different to that of a non-macro lens?
12
votes
2answers
471 views
Retrofocus lens? What's that?
I saw that in Why do some people prefer 50mm to 35mm prime lenses? , in @MattGrum's answer:
...
The 50mm is a simpler design compared to the retrofocus 35mm
...
What's retrofocus?
-1
votes
1answer
184 views
Below which focal length are lenses considered to be wide angle?
Focal length is the only factor that decides whether a lens is described as being normal or wide angle.
Below which focal length are lenses considered to be wide angle? Is this focal length the same ...
9
votes
2answers
629 views
What characteristics make a good lens good?
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 ...
7
votes
3answers
332 views
What are ED elements?
I find that some lenses are indicated with the letters "ED", referring to some special type of lens element. What are ED elements, and what advantages do they bring?
Note that this question isn't ...
1
vote
3answers
247 views
Do lenses need to be made with more precision for Hasselblad's 60MPix camera?
One of Hasselblad's cameras has a Double-Full-Frame sensor.
Does that mean that the lenses needed for it are incredibly complex to build (to have a sharp, high quality, abberation free image on the ...
10
votes
2answers
731 views
What is the benefit of an internal focus lens?
The "IF" in Pentax DA★ 200mm f/2.8 ED (IF) SDM stands for "Internal Focus". I know what this means: the lens doesn't change in size as I focus. (And it's true; it doesn't.) What's the point of this, ...
4
votes
5answers
449 views
What about lens construction influences bokeh?
I can understand how certain elements of a lens can correct an aberrations or make it sharper - but specifically, how do lens manufacturers influence the bokeh - the quality of the blur? There's a ...
3
votes
1answer
335 views
Why are there no fast APS-C zooms beyond 55mm?
I am looking to add a longer lens to my current zoom (a Tamron 17-50) for my Nikon D300 (but I believe this question is relevant across aps-c lens manufacturers).
There is just one currently in ...
7
votes
3answers
327 views
What is the limiting factor in lens construction when it comes to f-stop values?
This widely praised Nikon 105mm macro lens has a maximum f-stop value of 2.8. I've held it in my hands, it's a big lens. Meanwhile, this 50mm Nikon lens can go up to f/1.2, despite being 25% cheaper ...
4
votes
1answer
659 views
19
votes
3answers
1k 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 ...
12
votes
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 ...
44
votes
5answers
889 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
...
23
votes
3answers
5k 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 ...
9
votes
2answers
1k views
Why do zoom lenses and compact cameras have varied maximum aperture across the zoom range?
Why does a camera's maximum (allowed) aperture get smaller when you increase its zoom?
4
votes
2answers
573 views
What's the base f-stop when counting an ideal f-stop for lens?
I've read a lot around this site that an ideal quality of the lens is achieved when using f-stop roughly 2 stops slower than the fastest value of the lens.
Firstly, I'm not exactly sure what "2 ...
13
votes
9answers
2k views
Are all kit lenses poor? (And if so, why?)
Kerri Shotts says (emphasis mine):
Also, if you already have great glass, there is little reason to get more (unless you need it for a certain reason). E.g., if you have a 70-200 f/4, don't rush ...
7
votes
2answers
2k views
What are the advantages of a lens having a fixed maximum aperture?
What are the advantages of a lens having a Fixed Maximum Aperture? Previous answers have indicated that "pros tend to want constant apertures in zoom lenses".
While in general lenses with a fixed ...
11
votes
3answers
4k views
How does a spherical lens differ from an aspherical lens?
Many lenses (like the Pentax DA 15mm f/4 Limited, or the Nikon AF-S 35mm f/1.4G) are described as having "aspherical lens elements". Does this mean that regular lenses are spherical lenses? What's the ...
7
votes
4answers
394 views
Were lenses for film designed to focus different colors at different depths, and what does that mean for digital?
I was reading the book Adobe Photoshop CS5 for Photographers: The Ultimate Workshop by Martin Evening & Jeff Schewe (Focal Press. 2011) and read this paragraph about film lenses and DSLRs:
… ...
9
votes
1answer
352 views
Can anyone identify this lens?
I read once, in a book, about a lens that was an "inverse fisheye". Basically a hemispherical mirror mounted at one end of a glass tube.
I can't remember what it was called, nor can I find any ...
14
votes
4answers
5k views
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 ...
13
votes
4answers
2k views
What's the difference between the Canon and Nikon lenses mounts?
I was wondering what, if any, are the technical differences between the two mounting systems. Does one auto focus faster? Can one hold more weight? Things along those lines that make them different.
...
27
votes
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 ...
10
votes
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 ...
6
votes
7answers
901 views
How come there are no 24-70mm f/2.8 lenses with image stabilization?
There definitely aren't any Canon or Nikon lenses. I also have not seen any third party lenses. I can think of two reasons for this:
There is some technical limitation (which I tend to doubt since ...
12
votes
4answers
628 views
How close can a lens focus?
From my understanding, if you want to do some macro photography it is better to have a lens that can focus when it is really close to the subject. Sometimes people buy extension tubes to help them ...
-5
votes
5answers
2k views
How can I get bokeh with an aperture of 3.5 as my max?
I am trying to get DOF portraits of my daughter with my Nikon d7000, as per my previous post.
I have zoomed in to 100mm or so and tried to get a large aperture but as I zoom, the camera decreases f# ...
9
votes
4answers
739 views
Lens “family” names - what do they mean and should I care?
Some lens manufacturers have special names for their lens designs/families. Just to name a few:
Leica - Summar/Summarit/Summilux, Elmar/Elmarit, Noctilux
Carl Zeiss - Planar, Tessar, Sonnar, ...
24
votes
2answers
2k 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 ...
21
votes
0answers
559 views
Is Image Stabilization better in the lens or the body? [duplicate]
Possible Duplicate:
What is the difference between in-lens image stabilizing and in-sensor image stabilizing?
Some DSLR manufacturers have image stabilization (IS) in the body of their ...
12
votes
4answers
3k views
How can a lens like a 18-55mm have more than one focal length?
How can a lens have a range of focal lengths? Shouldn't it be a single number?
Isn't focal length supposed to be fixed for a lens of a particular shape and geometry?
What am I missing?
How many ...
