Tagged Questions
3
votes
2answers
750 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
427 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.
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?
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 ...
2
votes
1answer
593 views
How does the quantity of elements and blades in a lens affect the optics?
I am trying to get a greater understanding of how lenses work. Basically I bought this lens, the Sigma 10-20 f4-5.6:
The construction has really fascinated me. 14 Elements in 10 Groups?! What ...
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
4answers
738 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 ...
