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Old Apr 8, 2007, 9:09 PM   #1
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It seems like no matter what type of photography you want to do, good lenses of any focal range are very expensive.
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Old Apr 8, 2007, 9:16 PM   #2
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What about"prime" wide-angle lenses? Can you get a similiar value ona "prime" wide-angle lensas youget with a50mm prime. Meaning, are fixed focal length wide-angle lenses a lot cheaper than wide-angle zoom lenses?
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Old Apr 9, 2007, 1:36 AM   #3
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Well here is an example you can Pick up a used Pentax-A 50mm (MF but is AE) for around $20 A fine sharp lens actually.... and still 2 stops faster than most even low/same range zoom lenses. Not THE fastest thing on earth but real bargains.


A 1.7 OR 1.4..... over $100 often (sometimes well, esp 1.4).... 1.2 big $$$.... and then if an AF version even bigger.

Simple reason, MUCH MORE.... & MUCH more high quality glass.

For a fast lens to be sharp/even side to side (or c to c) at 1.2 is a real feat of craftmanship and likey at least final polishing hand ground or at least C assist human supervised/tweaked.

A wide lenses is a very technically precise and expensive to accomplish thing you have to have for an un(or minimally) distorted wide lens.

The one BIG downside to typical DSLR's.... big zoom benefit, but costly to get wide. The most affordable is the 28+ med zooms and the kit 18-55mm's.... go below that gets pricey zoom or simple prime.

And 28mm on a crop camera is arround 45-50mm "normal" 35mm terms... not wide AT ALL.



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Old Apr 9, 2007, 12:36 PM   #4
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Are there any reasonably priced prime lenses that are less than 50mm? I think that I'd like to have one thats 40 or even 35mm. What makes the 50mm so popular?
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Old Apr 9, 2007, 1:47 PM   #5
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Contriver wrote:
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What makes the 50mm so popular?
To me it seems like the 50 mm is the easiest focal length to make with high quality. And since it was the "normal" lens it was made in huge numbers, reducing the cost per item in R&D. I've got a couple of really expensive lenses (the A*-series) and a FA 50 mm f1.4. The 50 mm lens being a lot less expensive can still compete with the A*-lenses in sharpness and contrast. I'd like a FA35 mm f2 to get the complete range covered with fast primes, but that will have to wait I'm afraid.

Kjell
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Old Apr 9, 2007, 8:56 PM   #6
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Contriver wrote:
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What about┬*"prime" wide-angle lenses?┬* Can you get a similiar value on┬*a "prime" wide-angle lens┬*as you┬*get with a┬*50mm prime.┬* Meaning, are fixed focal length wide-angle lenses a lot cheaper than wide-angle zoom lenses?

I would really suggest you look at this

http://www.youtube.com/watch?v=X7_wL...Dare%2Dmade%2F

And imagine the work that is involved in making a fisheye lens

It is mindboggingly difficult

Daniel
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Old Apr 9, 2007, 11:23 PM   #7
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Wide angle lenses are complex to make.

Telephoto lenses are actually SHORTER than the focal length specified (e.g. a 300mm telephoto lens is shorter than 300mm), because the designSHORTENS the lens optically, without modifying the "effective" focal length of the lens. This is called"telephoto" construction.

In Wide angle lenses, the distance from the back lens element to the film or CCD plane, is LONGER than the focal length of the lens.(e.g. a 28mm lens) So in Wide angle lenses, the design must LENGTHEN the lens optically to clear the reflex mirror, without modifying the effective focal length of the lens. This is called "retrofocal" construction. The combination of a wide field of view, and the "retrofocal" construction makes wide angle lenses complicated to design and build. There is a lot of glass involved, with complex shapes, which is even more complex if you have a zoom wide angle lens.


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Old Apr 10, 2007, 2:56 AM   #8
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danielchtong wrote:
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I would really suggest you look at this

http://www.youtube.com/watch?v=X7_wL...Dare%2Dmade%2F

That was really interesting, thanks for sharing the link!

Kjell
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Old Apr 10, 2007, 3:29 AM   #9
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dnas wrote:
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Wide angle lenses are complex to make.
And also why the low end (like 28-300mm) are pretty horrid especially long FL and low light.... trying to do two very diverse things well not even just one.

Yet why the other low end like 70-300mm's do so much better..... at least going from near NORMAL to TELE.... not trying to encompass WIDE as well..... TWO VERY DIFFERENT REALMS!!!!
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Old Apr 10, 2007, 7:35 PM   #10
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Hayward wrote:
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dnas wrote:
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Wide angle lenses are complex to make.
And also why the low end (like 28-300mm) are pretty horrid especially long FL and low light.... trying to do two very diverse things well not even just one.

Yet why the other low end like 70-300mm's do so much better..... at least going from near NORMAL to TELE.... not trying to encompass WIDE as well..... TWO VERY DIFFERENT REALMS!!!!
Definitely hard to design a lens to do both!!!
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