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Sony/Zeiss Sonnar T* FE 55mm f/1.8 ZA Lens.. Why the Concave Front Element?

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partly agree. i want good one. if i'll buy primes i want good primes :) for pure quality there is zooms and high MP cameras to attach those zooms for even purer quality :)

Zony FE 50-ish 1.8 OSS sounds very nice :) i can complain about the price, and when i get tired of complaining i can buy the lens :)
 
Jerry Canon said:
I'm sure there's a very simple optical explanation for it that I just don't understand, but I've never ran across another lens with a concave (not convex) front element such as the Sony/Zeiss Sonnar T* FE 55mm f/1.8 ZA has. It's also rather amazing to me that a lens this fast, has such a small front element and filter size (49 mm). Does this concavity someway help the lens to be able to be designed physically smaller in diameter PLUS be a fast f1.8?
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ka-spot said:
i couldn care less what do you think or how IBIS works :) i just want FE ~50mm with OSS. case closed. thank you :)

and i couldn care less do you care what i want or care about :)
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You are entitled to your opinion, and you are the only person who knows what you want. But, if you don't wish to engage in a discussion, why are you posting your opinion on this forum?

Jim
 
JimKasson said:
ka-spot said:
i couldn care less what do you think or how IBIS works :) i just want FE ~50mm with OSS. case closed. thank you :)

and i couldn care less do you care what i want or care about :)
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You are entitled to your opinion, and you are the only person who knows what you want.
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thank you very much! i cannot agree more with you here :)
JimKasson said:
But, if you don't wish to engage in a discussion,
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this may not be the truth.
JimKasson said:
why are you posting your opinion on this forum?
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cuz now there is one more opinion (that may matter) and someone who made lenses can read it.
JimKasson said:
Jim

--
http://blog.kasson.com
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But how can this lens have such a small front element (concave or convex) and still be a f 1.8 aperture though?
 
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Heck my 17-35/2.8 AFS Nikon has both a convex and (slightly) concave (totally aspherical) front element!

It also has super excellent ghosting characteristics - which some have attributed this to (but I have no idea).



17-35/2.8D AFS Nikon Optical Construction

17-35/2.8D AFS Nikon Optical Construction
 
ka-spot said:
i couldn care less what do you think or how IBIS works :) i just want FE ~50mm with OSS. case closed. thank you :)

and i couldn care less do you care what i want or care about :)
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The 55 and A7 series already have very high rates of tilted focal planes, decentered elements and generally not getting along that if he frightened to add OSS into the mix.
--
Dave Sanders
 
Jerry Canon said:
I'm sure there's a very simple optical explanation for it that I just don't understand, but I've never ran across another lens with a concave (not convex) front element such as the Sony/Zeiss Sonnar T* FE 55mm f/1.8 ZA has. It's also rather amazing to me that a lens this fast, has such a small front element and filter size (49 mm). Does this concavity someway help the lens to be able to be designed physically smaller in diameter PLUS be a fast f1.8?

--
http://500px.com/JerryBrendle
https://plus.google.com/photos/111563961755336887443/albums?banner=pwa
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5d98210ecd4d46989ccdb1e439085cde.jpg

I didn't even notice the 55 was concave for ages as the first thing I did was stick the hood on it (mustn't have looked very closely)......only when I saw some dust on the front one day did it dawn on me......yeah I can be slow sometimes!
 
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Aww, that's nuttin. Here's a concave lens...



Nikon 6mm Apparently it covers more than 180 degrees.
Nikon 6mm Apparently it covers more than 180 degrees.



--
Steve
Just an Armadillo on the shoulder of the information superhighway.
 
SLN001 said:
Aww, that's nuttin. Here's a concave lens...

Nikon 6mm Apparently it covers more than 180 degrees.
Nikon 6mm Apparently it covers more than 180 degrees.

--
Steve
Just an Armadillo on the shoulder of the information superhighway.
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I have seen those and others like the (fake) Gigantar 40mm f0.33.....the difference is that the Canon 17mm f4 TS-E is a common enough (if expensive) lens that works great on A7 series cameras (in fact, better than on my Canon DSLR).

It is actually quite serious in that it is the only lens I have used I can not rest on its front (as I often do) and not practical to rest on its rear cap as I do sometimes with others as well.

One of my all time favourite lenses but one that needs to be carefully handled and always need the lens cap with it.

Sure would be fun to try that 6mm or even a Nikon 8mm 2.8 on the A7s at night though!
 
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