[Brightcolours]

Hi all,

 

I read the excellent review on the

Zeiss Sonnar T* 135mm f/1.8 lens

at

http://www.opticallimits.com/sony-alpha-..._za_135_18

 

There were a couple of things that I wanted to ask, hopeing that perhaps

someone would know the answer. Partial answers are also welcome!

 

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1. "The front element does not rotate thanks to an IF (internal focusing) design."

Sure. But does ANY lens element rotate (inside), or the internal focus translates a

lens in the vertical direction without rotation?

Why is this important to know? Can not think of any valid reason.... That the front element does not rotate is important.

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2. "Unfortunately there're no seals against dust and humidity".

 

What sealing does this refer to?

Sealing at the rim of the front lens along the edge?

Or sealing of the focuser ring (how?).

Or there are "cracks"/discontinuities at various locations on this lens?

Sealing of everything. If you do not shoot in heavy rain or during sandstorms, it is not of that much importance.

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3. "In manual focusing mode it operates very smooth but there is a little

play when changing the focus direction - this is typical for non-SSM

Sony lenses."

 

How big is this backlash? ("play")? Is it consistent between lenses?

 

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4. "the lens shows a little vignetting at f/1.8 (~0.55EV)"

This is at the bottom/top or right/left side, or the corners?

A lens is round, the image rectangular. Evident how the vignetting would be...

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5. Regarding the "screw-driven AF" mechanism on the bottom: I assume that by turning

this around an internal component moves, but the manual focus ring does not turn around.

Could someone try this?

 

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6. Finally, a bonus question. Would manual focusing work by turning the manual focus ring

WITHOUT a camera body attached (i.e. no power); just projecting the light on a piece of

paper?

Of course. But WHY???

Best regards,

Sapkas