# Zeiss 50 Makro-Planar Infinity focus hard stop



## can0nfan2379 (Dec 18, 2013)

Hey all, 

Picked up this lens recently and I'm totally thrilled with the image quality. One question I have for current owners of this lens is regarding the hard stop at infinity. On my Zeiss 21 Distagon the hard stop coincides with infinity focus and the infinity focus confirmation chirp/indicator.

On the 50 MP, the hard stop at infinity DOES NOT coincide with focus at infinity or the infinity focus confirmation chirp/indicator. Is this normal or do you think my copy of this lens is out of spec? At any distance less than 4 meters or so the focus confirmation light pops up when the image is perfectly in focus -- confirmed with live view @ 10x. If I shoot at something say 6m away which should be at infinity focus and just set the lens at the infinity hard stop it is not focused -- I actually have to back off a bit to get the image perfectly focused.

I'm thinking it's probably normal and just a quirk of this lens but would like to know if others have noticed this.

Thanks,
Ryan


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## Arkarch (Dec 26, 2013)

can0nfan2379 said:


> I'm thinking it's probably normal and just a quirk of this lens but would like to know if others have noticed this.
> 
> Thanks,
> Ryan



Actually, I am also just over infinity on the stop with the 50MP. Mine was purchased used through one of the rental companies, so was not sure if it was common or if I had to make some micro-adjustments through the camera. My 21 and 100 are much closer if not exact on infinity at stop.


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## neuroanatomist (Dec 26, 2013)

Many lenses are designed to be able to focus a bit beyond infinity to allow for thermal effects on the elements.


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## can0nfan2379 (Dec 26, 2013)

Good to know that it's part of the design. Thanks for the feedback.



Arkarch said:


> can0nfan2379 said:
> 
> 
> > I'm thinking it's probably normal and just a quirk of this lens but would like to know if others have noticed this.
> ...


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## can0nfan2379 (Dec 26, 2013)

I was thinking it was probably just how it was built but had some doubt in the back of my mind since the 21 Distagon nails infinity at the hard stop.



neuroanatomist said:


> Many lenses are designed to be able to focus a bit beyond infinity to allow for thermal effects on the elements.


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