Archived posting to the Leica Users Group, 2014/02/20

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Subject: [Leica] OT - Sony Alpha 7R
From: roark.paul at gmail.com (Paul Roark)
Date: Thu, 20 Feb 2014 08:03:53 -0800
References: <CAH1UNJ3rpUAt8xxnMJdNGC9L_ncq8-ogF2Z1s_xSyqh9yHtR6Q@mail.gmail.com> <1442780B-17BA-4304-953A-58140190E65F@icloud.com> <CAFfkXxtG=Bn6-6KZKazX04TjwgLAeLOW77JZCWEoXSEB97DpJg@mail.gmail.com> <CAJ3Pgh6T-GGohk5c8+wO+TZkFo6SM+h0UpJswVyN3booNh3FVA@mail.gmail.com> <CAFfkXxs=W_0Ps1tUiKRjjdj0yFQXkJwuPOMQu1QiDbZr7X6+hA@mail.gmail.com> <CAJ3Pgh4Gtzd3MfbwwoMk-Ab9rMbGQq8X+AXL=dEMRySgHO9yPw@mail.gmail.com> <0b1301cf2e49$9fe66300$dfb32900$@verizon.net>

Frank Filippone <red735i at verizon.net> wrote:

> Paul... is this true for all native A7R lenses?  All AF is done at
> aperture?


I only have the 35mm FE, but I suspect it is the same as the others in
terms of how it focuses.


>  Ditto the A7?
>

I assume it is the same, but I don't have one.


>
> Sequence as I understand it then is....
>
> Push button to shoot
> Lens stops down
>

The lens is stopped down all the time.  I suspect this is, in part, to keep
the sensor as cool as possible.  I higher level of light hitting the sensor
probably generates some waste heat that increases image noise.


> AF happens
>

When I push the AF button, looking at the front of the camera, the closed
down iris appears to open about 1/2 stop for the focusing, then closing
back to it's original closed down position -- whatever the camera was set
to.

(I use "manual" exposure mode, but with auto ISO activated.)

Paul
www.PaulRoark.com


Replies: Reply from red735i at verizon.net (Frank Filippone) ([Leica] OT - Sony Alpha 7R)
In reply to: Message from jayanand at gmail.com (Jayanand Govindaraj) ([Leica] OT - Sony Alpha 7R)
Message from gwpics at icloud.com (Gerry Walden) ([Leica] OT - Sony Alpha 7R)
Message from sonc.hegr at gmail.com (Sonny Carter) ([Leica] OT - Sony Alpha 7R)
Message from roark.paul at gmail.com (Paul Roark) ([Leica] OT - Sony Alpha 7R)
Message from sonc.hegr at gmail.com (Sonny Carter) ([Leica] OT - Sony Alpha 7R)
Message from roark.paul at gmail.com (Paul Roark) ([Leica] OT - Sony Alpha 7R)
Message from red735i at verizon.net (Frank Filippone) ([Leica] OT - Sony Alpha 7R)