Archived posting to the Leica Users Group, 2016/02/11

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Subject: [Leica] RE; Autofocusing M lenses
From: boulanger.croissant at gmail.com (Peter Klein)
Date: Thu, 11 Feb 2016 22:17:54 -0800
References: <152d2db9fe1-45e0-1043c@webprd-a04.mail.aol.com> <CAFU3ovJ7DNJxVD4sAmeybBXxAiL-Wbr-01KuTHpUe--A0LihDA@mail.gmail.com> <CAH1UNJ2hJSqSXWDVxnRWrT=kp0P2VRHn_iBjQhxU-eo_i9NBzQ@mail.gmail.com>

Ah, another check mark on Fuji's chalkboard.  Didn't know they had a split
image. How accurate is it? One advantage of a "real" RF is that the
physical baselength can be as long as can fit on the camera body, whereas
the physical baselength of the digital split image is the diameter of the
lens. Although some magnification could mitigate that...?

I will sometimes put a Leica lens on my Olympus E-M5, usually for
telephoto.  A 90mm Leica mount lens makes a rather compact 180mm
equivalent.  I usually just use the digital focus magnifier.  Easy.

--Peter

On Thu, Feb 11, 2016 at 9:52 PM, Jayanand Govindaraj <jayanand at gmail.com>
wrote:

> Both a Digital Split Image overlay and Focus Peaking as manual focus aids
> are available on my Fuji XT-1, which accepts M lenses quite effortlessly
> with an adapter. In fact Fuji themselves make an adapter.
> Cheers
> Jayanand
>
> On Fri, Feb 12, 2016 at 8:42 AM, Peter Klein <
> boulanger.croissant at gmail.com>
> wrote:
>
> > In theory it should work just fine. You leave the lens on infinity, and
> the
> > adapter does the rest.  The adapter must:
> >
> > -Interface to the camera's AF electronics such that the camera can tell
> it
> > "forward, back, stop").
> > -Be thin enough to allow infinity focus.
> > -Contain motors and a mechanism that will rack the lens out sufficiently
> to
> > focus the lens to a reasonable close distance. The mechanism must fit in
> > the adapter. This is easier to do with SLR lens adapters. M lenses have a
> > shorter back focus distance, and M to mirrorless adapters are quiet short
> > compared to SLR adapters. Perhaps some of the mechanism could be below
> the
> > adapter, or concentric to it.)
> >
> > The major problems with M lenses on other cameras would still be corner
> > smearing and color shifts, unless the sensor's Bayer array was designed
> for
> > M lenses. And would the autofocus be fast and accurate enough, and would
> > using the adapter be convenient enough that you wouldn't get fed up with
> it
> > quickly?
> >
> > Personally, I'd love to have an autofocus M that also did RF focusing.
> But
> > as Larry mentions, it would have to be worth someone's while to
> > manufacture. Most manufacturers have already passed on making their own
> > rangefinder mechanism. Leica seems to be willing to make RF cameras along
> > traditional M lines, but not to do anything radical with them.  But what
> > about something entirely new by a third party--an AF camera that also did
> > some sort of visual rangefinder simulation in an EVF, and was designed to
> > take M lenses. Ideally, the version for M lenses would have a Bayer array
> > with microlens offsets licensed from Leica.  The SLR lens version would
> > have a more conventional sensor.
> >
> > All technically possible. The big question is whether there are enough
> > legacy(*) lens fans, and in particular M lens fans, to make such a camera
> > commercially viable.
> >
> > --Peter, who actually dislikes the word "legacy."
> >
> > On Thu, Feb 11, 2016 at 4:22 PM, Larry Zeitlin via LUG <
> > lug at leica-users.org>
> > wrote:
> >
> > > About 40 years ago, give or take a decade, a precision camera make,
> > > probably Zeiss. marketed a camera in which the focus was adjusted by
> > moving
> > > the film plane. This simplified lenses but had the downsides of
> increased
> > > expense for the camera body and the difficulty of providing enough
> motion
> > > for long focus lenses. The idea was abandoned after a few years but I
> > > believe that with modern electronics it could provide automatic focus
> > for M
> > > lenses. But, of course, there would be little incentive for Leica to
> > adopt
> > > such a system. Maybe a third party could sell a universal camera which
> > > would autofocus with all makers lenses.
> > > Larry Z
> > >
> > > + + +
> > > LUG:
> > >
> > > Any idea whether this would actually work or not?
> > >
> > >
> > >
> >
> http://www.thephoblographer.com/2016/02/11/the-techart-pro-lens-adapter-promises-autofocus-for-leica-m-mount-glass/#.VrywD_krJaQ
> > >
> > > Tina
> > >
> > > _______________________________________________
> > > Leica Users Group.
> > > See http://leica-users.org/mailman/listinfo/lug for more information
> > >
> >
> > _______________________________________________
> > Leica Users Group.
> > See http://leica-users.org/mailman/listinfo/lug for more information
> >
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>


Replies: Reply from jayanand at gmail.com (Jayanand Govindaraj) ([Leica] RE; Autofocusing M lenses)
In reply to: Message from lrzeitlin at aol.com (lrzeitlin at aol.com) ([Leica] RE; Autofocusing M lenses)
Message from boulanger.croissant at gmail.com (Peter Klein) ([Leica] RE; Autofocusing M lenses)
Message from jayanand at gmail.com (Jayanand Govindaraj) ([Leica] RE; Autofocusing M lenses)