Olympus-OM
[Top] [All Lists]

Re: [OM] Changing lens mount

Subject: Re: [OM] Changing lens mount
From: "Bill Pearce" <bs.pearce@xxxxxxx>
Date: Sat, 4 Dec 2010 17:49:54 -0600
Where I live, I think there are many who could make this, what with the
ready supply of machinists from the aircraft industry. There's probably a
bigger market for adapters than private jets, anyway. If it's being made by
a poorly trained worker with a worn out machine in a dirt floored shop,
could be different.

 

From: Chuck Norcutt [mailto:chucknorcutt@xxxxxxxxxxxxxxxx] 
Sent: Saturday, December 04, 2010 5:08 PM
To: Olympus Camera Discussion
Subject: Re: [OM] Changing lens mount

 

I've read that same stuff and simply don't understand it.  What is
inaccurate?  Even a guy with a simple lathe in a machine shop can turn
an adapter that's accurate to within 0.001".  If the thickness of the
adapter is off by +/- 0.001" how does that translate to terrible
results?  Or is it not the thickness of the adapter but whether the two
faces are plano-parallel?

Chuck Norcutt


On 12/4/2010 5:12 PM, Jeff Keller wrote:
> If the lens has floating elements to compensate for close focusing, an
error
> in register distance can degrade the performance significantly. 16-9
tested
> a Nikon lens with a cheap adapter and got terrible results. When they got
an
> accurate adapter the performance was dramatically better.
>
> Jeff Keller
>
> -----Original Message-----
> From: Chuck Norcutt [mailto:chucknorcutt@xxxxxxxxxxxxxxxx]
> Subject: Re: [OM] Changing lens mount
>
> To clarify, if the register distance of the adapted lens is shorter than
> that of the body being adapted to you can never reach infinity without
> inserting an optical element (which acts like a low power
> tele-converter).  But you could use such a setup as a macro lens
> provided you don't mind not being able to focus further than a meter or
> two or three.  However, even if the register distance of the lens is
> longer than that of the body it must be enough longer to accommodate the
> thickness of an adapter.  One millimeter or thereabouts is probably
> about the practical minimum.  The has to be enough metal for strength.
>
> Chuck Norcutt
>
> On 12/3/2010 3:43 PM, Andrew Fildes wrote:
>> No, but it means that you may not achieve infinity focus.
>> And as most lenses move a lot at the close end but not much at the long
> end, you may miss inf. by quite a lot.
>> Andrew Fildes
>> afildes@xxxxxxxxxxxxx
>>
>>
>>
>> On 04/12/2010, at 7:24 AM, AS wrote:
>>
>>> The differences in register are very small....sometimes a mm or less,
> what difference does that make? Does this affect the ability to focus?
>>
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

  _____  

No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1170 / Virus Database: 426/3297 - Release Date: 12/04/10

-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz