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Re: [OM] mount mod: nikon/canon to OM

Subject: Re: [OM] mount mod: nikon/canon to OM
From: "Jim Nichols" <jhnichols@xxxxxxxxxxxxx>
Date: Sun, 21 Aug 2011 20:07:02 -0500
Chuck & Chris,

I have a medical appointment tomorrow morning, so I may be tied up for a 
while.  When I get that behind me, I will get out the Leica-R 50 Summicron, 
with a different adapter, and repeat the shots that I made today.  From 
experience with that lens, I know that the focusing mechanism will go past 
the infinity mark, so I should be able to compensate for any errors in that 
adapter, though from using it with other lenses, I feel it is pretty close 
to correct.

Hopefully, the cars beyond the next street will be in better focus.

Jim Nichols
Tullahoma, TN USA
----- Original Message ----- 
From: "Chuck Norcutt" <chucknorcutt@xxxxxxxxxxxxxxxx>
To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
Sent: Sunday, August 21, 2011 6:57 PM
Subject: Re: [OM] mount mod: nikon/canon to OM


>I don't know what lens you're using but, assuming a 50mm lens and a
> thickness error on the adapter of 0.1mm the lens will be precluded from
> focusing beyond 25 meters.  But, at f/5.6, and assuming a CoC of 0.017mm
> (suitable for 4/3) you should have DOF out to 365 meters.  At f/2,
> however, your far focus will be limited to about 37 meters or about 120
> feet.  Your pixel peeping view may be more stringent than my assumptions.
>
> Chuck Norcutt
>
>
> On 8/21/2011 7:03 PM, Jim Nichols wrote:
>> Chuck,
>>
>> I think you may be correct.  From a crude inspection of jpgs at 100%, 
>> lens
>> set at the infinity mark, it appears to go OOF beyond 100 -150 feet.
>> Close-ups, of course, are fine.  I may take a look at applying some wet 
>> or
>> dry paper to the flange, to try to get closer to spec.
>>
>> Jim Nichols
>> Tullahoma, TN USA
>> ----- Original Message -----
>> From: "Jim Nichols"<jhnichols@xxxxxxxxxxxxx>
>> To: "Olympus Camera Discussion"<olympus@xxxxxxxxxxxxxxxxx>
>> Sent: Sunday, August 21, 2011 4:32 PM
>> Subject: Re: [OM] mount mod: nikon/canon to OM
>>
>>
>>> Hi Chuck,
>>>
>>> Thanks for the data.  Since I squeezed Superglue into the adapter, I may
>>> have altered the spacing a little.  At different points around the
>>> adapter,
>>> I measured from 7.0 to 7.2mm.
>>>
>>> I seldom work at infinity, and when I do, DOF may bail me out.  I will
>>> check
>>> next time I use the adapter.  I can't say for sure about the Pentax
>>> lenses,
>>> but several SLR lenses will focus past infinity.  For sure, my Leica
>>> Summicron 50 will do that.
>>>
>>> Jim Nichols
>>> Tullahoma, TN USA
>>> ----- Original Message -----
>>> From: "Chuck Norcutt"<chucknorcutt@xxxxxxxxxxxxxxxx>
>>> To: "Olympus Camera Discussion"<olympus@xxxxxxxxxxxxxxxxx>
>>> Sent: Sunday, August 21, 2011 2:39 PM
>>> Subject: Re: [OM] mount mod: nikon/canon to OM
>>>
>>>
>>>>
>>>> Register distances in mm - M42, 4/3, Micro 4/3
>>>>
>>>> |------------M42-45.46------------------------>|
>>>> |
>>>> |------------4/3-38.58----------------->|<6.88>|
>>>> |
>>>> |------Micro-4/3-20->|<-----------25.46------->|
>>>>
>>>>
>>>> According to the specs I have, both of you should be having some
>>>> difficulty getting to infinity.  There seems to be some confusion
>>>> whether the M42 register distance is 45.46mm or 45.50mm but, in any
>>>> case, the difference between the 4/3 and M42 doesn't quite reach 7mm 
>>>> and
>>>> certainly not 8mm.
>>>>
>>>> Chuck Norcutt
>>>>
>>>>
>>>> On 8/21/2011 3:07 PM, Chris Trask wrote:
>>>>>>
>>>>>> As added information, the flange-to-flange thickness of the Fotodiox
>>>>> adapter
>>>>>> is 7mm, excluding the bayonet length.
>>>>>>
>>>>>
>>>>>       Mine is 8.0mm.  Judging from the picture in the eBay listing, I
>>>>> would
>>>>> say that the one I just bought from India is in the order of 1.5mm, 
>>>>> same
>>>>> as
>>>>> the depth of the locking recess on this one.  We shall soon (3-4 
>>>>> weeks)
>>>>> know.
>>>>>
>>>>> Chris
>>>>>
>>>> --
>>>> _________________________________________________________________
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>>>>
>>>>
>>>
>>>
>>> --
>>> _________________________________________________________________
>>> Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
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>>>
>>>
>>
>>
> -- 
> _________________________________________________________________
> Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
> Archives: http://lists.thomasclausen.net/mailman/private/olympus/
> Themed Olympus Photo Exhibition: http://www.tope.nl/
>
> 


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