Chuck,
I believe I see what you are looking at. The front half of the lens seems
to be made up of two elements, one slightly larger than the other. There is
some brassing where the rear element of this group has pressed against the
mount. But, since the exit diameter of the rear element matches the 1/2
inch dia of the f/16 stop, I can't see how it can cause a reflection. You
are right, it might reflect off the rear of the front element of the two. I
will see if I can blacken that point of contact.
Thanks,
Jim Nichols
Tullahoma, TN USA
----- Original Message -----
From: "Chuck Norcutt" <chucknorcutt@xxxxxxxxxxxxxxxx>
To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
Sent: Saturday, July 07, 2012 5:02 PM
Subject: Re: [OM] A shot with higher dilution for contrast control
> How can it be masked off by the Waterhouse stop wheel if I can see that
> brassy bits in front of the stop wheel? True, a view from the focal
> plane through the stop can't directly see the brassy bits but it can
> most certainly catch reflections of same off the back of the front
> element. But it's just a suggestion for image improvement. For all I
> know trying to re-brass the interior might lower the value of the lens.
> (like don't clean your coin collection)
>
> Chuck Norcutt
>
>
> On 7/7/2012 5:32 PM, Jim Nichols wrote:
>> Chuck,
>>
>> Internally, all of those areas are masked off by the Waterhouse stop
>> wheel.
>> I'll consider your point, but I'm not sure the blackening would change
>> things enough to make it worthwhile.
>>
>> Jim Nichols
>> Tullahoma, TN USA
>> ----- Original Message -----
>> From: "Chuck Norcutt" <chucknorcutt@xxxxxxxxxxxxxxxx>
>> To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
>> Sent: Saturday, July 07, 2012 4:00 PM
>> Subject: Re: [OM] A shot with higher dilution for contrast control
>>
>>
>>> Everything I see between the front element and the waterhouse stop has
>>> lots of brass showing... including the waterhouse stop ring. I assume
>>> it's similar behind the stop on those parts I can't see. All these
>>> parts are reflective and, in particular, will reflect off the back side
>>> of the front element which is uncoated. All this will cause loss of
>>> contrast.
>>>
>>> Chuck Norcutt
>>>
>>>
>>> On 7/7/2012 2:14 PM, Jim Nichols wrote:
>>>> Hi Chuck,
>>>>
>>>> I quickly disassembled the Ross lens to refresh my memory. Most of the
>>>> original internal blackening remains, and I don't see anything that
>>>> will
>>>> obviously cause reflections. If I were to try to improve on it, I
>>>> would
>>>> probably choose a dull black waterbased paint, applied with a small
>>>> brush.
>>>> Thanks for the link, it was interesting.
>>>>
>>>> Jim Nichols
>>>> Tullahoma, TN USA
>>>> ----- Original Message -----
>>>> From: "Chuck Norcutt" <chucknorcutt@xxxxxxxxxxxxxxxx>
>>>> To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
>>>> Sent: Saturday, July 07, 2012 10:31 AM
>>>> Subject: Re: [OM] A shot with higher dilution for contrast control
>>>>
>>>>
>>>>> Hi, Jim.
>>>>> In looking at your old Ross it appears that the interior parts used to
>>>>> be blackened to cut reflections. It doesn't look like it would be too
>>>>> hard to disassemble, clean it and re-treat it to restore the blacking.
>>>>>
>>>>> I looked up how to blacken brass and was surprised to see Palmolive
>>>>> dish
>>>>> soap recommended as the way to do it. Says it only takes a few
>>>>> minutes.
>>>>> A short way down on this page
>>>>> <http://www.finishing.com/1000-1199/1198.shtml>
>>>>>
>>>>> Chuck Norcutt
>>>>>
>>>>>
>>>>>
>>>>> On 7/7/2012 10:42 AM, Bob Whitmire wrote:
>>>>>> My guess is that no one ever expected to see an old brass lens mated
>>>>>> to
>>>>>> an Olympus E-1 or any other digital camera. And the image is quite
>>>>>> nice.
>>>>>> I like the quality of the shot. How about doing more of those?
>>>>>>
>>>>>> --Bob
>>>>>>
>>>>>>
>>>>>> On Jul 6, 2012, at 9:54 PM, Jim Nichols wrote:
>>>>>>
>>>>>>> Michael,
>>>>>>>
>>>>>>> Your reference to an 1892 brass lens reminded me of my experience
>>>>>>> with
>>>>>>> a
>>>>>>> lens from that period. Mine was by Ross London, and is marked
>>>>>>> 8-inch
>>>>>>> No. 6
>>>>>>> Symmetrical. It has Waterhouse stops, with the largest being
>>>>>>> 1/2-inch
>>>>>>> in
>>>>>>> dia., making it an f/16 lens. Rather than try to use my old 4x5
>>>>>>> Speed
>>>>>>> Graphic, I fitted it to a bellows and used it on my Olympus E-1.
>>>>>>> The
>>>>>>> images
>>>>>>> linked below show the hardware and an image made with this setup.
>>>>>>>
>>>>>>> The lens:
>>>>>>> http://gallery.leica-users.org/v/OldNick/Ross+Lens+2.jpg.html
>>>>>>>
>>>>>>> The assembly:
>>>>>>> http://gallery.leica-users.org/v/OldNick/Final+Assembly.jpg.html
>>>>>>>
>>>>>>> The image, made on a very cold day in January:
>>>>>>> http://gallery.leica-users.org/v/OldNick/Mocking+Bird.jpg.html
>>>>>>
>>>>>
>>>>> --
>>>>> _________________________________________________________________
>>>>> Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
>>>>> Archives: http://lists.thomasclausen.net/mailman/private/olympus/
>>>>> Themed Olympus Photo Exhibition: http://www.tope.nl/
>>>>>
>>>>>
>>>>
>>>>
>>>
>>> --
>>> _________________________________________________________________
>>> Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
>>> Archives: http://lists.thomasclausen.net/mailman/private/olympus/
>>> Themed Olympus Photo Exhibition: http://www.tope.nl/
>>>
>>>
>>
>>
>
> --
> _________________________________________________________________
> 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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