Try taking a long exposure of a black card. See what you get.
Chuck Norcutt
On 7/7/2012 6:54 PM, Jim Nichols wrote:
> 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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