I applied some black "laundry marker" with a felt-tipped applicator, and it
covered most of the bright areas. When I get a chance, I will try the black
card.
A question: How can I detect loss of contrast when photographing a black
card?
Jim Nichols
Tullahoma, TN USA
----- Original Message -----
From: "Chuck Norcutt" <chucknorcutt@xxxxxxxxxxxxxxxx>
To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
Sent: Saturday, July 07, 2012 6:06 PM
Subject: Re: [OM] A shot with higher dilution for contrast control
> 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/
>>>
>>>
>>
>>
>
> --
> _________________________________________________________________
> 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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