Moose,
Thanks for the explanations. I have no Oly gear except for the E-510, the
14-54 lens, and a Fotodiox adapter with chip that allows me to use my M42
lenses. I have a long way to go in mastering what I have at present. Then,
perhaps, another autofocus lens.
Jim Nichols
Tullahoma, TN USA
----- Original Message -----
From: "Moose" <olymoose@xxxxxxxxx>
To: <olympus@xxxxxxxxxx>
Sent: Saturday, August 02, 2008 3:03 AM
Subject: [OM] Re: More Experimentation
> Jim Nichols wrote:
>> Moose,
>>
>> First off, I'm cheap. I use what I have at hand, or, can obtain cheaply.
> As was I, but what I have at hand, not what you have at hand. :-) But
> for a reversed lens, it would be a Zuiko, and the Oly bellows provides a
> means to use, and focus, a reversed lens while retaining auto-aperture
> operation with double cable release.
>> I have a 50/1.4 Takumar, but have it dedicated to my film SLR.
> I am somewhat more flexible. The Tamron 90/2.5 macro is in the copystand
> kit along with a 50/3.5 macro, but I am free to use it for other purposes.
>> That left the 55/1.8 and 2x extender free to play with.
>>
>> I assume that, to reverse the lens, the adapter would have to attach to
>> the filter threads.
> That's correct, except for more complex ones, like the bellows. The Oly
> bellows slides and clamps onto the outer front of the lens, 49mm Zuikos
> by default, 55mm with an adapter.
>
> I believe Scott said you can only focus by moving the camera when using
> a reversed lens. That is true of AF designs without the option of
> mechanical manual focus, like the ones he used. With MF lenses like your
> Takumar, the focusing helicoid works fine reversed. About the easiest
> way to use it with a simple reverse adapter is to set it in the middle
> of its range, get the camera where the image is close to focus, then use
> the focusing ring for fine focus.
>
> Setting the aperture also depends on the age and design of the lens.
> Early Pentax screw mount lenses were preset. Later ones, which you
> probably have, require a pin on the back to be pressed to stop down the
> diaphragm. If you tape or otherwise keep the pin pushed in, the aperture
> ring then works to adjust the diaphram when reversed.
>> I really don't understand what this would do for me, unless it would give
>> me a different distance to the sensor which could be used beneficially.
>>
> Chuck has already explained some of the optical reasons. Scott got some
> good central results with a reversed zoom. You can expect better results
> over the whole frame with a reversed prime lens of basically symmetrical
> design, like most standard 50mmish lenses for 35mm film, which are all
> variations of the symmetrical double-gauss design.
>
> Moose
>
> ==============================================
> List usage info: http://www.zuikoholic.com
> List nannies: olympusadmin@xxxxxxxxxx
> ==============================================
>
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|