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Re: [OM] Speaking of lenses [was Speaking of sharpness ...revisit to SS

Subject: Re: [OM] Speaking of lenses [was Speaking of sharpness ...revisit to SS for handheld macro
From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
Date: Wed, 18 Sep 2013 22:42:01 -0400
I think you're on shaky ground when you consider the displacement as 
relative to the object.  The displacement of the image is relative to 
the exit pupil but that motion is inherent in the magnification, ergo 
focal length bows out except insofar as it's used in calculating the 
magnification.  Consider a bucket with its handle tied to a rope, its 
upper end on a hook hanging from the ceiling and the loose end following 
the knot hanging down into the bucket.  Push the bucket to one side and 
the rope (light beam) will be deflected by a linear displacement 
controlled by the length of the rope extending into the bucket.  The 
place where the rope is tied to the handle is like the exit pupil and 
where the incoming beam is bent.  The length of the rope is like 
magnification.  That's my story and I'm stickin' to it.

Chuck Norcutt

On 9/18/2013 4:27 PM, usher99@xxxxxxx wrote:
> CN writes:
>>> If relative to the exit pupil focal length will disappear
>> >from the calculation and leave only magnification.
>
>
> Well I agree that the exit pupil motion is important and amplified by
> the magnification but at the end of the day the
> only motion that matters is the image on the sensor that induces
> blurring by camera shake, lateral or rotational.
>
> Angular shake must cause proportionally more blurring as mag increases.
> However FL never drops out, IMO. Don't think of FL but working distance
> instead. Unless I fell into a rabbit hole and a non-Euclidean world a
> displacement resulting in angle of displacement theta (angle between
> original position of the object to sensor to displaced location by
> shake)
> will result in the image moving on the sensor by d *(tan(theta) where d
> is the object distance to the sensor. So the further away the object is
> the more image movement on the sensor for the same mag and MORE
> blurring. It is fortunate I am not a tort lawyer as I can't convince
> anyone.
> Look at the Canyon link again too.
>
> Where is our own recovering physicist from Berkeley? Mooooooooooose,
> weigh in here please . I also have it on good authority that one of
> your in house  but very reclusive consultants, Dr. Shake, (3rd cousin
> once removed of Dr. Diffraction) made the move to NY. I am moving this
> issue to the Court of Appeals with Dr. Shake and Moose to adjudicate. I
> don't mind being incorrect if it clarifies a burning issue, but this is
> not the case here.
>
> I have revisited this issue and am not on shaky ground, Mike
>
>
>
>
-- 
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