<Good to see you back, Tim. >
Hi Chuck,
thanks, I have not been checking this list much lately, although I had
some off list correspondence with some people about a few things recently.
I have been playing with a Mobilight 300J Studio flash at the moment, which was
a keh non working unit. Fairly simple unit which comes with a battery pack too,
so you can use it away from the studio, off line. They have a rather dangerous
high voltage connector on it, which you can easily stick your fingers in , if
not careful. Quite amazing in a modern unit to have such a dangerous setup. I
am going to change the connector ,so I can use it with Quantum turbo style
cables as well.
Tim Hughes
--- On Tue, 5/5/09, Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx> wrote:
> From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
> Subject: Re: [OM] clever use of available sensor real estate
> To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
> Date: Tuesday, May 5, 2009, 4:05 AM
> Good to see you back, Tim. It's been a long time since
> one of these
> insightful posts.
>
> Chuck Norcutt
>
> Tim Hughes wrote:
> > I read their position paper and I think some of the
> claims are
> > overblown and maybe in some cases specious:
> >
> >
> http://www.fujifilm.com/photokina2008/pdf/release/super_ccd_exr_e.pdf
> >
> >
> > It looks like when running in 6Mpixel modes there are
> some advantages
> > in some ways, but not really in 12 mpixel mode. The
> mode with
> > increased dynamic range is an example where it maybe a
> fairly good
> > tradeof, but you land up in a mode pretty close to
> 6Mpixel rather
> > than 12.
> >
> > For example it appears the traditional beyer pattern,
> which is
> > optimised for highest resolution in green, since this
> is human eyes
> > peak sensitivity and peak sunlight wavelength, will
> have higher
> > horizontal resolution than the new exp pattern. This
> actually even
> > adds a little more since the eye/brain aparently also
> subjectively
> > percieves it to be highest reolution if it has
> greatest resolution in
> > the horizontal direction.
> >
> > The new exp patern is quite strange in that the
> highest resolution in
> > green is on the left diagonal , with all other
> directions being
> > lower! This is non-optimal since horizontal is best
> subjectively. The
> > beyer has equal, but reduced by 45% resolution on
> both
> > diagonals,while the vertical and horizontal are the
> the highest and
> > equal.
> >
> > The exr horizontal green resolution, is lower than the
> beyer, at
> > 12Mpix because of diagonal pattern. Because of the
> unsymetrical
> > spacing of exp, it also aliases at even lower
> resolution than you
> > would normally imagine from that raw color pixel
> count. If you
> > photographed a thin curved line object like a hair
> say, it would
> > produce some additional low frequency aliasing because
> sampling was
> > more non-uniform ,at different angles than beyer.
> (think: if a line
> > pair is sampled by two close spaced pixels then they
> get resolved,
> > but the next pair of pixels in exp are now more widely
> spaced, so the
> > next adjacent line pair is not resolved)
> >
> > The wide dynamic range option which is really more
> like 6mpixel,
> > since it selects best exposure from two diagonal
> pixels, then has
> > uniform sampling, at least at a particular brightness
> level.
> >
> > The claim that there is less aliasing from binning
> diagonally left
> > adjacent pixels in exr, rather than more widely
> separated ones
> > (bayer), is complex to analyse and is more orientation
> dependent than
> > beyer.
> >
> > However, because the beyer samples at a higher
> horizontal frequency
> > than the non-uniform exr, then binning two horizontal
> (or vertical)
> > pixels in beyer, still has lower aliasing, since the
> actual sampling
> > was done at a higher resolution (frequency) thus
> having lowest
> > aliasing.
> >
> > The s/n ratio improvement is exactly the same for
> equal area
> > photo-diodes in the two technologies. In this
> comparison for the
> > bayer at 6mpixels, the optimal bining for best
> subjective and actual
> > resolution, would be combining vertical pixels.
> >
> > Tim Hughes
> >
> >
> >
> >
> > --- On Fri, 5/1/09, usher99@xxxxxxx
> <usher99@xxxxxxx> wrote:
> >
> >> From: usher99@xxxxxxx <usher99@xxxxxxx>
> Subject: [OM] clever use of
> >> available sensor real estate To:
> olympus@xxxxxxxxxxxxxxxxx Date:
> >> Friday, May 1, 2009, 2:12 PM
> >>
> http://www.dpreview.com/reviews/fujifilmf200exr/page2.asp
> >>
> >> Moose might be amused that low light performance a
> few generations
> >> later still doesn't really exceed the
> F30/31--the latter are still
> >> expensive.
> >>
> >> Not many Moose sightings of late.
> >>
> >> A Trace Worried Mike --
> >>
> _________________________________________________________________
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