Moose,
As I said, I am experimenting. A friend on the LUG asked me for the RAW
image of the first one, and he could do no better than I did with it. He
suggested I look at +.3, so I put it up in the gallery because that was the
only way I could read all of the exif data. I agree, from my simple
experiments, "zero" begins to look better and better.
I am confused by your definition of ETTR. I thought that the purpose was to
bias the histogram to the right because that allowed more pixels to be used
in the shadow area. I agree, that going beyond 255 will cause the
highlights to flare, so it should only be used when the full range can be
captured by the sensor.
Is there a simple way to read the exif data in the RAW converter? All I get
is ISO, shutter speed, and aperture. EV is not shown in my software.
Jim Nichols
Tullahoma, TN USA
----- Original Message -----
From: "Moose" <olymoose@xxxxxxxxx>
To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
Sent: Thursday, September 08, 2011 11:20 PM
Subject: Re: [OM] IMG: More Experiments with ETTR
> On 9/8/2011 11:01 AM, Jim Nichols wrote:
>> In continuing to get a better understanding of proper exposure as it
>> applies to the E-1 and its CCD sensor, I finally got a brief period of
>> sunshine, and took a few more images. I should mention that articles I
>> have read report that ETTR will be helpful IF the range of brightness of
>> the subjects does not exceed the range that the sensor can capture.
>>
>> An extreme range of brightness showed me that I could not find a setting
>> capable of capturing the full image without blowing the highlights. This
>> example was about as good as I could do, and it used EV +1.3.
>> http://gallery.leica-users.org/v/OldNick/P9081077edit.jpg.html
>>
>> Using this same setting worked very well in capturing an image containing
>> a lot of shadow area.
>> http://gallery.leica-users.org/v/OldNick/P9081079edit.jpg.html
>
> OK, I'll admit to some confusion. The subject is ETTR (Expose To The
> Right). That means, in common usage, pulling
> exposure down (usually negative EV compensation) in order to avoid
> highlight clipping. In ideal ETTR of typical
> subjects, just a few pixels may reach a value of 255 in one or more
> channels, but no pixels, in any channel, would have
> required a higher value, if it were available, but were clipped to 255.
>
> This is done where the camera/film can't capture the whole DR of the
> subject and the photographer decides to sacrifice
> shadow detail to avoid blowing highlights.
>
> What you have done in these two examples is the opposite, exposing to
> retain shadow detail at the expense of highlights,
> i.e. ETTL(eft). There are huge areas of the first example where the image
> has gone pure white, all tonal and textural
> detail in the highlights just gone. Tonal detail in the shadows is nicely
> retained, but it's strictly OOF background, of
> no importance I can see to the image. Personally, I think it looks awful,
> but tastes vary.
>
> The second one isn't as bad. Although there are still areas badly clipped,
> they are much smaller. Again I don't see
> where the deep shadow tonal detail contributes to the overall image,
> whereas the blown highlights detract from it.
>
> The next image in your gallery has a close to perfect ETTR histogram, with
> just a small amount of clipping. In fact,it's
> a pretty good exposure, with only a small amount of shadow clipping that
> will never be visible. Taken in flat light,
> +1/3 EV was good; +1 1/3 would have ruined it. As is usual with properly
> designed cameras in proper adjustment in flat
> light, 0 EV, no adjustment, would have been a perfect.
>
> Exposed Moose
> --
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