Olympus-OM
[Top] [All Lists]

Re: [OM] IMG: More Experiments with ETTR

Subject: Re: [OM] IMG: More Experiments with ETTR
From: Moose <olymoose@xxxxxxxxx>
Date: Thu, 08 Sep 2011 21:20:14 -0700
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
-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz