dynamic range K20D

dafiryde · 01-07-2009, 12:46 PM

the dynamic range option in the ISO menu
what is this for and when should you use it

Dave

ftpaddict · 01-07-2009, 12:49 PM

It's there in case you need to extract more shadow detail from the picture and you use it when you need to extract more shadow detail from the picture.

PENTAXFTW12 · 01-07-2009, 11:25 PM

Originally posted by ftpaddict

It's there in case you need to extract more shadow detail from the picture and you use it when you need to extract more shadow detail from the picture.

LOL.

So is it like...adding adaptive exposure?

blende8 · 01-08-2009, 01:02 AM

Actually it is highlight detail.

This is from Gordon Goodsman's description: (slightly changed)
What the EDR mode does is to drop the ISO sensitivity to one half of that set in the ISO menu, so that an ISO 200 shot with EDR turned on will actually be using the ISO gain as for a ISO 100 shot but with the exposure values as for the ISO 200 setting, resulting in one stop of extra highlight.
This allows Pentax to expose more "to the right" in the "normal" mode so as to minimize noise while still getting points for a fairly high DR using the "EDR" mode. The downside is "slighly worse noise in the shadows", and the actual effect will be to almost double the deep shadow noise when used at low ISO and reduce the DR at the dark end almost as much as the DR is being increased at the bright end.
It seems to me that one could achieve the same thing more easily by just using a slight negative EV of 0.3 to 0.7 stops with the one stop lower ISO setting and then not require any abnormal post processing of raw images. I can't speak for in-camera JPEG processing of EDR images, as we don't know what extra tone curve manipulations that may be combined with EDR for those.

Das Boot · 01-08-2009, 10:51 AM

I tried to explain it here: D-Range A Technical View

-Brian

01-07-2009, 12:46 PM	#1
dafiryde Veteran Member Join Date: Nov 2007 Location: Trinidad and Tobago Posts: 419	dynamic range K20D the dynamic range option in the ISO menu what is this for and when should you use it Dave

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01-07-2009, 12:49 PM	#2
ftpaddict Veteran Member Join Date: Jan 2008 Location: Yurp Photos: Gallery Posts: 4,666	It's there in case you need to extract more shadow detail from the picture and you use it when you need to extract more shadow detail from the picture.

01-07-2009, 11:25 PM	#3
PENTAXFTW12 New Member Join Date: Dec 2008 Posts: 7	Originally posted by ftpaddict It's there in case you need to extract more shadow detail from the picture and you use it when you need to extract more shadow detail from the picture. LOL. So is it like...adding adaptive exposure?

01-08-2009, 01:02 AM	#4
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521	Actually it is highlight detail. This is from Gordon Goodsman's description: (slightly changed) What the EDR mode does is to drop the ISO sensitivity to one half of that set in the ISO menu, so that an ISO 200 shot with EDR turned on will actually be using the ISO gain as for a ISO 100 shot but with the exposure values as for the ISO 200 setting, resulting in one stop of extra highlight. This allows Pentax to expose more "to the right" in the "normal" mode so as to minimize noise while still getting points for a fairly high DR using the "EDR" mode. The downside is "slighly worse noise in the shadows", and the actual effect will be to almost double the deep shadow noise when used at low ISO and reduce the DR at the dark end almost as much as the DR is being increased at the bright end. It seems to me that one could achieve the same thing more easily by just using a slight negative EV of 0.3 to 0.7 stops with the one stop lower ISO setting and then not require any abnormal post processing of raw images. I can't speak for in-camera JPEG processing of EDR images, as we don't know what extra tone curve manipulations that may be combined with EDR for those.

01-08-2009, 10:51 AM	#5
Das Boot Veteran Member Join Date: Feb 2008 Location: Sparkle City, South Cackalacky Photos: Gallery Posts: 689	I tried to explain it here: D-Range A Technical View -Brian