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Difference between DPP and ACR linear images
Posted: Wed Feb 22, 2012 11:39 am
by cocasana
When I open a raw file in DPP and I set it to linear its quite darker then the same file opened in ACR with all the sliders set to 0 and the curve to linear. I'm missing something, shouldn't they look the same?
Posted: Wed Feb 22, 2012 11:47 am
by E.J. Peiker
Two completely different things. DPP is giving you a linear representation of the RAW sensor data, ACR is just applying no contrast curve when selecting linear. they aren't the same thing and shouldn't be confused with each other. one refers to sensor level data while the other refers to nothing more than a linear line for your contrast curve.
Posted: Wed Feb 22, 2012 11:57 am
by ahazeghi
EJ is right,
Linear in DPP is not the same as linear in ACR. linear in DPP is how the sensor output looks like without any tone curve applied. Linear in ACR is just a neutral tone curve. In other words, ACR does not provide a linear RAW output.
Posted: Wed Feb 22, 2012 12:05 pm
by cocasana
Thanks a lot! But then..., what are the enhancements ACR applies to the linear representation of the RAW sensor data? The Gamma correction?! Wouldn't it be possible to have the same linear representation of the RAW sensor data in ACR?
Re:
Posted: Wed Feb 22, 2012 12:18 pm
by ahazeghi
cocasana wrote:Thanks a lot! But then..., what are the enhancements ACR applies to the linear representation of the RAW sensor data? The Gamma correction?! Wouldn't it be possible to have the same linear representation of the RAW sensor data in ACR?
It applies a standard tone curve like the one you see in DPP when you select "neutral" picture style.
No, ACR will not show you the linear RAW output.
Posted: Wed Feb 22, 2012 1:18 pm
by jwaif
Slightly off topic, but are there any Windows compatible raw converters that display a linear histogram for Nikon NEF files like the one available in DPP?
Thanks.
John S.
Re: Difference between DPP and ACR linear images
Posted: Wed Feb 22, 2012 1:48 pm
by cocasana
... and when it comes to ETTR shouldn't it be referred to the real RAW histogram (that -BTW- you can't see on the camera). And the same when speaking of "scene referred"?
Posted: Wed Feb 22, 2012 2:39 pm
by ahazeghi
yup, what should be used for ETTR is the RAW histogram pre-demosaic which is what is shown in DPP in the RAW tab (notice x-axis is in EV units, this shows the full sensor DR) not the RGB histogram post-demosaic and once the tone curve is applied. But no camera on the market shows the real RAW histogram...this was discussed in another thread recently