DNG files - what am I seeing?

bxf · 07-18-2011, 08:02 PM

Typically, when viewing a DNG file, one is presented with the embedded JPG, produces by the camera. With some viewers one is able to request to see the "actual DNG". e.g. Fatpictureviewer (hit R), Faststone Viewer (Hit A), Irfanview (select in settings).

When viewing the actual DNG, I am presented with an image that is VERY different from what I see when opening the file with ACR or PDCU. Both of these applications show the file more-or-less as it appears in the embedded preview.

Ironically, I have images that strike me as being easier to manipulate using the non-ACR (or PDCU) version as a starting point. For example, I can use Faststone to make lighting changes to a difficult image, and I obtain results that I'd find difficult to replicate using ACR.

So the question is: what am I seeing when the display is "actual DNG", and why do ACR and PDCU not show this same image when the file is initially opened?

Thanks for any input.

adr1an · 07-18-2011, 08:52 PM

ACR applies a bunch of defaults based on the embeeded profile in the image.
PDCU applies the same 'settings' to the RAW file by default that the JPEG version would have gotten.

You are getting the 'raw' file in both - just they auto-apply settings.. which is why you can often see the image dramatically change between 'preview' and the actual display..

At least thats my experience...

simico · 07-19-2011, 12:09 AM

Originally posted by bxf

So the question is: what am I seeing when the display is "actual DNG", and why do ACR and PDCU not show this same image when the file is initially opened?

Because every software processes the raw data in a different way. The raw data must be processed (demosaicing, color profiling, etc) to be able to see any image and each software applies its own default processing parameters and algorithms.
If you give the same raw materials to 3 cooks, each of them will cook them in their own way and the resulting meals will be slightly or very different in taste and look

bxf · 07-19-2011, 03:02 AM

Originally posted by adr1an

ACR applies a bunch of defaults based on the embeeded profile in the image.
PDCU applies the same 'settings' to the RAW file by default that the JPEG version would have gotten.

You are getting the 'raw' file in both - just they auto-apply settings.. which is why you can often see the image dramatically change between 'preview' and the actual display..

At least thats my experience...

Ah, OK, that explains things. Makes sense, I guess. Still, It's interesting that sometimes the K5 seems to "get it all wrong". See the samples in my reply to the next post.

Thanks.

bxf · 07-19-2011, 03:16 AM

Originally posted by simico

Because every software processes the raw data in a different way. The raw data must be processed (demosaicing, color profiling, etc) to be able to see any image and each software applies its own default processing parameters and algorithms.
If you give the same raw materials to 3 cooks, each of them will cook them in their own way and the resulting meals will be slightly or very different in taste and look

I am sure that what you say is correct, but I believe that the differences I'm talking about are too large for this to be the ONLY reason. Have a look at the these two sets of images. In each case, the embedded JPG is on the left and the "actual DNG" on the right. These, by the way, are extracted from shots taken during a time that my K5 + AF540 flash decided to go gaga while I was trying out Liveview in dim lighting. Although both JPGs are terrible, the corresponding DNGs are OK - as far as lighting and colour go, that is.

Thanks for your input.

**Just1MoreDave** · 07-19-2011, 11:43 AM

Is Adobe Camera RAW using an Adobe-made camera profile for the K-5 or a Pentax one? It's just a guess but that's the kind of alterations I get with the Adobe profile for the K-7.

bxf · 07-19-2011, 12:37 PM

Originally posted by Just1MoreDave

Is Adobe Camera RAW using an Adobe-made camera profile for the K-5 or a Pentax one? It's just a guess but that's the kind of alterations I get with the Adobe profile for the K-7.

Well, you can chose to use the embedded profile or an Adobe one. However, the above samples have nothing to do with ACR. They show the JPG embedded in the DNG file (which is similar to the camera-created JPG file, and the DNG file without any processing applied, as can be seen using a viewer that has the capability to display such.

Marc Sabatella · 07-19-2011, 07:35 PM

If those are images produced by an Adobe product from a DNG file, then ACR most definitely created them. And there is no such things as a DNG image with no processing applied. If you can see it, then it has neen processed. An unpocressed DNG file cannot be displayed on an RGB monitor.

wildman · 07-19-2011, 11:58 PM

Originally posted by bxf

So the question is: what am I seeing when the display is "actual DNG"

There is no "actual DNG", at least visually, only various software interpretations of the data in a RAW file. A RAW file is not an image file like JPG is but just a simple binary data file so far as I know.

"With raw, the only
on-camera settings that have an effect on the captured pixels are the ISO
speed, shutter speed, and aperture."

Jeff Schewe
Real World Camera RAW with Adobe photoshop CS5

bxf · 07-20-2011, 04:51 AM

Originally posted by Marc Sabatella

If those are images produced by an Adobe product from a DNG file, then ACR most definitely created them. And there is no such things as a DNG image with no processing applied. If you can see it, then it has neen processed. An unpocressed DNG file cannot be displayed on an RGB monitor.

Originally posted by wildman

There is no "actual DNG", at least visually, only various software interpretations of the data in a RAW file. A RAW file is not an image file like JPG is but just a simple binary data file so far as I know.

Jeff Schewe
Real World Camera RAW with Adobe photoshop CS5

I understand what both of you are saying.

Quite coincidentally, just after I opened this thread, I came across some comments that propmpted me to install onOne Software's "Presets for Camera Raw". Three of the presets are labeled Reset Auto, Reset Default, and Reset Zeroed. The first two, as would be expected, produce results corresponding to the Auto and Default options in ACR's Basic panel, respectively. The Zeroed profile produces an image that is similar to what one sees with Fastpictureviewer's and Faststone's "actual RAW" (using my terminology) displays.

This leads me to understand that adr1an's comments in post #2 must have some validity:

ACR applies a bunch of defaults based on the embedded profile in the image.
PDCU applies the same 'settings' to the RAW file by default that the JPEG version would have gotten.

In other words, ACR, by default, processes the image aiming for some specific results as its objective, whatever that objective may be, and the "Reset Zeroed" profile changes that objective, and I'd be curious to know what each of these objectives is.

adr1an · 07-20-2011, 05:00 AM

Originally posted by bxf

In other words, ACR, by default, processes the image aiming for some specific results as its objective, whatever that objective may be, and the "Reset Zeroed" profile changes that objective, and I'd be curious to know what each of these objectives is.

Its a little confusing, and I once found a good article at Adobe about it.. but do you think I can find it now ?

Basically - ACR can be configured to apply "defaults" based on the Camera Body and ISO. So it will have different 'defaults' for ISO 100 images from Body A compared to ISO200 images from Body A.. which can be entirely different from Body B etc.

Now - there is a way to 'reset' the defaults.. and there is also a way to 'save as default' various settings... and a further option to make those defaults either Camera or ISO specific... but sorry - can't recall the specifics of how to drive the menus to get there as I use Lightroom - I rarely interact with ACR Directly, and instead use develop settings within LR which does the same thing (storing defaults based on ISO etc etc.) LR also 'remembers' various settings automagically for you based on ISO that you can apply at import time automatically...

What the 'out of the box' defaults are - I can't recall either. From memory they are based on the Camera Profile that is embedded/selected for the image.. then you as I said tweak the baseline from there...
"reset" I believe sets every value to 0, and selects the embedded camera profile ?

Only other suggestion if it still bugs you is read the Adobe community help pages on ACR Defaults... I did find a nice page that sort of kinda explained it enough to make me dangerous...

PDCU references the embeded EXIF data to apply the JPEG settings as configured 'in-camera'... if you use exiftool to view 'all' data on a DNG file, you'll see towards the bottom all the Saturation, Vibrance etc values... it just grabs those and applies them for you as a baseline giving you the equivalent of what an in-camera JPEG would have looked like...

bxf · 07-20-2011, 08:54 AM

Originally posted by adr1an

Its a little confusing, and I once found a good article at Adobe about it.. but do you think I can find it now ?

I suppose it would be appropriate for me to do some more reading on the subject.

Just to add to the confusion, though, I just discovered that my statement "The Zeroed profile produces an image that is similar to what one sees with Fastpictureviewer's and Faststone's "actual RAW" (using my terminology) displays" does not hold for all images (not valid for the second pair I posted above, for example). Strange.

Thanks for all your input.

07-18-2011, 08:02 PM	#1
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660	DNG files - what am I seeing? Typically, when viewing a DNG file, one is presented with the embedded JPG, produces by the camera. With some viewers one is able to request to see the "actual DNG". e.g. Fatpictureviewer (hit R), Faststone Viewer (Hit A), Irfanview (select in settings). When viewing the actual DNG, I am presented with an image that is VERY different from what I see when opening the file with ACR or PDCU. Both of these applications show the file more-or-less as it appears in the embedded preview. Ironically, I have images that strike me as being easier to manipulate using the non-ACR (or PDCU) version as a starting point. For example, I can use Faststone to make lighting changes to a difficult image, and I obtain results that I'd find difficult to replicate using ACR. So the question is: what am I seeing when the display is "actual DNG", and why do ACR and PDCU not show this same image when the file is initially opened? Thanks for any input.

07-19-2011, 03:16 AM	#5
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by simico Because every software processes the raw data in a different way. The raw data must be processed (demosaicing, color profiling, etc) to be able to see any image and each software applies its own default processing parameters and algorithms. If you give the same raw materials to 3 cooks, each of them will cook them in their own way and the resulting meals will be slightly or very different in taste and look I am sure that what you say is correct, but I believe that the differences I'm talking about are too large for this to be the ONLY reason. Have a look at the these two sets of images. In each case, the embedded JPG is on the left and the "actual DNG" on the right. These, by the way, are extracted from shots taken during a time that my K5 + AF540 flash decided to go gaga while I was trying out Liveview in dim lighting. Although both JPGs are terrible, the corresponding DNGs are OK - as far as lighting and colour go, that is. Thanks for your input. Attached Images

07-19-2011, 07:35 PM	#8
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	If those are images produced by an Adobe product from a DNG file, then ACR most definitely created them. And there is no such things as a DNG image with no processing applied. If you can see it, then it has neen processed. An unpocressed DNG file cannot be displayed on an RGB monitor. Last edited by Marc Sabatella; 07-19-2011 at 07:41 PM.

07-20-2011, 05:00 AM	#11
adr1an Veteran Member Join Date: Sep 2010 Location: Canberra Photos: Gallery \| Albums Posts: 739	Originally posted by bxf In other words, ACR, by default, processes the image aiming for some specific results as its objective, whatever that objective may be, and the "Reset Zeroed" profile changes that objective, and I'd be curious to know what each of these objectives is. Its a little confusing, and I once found a good article at Adobe about it.. but do you think I can find it now ? Basically - ACR can be configured to apply "defaults" based on the Camera Body and ISO. So it will have different 'defaults' for ISO 100 images from Body A compared to ISO200 images from Body A.. which can be entirely different from Body B etc. Now - there is a way to 'reset' the defaults.. and there is also a way to 'save as default' various settings... and a further option to make those defaults either Camera or ISO specific... but sorry - can't recall the specifics of how to drive the menus to get there as I use Lightroom - I rarely interact with ACR Directly, and instead use develop settings within LR which does the same thing (storing defaults based on ISO etc etc.) LR also 'remembers' various settings automagically for you based on ISO that you can apply at import time automatically... What the 'out of the box' defaults are - I can't recall either. From memory they are based on the Camera Profile that is embedded/selected for the image.. then you as I said tweak the baseline from there... "reset" I believe sets every value to 0, and selects the embedded camera profile ? Only other suggestion if it still bugs you is read the Adobe community help pages on ACR Defaults... I did find a nice page that sort of kinda explained it enough to make me dangerous... PDCU references the embeded EXIF data to apply the JPEG settings as configured 'in-camera'... if you use exiftool to view 'all' data on a DNG file, you'll see towards the bottom all the Saturation, Vibrance etc values... it just grabs those and applies them for you as a baseline giving you the equivalent of what an in-camera JPEG would have looked like... Last edited by adr1an; 07-20-2011 at 05:08 AM.

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07-18-2011, 08:52 PM	#2
adr1an Veteran Member Join Date: Sep 2010 Location: Canberra Photos: Gallery \| Albums Posts: 739	ACR applies a bunch of defaults based on the embeeded profile in the image. PDCU applies the same 'settings' to the RAW file by default that the JPEG version would have gotten. You are getting the 'raw' file in both - just they auto-apply settings.. which is why you can often see the image dramatically change between 'preview' and the actual display.. At least thats my experience...

07-19-2011, 12:09 AM	#3
simico Veteran Member Join Date: Jan 2009 Location: Budapest Posts: 821	Originally posted by bxf So the question is: what am I seeing when the display is "actual DNG", and why do ACR and PDCU not show this same image when the file is initially opened? Because every software processes the raw data in a different way. The raw data must be processed (demosaicing, color profiling, etc) to be able to see any image and each software applies its own default processing parameters and algorithms. If you give the same raw materials to 3 cooks, each of them will cook them in their own way and the resulting meals will be slightly or very different in taste and look

07-19-2011, 03:02 AM	#4
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by adr1an ACR applies a bunch of defaults based on the embeeded profile in the image. PDCU applies the same 'settings' to the RAW file by default that the JPEG version would have gotten. You are getting the 'raw' file in both - just they auto-apply settings.. which is why you can often see the image dramatically change between 'preview' and the actual display.. At least thats my experience... Ah, OK, that explains things. Makes sense, I guess. Still, It's interesting that sometimes the K5 seems to "get it all wrong". See the samples in my reply to the next post. Thanks.

07-19-2011, 11:43 AM	#6
Just1MoreDave Site Supporter Join Date: Feb 2007 Location: Aurora, CO Photos: Gallery \| Albums Posts: 6,340	Is Adobe Camera RAW using an Adobe-made camera profile for the K-5 or a Pentax one? It's just a guess but that's the kind of alterations I get with the Adobe profile for the K-7.

07-19-2011, 12:37 PM	#7
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by Just1MoreDave Is Adobe Camera RAW using an Adobe-made camera profile for the K-5 or a Pentax one? It's just a guess but that's the kind of alterations I get with the Adobe profile for the K-7. Well, you can chose to use the embedded profile or an Adobe one. However, the above samples have nothing to do with ACR. They show the JPG embedded in the DNG file (which is similar to the camera-created JPG file, and the DNG file without any processing applied, as can be seen using a viewer that has the capability to display such.

07-19-2011, 11:58 PM	#9
wildman Veteran Member Join Date: Jun 2008 Location: Flyover America Posts: 4,469	Originally posted by bxf So the question is: what am I seeing when the display is "actual DNG" There is no "actual DNG", at least visually, only various software interpretations of the data in a RAW file. A RAW file is not an image file like JPG is but just a simple binary data file so far as I know. "With raw, the only on-camera settings that have an effect on the captured pixels are the ISO speed, shutter speed, and aperture." Jeff Schewe Real World Camera RAW with Adobe photoshop CS5

07-20-2011, 04:51 AM	#10
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by Marc Sabatella If those are images produced by an Adobe product from a DNG file, then ACR most definitely created them. And there is no such things as a DNG image with no processing applied. If you can see it, then it has neen processed. An unpocressed DNG file cannot be displayed on an RGB monitor. Originally posted by wildman There is no "actual DNG", at least visually, only various software interpretations of the data in a RAW file. A RAW file is not an image file like JPG is but just a simple binary data file so far as I know. Jeff Schewe Real World Camera RAW with Adobe photoshop CS5 I understand what both of you are saying. Quite coincidentally, just after I opened this thread, I came across some comments that propmpted me to install onOne Software's "Presets for Camera Raw". Three of the presets are labeled Reset Auto, Reset Default, and Reset Zeroed. The first two, as would be expected, produce results corresponding to the Auto and Default options in ACR's Basic panel, respectively. The Zeroed profile produces an image that is similar to what one sees with Fastpictureviewer's and Faststone's "actual RAW" (using my terminology) displays. This leads me to understand that adr1an's comments in post #2 must have some validity: ACR applies a bunch of defaults based on the embedded profile in the image. PDCU applies the same 'settings' to the RAW file by default that the JPEG version would have gotten. In other words, ACR, by default, processes the image aiming for some specific results as its objective, whatever that objective may be, and the "Reset Zeroed" profile changes that objective, and I'd be curious to know what each of these objectives is.

07-20-2011, 08:54 AM	#12
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by adr1an Its a little confusing, and I once found a good article at Adobe about it.. but do you think I can find it now ? I suppose it would be appropriate for me to do some more reading on the subject. Just to add to the confusion, though, I just discovered that my statement "The Zeroed profile produces an image that is similar to what one sees with Fastpictureviewer's and Faststone's "actual RAW" (using my terminology) displays" does not hold for all images (not valid for the second pair I posted above, for example). Strange. Thanks for all your input.