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Rider
3-Feb-2011, 21:18
I am considering getting Vuescan to use with Epson 4990 and Coolscan 5000.

I see there is a format they call "RAW" which can be saved as a DNG and a TIFF.

Since ACR can open both, is there any difference between the two? They are they are about the same size, 170MB for a 35mm scan at 4000dpi, 64bit RGBI (which includes the 16bit infrared channel that I understand only Vuescan can decipher).

urs0polar
3-Feb-2011, 22:08
As I understand it, Vuescan can save as the DNG (Their "raw") and then re-scan it later using different curves, adjustments, etc. It kind of open in Adobe Camera Raw, but it's all messed up and doesn't really work well as it's not a true "raw" file in the same sense as a DSLR raw file is.

So, I just scan in TIFF and set my curve at .25 and .75, and do the advanced workflow (from the vuescan manual) so that I'm scanning down to the base+fog(+base color if color neg), and I set the white balance. This gives me a pretty neutral scan that cleans up nicely in Photoshop with levels and curves, and I save as a PSD with layers and I have a good base to make JPEGs from.

So, in my opinion, Photoshop is much easier to use than Vuescan to do after-scan adjustments.... if you are a Vuescan expert and/or don't have Photoshop, and you feel like you want multiple interpretations of a single scan without having to re-scan, then perhaps Vuescan RAWs are a good fit. For me, I would just re-scan, but what do I know :p

Good luck.

urs0polar
3-Feb-2011, 22:22
Also, check this thread http://www.largeformatphotography.info/forum/showthread.php?t=38366

domaz
4-Feb-2011, 00:08
I open Vuescan Slide Film DNG files all the time in Photoshop and they appear to work the same as DSLR raw files. The problem is when you scan negative film- then the RAW files are reversed and Photoshop (and other tools) don't really know how to deal with them properly.

Rider
4-Feb-2011, 05:36
domaz, have you seen any difference between Vuescan's (i) raw TIFF files and (ii) raw DNG files?

Since they both can be opened by Lightroom, ACR or Vuescan itself for later editing, I was wondering whether there was any documented difference between them.

I like the idea of scanning a slide once and then editing it later. I found Nicon Scan daunting in that I have to make so many decisions up front (not to mention that it doesn't support 64 bit Windows, although there are work-arounds). I found Silverlight confusing, and expensive. Vuescan seems just right, but I want to make sure I am using the more flexible raw file format.

One issue I had with redeveloping TIFFs and DNGs with Vuescan is that the color settings didn't seem to work as well as on the initial scan.

I will have to try it with negatives as well before I buy it.

domaz
4-Feb-2011, 09:53
domaz, have you seen any difference between Vuescan's (i) raw TIFF files and (ii) raw DNG files?


Well technically the output between the two files is probably the same. However, when you open a raw TIFF in a photo editing software I don't think it "knows" it's raw- you just get a file with no curve applied. When I open a raw DNG file in Photoshop it brings up the nice RAW editing adjustment tool. If you don't want to use the RAW editing adjustment tools and instead do everything manually then I don't know if it woudl matter.


I like the idea of scanning a slide once and then editing it later. I found Nicon Scan daunting in that I have to make so many decisions up front (not to mention that it doesn't support 64 bit Windows, although there are work-arounds). I found Silverlight confusing, and expensive. Vuescan seems just right, but I want to make sure I am using the more flexible raw file format.

One issue I had with redeveloping TIFFs and DNGs with Vuescan is that the color settings didn't seem to work as well as on the initial scan.

I will have to try it with negatives as well before I buy it.

The color on the subsequent scans has never been a problem for me. However, it is probably best to do the Lock exposure workflow (http://www.flickr.com/groups/ishootfilm/discuss/72157608204093047/) on the initial raw scan. That will ensure your exposure is consistent and correct.

Rider
6-Feb-2011, 06:23
I assume that only Vuescan can interpret the extra Infrared information in a 64-bit RGBI file, whether it's DNG or TIFF, right?

Rider
6-Feb-2011, 09:58
Well I figured out how to get the IR data as a separate channel out of Vuescan. It can be done either at the initial scan phase, but producing two files (one 48bit RGB file and one 16bit infrared file), or, more conveniently, but re-processing the 64bit RGBI file in Vuescan and extracting the IR channel into a separate 16bit file. Doesn't do me much good because my Photoshop skills are not such that I would know how to combine the two files into one file. So I am stuck having to do much post-processing in Vuescan if I want to do IR spot removal.

It is remarkable to see just how accurate the Coolscan 5000 IR channel is. The color and the IR channels match up perfectly, pixel for pixel.

domaz
7-Feb-2011, 20:26
I assume that only Vuescan can interpret the extra Infrared information in a 64-bit RGBI file, whether it's DNG or TIFF, right?

You can output a raw film with the file already Infrared cleaned by using the Raw Save film option (http://www.hamrick.com/vuescan/html/vuesc32.htm#outputrawsavefilm).

urs0polar
7-Feb-2011, 21:38
This is a great thread; I think I'm going to monkey around with Vuescan's DNG a bit more.... Thanks guys

Rider
8-Feb-2011, 06:10
You can output a raw film with the file already Infrared cleaned by using the Raw Save film option (http://www.hamrick.com/vuescan/html/vuesc32.htm#outputrawsavefilm).

Thanks for pointing that out. It's very subtle!

Greg Miller
8-Feb-2011, 10:24
DNG is a open source RAW format created by Adobe. The rationale was to have a non-proprietary RAW format (as opposed to the many proprietary RAW formats that the camera manufacturers like Canon and Nikon have created) - so in theory 100 years from now you could still open a DNG file and process it where proprietary formats rely on the camera manufacturers to still be around since they do not divulge all of the details of their formats (although most people are not bothered by the fact that ACR processes proprietary RAW formats without knowing the full details of the format - Adobe basically reverse engineers the the format)

In theory, DNG should be better than TIFF since the DNG file would be unprocessed and you can perform processing such a color balance and contrast that is non-destructive. A TIFF file already has RGB values assigned so you are limited in the extent of processing that you can do. I do not know if Vuescan is using the full capabilities of DNG so the actual benefits may or may not exist in reality.

domaz
8-Feb-2011, 11:47
In theory, DNG should be better than TIFF since the DNG file would be unprocessed and you can perform processing such a color balance and contrast that is non-destructive. A TIFF file already has RGB values assigned so you are limited in the extent of processing that you can do. I do not know if Vuescan is using the full capabilities of DNG so the actual benefits may or may not exist in reality.

Greg what do you consider the full capabilities of DNG? Vuescan puts unprocessed RGB image data from the scanner in DNG similar to what a Camera's CCD/CMOS woud output. DNG does have the ability to do some complex stuff like embed various Image transform functions so the viewing program knows how to best interpret the data. One example in the DNG spec is the WarpFishEye transform that tells the viewer to "unwrap an image captured with a fisheye lens and map it instead to a perspective projection". So DNG can do some very interesting things but does a Scanner need to take advantage of this? I doubt it. Also remember that DNG is actually a TIFF 6.0 file at it's heart. TIFF is known as "thousands of image file formats" for good reason. So the difference between a Vuescan RAW TIFF and RAW DNG is probably very minimal.

Greg Miller
8-Feb-2011, 20:28
Greg what do you consider the full capabilities of DNG? Vuescan puts unprocessed RGB image data from the scanner in DNG similar to what a Camera's CCD/CMOS woud output. DNG does have the ability to do some complex stuff like embed various Image transform functions so the viewing program knows how to best interpret the data. One example in the DNG spec is the WarpFishEye transform that tells the viewer to "unwrap an image captured with a fisheye lens and map it instead to a perspective projection". So DNG can do some very interesting things but does a Scanner need to take advantage of this? I doubt it. Also remember that DNG is actually a TIFF 6.0 file at it's heart. TIFF is known as "thousands of image file formats" for good reason. So the difference between a Vuescan RAW TIFF and RAW DNG is probably very minimal.

Well, if it were a RAW file coming form a digital camera, then a huge advantage to the RAW file is that color balance, lightness, saturation, contrast,... can be changed radically with much fewer consequences than a tiff file because the data has not been associated with a specific RGB color space (e.g. Adobe RGB) . That cannot be said for a tiff file with the the data having been converted to RGB values.

While DNG does use a tiff structure at its foundation, that does not necessarily mean the data had been converted to RGB. DNG is certainly capable of storing non RGB data same as it is structured in a proprietary RAW format, maintaining the RAW file's ability to be adjusted for color balance, lightness, saturation. contrast,...

Again, I do not know much about how Vuescan creates the DNG file, so I am speaking in hypothetical terms. If the data Vuescan provides is similar to a digital camera's RAW file, then this is a significant advantage over a tiff file.

Ben Syverson
8-Feb-2011, 20:38
The "raw" DNG file that Vuescan produces is the same as the TIFF file, data-wise. It's just a question of whether the software you are importing to prefers DNG or TIFF.

There is no advantage to either.

domaz
9-Feb-2011, 10:15
Well, if it were a RAW file coming form a digital camera, then a huge advantage to the RAW file is that color balance, lightness, saturation, contrast,... can be changed radically with much fewer consequences than a tiff file because the data has not been associated with a specific RGB color space (e.g. Adobe RGB) . That cannot be said for a tiff file with the the data having been converted to RGB values.

While DNG does use a tiff structure at its foundation, that does not necessarily mean the data had been converted to RGB. DNG is certainly capable of storing non RGB data same as it is structured in a proprietary RAW format, maintaining the RAW file's ability to be adjusted for color balance, lightness, saturation. contrast,..

Again, I do not know much about how Vuescan creates the DNG file, so I am speaking in hypothetical terms. If the data Vuescan provides is similar to a digital camera's RAW file, then this is a significant advantage over a tiff file.

VueScan's RAW file seems to be a Linear RGB file- i.e. a RGB file with no curve or color space applied. Camera RAW files are often mosaiced bayer data. I am not sure a Scanner can even output mosaiced bayer data since it has a different CCD design than Digital Camera's but I could be wrong. In any case if you open a VueScan RAW file in a RAW processing program it has no problem adjusting it like a Camera RAW file.

Rider
7-Aug-2011, 08:41
The "raw" DNG file that Vuescan produces is the same as the TIFF file, data-wise. It's just a question of whether the software you are importing to prefers DNG or TIFF.

There is no advantage to either.

I found that although Lightroom supports both TIFF and DNG, there is no practical way to use the TIFFs because Lightroom does allow setting the gamma. Raw TIFFs imported into Lightroom look awful, whereas the same file as a DNG looks just fine straight away.

The other advantage of the DNGs is that it makes it easy for me to know what's a RAW file what isn't. If I scan RAW TIFFs and then convert some of them into output TIFFs, it would be a book-keeping nightmare for me.

D. Bryant
8-Aug-2011, 05:48
Vuescan doesn't produce a true RAW file compared to the data in a RAW file produce by digital cameras.

A scanner produces true RGB data, including Vuescan RAW data files. A digital RAW file containing a single channel grayscale unrendered data. A DNG file can contain rendered data but the data in a Vuescan DNG file isn't RAW data like that contained in a digital camera file.

A Vuescan RAW file was never intended to be edited directly with image editing software like PS or LR, etc. Creating a DNG file with rendered data is really muddying the water, I have yet to understand Hamrick's rational for doing that. DNG is just a variant of a TIFF file.

When processing a TIFF or Vuesan DNG file or any RAW camera file in ACR, LR, or other RAW processing software the file is edited in linear editing space (exactly why a Vuescan file edited directly in PS appears totally whacked out.)

A Vuescan DNG file is really a broken idea with no practical value, IOW a gimmick.

Rider
8-Aug-2011, 06:54
At a minimum, it lets me manage my files in a DAM program like Lightroom, something you can't do effectively with a linear RAW TIFF.

Also, my understanding is that DNG was never meant to be limited to digital camera files. The specification allows for both. I have no problem outputting great images from the DNG files using LR and ACR.

The only fly in the ointment is that Lightroom doesn't know what to do with the fourth channel of the DNG, the one that contains the IR data. But this is a failing of Adobe; they are often behind the curve on stuff like this.

Another problem is that LR probably doesn't support IT8 targets.

D. Bryant
8-Aug-2011, 07:40
At a minimum, it lets me manage my files in a DAM program like Lightroom, something you can't do effectively with a linear RAW TIFF.

Also, my understanding is that DNG was never meant to be limited to digital camera files. The specification allows for both. I have no problem outputting great images from the DNG files using LR and ACR.

The only fly in the ointment is that Lightroom doesn't know what to do with the fourth channel of the DNG, the one that contains the IR data. But this is a failing of Adobe; they are often behind the curve on stuff like this.

No it's not Adobe's problem and never will be. The data in the Vuescan DNG file has already been rendered, you might as well output in TIFF which can BTW, contain metadata. As I said before the RAW Vuescan file was intended to be used by Vuescan not other image editing programs.

And LR isn't supposed to support IT8 targets nor does ACR. You are demostrating my point about the VS DNG being an aberrant bastardized file format.

Strictly speaking DNG files were invented to address issues related to the digital camera RAW file tower of Babel, not the rendered output of from a scanner. Vuescan simply stuffs rendered data into a DNG container which in itself has it's DNA from the TIFF format. In short it's a hack.

If you like it great, but VS DNG ain't the same since it contains scene referenced data which digital camera RAW files do not.

Rider
8-Aug-2011, 08:08
No it's not Adobe's problem and never will be. The data in the Vuescan DNG file has already been rendered.

IR Data has NOT been rendered; it's in a separate channel ready to be combined with RGB data. 64 bit RGBI file! I'm no expert but I did read the Vuescan Bible and had conversations with both the author and Hamrick.

Just because these RAW files are different than DSLR RAW files doesn't mean anything; DNG supports both types. And it's a lot more convenient to edit files in LR than in VS.

As as I said, I am aware of only two problems:

(1) The lazy bums at Adobe (just kidding!) do not have an algorithm for removing dust, ala Digital Ice (btw, this also extends to DSLR RAW files; the only way to remove dust automatically is to use the manufacturer's program. Adobe products lack that functionality across the board.)

(2) VS supports IT8 calibration, but as far as I know Adobe does not.

Adobe just doesn't care about scanners anymore; they're too busy writing iPhone apps (Hey you can't blame them. Hamrick is also writing an iPad app.)

If it weren't for the above two things, you could output RAW files from VS and not have to reprocess them again in VS.

The solution to (1) as it stands, is to output a RAW file that already has the dust removal applied, but that is not as elegant as outputting a 64-bit RGBI file. I usually do this in two steps: Output a 64-bit RGBI file and then use that to create a 48-bit RGB file; the second one doesn't have to be RAW.

I don't know whether it's possible to get Adobe LR to do IT8 calibration; maybe it is.

Again, I am not an expert but I have read The Vuescan Bible and had email conversations with Sascha Steinhoff and Ed hamrick.

Rider
8-Aug-2011, 08:14
Strictly speaking DNG files were invented to address issues related to the digital camera RAW file tower of Babel.


That is (i) humorous and (ii) what Adobe wants you to believe.

DNG actually added to the Tower of Babel because it's yet another format that has no advantages over the RAW that comes off a DSLR and is much less compatible. Every third-party RAW converter supports my Nikon NEF files, but most would not support my NEF files if I was foolish enough to convert them to DNG.

VS DNG are actually the first good use I've ever seen for the DNG format, and that's only because LR is too limited to be able to interpret linear TIFF files.

D. Bryant
8-Aug-2011, 10:15
That is (i) humorous and (ii) what Adobe wants you to believe.

DNG actually added to the Tower of Babel because it's yet another format that has no advantages over the RAW that comes off a DSLR and is much less compatible. Every third-party RAW converter supports my Nikon NEF files, but most would not support my NEF files if I was foolish enough to convert them to DNG.

VS DNG are actually the first good use I've ever seen for the DNG format, and that's only because LR is too limited to be able to interpret linear TIFF files.

I guess that's why Pentax and Leica utilize the DNG format instead of a proprietary format like others. New copies of the Leica M9 ship with LR. I personally don't convert to DNG in any case and as a long time user of Vuescan I never will. I do create DNG camera profile using Xrite ColorChecker for digital cameras but I don't expect film scans to ever be supported by any mainstream RAW processor.

Nikon RAW isn't a loss less format and they actually sharpen RAW data. So the field is wide open. All Adobe was trying to do is ti allow users to convert their RAW camera files to DNG so that they can use older versions of ACR & LR avoiding an upgrade.

Anyway I'm not a defender of Adobe, my primary point is that Hamrick DNG is not supported by Adobe, and never will be for various good reasons so why bother in the first place. What other RAW file converters support it?

My biggest point is that Hamrick DNG files do not contain RAW data and it confuses the issue to suggest that it does. Unfortunately a lot of people think that Vuescan RAW is equivalent to digital RAW files. And who uses spot removal software if you want maximum sharpness.

And quoting Sascha Steinhoff (since you quote him as an authority) from one of his articles listed on his webpage on Vuescan DNG:

"... but be aware that you cannot use this feature with adobe lightroom. lightroom is designed for digital camera raw file and lacks a lot of functionality regarding raw-scans. just for viewing it's ok, though.

all in all scanning with dng gives you a wide flexibility, while scanning in tiff (not in raw-tiff!) is much more easier to handle."

You should take the time to read what Andrew Rodney has to say about the topic:

http://photo.net/digital-darkroom-forum/00Z2Sy

Anyway I've made my points take them as you wish.

Don Bryant

Rider
8-Aug-2011, 10:39
D-I am not trying to force you to scan in RAW. For me it works great. I got there thanks to the advice of the other participants in this forum (see the posts above) and Sascha Steinhoff's book and emails.

Anyone reading this in the future should know that your last post is riddled with inaccuracies and your quote from Sascha Steinhoff's website is outdated, out of context, and actually supports the point that Vuescan RAW DNG is better than Vuescan RAW TIFF because it lets you open and manage the files in LR more easily, which was the start of this discussion earlier today!

ps: I have no problem with DNG files coming off the hardware--as with Leica or Vuescan--but recommending that customers should convert "proprietary" Nikon or Canon files to DNG is practically criminal.

domaz
8-Aug-2011, 11:17
Anyway I'm not a defender of Adobe, my primary point is that Hamrick DNG is not supported by Adobe, and never will be for various good reasons so why bother in the first place. What other RAW file converters support it?

My biggest point is that Hamrick DNG files do not contain RAW data and it confuses the issue to suggest that it does. Unfortunately a lot of people think that Vuescan RAW is equivalent to digital RAW files. And who uses spot removal software if you want maximum sharpness.

And quoting Sascha Steinhoff (since you quote him as an authority) from one of his articles listed on his webpage on Vuescan DNG:

"... but be aware that you cannot use this feature with adobe lightroom. lightroom is designed for digital camera raw file and lacks a lot of functionality regarding raw-scans. just for viewing it's ok, though.

all in all scanning with dng gives you a wide flexibility, while scanning in tiff (not in raw-tiff!) is much more easier to handle."

You should take the time to read what Andrew Rodney has to say about the topic:

http://photo.net/digital-darkroom-forum/00Z2Sy


Vuescan produces what is known as a Linear DNG (http://www.barrypearson.co.uk/articles/dng/linear.htm). It is a valid DNG file- complies to all specifications. It can contain non-RGB data like the Infrared channel etc. However, your argument seems to be (like Andrew Rodney's on Photo.net) that since Vuescan doesn't produce a DNG file with mosaiced bayer data that somehow it's not a RAW file. A scanner has a linear CCD so could never produce such a RAW file. Vuescan produces a RAW file with basically RGB data that has no curve applied- it's straight from the scanner. What exactly is wrong with producing such a RAW file? RAW files have been around for year and before the advent of digital cameras they contained RGB data.

D. Bryant
8-Aug-2011, 11:31
D-I am not trying to force you to scan in RAW. For me it works great. I got there thanks to the advice of the other participants in this forum (see the posts above) and Sascha Steinhoff's book and emails.

Anyone reading this in the future should know that your last post is riddled with inaccuracies and your quote from Sascha Steinhoff's website is outdated, out of context, and actually supports the point that Vuescan RAW DNG is better than Vuescan RAW TIFF because it lets you open and manage the files in LR more easily, which was the start of this discussion earlier today!

ps: I have no problem with DNG files coming off the hardware--as with Leica or Vuescan--but recommending that customers should convert "proprietary" Nikon or Canon files to DNG is practically criminal.

Ah but I do scan in RAW I just don't save as a DNG, instead a TIFF file. I don't see that providing a means to convert to DNG is criminal if the customers version of camera RAW files are not supported. It simply allows users to use older versions of ACR/PS and LR if they wish.

If you wish to use Vuescan DNG go ahead but it ain't a true RAW file. It has scene rendered RGB data.

Time for me to move along any further comments may be construed as arguing.


Don Bryant

D. Bryant
8-Aug-2011, 11:36
Vuescan produces what is known as a Linear DNG (http://www.barrypearson.co.uk/articles/dng/linear.htm). It is a valid DNG file- complies to all specifications. It can contain non-RGB data like the Infrared channel etc. However, your argument seems to be (like Andrew Rodney's on Photo.net) that since Vuescan doesn't produce a DNG file with mosaiced bayer data that somehow it's not a RAW file. A scanner has a linear CCD so could never produce such a RAW file. Vuescan produces a RAW file with basically RGB data that has no curve applied- it's straight from the scanner. What exactly is wrong with producing such a RAW file? RAW files have been around for year and before the advent of digital cameras they contained RGB data.

The data is not straight from the scanner sensor. The file that is created is based on a rendered Preview, that's the point. Files that contain scene referenced data are not RAW.


I moving on.

Rider
8-Aug-2011, 11:48
This is not aimed at D, who is moving on--

In summary:

(1) If you are scanning to Vuescan RAW, then the choice between TIFF and DNG comes down to the program you wish to use to view or process that RAW file. Vuescan can process both files equally well. LR does better with a DNG file, but has limitations with both kinds because of files because (i) LR has no algorithm for removing dust and (ii) LR does not support IT8 targets. These are limitations of LR that VS can do nothing about.

(2) The argument about whether or not VS produces "true RAW" is a red herring, to put it kindly (remind me how many angels dance on the head of a pin?). Even DSLRs apply some processing before outputting a RAW. The VS RAW is about as RAW as it gets. It even includes the Infrared data in a separate channel. (And this applies to both TIFF and DNG, by the way.)

(3) I have no idea where D got the info that the DNG file is based on a rendered Preview. I think it's incorrect.

(4) I highly recommend the Vuescan Bible.

(5) I am grateful to everyone who chimed in on this thread and helped me understand the processing of scanning with Vuescan.

D. Bryant
8-Aug-2011, 12:46
This is not aimed at D, who is moving on--

In summary:

(1) If you are scanning to Vuescan RAW, then the choice between TIFF and DNG comes down to the program you wish to use to view or process that RAW file. Vuescan can process both files equally well. LR does better with a DNG file, but has limitations with both kinds because of files because (i) LR has no algorithm for removing dust and (ii) LR does not support IT8 targets. These are limitations of LR that VS can do nothing about.

(2) The argument about whether or not VS produces "true RAW" is a red herring, to put it kindly (remind me how many angels dance on the head of a pin?). Even DSLRs apply some processing before outputting a RAW. The VS RAW is about as RAW as it gets. It even includes the Infrared data in a separate channel. (And this applies to both TIFF and DNG, by the way.)

(3) I have no idea where D got the info that the DNG file is based on a rendered Preview. I think it's incorrect.

(4) I highly recommend the Vuescan Bible.

(5) I am grateful to everyone who chimed in on this thread and helped me understand the processing of scanning with Vuescan.

I will direct you to this thread on the Luminous Landscape:

http://www.luminous-landscape.com/forum/index.php?topic=52578.msg432468#msg432468

Saying that Vuescan DNG data is raw data from the scanner is simply bogus.

Don

Rider
8-Aug-2011, 13:05
So much for moving on D--now you are beginning to look like you're arguing. But what are you arguing exactly? You've already said that you scan RAW, you just don't like the fact that Hamrick gives you two choices of containers? Ok, use the RAW TIFF and be happy. I use the RAW DNG for the reasons already stated, and I am happy. I use LR to look through my DNG files, which it can't do if they were RAW TIFFs. That's not reason enough for you to use DNG--fine, don't use it! It is enough for me, and there is no drawback I'm aware of for using DNG. As a bonus, I occasionally I process the DNG files in LR, which would be virtually impossible with the RAW TIFFs. Oftentimes, I reprocess the DNG files in VS first in order to (i) apply scratch and dust removal and (ii) apply the IT8 profile. That gives me non-RAW TIFFs, which I can open in LR or Photoshop or anything I want. I am struggling to know what your point is, frankly.

D. Bryant
8-Aug-2011, 13:25
So much for moving on D--now you are beginning to look like you're arguing. But what are you arguing exactly? You've already said that you scan RAW, you just don't like the fact that Hamrick gives you two choices of containers? Ok, use the RAW TIFF and be happy. I use the RAW DNG for the reasons already stated, and I am happy. I use LR to look through my DNG files, which it can't do if they were RAW TIFFs. That's not reason enough for you to use DNG--fine, don't use it! It is enough for me, and there is no drawback I'm aware of for using DNG. Occasionally I process the DNG files in LR. Other times, I reprocess the files in VS first in order to (i) apply scratch and dust removal and (ii) apply the IT8 profile. That gives me non-RAW TIFFs, which I can open in LR or Photoshop or anything I want. I am struggling to know what your point is, frankly.

I 'll state my point to you one more time since you seem to be reading impaired.

A Vuescan DNG file is not a RAW file which you keep insisting that it is. It is a scene referenced file, that contains RGB data.

It much more straight forward to scan to a TIFF file and use that in LR/ACR or PS.

Do you not understand the use of a Vuescan RAW file? Apparently not.

Read the posts on the Luminous Landscape and you will understand some of the pitfalls of using the Vuescan DNG files. The concept is basically a scam that does not work properly all of the time.

However it was never my intent to dissuade you from using Vuescan DNG. Just don't insist it is a RAW data file which it is not.


Don

Rider
8-Aug-2011, 14:20
I 'll state my point to you one more time since you seem to be reading impaired.

A Vuescan DNG file is not a RAW file which you keep insisting that it is. It is a scene referenced file, that contains RGB data.

It much more straight forward to scan to a TIFF file and use that in LR/ACR or PS.

Do you not understand the use of a Vuescan RAW file? Apparently not.

Read the posts on the Luminous Landscape and you will understand some of the pitfalls of using the Vuescan DNG files. The concept is basically a scam that does not work properly all of the time.

However it was never my intent to dissuade you from using Vuescan DNG. Just don't insist it is a RAW data file which it is not.


Don

You promised to move on, instead you came back and accused an honest business person of being a scam artist. You must be having a long day; let's cool down, eh?

domaz
9-Aug-2011, 10:44
A Vuescan DNG file is not a RAW file which you keep insisting that it is. It is a scene referenced file, that contains RGB data.


Ok I did some empirical testing to test your assertion that a DNG file is "scene referenced", which I'm assuming means that the Color balance etc.. you see in the Preview will get written to the DNG file. So here's what I did:
I scanned a negative with an "Auto Levels" color balance on Preview. Then I scanned it with a radically different Color balance setting like "Flourescent" to make the color balance change obvious. I outputted two DNG files each with the different Color balance setting. Then I took the two DNG files and processed them with "dcraw", a common and respected raw processor to TIFF. The two DNG files, when processed, look exactly the same. Color balance is the same right down to the pixel level where RGB values are basically the same. Therefore it's obvious that the DNG file being written by Vuescan really is "RAW". It's not writing the color balanced RGB value- it's writing the RAW RGB values from the scanner that can then be interpreted later by a RAW processor.

Rider
9-Aug-2011, 11:12
Thanks domaz. I took a look at the luminous-landscape thread posted above. The poor fellow there managed to have his DNGs mangled somehow by ACR. I wasn't able to replicate what he did, and no one on that forum was able to either. Somehow, his DNG files were overritten by ACR, and shrunk by 33% after they were processed, making them, obviously, not readable by VS any more. It's not clear whether that was the result of user error, a software design glitch or both. This is no cause for alarm, as far as I'm concerned, but it demonstrates once again the importance of having at least one backup of any important files.

polyglot
9-Aug-2011, 18:31
Domaz is correct. DNG files from VueScan are mostly RAW sensor data despite D.Bryant's assertions, as long as you don't have "RAW Save Colour" or whatever option it is selected. If you select that option, then it's *possibly* no longer RAW, though I think the option just saves the settings from the Colour tab in metadata without affecting the samples.

For those of us on linux, the DNG option is nice because it means we can open files in dcraw/ufraw for a bit more curve adjustment in 16 bits without having to go straight to 8-bit gimp.

And DNG is just a TIFF anyway, with some different tags (it includes EXIF!) defined. I'm amused by posts above saying it's an Adobe invention and then in the same paragraph, asserting that Adobe programs can't read it properly because they "reverse engineered" the format! It's just a TIFF container.