Handling of DMG raw files

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BobK
Posts: 3
Joined: November 21st, 2011, 2:25 pm
What is the make/model of your primary camera?: unknown

Handling of DMG raw files

Postby BobK » November 21st, 2011, 3:47 pm

While I have been a PWP user for several years, I have not used the RAW conversion feature. I started using it yesterday with the following results.

1. Scanned a color negative using a Nikon Coolscan V ED scanner. Used Vuescan program.

2. Saved the output as RAW DNG file.

3. Opened the DNG file using PWP 6.0 Beta.

4. The file was displayed as a negative!

5. Using the Color > Negative transformation gave awful results.

6. Using the Fastone Image Viewer displayed the DNG file properly. sometimes the viewer hung.

7. So it would be very helpful if PWP 6.0 would convert DNG files from negatives (B/W or Color).

Thanks! Bobk

ksinkel
Posts: 593
Joined: April 2nd, 2009, 11:58 am
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Re: Handling of DMG raw files

Postby ksinkel » November 21st, 2011, 4:25 pm

Bob,

I would suggest scanning to produce a tiff image and not a raw file. Tiff supports both 24 bit and 48 bit images and thus will preserve all the information provided by the scanner. I can see no advantage of encoding as a raw file. In fact there may be a serious disadvantage -- you may be throwing information away, if the raw file converts the 3 colors per pixel that are output by the scanner to the usual 1 color per pixel bayer array typical of raw files.

Another advantage of outputing as a tiff is that it is difficult to judge raw conversion on a negative image, thus it is desireable to eliminate the raw conversion step. Also check to see if your scanner software gives you the option of outputing either positive or negative -- if so you can save a negative to positive conversion step as well.

Kiril
Kiril Sinkel
Digital Light & Color

BobK
Posts: 3
Joined: November 21st, 2011, 2:25 pm
What is the make/model of your primary camera?: unknown

Re: Handling of DMG raw files

Postby BobK » November 21st, 2011, 4:58 pm

Thank you Kiril. I will investigate saving the file as RAW TIF, which is an option of Vuescan. There is no option to save the file as a positive DNG. Since the Faststone viewer appears to convert to a positive image, I imagine there must be a tag that indicates the file is of a negative.... Thank you again. BobK

Winfried
Posts: 51
Joined: June 18th, 2010, 4:27 pm
What is the make/model of your primary camera?: Pentax K7

Re: Handling of DMG raw files

Postby Winfried » November 21st, 2011, 6:09 pm

Using the *dng-Format with VueScan is normally useless unless you use Lightroom as a rawconverter or as a "micky-mouse" DAM.
If you use *.dng for your scans you do not have the full Vuescan rawdata, since *.dng can not handle the infrared-channel. This is only posasible with the natic 4-channel VueScan Tiff-format.
So *.dng für scanner-data is just for Lightroom user who what to have all image in this DAM.

Winfried

BobK
Posts: 3
Joined: November 21st, 2011, 2:25 pm
What is the make/model of your primary camera?: unknown

Re: Handling of DMG raw files

Postby BobK » November 21st, 2011, 6:58 pm

Thank you Winfried. It looks like it is possible to handle Vuescan DNG format, since Lightroom handles it... Vuescan outputs 64 bit DNG files ( RGB plus IR channel). The Vuescan documentation indicates that the IR channel can only be handled by Vuescan when the DNG file is used as input to Vuescan. What does "DAM" mean?

Winfried
Posts: 51
Joined: June 18th, 2010, 4:27 pm
What is the make/model of your primary camera?: Pentax K7

Re: Handling of DMG raw files

Postby Winfried » November 22nd, 2011, 2:45 pm

DAM means digital assets management, normally a database program to handle the digital assets: images, videos, mp3, documents, etc.


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