Author Topic: RAW Previews  (Read 4696 times)

Offline William R Wood

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RAW Previews
« on: December 15, 2007, 11:31:37 AM »
Two questions.  I shoot mostly Canon CR2s and convert them to DNG mainly to avoid the need for annoying sidecar files.  When I convert the Canon CR2s to DNG, I tell the Adobe converter to embed full size JPG previews.

1) If I then use PM to view the two types of RAW files, the CR2 previews are only about half as big as the DNG previews.  Is this normal?  Does this mean my camera (1DMkII) makes smaller previews than the DNG converter?  I cannot figure out a way to see the actual dimensions of the embedded JPG previews in the RAW files.

2) PM will not let me use the Save As command on any CR2 or DNG files.  An error message says "None of the images can be saved at high resolution."  Is this normal?  Seems odd that the embedded previews are not considered high resolution since the previews that I see in PM are as about as good as the previews in Lightroom or ACDSee Pro which are rendered from the RAW files.  The 4.5.3 PM User Manual, page 72, makes it sound like I should be able to save resized JPGs from RAWs (CR2 or DNG) for web images or other uses.  PM does let me email resized JPGs created from CR2 or DNG previews so it is not obvious why Save As does not work.

Thanks

Bill Wood

Offline Kirk Baker

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Re: RAW Previews
« Reply #1 on: December 15, 2007, 09:20:56 PM »
Bill,

Two questions.  I shoot mostly Canon CR2s and convert them to DNG mainly to avoid the need for annoying sidecar files.  When I convert the Canon CR2s to DNG, I tell the Adobe converter to embed full size JPG previews.

1) If I then use PM to view the two types of RAW files, the CR2 previews are only about half as big as the DNG previews.  Is this normal?  Does this mean my camera (1DMkII) makes smaller previews than the DNG converter?  I cannot figure out a way to see the actual dimensions of the embedded JPG previews in the RAW files.

Yes, the previews that your camera puts in CR2 files are not full size.  It is half width and half height.

Quote from: William R Wood
2) PM will not let me use the Save As command on any CR2 or DNG files.  An error message says "None of the images can be saved at high resolution."  Is this normal?  Seems odd that the embedded previews are not considered high resolution since the previews that I see in PM are as about as good as the previews in Lightroom or ACDSee Pro which are rendered from the RAW files.  The 4.5.3 PM User Manual, page 72, makes it sound like I should be able to save resized JPGs from RAWs (CR2 or DNG) for web images or other uses.  PM does let me email resized JPGs created from CR2 or DNG previews so it is not obvious why Save As does not work.

It was a design decision made when most cameras put fairly small previews inside the RAW files.  I will be making it possible to enable "Draft mode" which will allow Save As from RAW files.  Of course you will only be able to get the resolution of the preview as your maximum saved size or upscaling will occur.

-Kirk


Offline Nick Rains

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Re: RAW Previews
« Reply #2 on: December 17, 2007, 01:16:13 PM »
2) PM will not let me use the Save As command on any CR2 or DNG files.  An error message says "None of the images can be saved at high resolution."  Is this normal?  Seems odd that the embedded previews are not considered high resolution since the previews that I see in PM are as about as good as the previews in Lightroom or ACDSee Pro which are rendered from the RAW files.  The 4.5.3 PM User Manual, page 72, makes it sound like I should be able to save resized JPGs from RAWs (CR2 or DNG) for web images or other uses.  PM does let me email resized JPGs created from CR2 or DNG previews so it is not obvious why Save As does not work.

Thanks

Bill Wood

You need to use Tools / Extract Jpeg Preview. See 4.5.3 Manual P101.

Nick Rains
Nick Rains

Offline William R Wood

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Re: RAW Previews
« Reply #3 on: December 17, 2007, 05:12:30 PM »
Thanks for the tip Nick; can't believe I missed that.  :-[

I just tried it and Extract JPEG Preview works fine but it outputs only the full size preview (1536x1024 from the CR2 files and 3504x2336 from the DNG files).  We still need the ability to use the Save As command so we can resize the preview as necessary.  Fortunately, Kirk will be adding that feature.

Regards

Bill Wood

Offline mervifwdc

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Re: RAW Previews
« Reply #4 on: December 20, 2007, 05:33:19 AM »
There is a workaround, if you create a web gallery, you can change the size of the images, and the quality etc. After you've created the web pages, you can easily find the directory where it's created the images.

It's handy for generating files of a fixed max size from a set of images.

Merv.
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Offline Nick Rains

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Re: RAW Previews
« Reply #5 on: December 22, 2007, 09:14:55 PM »
There is a workaround, if you create a web gallery, you can change the size of the images, and the quality etc. After you've created the web pages, you can easily find the directory where it's created the images.

It's handy for generating files of a fixed max size from a set of images.

Merv.


I forgot to mention this - it's an excellent way to extract and resize - in fact it almost makes Extract form RAW redundant.

Works best with DNG files since the enclosed jpeg previews accurately reflect the RAW adjustments you make, as opposed to CR2 files which simply contain a generic jpeg preview from the camera.
Nick Rains

Offline William R Wood

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Re: RAW Previews
« Reply #6 on: December 29, 2007, 04:43:23 AM »
Thanks Merv and Nick,  I did try this and the Export command does extract and resize the JPG previews from CR2 and DNG files and puts the new files in a directory of your choice, but the Exporter is really intended for web galleries and does much more - quote from User Manual:

"The Export option creates a full set of files from a selection of images. With this command you can make a web gallery with all the internal links already set up. This can be posted directly to a web site and can be very useful to show a client proofs from a shoot, quickly and easily. The web pages are fully customizable with respect to colors, type faces etc, and Variables can be used to add metadata into the layouts."

The Exporter creates not only resized JPGs, but also an HTML file for each image, a full set of thumbnails, 2 folders, 2 index files and a .css file - and all of that stuff is unnecessary if you simply want resized image files and must be manually deleted.

I am still holding out for an upgraded Save As command.  :)  Since the code to extract the JPG previews and resize them is already in PM, Kirk can use that to expand the usefulness of the Save As command and even the Burn Photos to Disk command.

Bill Wood