Tips & Techniques: An Unexpected Benefit Of Smart Previews—Small Raw E-Mail Attachments

by George on August 12, 2013

Dinner On The Lake

Photograph © George A. Jardine

Update from George: Before you spend a lot of time noodling around with this technique, maybe read Victoria Bampton’s comment on the posting below. Seems there has always been a much easier way of accomplishing the same thing!

How many times have you wished you could send someone a raw file so they could actually look at your settings, and maybe adjust them with you in a conference call or something? Of course the trouble is that many times the raw file is simply too large to e-mail, and throwing it up on an ftp site might be inconvenient. Maybe you’re traveling and simply don’t have the bandwidth to send the whole raw file. Or even a compressed DNG version.

Or worse, you have a client or a relative who keeps sending you 20MB attachments just so you can see their settings. I get this all the time, and sometimes it’s not even a raw file. Just yesterday I received an e-mail with an attached JPEG file that was 6100 x 4600 pixels, just to ask me a retouching question. That’s 8MB in my mailbox, when a 150kb file 1/10th of the original width would have done just fine.

It was when researching Smart Previews for my new Lightroom 5 Develop videos that I stumbled onto an elegant solution to this problem. If you want to send someone a raw file in an e-mail, complete with your Lightroom settings, you can now do it with an attachment that is less than 2MB, using a Smart Preview.

It’s this easy. First, if you’ve created Smart Previews for your master catalog, you’re never going to go into the Smart Previews.lrdata package and find the one you’re looking for. So, start by selecting the one image in the Library grid, and exporting just that one image as a new catalog.

In the Export As Catalog dialog box, make sure you have these two items checked ON, and navigate somewhere easy to remember for the new mini-catalog, like your Desktop.

Export As Catalog Options

Don’t bother with exporting “negatives”, or previews.

Once the catalog export is complete, you can quit Lightroom if you like, and go find and open the new catalog folder. Right-click on the Smart Previews.lrdata file and choose Show Package Contents… (on Windows, it’s just a folder, so just double-click it to open it…), and then dig a couple of folders down, until you come to the DNG file.

Once you find that, drag it out of the folder onto your desktop. (You won’t be able to open it in Camera Raw while it’s stil inside the .lrdata package unless you’re on Windows.) You’ll probably want to rename it (but keep the .dng extension!), and while you’re at it, notice how small it is. The 2560 pixel wide DNG’s created from my 5D MKIII are usually less than 2MB. Then, just drag it onto the PS icon, or back into Lightroom, so see what you’re dealing with.

Finally, here’s the interesting part. If you have never saved your XMP settings out to a sidecar file or into the original source DNG, then the resulting Smart Preview DNG won’t have any settings contained within it at all. But if you take time to save your settings out to XMP just before you export the new catalog creating the Smart Preview, then both the current settings for the raw file, and… all your snapshots will be saved into the Smart Preview DNG!

Now you can e-mail your editor or whomever, a < 2MB raw file, with all your settings, in a format that's easy to download and look at. I wonder if I can now teach my cousin to do it this way?

{ 9 comments… read them below or add one }

Floyd Gustafson August 12, 2013 at 11:49 PM

George, I think someone should get to work on a plugin for Lightroom 5 that can do what you just described, except be able to find the smart preview no mater how many your smart preview file contains and allow you to copy into your email.

Just a thought…

Floyd Gustafson August 13, 2013 at 12:25 PM

Hi George, and thanks for all your hard work.

What do you think about this workflow?
Adjust 10 images in LR using all sliders.
I selected those 10 images in LR and clicked export.
In the export to dialog I locate and select my external USB thumb drive which is not currently part of the LR catalog.
I choose add a subfolder and use the same name as the original folder.
Click add to catalog.
Under file settings select, original which are Canon files .cr2 raw.
Click export.
The results:
1-Copies of .cr2 files on thumb drive that show in LR.
2-Original files still in original location.
3-Original files did not have XMP files, however LR automatically created XMP’s during export, however the exported files do not automatically update with LR setting. You can read metadata from files to update previews or just save out metadata before exporting and your exported previews will show you develop settings.
4-With jpg’s if you saved metadata and select original your settings will show in LR but not in the file system.
5-Select all newly exported files on thumb drive and create smart previews.
6-Remove thumb drive from computer.
7-Select all images on thumb drive, which now are only smart previews with originals missing because you removed the thumb drive.
8-Select export and in the Export To: find your original location and create a subfolder named smart preview dng or whatever you want.
9-In file settings choose dng and only check Use Lossy Compression.
10-Click export.
Results: you have a subfolder with small dngs which you can use for email or whatever.
The dng small files with setting can be adjust again or ever reset.
Note: My original cr2 from 1D MKIII are between 13-15MBs in size and 3888×2592 in resolution. The new dngs are between 1-1.5MBs in size, 2560×1707 resolution and have settings.
Is this any better or just a different way to get the same result you shared?

George August 14, 2013 at 7:28 AM

Hi Floyd!

This works too. Which I find very interesting! To summarize your workflow for my readers, I would say it like this: once you’ve created a Smart Preview for a photo in a catalog, you can export a compressed DNG that is also very small, and at the Smart Preview resolution. You just need to take the original offline before you do the export.

My tests reveal your method actually creates a slightly less compressed version than the actual Smart Preview, but they are both very small and easy to e-mail.


Victoria Bampton August 16, 2013 at 11:33 AM

Export the file with it set to DNG format, medium preview, lossy compression, and set the size to 2560px long edge. You get the same result without having to dig through package files or take files offline. No need to even create smart previews.

George August 16, 2013 at 11:49 AM

I figured there was an easier way. :-)

Floyd Gustafson August 16, 2013 at 1:54 PM

Wow, thanks Victoria!!!
Makes me think the world might just be a better place with more women in charge.

Bob DiNatale August 19, 2013 at 1:44 PM

Am I missing something?

Where do you set the “2560px on the long edge” once you set “Image Format” to DNG ?

George August 19, 2013 at 1:55 PM

It’s under Image Sizing, Bob. Right under File Settings, in Export.

Nathan Chilton November 27, 2013 at 7:57 AM

I’m glad Victoria pointed out the very thing I was going to say. I actually export reduced-resolution lossy-compressed DNGs all the time. I have export presets for a 2mp DNG and a 6mp DNG. All of my low star images, which I would formerly either delete or convert to JPG, I now convert to small DNGs. The 2mp lossy-compressed DNG files are a high enough resolution for small prints and still have many of the advantages of a RAW file, but take up very little space.

Leave a Comment

{ 1 trackback }

Previous post:

Next post: