Photographer's Corner - equipment

[walkinwood]

Quote:

Originally Posted by audreyh1 I Since I started using Lightroom (4?) I made a DNG copy when importing selected photos. So my photos chosen for processing are in that format. That covers the last 3 years or 4 years of photos.

Is there an advantage to processing DNG images over RAW images in Lightroom?

[walkinwood]

I decided to take a cautious step into the mirrorless interchangeable lens camera world last month by purchasing a Sony A6000 with a kit lens (16-50mm) on ebay. (with perfect timing since a new A6000 dropped in price by $100 a day after I purchase it Earlier, I thought I would buy the new EOS 760, but decided to make a more radical change.

I also bought an adapter for my EF-S lenses so I can use them on the A6000.

I'm just a couple of weeks into using it and so far, I like it:

- the camera body and the native lenses are much lighter than a dSLR. I had given up my 20D for an EOS450D to lighten up my load while hiking, but the A6000 is much lighter than that.

- Manual focusing is actually usable with magnification in the EVF and focus peaking. While auto focus works on the EF-S lenses using the adapter, it is very slow and not always reliable.

- The EVF takes some getting used to. I needed to boost the brightness just to make it usable. And with glasses I can just barely see all of it.

- I love the image quality, but then I was using a pretty old camera. Any current APC camera image would have impressed me.

- A lot of people online are enjoying the new life these cameras have given to old lenses. You have to use them in fully manual mode, but there's some very good quality available at affordable prices.

I'm a hobbyist photographer and I've just loved reading all your posts and seeing the pictures.

[audreyh1]

Quote:

Originally Posted by walkinwood Is there an advantage to processing DNG images over RAW images in Lightroom?

I don't think there is a processing difference. DNGs are raw files too. I just prefer to work with the raw images in a non-camera specific/vendor proprietary format.

[RonBoyd]

Quote:

Originally Posted by walkinwood Is there an advantage to processing DNG images over RAW images in Lightroom?

What some call an advantage is that modifications to RAW images are written to a separate (.XMP) file while these settings are incorporated into the .DNG file. Otherwise, there is no difference.

Having said that, I am unsure where Lightroom settings are stored -- the XMP/DNG file or in the LR Catalog. I suspect not in the XMP/DNG file. (I have been told but have forgotten the answer.) That would mean that those modifications could only be read by LR.

[audreyh1]

Quote:

Originally Posted by RonBoyd What some call an advantage is that modifications to RAW images are written to a separate (.XMP) file while these settings are incorporated into the .DNG file. Otherwise, there is no difference. Having said that, I am unsure where Lightroom settings are stored -- the XMP/DNG file or in the LR Catalog. I suspect not in the XMP/DNG file. (I have been told but have forgotten the answer.) That would mean that those modifications could only be read by LR.

You bring up a critical point. The lightroom settings are in the LR catalog until you tell LR to save them back into the DNG metadata. Same with other camera raw files - LR doesn't create the XMP files until you tell it to.

I just ran across this today when I moved the above pano from the laptop to another computer.

At some point you need to update the DNG or XMP a files with your settings if you want to keep it independent of the LR catalog.

[RonBoyd]

Quote:

Originally Posted by audreyh1 You bring up a critical point. The lightroom settings are in the LR catalog until you tell LR to save them back into the DNG metadata. Same with other camera raw files - LR doesn't create the XMP files until you tell it to. I just ran across this today when I moved the above pano from the laptop to another computer. At some point you need to update the DNG or XMP a files with your settings if you want to keep it independent of the LR catalog.

There are two options for writing to XMP files -- 1. (Manually) Ctrl S (>Metadata>Save Metadata to file) or 2. >Catalog Settings> Automatically write changes to XMP

In any event, Flags, Virtual Copies, Collection membership, Develop History, Stacks, Develop module panel switched and Zoomed image pan positions are NOT stored in XMP files -- only saved in the LR Catalog. I don't know if these settings are stored in the DNG file.

[explanade]

There's a Photofocus.com podcast with one of the product managers of LR. Runs down the new features and also how the HDR and Pano options are different than those in Photoshop.

[RonBoyd]

Quote:

Originally Posted by explanade There's a Photofocus.com podcast with one of the product managers of LR. Runs down the new features and also how the HDR and Pano options are different than those in Photoshop.

In addition, Adobe has over 60 videos covering Lightroom v6 (CC):

https://www.youtube.com/user/AdobeLightroom/videos

[photoguy]

One thing to keep in mind if you write changes into the DNG/TIFF/JPEG files (instead of keeping it in the catalog or sidecar), you will modify the file and change timestamps. This may cause the entire image to be recopied by backup software.

[RonBoyd]

Quote:

Originally Posted by photoguy One thing to keep in mind if you write changes into the DNG/TIFF/JPEG files (instead of keeping it in the catalog or sidecar), you will modify the file and change timestamps. This may cause the entire image to be recopied by backup software.

Changes made to TIF/JPG files are hard coded anyway. So it wouldn't make a difference what date is used.

But... now I think about it; why would that be important for a DNG file since the changes are still available to back out of even after a "save." (What did I miss?)

[audreyh1]

Quote:

Originally Posted by photoguy One thing to keep in mind if you write changes into the DNG/TIFF/JPEG files (instead of keeping it in the catalog or sidecar), you will modify the file and change timestamps. This may cause the entire image to be recopied by backup software.

Which would work just fine.

I think photo guy is just pointing out that more files would be backed up.

[photoguy]

Quote:

Originally Posted by RonBoyd But... now I think about it; why would that be important for a DNG file since the changes are still available to back out of even after a "save." (What did I miss?)

As Audreyh1 notes, I just mean for backup purposes, storing the metadata in the file itself can lead to extra copying.

For example, lets say I have 1000 RAW photos of prague in my master library. These have been edited and backed up to multiple drives. I then realize that I want to add a few more keywords to all of those images like Praha, Czech Republic, Europe, etc.

If I save these metadata changes in the DNG file, then the next time I run my backup software (rsync), it will copy all 1000 images again which could be tens of gigs times the number of backups.

Instead if I keep the changes in the catalog, or write to XMP sidecar files, my next backup will be relatively painless and I will only need to copy the catalog (maybe 1GB) or 1000 very small xmp files (20kb * 1000 = 20MB).

[RonBoyd]

Quote:

Originally Posted by photoguy As Audreyh1 notes, I just mean for backup purposes, storing the metadata in the file itself can lead to extra copying. For example, lets say I have 1000 RAW photos of prague in my master library. These have been edited and backed up to multiple drives. I then realize that I want to add a few more keywords to all of those images like Praha, Czech Republic, Europe, etc. If I save these metadata changes in the DNG file, then the next time I run my backup software (rsync), it will copy all 1000 images again which could be tens of gigs times the number of backups. Instead if I keep the changes in the catalog, or write to XMP sidecar files, my next backup will be relatively painless and I will only need to copy the catalog (maybe 1GB) or 1000 very small xmp files (20kb * 1000 = 20MB).

I am still not sure whether I am missing something. If you change a file (any file), the backup program should copy (or "save" if you will) that file. And yes that would add some volume to the backup. However, this would only be true if you are creating incremental backups. In which case, one needs to set a limit at which point a complete new "back up" is created -- say 5 versions. It is all well and good to have copies of "earlier" versions of a file but if it causes distress, I would simply create a new backup each time. In which case, changes would not be an issue.

Again. I probably am completely "off the rails" here.

[explanade]

Wouldn't rsync replace the older file with the newer one?

So while it would use up resources to copy, at the end of it, it wouldn't take up more space on the backup media, unless it retains multiple copies of the backups? Like multiple snapshots?

[photoguy]

Quote:

Originally Posted by RonBoyd I am still not sure whether I am missing something. If you change a file (any file), the backup program should copy (or "save" if you will) that file. And yes that would add some volume to the backup. However, this would only be true if you are creating incremental backups. In which case, one needs to set a limit at which point a complete new "back up" is created -- say 5 versions. It is all well and good to have copies of "earlier" versions of a file but if it causes distress, I would simply create a new backup each time. In which case, changes would not be an issue. Again. I probably am completely "off the rails" here.

Let me take another stab at explaining this (sorry for not being clearer).

DNG is a file format which can store (1) the image bits and (2) metadata like captions, keywords, develop settings, etc. DNG stores both pieces of information in a single file.

If I add a keyword, then any file based backup program will see that the DNG file has changed and will recopy the entire DNG from my source drive to my backup. The recopy will transfer both the image bits (which haven't changed) and the metadata (which has changed) because these are bundled in a single file.

For my camera, the image data is about 25MB and the metadata is about 20kb. So even though we've added a single keyword, the backup program is going to recopy 25.02 MB of data. This isn't very efficient.

In a RAW + XMP setup, the image data is in the RAW file and the metadata is in a separate in the sidecar file (which is basically a small text file). If I add a keyword, only the XMP file needs to change. So the backup program will only copy the XMP (about 20kb) and it will not recopy the RAW file (25MB).

Quote:

Originally Posted by explanade Wouldn't rsync replace the older file with the newer one? So while it would use up resources to copy, at the end of it, it wouldn't take up more space on the backup media, unless it retains multiple copies of the backups? Like multiple snapshots?

Yes rsync just replaces the older file with the newer one so it doesn't require any more space on the backup drive. However, if I use XMP I only have to recopy the sidecar files (which are small text files) and I don't have to recopy the image data. With DNG, I'm going to be copying both metadata and the image bits because the format stores both in a single file.

In practice, I don't think it makes much difference unless you are in the habit of making large batch edits to your images.

[RonBoyd]

Quote:

Originally Posted by photoguy Let me take another stab at explaining this (sorry for not being clearer).

So it is a "time spent backing up" issue rather than a "storage" issue. Got it.

[audreyh1]

I'll probably write out the metadata when I think I'm pretty much finished with a given catalog.

The problem is I'm pretty bad about "finishing".

I may do a once a year archival thing that involves writing the data for a given catalog back to the DNGs that are processed. We'll see.......

[photoguy]

Quote:

Originally Posted by audreyh1 The problem is I'm pretty bad about "finishing".

I don't think I'm ever going to finish. I keep at looking at my older photos and think why did I process it like that. I even started a list of photos/collections that I want to redo (must be my to-do list habit extending over from work).

I think it's 1/3 improved skill on my part, 1/3 improved tools, and 1/3 my tastes have changed.

[RonBoyd]

Quote:

Originally Posted by audreyh1 The problem is I'm pretty bad about "finishing".

I saw a quote today that resonated which went something like "A work of Art is never finished... only abandoned."

Now, I wish I could remember why I didn't write it down.


Update: “A work of art is never finished. It is merely abandoned.” ― E.M. Forster

[photoguy]

Some dynamic range tests on the canon 5ds and 5dsr can be seen here:

Canon EOS 5DS / 5DS R First Impressions Review: Digital Photography Review

If you click on the dropdown menus, you can change the camera to see how it compares to other brands.

The conclusion:

Quote:

Our preliminary Raw dynamic range analyses indicate that Canon's new 50MP resolution cameras bring not only a whole lot of resolution to the table, but also some increases in dynamic range over its predecessors. As we saw with the 7D Mark II, Canon’s been making some, albeit arguably slow, progress with respect to dynamic range, and we're pleased to see this trickle down to the 5DS cameras. We were skeptical when Canon first told us that dynamic range would be similar to the 5D Mark III - if the 5DS' sensors are essentially scaled 7D Mark II sensors, then we’d have expected roughly 1EV (at best) dynamic range improvement over the 7D Mark II, which itself was almost on par with the 5D Mark III with respect to dynamic range. Indeed, this is essentially what we see, with the 5DS R ISO 100 shot pushed 6 EV appearing to have roughly similar noise levels to the 5D Mark III ISO 200 shot pushed 5 EV. That's at least a stop improvement over the 5D Mark III, with little to no banding to boot, and this is particularly impressive given the massive increase in resolution. That said, the 5DS cameras cannot compete with the massive base ISO dynamic range we see from on-chip ADC architectures from Sony sensors in cameras from competitors like Nikon, Pentax, and Sony itself. Those shooting high dynamic range scenes may still have to rely on filters and HDR techniques more than they might have had to if shooting with some of the better performing peers, and in general you will have to take more care to ensure proper exposure due to the more limited exposure latitude compared to some of the competition.