Exif Data

[Dougg]

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We're going in circles with ExifTool I think. It's all about the interface. I made that choice when I opted for the Mac in 1984 despite all the other disadvantages at the time. So ExifTool works on the Mac, but in a most un-Mac-like way. It needs a GUI, which ironically is only available on Windows. Doing without ExifTool may be the preferred option.

[perb]

...who the hell still uses command lines?

 

You know, this kind of attitude in the computer world is the equivalent of saying something like "...who the hell still uses manual focus?" in the camera world. And yet, if I understand you correctly, you are into the fully manual focus Leica M System

 

No offence, but I hope you can appreciate that just like some photographers find the manual control of the Leica M useful in todays fully automated camera world, some of us actually find the power of the command line useful in todays world of GUI's. I'm not saying you personally should embrace the command line, just understand that some of us find it powerful.

 

Oh, and DOS doesn't compare well with a modern shell

 

Regards

Per

[nggalai]

Well, for Mac users who don’t like the command line, there’s always ExifChanger: ExifChanger im Mac App Store

 

You might have heard from the developer before; he’s the one behind ImageIngester.

 

ExifChanger pretty much is a OSX GUI on top of ExifTool. Unfortunately, it doesn’t recognise/understand MakerNotes Leica uses for lens types etc. just yet. i.e. you won’t be able to change “Lens” in such a way other applications will accept it with ExifChanger just yet.

 

But it’s only a 1.0.1 right now, let’s see how this develops.

[Beyder28]

ExifTool is not Windows-only; it can be used on any platform. And it sure will extract all metadata out of your image files, including all MakerNotes. For direct reading and manipulation of image metadata, it's the most powerful tool available. When you're having an issue with your images' metadata then turning down ExifTool just out of ignorance is not a very clever move. And when you feel ExifTool was too clunky to use then my suggestion is to leave your image files just the way they are.

 

And oh, didn't you say you already tried ExifTool before? So why do you keep purporting it was Windows-only; you should know better. Sure, it's not the most comfortable software product to use ... but tinkering with image metadata is a low-level task, so you better get used to a low-level (hence universal and powerful) tool.

 

First of all, don't speak of ignorance if you are wrong on the most basic issue of ExifTool. It is WINDOWS ONLY GUI and there is NO Mac version. If I wanted to use a command line tool, there are other's that are simpler. I have used it before on a friends PC. I don't use PC's because I have Macs. I have gone through this in earlier posts and since you didn't read them, you should put YOUR ignorance in your back pocket and try to READ a bit.

 

The thread was started because I was looking to see IF there is a solution for the Mac that has a simple GUI. For you continuing to talk nonsense does not help anyone.

[Beyder28]

You know, this kind of attitude in the computer world is the equivalent of saying something like "...who the hell still uses manual focus?" in the camera world. And yet, if I understand you correctly, you are into the fully manual focus Leica M System

 

No offence, but I hope you can appreciate that just like some photographers find the manual control of the Leica M useful in todays fully automated camera world, some of us actually find the power of the command line useful in todays world of GUI's. I'm not saying you personally should embrace the command line, just understand that some of us find it powerful.

 

Oh, and DOS doesn't compare well with a modern shell

 

Regards

Per

 

You are taking my words out of context. When I said, "Who the hell still uses command lines," I was referring to end users who are trying to complete a specific technical task (not a creative one like manual focus) and not computer programmers. A command line does not give you more control and or power over GUI applications like MF does on an RF over SLRs. Its a very bad analogy.

 

Again, since for some reason, people have given up on reading; I was looking to see IF anyone knew of a solution that has a clean and simple GUI for the Mac. A command line app clearly does not fit the bill so stop shoving things into people's throats that were not asked for. Why do you think that you know better than I do of what I am looking for? If you don't know of a solution (or if one does not exist) then just don't post but if you do post and start pushing a product that others including myself were not looking for, then you're just posting to stir things up and create conflict. If you were interested in helping, you would read the other posts and see what is going on in this thread and what were the people looking for.

[mjh]

A command line does not give you more control and or power over GUI applications

Oh, but most certainly it does. That’s why many Mac OS X hints involve starting up the shell and entering obscure command lines; many GUI applications have hidden preference settings that are only available through the shell. There’s a lot you can do with a GUI and in the good old days of the classic Mac OS it was all you could do since there was no command line, but Mac OS X has changed that.

[pico]

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Oh, but most certainly it does. That’s why many Mac OS X hints involve starting up the shell and entering obscure command lines; many GUI applications have hidden preference settings that are only available through the shell. There’s a lot you can do with a GUI and in the good old days of the classic Mac OS it was all you could do since there was no command line, but Mac OS X has changed that.

 

First, I understand Beyder28 wants a GUI. I can understand that. And as nggalai wrote, ExifChanger has a GUI but does not show MakerNotes. I'll bet it will be upgraded soon.

 

But of course one can do some things at the command shell that blew my Boss' mind, eliminating some very complex GUI procedures almost as fast as a double-click. One can even enter Photoshop as a foreign entry to drive it on a server, although I promised Adobe I'd never talk about that again.

 

I'm retired and really weary of writing shell command procedures or any Mac development whatsoever, but ExifTool can be driven by an input text file of commands. If he has a reasonable number of things he wishes to view or change, someone (I am not volunteering), could create a text file of commands, it could be put here. He could copy and edit the values with TextEdit, but would still have to invoke Terminal. To keep it simple.

 

For some rather daunting information that the Mac uses and changes (besides the Libraries), go into Terminal and type: defaults read > x.txt

 

Then go into your user folder and use TextEdit to look at x.txt

Ignore the stuff you don't understand.

 

Kuel?

[Beyder28]

So I have actually gotten in touch with the developer of ExifChanger. He seems like a very good guy and is at the moment working on the update for this application. He did not have the unique problems in mind faced by us Leica users especially in regards to Maker Notes. I have spoke to him through email and explained what we are looking for in the app. He has replied to my email but unfortunately I am not technical enough with this to explain to him what he needs to do on his end and make sure he is putting in the features we need. Below is his reply. Can anyone that knows a bit about his give me a more technical answer to his reply?

 

"There are several fields that contain aperture and lens info, such as what ExifChanger refers to as ExifAux.LensModel, Exif.FocalLength, and Exif.FocalLenIn35mmFilm. All of these are editable and also show up in Aperture.

 

Below is the ExifChanger screen where I edited them in an M9 DNG:

Below that, I show where they show up in Aperture:

 

 

 

So, does this meet you needs, or do you really need to get into the maker's notes themselves, which is something I don't think ExifChanger can do.

 

 

I didn't edit the maker's notes.

 

The field that MacOS refers to as ExifAux.LensModel is known to ExifTool as LensModel, and that's the field that ExifChanger updates. As I understand it, this is a standard field, not one defined by the manufacturer in maker's notes. As my test shows, it is also the field that Aperture uses for its display of "Lens". (Lightroom also displays it and calls it "Lens".) It may be that this information, and maybe more, is in the maker's notes as well."

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[mjh]

The field that MacOS refers to as ExifAux.LensModel is known to ExifTool as LensModel, and that's the field that ExifChanger updates. As I understand it, this is a standard field, not one defined by the manufacturer in maker's notes.

LensModel is indeed a standard field introduced in Exif 2.3. The Exif 2.3 specification was published in April 2010 and as far as I can tell the M9 doesn’t make use of any of those new fields. You could enter your own info here but to automate the transfer of lens data from the MakerNotes to the LensModel field, the application would have to access the MakerNotes which I understand ExifChanger doesn’t do.

 

Reading or editing MakerNotes isn’t that difficult as its structure is basically the same as that of standard EXIF data, but software developers planning to support MakerNotes would have to keep track of which fields the various vendors are storing in the MakerNotes so they could display meaningful names rather than just hexadecimal tag values.

[Beyder28]

LensModel is indeed a standard field introduced in Exif 2.3. The Exif 2.3 specification was published in April 2010 and as far as I can tell the M9 doesn’t make use of any of those new fields. You could enter your own info here but to automate the transfer of lens data from the MakerNotes to the LensModel field, the application would have to access the MakerNotes which I understand ExifChanger doesn’t do.

 

Reading or editing MakerNotes isn’t that difficult as its structure is basically the same as that of standard EXIF data, but software developers planning to support MakerNotes would have to keep track of which fields the various vendors are storing in the MakerNotes so they could display meaningful names rather than just hexadecimal tag values.

 

This is his response:

 

What he wrote, as far as I can tell is correct.

 

However, I have photos taken with an M8 with a coded lens, and aperture shows an empty Lens field, which is consistent with ExifChanger, since I think both are using the same facility in MacOS to read the EXIF data. Lightroom doesn't show the lens data, either.

 

So, these two apps are not accessing the maker's notes. (If you click the Quick Apply button in ExifChanger with an image selected without changing any metadata, you see the raw output from ExifTool, and the lens data is there.)

 

Are you or the other member's getting lens info in Aperture when they use a coded lens? I'm not.

 

What is meant by "transfer of lens data from the MakerNotes to the LensModel field"? In what app is this occurring?

[cbretteville]

Lightroom does it on a virgin M8 file. If it doesn't it is either because lens detection was set to 'off' or the maker notes have been nuked by an application such as ACR that rewrites all the metadata and as Jenoptik forgot to set the maker notes safety tag, the maker notes are ignored when ACR writes the metadata back to disk.

Carl

[hoppyman]

Here is an update that may be useful for some people. I have now got this all working for me. I don't know what mistakes I made before. This below worked for me when I tried again today following O1af's instructions here:

 

I have Windows7 and Lightroom 3.4.1. I had 200 files from two lenses shot with Lens detection off.

 

I made temporary folders and put new copies of all my original DNG files into folders according to the lens used (which I could work out by reviewing, including the timestamp in the files). These were new copies directly from the SD card, not versions after import by Lightroom

 

In each folder I placed a copy of exiftool.exe and an argument file shown earlier in the same folder (one for my 50 and one for my 75)

I used command line and changed to that folder

I typed exiftool @ blahblah50.txt *.DNG.

That applied the fixes to every DNG in the folder

 

I then imported the amended files anew with Lightroom using Copy as DNG (since I want the lossless compression) and all of the information now shows correctly

 

Now I have to synchronise everything I have done to the original 200 photos but that is separate from the actual EXIF editing that is the subject here

[01af]

LensModel (or just Lens in EXIF 2.2) is an arbitrary string of characters which is supposed to hold the lens' name, such as "Leica Summicron-M 35 mm 1:2 Asph", for example. The fields FocalLength, ApertureValue, FNumber, MaxAperture, and FocalLengthIn35mmFilm will be filled by the camera if a coded lens was used or a lens was selected from the camera's lens menu. The LensModel and LensInfo fields, however, need to be filled by someone who can read and properly interpret the LensType field in the Leica MakerNotes section. Adobe Bridge and Adobe Lightroom can do that (mostly).

 

The LensInfo field, by the way, contains four rational numbers, separated by blanks, which describe the lens' shortest and longest focal lengths and the lens' speed—for a 28-85 mm 1:3.5-4.5 lens, LensInfo would be "28/1 85/1 35/10 45/10", for example. For a prime lens, longest and shortest focal length are equal, so for a 35 mm 1:2 lens, it would be "35/1 35/1 2/1 2/1". This is mostly useful for zoom lenses and for the Leica Tri-Elmar lenses. When the LensInfo field is properly filled then Camera Raw or Lightroom's development module can properly display the lens type, like for example "28-85 @ 40 mm"; if LensInfo is empty then only the actual focal length will appear here (which is just fine for prime lenses).

 

The LensType field in Leica's MakerNotes section has, umm, 16 or 32 bit (don't know exactly) but only the lowest eight bits contain actual data; the other bits are always zero. Of the lowest eight bits, the lowest two contain the 2-bit frameline code, the other six contain the 6-bit lens code.

 

When an uncoded lens was used (and no lens was selected from the camera's lens menu) then the LensType will be zero, and all the EXIF fields for lens, focal length, and aperture will be empty.

 

 

These were new copies directly from the SD card, not versions after import by Lightroom [...] Now I have to synchronise everything I have done to the original 200 photos

You can update the lens data using ExifTool anytime; no need to start with the original files from the SD card. So you can just as well do the lens data update directly to your working files (or to a copy thereof, just in case). This way you'd spare the hassle of synchronising the updated originals with the current working files.

[cbretteville]

The LensType field in Leica's MakerNotes section has, umm, 16 or 32 bit (don't know exactly) but only the lowest eight bits contain actual data; the other bits are always zero. Of the lowest eight bits, the lowest two contain the 2-bit frameline code, the other six contain the 6-bit lens code.

 

LensID is a full 32 bit unsigned long of which only 8 is in use in the M8/M9 files.

Carl

[mjh]

What is meant by "transfer of lens data from the MakerNotes to the LensModel field"? In what app is this occurring?

I don’t know whether there’s an app that does this, but if you have an application reading the standard LensModel field but not the lens info in the MakerNotes, you would need some app/command line tool/whatever to interpret the relevant data in the MakerNotes and build a suitable string to insert into the LensModel field (there’s also LensMake, LensSpecification, and LensSerialNumber that have been added to the EXIF standard in April 2010).

[hoppyman]

[You can update the lens data using ExifTool anytime; no need to start with the original files from the SD card. So you can just as well do the lens data update directly to your working files (or to a copy thereof, just in case). This way you'd spare the hassle of synchronising the updated originals with the current working files.

 

I initially tried to do this in situ with my files already imported with Lightroom however for whatever reason I did not see the updated information afterwards in Lightroom., despite it being visible in exiftool

 

So my last post was just intended to detail for others the exact method I used this time when it worked. I wanted to remove as many variables as possible when I tried again, that's all. An empirical fix but a complete one nonetheless.

[sandymc]

I don’t know whether there’s an app that does this, but if you have an application reading the standard LensModel field but not the lens info in the MakerNotes, you would need some app/command line tool/whatever to interpret the relevant data in the MakerNotes and build a suitable string to insert into the LensModel field (there’s also LensMake, LensSpecification, and LensSerialNumber that have been added to the EXIF standard in April 2010).

 

CornerFix has done that for years now...tick the update EXIF box...

 

Sandy

[nggalai]

I did some more testing with ExifChanger and think I found my error – I was too all-emcompassing in my reply above.

 

I found I can change lens metadata quite easily in ExifChanger as long as I didn’t manually set a code (say, to have some correction for a wide-angle CV lens). In such clean files, the info I enter will also show up in all EXIF aware applications.

 

If I do manually set a lens code in camera, though, it seems these take precedent over what I might change in the standard EXIF fields using ExifChanger. But this might just be me.

 

Can anybody reproduce this behaviour?

 

Cheers,

-Sascha

[MarcRochkind]

Hi Everybody!

 

I'm Marc Rochkind, the developer of ExifChanger, ImageIngester, and more, who Beyder28 has been quoting here on the matter of lens info, maker's notes, etc., etc.

 

I'm now going to read this whole thread and figure out what's going on and what ExifChanger can do to help. I see a post here already indicating that DNG Converter or ACR may have removed the maker's notes from my original M8 files, so I'm going to go back to the originals and rerun my tests.

 

Be back to you shortly...

 

--Marc

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[Beyder28]

Does anyone know of any other features I should ask the developer to include in the next version? Something that may make things easier in any way and better than the other apps out there right now?