How to search files for lens info?

[Phill D]

Does anyone know a good way of searching photo files for what lens was used to take the image? I've been through several folders worth of files so fat pulling up exif info looking at fl to narrow it down but it's pretty tedious and not definitive. Is it possible to just search for the lens used? What I'm trying to do is to find the last time I used my 75-300 lens. Is there an easy way to search files & folders for that lens?

[Jim Ford]

It could be done by 'bash' experts, using Unix/Linux command line utilities. Unfortunately I'm not an expert and would have to get up to speed with bash. The scheme would be to:

a) Search through the directories for JPEG files.
b) Pass the file to the exif command line utility.
c) Search in the exif output for the focal length.

It would probably look like this sort of thing (which doesn't work as it stands!)

for i in `find . -name '*.jp*g'`; do exif $i | grep 'Focal Length'; done

Jim

[StephenL]

There are many applications you can use to search exif files for data, such as Irfanview. Or, you could simply use the metadata search filter within Lightroom, if you use that programme.

[Jim Ford]

Originally Posted by StephenL

There are many applications you can use to search exif files for data, such as Irfanview. Or, you could simply use the metadata search filter within Lightroom, if you use that programme.

But will they descend a directory tree searching for files, or do you have to read in a file at a time?

Jim

[StephenL]

I don't have such a product any more, but as I recall they can be used in batch mode.

[David M]

Lightrooms Metadata Browser will show the number of photos taken with each lens unless it's a legacy/third party lens.

[OlyPaul]

Originally Posted by David M

Lightrooms Metadata Browser will show the number of photos taken with each lens unless it's a legacy/third party lens.

As will most image management programs.

[Jim Ford]

Originally Posted by OlyPaul

As will most image management programs.

I've got 'Faststone' which is pretty powerful, but don't use it much. I've just had a look and can't see what you suggest. It'll batch convert and rename, but you need to select the images first, rather than the program search for them as well. Just curious!

Jim

[StephenL]

PIE is a useful programme, if you're on Widows.

[Jim Ford]

Cracked it (sort of!):

for i in `find . -name '*.jpg'`; do echo $i; exif --no-fixup $i | grep 'Focal Length '; done > dummy.txt

It's not pretty, but it works.

It creates a file 'dummy.txt' in a few seconds, with entries of this sort on my machine:

./Jack_and_Carmels_40th/P5195171-1024px.jpg
Focal Length |17.0 mm
./Jack_and_Carmels_40th/P5195174-800px.jpg
Focal Length |21.0 mm
./Jack_and_Carmels_40th/P5195192-800px.jpg
Focal Length |21.0 mm
./Jack_and_Carmels_40th/P5195208-800px.jpg
Focal Length |39.0 mm
./Jack_and_Carmels_40th/P5195215-800px.jpg
Focal Length |20.0 mm
./Jack_and_Carmels_40th/P5195212-800px.jpg
Focal Length |35.0 mm
./Jack_and_Carmels_40th/P5195177-800px.jpg
Focal Length |17.0 mm
./Jack_and_Carmels_40th/P5195216-800px.jpg
Focal Length |29.0 mm
./Jack_and_Carmels_40th/P5195201-800px.jpg
Focal Length |39.0 mm
./Jack_and_Carmels_40th/P5195179-800px.jpg
Focal Length |19.0 mm
./Jack_and_Carmels_40th/P5195198-800px.jpg
Focal Length |33.0 mm
./Jack_and_Carmels_40th/P5195169-1024px.jpg
Focal Length |14.0 mm
etc.

As there were lots of JPEG files in the directory without EXIF data, there was lots of junk which I've stripped out.

With a bit more fiddling about I expect 'sort' could be used to sort the output according to focal length.

With 'Windoze' I expect you could use Cygwin to do it.

Jim

[StephenL]

Very good, but not everyone wants to mess about with code when there are dozens of applications, many free, which can do this for you. But as a coder's exercise, very interesting as it shows that the exif contains a great deal of information which can be extracted if required.

[Jim Ford]

Originally Posted by StephenL

Very good, but not everyone wants to mess about with code when there are dozens of applications, many free, which can do this for you.

But in my experience you need to fire up the application and then select the files or groups of files you want to examine. The application will then display the data. A command line will run before even a GUI has started up. It also finds the files, if necessary descending a directory tree, rather than the user having to select them.

Jim

[Phill D]

This is great support guys thanks. It's going to take me a while to get up to speed and understand what you are telling me though. If I have to go for coding then I'll need to enlist my son's help as that's way out of my league. A programme that can do it for me would be ideal. I'm surprised no one asked why I wanted to do this? Well basically it's because I seem to have lost my 75-300mm lens and I was trying to work out the last time I had used it to see if it gave me a clue as to where I'd lost it or more hopefully where I'd put it. Having turned the house inside out three times now I'm beginning to suspect it got left behind on our recent trip to London I'll probably have to start tying my gloves together with elastic soon Anyway back to re-read the info you've all given me and fingers crossed hoping it turns up soon.

[Jim Ford]

The EXIF doesn't give the maximum focal length, only that at which it was used. This means that the EXIF might show 100mm, which could mean that the image was taken with a 75-300mm lens or a (say) 50-150mm one.

I hope you find the lens OK.

Jim

[OM USer]

I use the windows GUI "exiftool" to look at the exif data in my jpgs/orfs. If you select a directory and then select all the files in that directory you can "export" the exif data for all the selected files to a text file (file has the same name as the image file but with .txt extension). You can then search the text file(s) using standard windows tools.

The advantage of this is that all the exif data is exported so its easy to search for a lens (eg: "75-300").

I know this isn't quite what was required as the brief called for a hierarchical directory search. However the GUI exiftool has a command line version and one of the options is:
-r (-recurse) Recursively process subdirectories
which seems to be just the thing you are looking for. I haven't used the command line version but offer it up as something to look into that may meet your needs.