Issue with LR, lenses, & exif data

I use Pentax bodies, and mostly Sigma lenses, with some Pentax lenses.
In LR library module, the lens brand and model shows up only with
Pentax lenses, and in develop module, when I enable lens correction,
it automatically chooses the lens. With Sigma lenses, the entry for
"lens" is missing in the exif data, and when I enable lens correction,
nothing happens until I choose a brand, but then LR seems to know
exactly which lens it is, and fills in the rest.

I thought that maybe it was Pentax's exif data handling, because the
Sigma lenses do not show up in Pentax's software. But when I use DXO
Optics pro, the lens brand and model do display.

Anyone have any idea why this is, and what I can do about it, if
anything?

In article , Bill W
wrote:

I use Pentax bodies, and mostly Sigma lenses, with some Pentax lenses.
In LR library module, the lens brand and model shows up only with
Pentax lenses, and in develop module, when I enable lens correction,
it automatically chooses the lens. With Sigma lenses, the entry for
"lens" is missing in the exif data, and when I enable lens correction,
nothing happens until I choose a brand, but then LR seems to know
exactly which lens it is, and fills in the rest.

I thought that maybe it was Pentax's exif data handling, because the
Sigma lenses do not show up in Pentax's software. But when I use DXO
Optics pro, the lens brand and model do display.

Anyone have any idea why this is, and what I can do about it, if
anything?

switch to nikon ?

what does the exif data actually contain? check it with exiftool:
http://www.sno.phy.queensu.ca/~phil/exiftool/

sigma is well known for using the wrong lens info and what gets written
out is not necessarily correct (or even valid).

On Mon, 11 Jul 2016 22:27:29 -0400, nospam
wrote:

In article , Bill W
wrote:

I use Pentax bodies, and mostly Sigma lenses, with some Pentax lenses.
In LR library module, the lens brand and model shows up only with
Pentax lenses, and in develop module, when I enable lens correction,
it automatically chooses the lens. With Sigma lenses, the entry for
"lens" is missing in the exif data, and when I enable lens correction,
nothing happens until I choose a brand, but then LR seems to know
exactly which lens it is, and fills in the rest.

I thought that maybe it was Pentax's exif data handling, because the
Sigma lenses do not show up in Pentax's software. But when I use DXO
Optics pro, the lens brand and model do display.

Anyone have any idea why this is, and what I can do about it, if
anything?

switch to nikon ?

what does the exif data actually contain? check it with exiftool:
http://www.sno.phy.queensu.ca/~phil/exiftool/

sigma is well known for using the wrong lens info and what gets written
out is not necessarily correct (or even valid).

Well DXO sees all the info, and it is correct, so it must be in the
exif data. It's something with Adobe, and PS does the same thing.

And this has nothing to do with the recent exif data bug in the latest
update - LR has always done this.

On Mon, 11 Jul 2016 22:27:29 -0400, nospam
wrote:

In article , Bill W
wrote:

I use Pentax bodies, and mostly Sigma lenses, with some Pentax lenses.
In LR library module, the lens brand and model shows up only with
Pentax lenses, and in develop module, when I enable lens correction,
it automatically chooses the lens. With Sigma lenses, the entry for
"lens" is missing in the exif data, and when I enable lens correction,
nothing happens until I choose a brand, but then LR seems to know
exactly which lens it is, and fills in the rest.

I thought that maybe it was Pentax's exif data handling, because the
Sigma lenses do not show up in Pentax's software. But when I use DXO
Optics pro, the lens brand and model do display.

Anyone have any idea why this is, and what I can do about it, if
anything?

switch to nikon ?

what does the exif data actually contain? check it with exiftool:
http://www.sno.phy.queensu.ca/~phil/exiftool/

sigma is well known for using the wrong lens info and what gets written
out is not necessarily correct (or even valid).

Okay, I checked with exiftool. If I click on exif, the lens data is
not there. If I click on Maker, or All, it's there. Any ideas?

In article , Bill W
wrote:

I use Pentax bodies, and mostly Sigma lenses, with some Pentax lenses.
In LR library module, the lens brand and model shows up only with
Pentax lenses, and in develop module, when I enable lens correction,
it automatically chooses the lens. With Sigma lenses, the entry for
"lens" is missing in the exif data, and when I enable lens correction,
nothing happens until I choose a brand, but then LR seems to know
exactly which lens it is, and fills in the rest.

I thought that maybe it was Pentax's exif data handling, because the
Sigma lenses do not show up in Pentax's software. But when I use DXO
Optics pro, the lens brand and model do display.

Anyone have any idea why this is, and what I can do about it, if
anything?

switch to nikon ?

what does the exif data actually contain? check it with exiftool:
http://www.sno.phy.queensu.ca/~phil/exiftool/

sigma is well known for using the wrong lens info and what gets written
out is not necessarily correct (or even valid).

Okay, I checked with exiftool. If I click on exif, the lens data is
not there. If I click on Maker, or All, it's there. Any ideas?

i've only used the command line version to dump all tags it finds.

On 2016-07-12 02:48:36 +0000, Bill W said:

On Mon, 11 Jul 2016 22:27:29 -0400, nospam
wrote:

In article , Bill W
wrote:

I use Pentax bodies, and mostly Sigma lenses, with some Pentax lenses.
In LR library module, the lens brand and model shows up only with
Pentax lenses, and in develop module, when I enable lens correction,
it automatically chooses the lens. With Sigma lenses, the entry for
"lens" is missing in the exif data, and when I enable lens correction,
nothing happens until I choose a brand, but then LR seems to know
exactly which lens it is, and fills in the rest.

I thought that maybe it was Pentax's exif data handling, because the
Sigma lenses do not show up in Pentax's software. But when I use DXO
Optics pro, the lens brand and model do display.

Anyone have any idea why this is, and what I can do about it, if
anything?

switch to nikon ?

what does the exif data actually contain? check it with exiftool:
http://www.sno.phy.queensu.ca/~phil/exiftool/

sigma is well known for using the wrong lens info and what gets written
out is not necessarily correct (or even valid).

Well DXO sees all the info, and it is correct, so it must be in the
exif data. It's something with Adobe, and PS does the same thing.

And this has nothing to do with the recent exif data bug in the latest
update - LR has always done this.

I have had a similar issue with my old Sigma 12-24mm, LR would not
auto-ID the lens, so I had to give it a hint by selecting the lens
manufacturer. I also have an issue with my old Nikkor 80-400. Again
there is no auto-ID, and also no specific lens profile. So I just use
the new Nikkor 80-400mm VRII profile. With that lens I believe there is
a lens firmware issue as the EXIF always reports it as 82-400mm, not
80-400mm.

--
Regards,

Savageduck

Bill W wrote:
Okay, I checked with exiftool. If I click on exif, the lens data is
not there. If I click on Maker, or All, it's there. Any ideas?

The lens data is contained in the MakerNotes (which is
proprietary to the camera manufacturer), and is not
strictly speaking Exif data. Exiftool will show both,
and also IPTC data and some data (such as date stamps
and image size) that is available from the image file.
It also "creates" some data by heuristics combining
other data.

The lens data in the MakerNotes is not the full text
description of the lens. There is a "Lens ID Number"
and another number called "Lens Data Version". Other
fields are "Lens Type", which with Nikon will show
things like "G", "VR", and "D". Who knows what a Nikon
camera might list for a Sigma lens! :-)

The lens data fields labeled "Lens ID" and "Lens" are
created by Exiftool and are not specifically what the
camera has put in the metadata. They have text that
Exiftool decides should be there, given other data such
as what the numbers are in the "Lens ID Number", "Lens
Type", and "Lens Data Version" tags. Obviously a
different Exif reader might present less information.
Exiftool is probably the best...


--
Floyd L. Davidson http://www.apaflo.com/
Ukpeagvik (Barrow, Alaska)

On Mon, 11 Jul 2016 20:07:32 -0800, (Floyd L.
Davidson) wrote:

Bill W wrote:
Okay, I checked with exiftool. If I click on exif, the lens data is
not there. If I click on Maker, or All, it's there. Any ideas?

The lens data is contained in the MakerNotes (which is
proprietary to the camera manufacturer), and is not
strictly speaking Exif data. Exiftool will show both,
and also IPTC data and some data (such as date stamps
and image size) that is available from the image file.
It also "creates" some data by heuristics combining
other data.

The lens data in the MakerNotes is not the full text
description of the lens. There is a "Lens ID Number"
and another number called "Lens Data Version". Other
fields are "Lens Type", which with Nikon will show
things like "G", "VR", and "D". Who knows what a Nikon
camera might list for a Sigma lens! :-)

The lens data fields labeled "Lens ID" and "Lens" are
created by Exiftool and are not specifically what the
camera has put in the metadata. They have text that
Exiftool decides should be there, given other data such
as what the numbers are in the "Lens ID Number", "Lens
Type", and "Lens Data Version" tags. Obviously a
different Exif reader might present less information.
Exiftool is probably the best...

Well then it looks like LR & PS don't read the MakerNotes initially,
but they do after you click on the lens brand in the lens correction
panel. And I guess DXO does read that data from the start. That being
the case, it looks like there's nothing I can do about it. I can't
find anything in the options.

Thanks.

Bill W wrote:
On Mon, 11 Jul 2016 20:07:32 -0800, (Floyd L.
Davidson) wrote:

Bill W wrote:
Okay, I checked with exiftool. If I click on exif, the lens data is
not there. If I click on Maker, or All, it's there. Any ideas?

The lens data is contained in the MakerNotes (which is
proprietary to the camera manufacturer), and is not
strictly speaking Exif data. Exiftool will show both,
and also IPTC data and some data (such as date stamps
and image size) that is available from the image file.
It also "creates" some data by heuristics combining
other data.

The lens data in the MakerNotes is not the full text
description of the lens. There is a "Lens ID Number"
and another number called "Lens Data Version". Other
fields are "Lens Type", which with Nikon will show
things like "G", "VR", and "D". Who knows what a Nikon
camera might list for a Sigma lens! :-)

The lens data fields labeled "Lens ID" and "Lens" are
created by Exiftool and are not specifically what the
camera has put in the metadata. They have text that
Exiftool decides should be there, given other data such
as what the numbers are in the "Lens ID Number", "Lens
Type", and "Lens Data Version" tags. Obviously a
different Exif reader might present less information.
Exiftool is probably the best...

Well then it looks like LR & PS don't read the MakerNotes initially,

But if they get it right with a Nikon lens, they must be
reading the Makernotes.

It appears they only look through their Nikon lens data
to get a match, unless you tell it the lens is some
brand other than that of the camera.

It doesn't change the effect you see though, as there is
nothing you apparently can do with the Exif data to make
those programs consider other than the camera brand
lenses.

but they do after you click on the lens brand in the lens correction
panel. And I guess DXO does read that data from the start. That being
the case, it looks like there's nothing I can do about it. I can't
find anything in the options.

Thanks.

--
Floyd L. Davidson http://www.apaflo.com/
Ukpeagvik (Barrow, Alaska)

On Mon, 11 Jul 2016 21:01:35 -0800, (Floyd L.
Davidson) wrote:

Bill W wrote:
On Mon, 11 Jul 2016 20:07:32 -0800, (Floyd L.
Davidson) wrote:

Bill W wrote:
Okay, I checked with exiftool. If I click on exif, the lens data is
not there. If I click on Maker, or All, it's there. Any ideas?

The lens data is contained in the MakerNotes (which is
proprietary to the camera manufacturer), and is not
strictly speaking Exif data. Exiftool will show both,
and also IPTC data and some data (such as date stamps
and image size) that is available from the image file.
It also "creates" some data by heuristics combining
other data.

The lens data in the MakerNotes is not the full text
description of the lens. There is a "Lens ID Number"
and another number called "Lens Data Version". Other
fields are "Lens Type", which with Nikon will show
things like "G", "VR", and "D". Who knows what a Nikon
camera might list for a Sigma lens! :-)

The lens data fields labeled "Lens ID" and "Lens" are
created by Exiftool and are not specifically what the
camera has put in the metadata. They have text that
Exiftool decides should be there, given other data such
as what the numbers are in the "Lens ID Number", "Lens
Type", and "Lens Data Version" tags. Obviously a
different Exif reader might present less information.
Exiftool is probably the best...

Well then it looks like LR & PS don't read the MakerNotes initially,

But if they get it right with a Nikon lens, they must be
reading the Makernotes.

It appears they only look through their Nikon lens data
to get a match, unless you tell it the lens is some
brand other than that of the camera.

When I have a Pentax lens on the Pentax body, everything appears in
the exif data. I have to assume that the camera body writes the data
differently depending on whether it's their lens or not. What you're
saying there makes sense, except that it makes no sense from the
user's standpoint. It's just a choice Adobe made for some unknown
reason.

I do have a couple of other brand lenses. Maybe I'll dig those out and
experiment, but I believe that they are all pre-digital age. I'm
guessing those lenses don't transfer any data at all.

It doesn't change the effect you see though, as there is
nothing you apparently can do with the Exif data to make
those programs consider other than the camera brand
lenses.

but they do after you click on the lens brand in the lens correction
panel. And I guess DXO does read that data from the start. That being
the case, it looks like there's nothing I can do about it. I can't
find anything in the options.

Thanks.