Pentax Teleconverter lens combo naming

[Beholder3]

Hi,

when looking at the metadata of pictures taken with a Pentax DSLR and using the current "1.4x HD PENTAX-DA AF Rear Converter" I did notice that the camera saves the original focal length in tag 0x0009 (e.g. "250.0 mm") and the one after calculating in the TC (e.g. "350.0 mm") in tag 0x001d.
This seems to only work and happen in the new TC.

I'd now ask for a feature in exiftool to automatically  detect the use of the new TC by comparing those two entries and then (if a TC was used) to append a "+ 1.4x HD PENTAX-DA AF Rear Converter" text to the long text of the makernotes:LensType tag, so the use of the TC is visible for the users without any manual work.

[Phil Harvey]

Sounds like an interesting idea.  Could you send me a sample which uses this TC?  (philharvey66 at gmail.com)

Thanks.

- Phil

[Beholder3]

Great. Sent email with 6 sample shots.

[Phil Harvey]

I think I have a solution which will add " + 1.4x converter" to the LensID for these images.  I can't see yet how to uniquely identify the HD PENTAX-DA AF Rear Converter, so I resist adding this description for now.

This investigation also pointed out the fact that the FocalLength in the LensData for the 645D is not decoded properly.  Apparently there is a different conversion equation for the medium format camera.  I need to look into this.

- Phil

[Beholder3]

I think a neutral text extension is fine as well.

It is just that I think currently this is the only Pentax K mount TC which shows these differences in focal length as both the camera firmware seem to recognize this TC and allow saving AF fine tuning data for a combo separately from a single lens.
So I do not think you get these values with any other TC.

[Beholder3]

I think I have a solution which will add " + 1.4x converter" to the LensID for these images.  I can't see yet how to uniquely identify the HD PENTAX-DA AF Rear Converter, so I resist adding this description for now.

This investigation also pointed out the fact that the FocalLength in the LensData for the 645D is not decoded properly.  Apparently there is a different conversion equation for the medium format camera.  I need to look into this.

Will that feature get into the next version as well?

[Phil Harvey]

Yes.  It seems to do well with testing.  I just need to sort out the 645 problem.

- Phil

[Beholder3]

Very nice! 

[Beholder3]

Hi,

I tried the new v10.01 and yes, now the composite tag LensID is mentioning the teleconverter.

Usually I do run the following command on all my Pentax photos:

Code Select Expand

-exif:LensModel<makernotes:LensType -XMP:Lens<makernotes:LensType -exif:LensInfo<LensID -exif:LensMake<LensManufacturer
to populate the lens naming fields which other programs use.

That does not fill in the teleconverter in these other fields.
Nor does it work with:

Code Select Expand

-exif:LensModel<makernotes:LensID -XMP:Lens<makernotes:LensID -exif:LensInfo<LensID -exif:LensMake<LensManufacturer

Do you have any idea how I could populate exif:LensModel and XMP:Lens?

[Phil Harvey]

I'm not sure I understand because I think you must have considered this answer: -exif:lensmodel<lensid

- Phil

[Beholder3]

Hm. Now I am a little confused.

When I display just the "exif" Metadat of a pciture then I do not see the tag "LensID" there. But I see it listed under makernotes.

That is why I tried "-exif:lensmodel<makernotes:LensID" and this does not do anything.

Now using your -exif:lensmodel<lensid works.

Why does one work and the other not?

[Phil Harvey]

When I display just the "exif" Metadat of a pciture then I do not see the tag "LensID" there. But I see it listed under makernotes.

LensID is only a MakerNote tag for some obscure makes (like Leaf).  For most common makes it is a Composite tag.

- Phil