Another PAF 1.7X TC Question...


Classvino

Link Posted 05/02/2008 - 01:51
I only have Sigma lenses - I'd own Pentax lenses but cant justify the extra cash for equivalent range/speed combinations... But that is only a setup for the question...

I've noticed that when I use the camera without the Converter, the exif data (well, the parts that are reported by Windows - I realize there's loads more data) is exactly correct - aperture, lens length,speed,iso,etc.... but if I use the TC, the lens length is reported as zero while all the rest is fine.

Is this the TC, or do the Sigma's not talk thru the TC properly? Could I bother someone that has the 1.7x AF TC to take a photo with a Pentax zoom and let me know if the lens length is reported correctly, or at all ?

Thanks
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MZ-6,K10D,K20D,Grip,DA*Zooms,DA 18-55-200 Kit,FA50,1.7TC,AFZ360
For Saleentax FA28-90,FA100-300,Sigma EX28-80,DC18-200,
Makinon 500mm Mirror

MattMatic

Link Posted 05/02/2008 - 09:18
EXIF data is not transferred through the 1.7xAF. You'll notice on the K10D that focal length needs to be entered manually because the camera doesn't know that (a) there's a TC, (b) doesn't know the lens.

I presume that if full lens info were transferred the TC would have to somehow "cook" the lens data to make it appear 1.7x longer!

So, everything is normal. All TCs will "hide" the lens data
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)

Classvino

Link Posted 05/02/2008 - 15:01
Thanks for the quick reply, Matt.

Sounds like a suggestion for Pentax if they ever do release another TC - with my extremely limited knowledge of h/w, it doesn't seem like it'd be terribly difficult to pass all the data through the TC, and trap and multiply (cook) the focal length by the appropriate factor...

Leads to the next question - since I'm still in the habit of noting down the length when I'm shooting (a throwback from my film days), what's the easiest way, if any, for me to enter the focal length (and perhaps any other missing info I think I need) into the exif for the odd occasions when I do use the TC?
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MZ-6,K10D,K20D,Grip,DA*Zooms,DA 18-55-200 Kit,FA50,1.7TC,AFZ360
For Saleentax FA28-90,FA100-300,Sigma EX28-80,DC18-200,
Makinon 500mm Mirror

Daniel Bridge

Link Posted 05/02/2008 - 15:10
When you use the convertor, the K10D will (should) ask for the focal length for the SR (although that might only be if you've got SR switched on). That focal length will appear in the EXIF.

Dan
K-3, a macro lens and a DA*300mm...

MattMatic

Link Posted 05/02/2008 - 15:11
Well, it's nearly possible

If the data were cooked, it still wouldn't show there was a TC there I suppose they could pass and cook the focal length (which is great for the multiplication and zooms), but the lens ID may have to be dropped... otherwise you'd have an SMC-DA 50-135 reaching 230mm

I did see that an SDM TC was listed on their roadmap

EDIT: Re EXIF editing... I've not used anything (yet) to do that. A quick Google shows that Opanda do a product that purports to do it: http://www.opanda.com/
There should be a GNU/GPL version somewhere...

Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)

Daniel Bridge

Link Posted 05/02/2008 - 15:29
MattMatic wrote:
A quick Google shows that Opanda do a product that purports to do it: http://www.opanda.com/

I think that's just for jpegs and Tiffs, so if you're wanting the Raw file EXIF data changed I don't think that will do it. I think there was a discussion about this before, and I don't think there was a solution for Raws.

Dan
K-3, a macro lens and a DA*300mm...

MattMatic

Link Posted 05/02/2008 - 15:39
Quote:
I don't think there was a solution for Raws

Think you'll find that a RAW file bears a striking resemblance to TIFF... just with a different extension
Must double check this....
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)

Daniel Bridge

Link Posted 05/02/2008 - 15:40
Just having a look through the forum on the Opanda site, because I'm not sure if Raw files are supported or not, and saw the following entry:

An Opanda Forum User wrote:
I Have a Canon 350D

does Opand Power Exif edit EXIF Data of RAW files?

I want to change the camera model on the file.



Dan

By the way, the reply was "PowerExif Editor support jpeg and tiff (only for Pro version)."
K-3, a macro lens and a DA*300mm...

Classvino

Link Posted 05/02/2008 - 20:49
On further examination... (and I'm feeling pretty stupid now... )

Out of a dozen or so shots taken with the TC, only the last 3 or 4 don't have any focal length data... The others show 120mm - the length I told the camera to use for SR, and also specify an 'A Lens' because, I assume, of the Pentax TC. The lens used was actually a Sigma 28-70 f2.8.

SO... I've discovered that with the TC on, if SR is turned off, as was the case on my last 4 shots with the TC, there is no focal length but it still shows 'A Lens' on the exif. The focal length shows similarly on the on-camera display a well... (I'd be happy if the SR switch were more recessed and/or smaller. I've turned it off a few times now, and don't notice until I get a blurry picture that I was sure could be handheld...)

(on a new Pentax TC, if the camera did "cook" the focal length, it'd also solve any SR issues with having to choose a single setting for SR even though the "right" setting could change with a zoom.)
--------------
MZ-6,K10D,K20D,Grip,DA*Zooms,DA 18-55-200 Kit,FA50,1.7TC,AFZ360
For Saleentax FA28-90,FA100-300,Sigma EX28-80,DC18-200,
Makinon 500mm Mirror
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