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Lens Correction Also Enabled for 3rd Party Lens!!!

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YunZY655186

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Today I had a very interesting discovery. I enabled the Lens Correction function with the 18-55 on, and switch off and to the Tamron 70-300, which is famous for the severe PFs. Amazingly, when I took a few shots, I found the annoying PFs are just gone, though the function appeared disabled when shooting. Then I switch back the 18-55, and turn the function off, and switch back, the PFs are back.

Well done Pentax.:D

In case you would like to check the comparison images, so I share them below:

disabled:

http: photo.tuhigh.com/pics/950/1208/139159t448023867_o.jpg

enabled:

http: photo.tuhigh.com/pics/950/1208/139159t367916920_o.jpg
 
What's even more impressive is that the pattern of the CA of this lens is very difficult to correct with the common correcting algorithms, like that in the silkypix, which would just fail.
 
It is worth trying this with some other lenses. What this tells me is that the CA correction algorithm is not lens specific, like Nikon's, but Pentax chooses to make it available only for Pentax lenses.

Eric

--
I never saw an ugly thing in my life: for let the form of an object
be what it may - light, shade, and perspective will always make it
beautiful. - John Constable (quote)

See my Blog at: http://viking79.blogspot.com/ (9/9/09)
Flickr Photostream: http://www.flickr.com/photos/28177041@N03/ (updated daily)
See my PPG Shots: http://www.pentaxphotogallery.com/erictastad (8/31/09)
 
Is this on the K-x or the K-7?
I need to try this out with my K-x?
Does it work with raw, too?
 
it does correct for some 3rd party lenses like my tamron 17-50 (correction is valid & can be turned on/off) , however not for the older manual focus lenses, pentax or not. I'm guessing there will be an expanding database for lens distortion/PF characteristics for more lenses with future release of firmware.
 
Did you have processing lag on the tamron 70-300mm when you left the correction on from 18-55mm?
 
It is lens specific, the lens must have a certain ROM chip installed for the function to work. Now, Tamron has access to the official chip because of their co-operation with Pentax on many lenses - like the Pentax/Tamron 28-200, Pentax/Tamron 28-105 f/4-5.6 and Pentax/Tamron 18-250. Tamron uses a licensed an official version of K-mount and with offical ROM circuits after Pentax own specification.

--
Take care
R
http://www.flickr.com/photos/raphaelmabo
 
But to my knowledge the Tamron uses the older ROM-chips (same as in the FA lenses) and not the newest one found in the DA and D FA lenses.
So I do have my doubts about this actually working.

Purple fringing and chromatic abberation can be tricky to test since it depends on so many factors, most notably the ever changing light and reflections and you need to find exactly the same angle between shots after you have exchanged the lens.

Distorsion is easier to test... :)
--
Take care
R
http://www.flickr.com/photos/raphaelmabo
 
sleapyhead said:
it does correct for some 3rd party lenses like my tamron 17-50 (correction is valid & can be turned on/off) , however not for the older manual focus lenses, pentax or not. I'm guessing there will be an expanding database for lens distortion/PF characteristics for more lenses with future release of firmware.
Click to expand...
As far as I know - its not a database - but a chip in the lens.

Of course - it can also be done with a database. But - as there is no standardized ID scheme for the lens used - there might be conflicts.

And - of course - the database is probably then only used when converting from RAW in your computer. Its highly unlikely that any database data is found in firmware.

--
Roland

support http://www.openraw.org/

X3F tools : http://www.proxel.se/x3f.html
 
sleapyhead said:
Thanks for the correction. It doesn't work with my Sigma 170-500mm though.
Click to expand...
What is really a pity is two things:

1. The EXIF standard do not contain any data for lens used. So - the lens used data is vendor specific and stored in the MakerNote field. The MakerNote field has no formal specification. Therefore you have to crack each manufacturers format to be able to read the lens data.

2. The body-lens communication is vendor specific and secret. The third party lens makers have to crack that communication in order to make their lenses. Therefore - communication errors may exist. And - of course - the lens ID is just a number - and therefore it might be that a third party lens maker chooses the same number as the camera vendor.

--
Roland

support http://www.openraw.org/

X3F tools : http://www.proxel.se/x3f.html
 
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