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12-15-2011, 07:22 AM   #16
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QuoteOriginally posted by zapp Quote
The lens profile helps to significantly improve results from incomplete lenses, but it does not replace decent optical design.
Even Hasselblad are now offering lenses with optical "defects"
deliberately designed to be corrected digitally.

That option allows for a better overall performance
than could be obtained by optical design alone.

12-15-2011, 10:40 AM   #17
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QuoteOriginally posted by lytrytyr Quote
My English K-x manual (H01200909/53546) only has 324 pages,
and does not address the issue here:
where the lens correction data are stored.
My answer was solely for the opening post by cbope (sorry if that was not clear) where was indicated that he/she has a K5 and did not ask where the info was stored.
12-15-2011, 10:54 AM   #18
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QuoteOriginally posted by lytrytyr Quote
...Does the same apply to MTF data
used to guide the default Program mode?
The MTF data is stored in the lens. The F series lenses didn't have enough storage space for that data. The FA series introduced the feature.
12-15-2011, 11:52 AM   #19
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QuoteOriginally posted by sterretje Quote
My answer was solely for the opening post by cbope (sorry if that was not clear) where was indicated that he/she has a K5 and did not ask where the info was stored.
Ah, thanks for the clarification: It's a K-5 manual!

I was concerned about what valuable information
might be missing from my depleted copy of the K-x manual.

12-15-2011, 12:41 PM   #20
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QuoteOriginally posted by audiobomber Quote
The FA Ltd lenses had to be added in firmware, because "FA Limited" was an unrecognized designation. (Unfortunately FA lenses were not added at the same time) From the manual:

"Corrections can only be made when using a DA, DA L or D FA lens."

Note that FA Ltd were not originally corrected.
If I understand this right,
you're saying that the K-x will now correct FA Ltd lenses,
despite what the 2009 manuals say.
So on the way to Version 1.02,
that capacity was added?

QuoteOriginally posted by Just1MoreDave Quote
The MTF data is stored in the lens. The F series lenses didn't have enough storage space for that data. The FA series introduced the feature.
And this comment suggests that all FA lenses do have internal MTF data.
So for consistency with AudioBomber's comment (referring to the K-x),
either the FA Ltd's (at least) do not have internal correction data (despite having internal MTF data),
or else the K-x is unable to read that data from the lens
because the appropriate recognition was not set up for that camera.
(MTF data only, without correction data, would make sense for film,
where it was just a question of running a Program mode.)

This is all getting very complicated.

For those people who are interested in the option of real-time correction,
it would be good to have clarifiication
of which FA lenses can be corrected in-body,
by each of the K-x, K-r, and K-5.

As noted before, the only thing that has become clear so far
is that the K-x can correct any DA (including DA*), DA L, or D FA lens.
12-15-2011, 01:26 PM   #21
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QuoteOriginally posted by lytrytyr Quote
If I understand this right, you're saying that the K-x will now correct FA Ltd lenses, despite what the 2009 manuals say. So on the way to Version 1.02, that capacity was added?
Yes, it had to be done by camera firmware.

QuoteOriginally posted by lytrytyr Quote
And this comment suggests that all FA lenses do have internal MTF data. So for consistency with AudioBomber's comment (referring to the K-x), either the FA Ltd's (at least) do not have internal correction data (despite having internal MTF data), or else the K-x is unable to read that data from the lens because the appropriate recognition was not set up for that camera.
(MTF data only, without correction data, would make sense for film,
where it was just a question of running a Program mode.)
I don't know know what data are included in an FA Limited chip. I suspect that lenses developed before correction technology was implemented don't have correction data in the lens, it has to be added in camera firmware.

So when you mount an auto lens, the camera reads the lens data. The data includes the lens nomenclature. If the lens has the correct prefix (DA, etc), then the correction software is enabled. Pentax could, in a new firmware round, add FA lenses. They just choose not to.

QuoteOriginally posted by lytrytyr Quote
For those people who are interested in the option of real-time correction,
it would be good to have clarifiication
of which FA lenses can be corrected in-body,
by each of the K-x, K-r, and K-5.

As noted before, the only thing that has become clear so far
is that the K-x can correct any DA (including DA*), DA L, or D FA lens.
The FA Limited lenses, 31mm, 43mm and 77mm are also corrected, by all the named bodies, plus the K-7. FA lenses (FA 50mm 1.4, FA 35mm f2) are not. The Lens Correction feature is greyed out when an FA lens is mounted, enabled when an FA Ltd lens is mounted.
12-15-2011, 01:45 PM   #22
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QuoteOriginally posted by audiobomber Quote
The FA Limited lenses, 31mm, 43mm and 77mm are also corrected, by all the named bodies, plus the K-7.
Thanks for settling that.

I'd seen the post about the K-7 in shang's thread

https://www.pentaxforums.com/forums/pentax-dslr-discussion/107727-k-7-automat...orrection.html

but the information about the K-x is very helpful,
going beyond what's in the manual.
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