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01-21-2015, 09:22 AM   #1
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Lens Correction question

My friend and I disagree on this....
Does lens AF Fine adjustment apply for manual lenses too ?
Or as he claims...is it only for AF lenses ?
I have a Sigma 21-35 Manual focus lens and swear it DOES work with a +9 applied (only when I use this lens) ..... Or am I dreaming and way off base here.
The AF modern Pentax leses it does. But I was under the impression that the "Apply All" was a body adjustment for any lens ?

---------- Post added 01-22-15 at 12:39 AM ----------

Im not using the correct term....Im wanting to know about lens AF "FINE" adjustment .
Sorry I had to post a second time , but I am not allowed yet to edit my own posts. (now I am)


Last edited by Dlanor Sekao; 01-23-2015 at 08:19 AM.
01-21-2015, 10:13 AM   #2
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It applies if the lens has a chip which identifies the lens and the camera has a profile for the correction. I think maybe you two are talking about two different things - focus correction vs. lens correction - which removes distortion from pincushioning etc.
01-21-2015, 10:44 AM   #3
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There are 2 "corrections" related to lenses:

Lens correction, which is optical correction of inherent design flaws in modern lenses, only works with Pentax lenses.

AF fine adjustment works with any K-mount AF lens. It won't have any effect with manual lenses.
01-21-2015, 11:14 AM   #4
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QuoteOriginally posted by cbope Quote
There are 2 "corrections" related to lenses:

Lens correction, which is optical correction of inherent design flaws in modern lenses, only works with Pentax lenses.

AF fine adjustment works with any K-mount AF lens. It won't have any effect with manual lenses.
Im studying this right now.....I DO believe he/you are right.
I thought that fine lens correction worked with manual focus lenses also through program IQ or actual sensor shift.
However I believe now Im wrong.
Will wait to hear back from a few more if Fine lens correction actually has ANY place for Manual focus (non Chipped / non contact) lenses.
Thanks.

01-21-2015, 11:32 AM   #5
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Lens correction (barrel or pincushion) can also be done in pp. Photograph a rectangular image (I use my glass window blinds) and find the required adjustment to make parallel straight lines. It is independent of distance (well anyway for normal distances) and independent of aperture. If you have a "killer shot" nice to know it is always something that can be done.
01-21-2015, 12:23 PM   #6
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QuoteOriginally posted by dms Quote
Lens correction (barrel or pincushion) can also be done in pp. Photograph a rectangular image (I use my glass window blinds) and find the required adjustment to make parallel straight lines. It is independent of distance (well anyway for normal distances) and independent of aperture. If you have a "killer shot" nice to know it is always something that can be done.
Lightroom has presets for most lenses - but manual ones you may need to do on your own as described above. I haven't tried it, but if I were photographing artwork with a nice manual lens, I absolutely would create a profile.
01-21-2015, 12:51 PM   #7
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QuoteOriginally posted by cbope Quote
AF fine adjustment works with any K-mount AF lens. It won't have any effect with manual lenses.
That's not completely true.
AF lens correction does effectly correct focusing by using the green hexagon signal, no matter whether the lens is AF or manual.

Unfortunately, with very shallow DOF this signal is nearly useless because of hysteresis.
01-21-2015, 01:17 PM   #8
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The optical corrections are based on lens profiles. Pentax cameras only have lens profiles for (relatively modern) Pentax lenses. If you shoot raw, the PP software might allow its own lens corrections, either manual (inputting values by hand) or by using a lens profile (some come with the software, often you can find others on the internet made by users).
So manual lenses do not have in-camera lens profiles. This is also the reason why you cannot choose CA correction, distortion correction, diffraction correction when a lens like, for example, Helios 44 is mounted.

You can use SR with manual lenses as long as you input the focal length of the lens (that is all the info it needs). And also Catch in focus (and AF fine adjustment might affect this)

01-21-2015, 01:54 PM   #9
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I think that there is some confusion between in-camera lens distortion correction and in-computer lens distortion correction during PP.

In-camera lens distortion correction: as Na Horuk indicated, "Pentax cameras only have lens profiles for (relatively modern) Pentax lenses".

in-computer lens distortion correction during PP: this is done in-computer, using typically PP software. There are also some stand alone software to handle lens distortion correction only, like PTlens (PTlens is also available in plugin).

Practically, lens distortion correction is most relevant to zoom lenses. Most prime lenses generate minimal lens distortion. Further lens distortion correction is very rarely applied to fisheye lenses.

Personally I always do lens distortion correction in-computer during PP. This gives me more flexibility, and it allows me to use Hi-continuous shooting without being slowed down by in-camera processing times.

Hope that the comment may help.
01-21-2015, 02:31 PM   #10
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The question is about AF fine tuning, not lens (distortion) correction, guys.

As long as the camera recognises the lens (the chip) you can adjust the AF, I believe. If not, it will be affected by the "apply to all lenses" setting.

I have never tried it myself, though. The only third-party AF lens I have has never needed any adjusting.
01-21-2015, 07:29 PM   #11
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QuoteOriginally posted by RKKS08 Quote
That's not completely true.
AF lens correction does effectly correct focusing by using the green hexagon signal, no matter whether the lens is AF or manual.

Unfortunately, with very shallow DOF this signal is nearly useless because of hysteresis.
Could you or someone else elaborate on this ? I know a modern AF lens is able to have a setting of -10 to +10
But I was also under the impression that a "Apply all" setting would be for manual lenses too?
I have NO problem changing the setting frequently for various manual lenses as that is what I mainly use.
The setting is called AF fine adjustment , but the manual doesn't say for my specific question.
Im not sure if it is shifting/adjusting the in focus indicator or not. Also not sure if it is actually shifting the cameras sensor or just changing the alogorythem to achieve a finer focus.
Very confused if it even for anything other than AF modern chipped lenses ?
01-21-2015, 09:33 PM   #12
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QuoteOriginally posted by TER-OR Quote
Lightroom has presets for most lenses - but manual ones you may need to do on your own as described above. I haven't tried it, but if I were photographing artwork with a nice manual lens, I absolutely would create a profile.
While Lightroom has presets for most recent, popular lenses, it most certainly does not have presets for most k-mount lenses in general. In any event, I have found the majority of Adobe-created profiles to be especially poor for Pentax lenses (better efforts for Canon lenses - L series especially). It is easier to apply adjustments manually - if you want to get the correction just right. Even then, in the vast majority of situations you simply can't get to the quality of output available in Capture One v.8 - the color and contrast controls are more precise.
01-22-2015, 08:10 AM - 1 Like   #13
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QuoteOriginally posted by RKKS08 Quote
That's not completely true.
AF lens correction does effectly correct focusing by using the green hexagon signal, no matter whether the lens is AF or manual.

Unfortunately, with very shallow DOF this signal is nearly useless because of hysteresis.
Yes, thats right, "AF Fine Adjustment" "Apply All" does work for manual lenses and can be used via the green hexagon signal. In addition, its useful for Catch in Focus (as long as AF button customization is set to AF1). For my Samyang 85mm F1.4 lens, the available adjustment isn't quite enough though.

John.
01-22-2015, 03:17 PM   #14
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I tried the "Apply to all" but I did not see any difference when focused on one spot i manual. It did not move the sensor like when doing an adjustment in the Debug Menu AF_TEST, it adjusts the AF which is logical. On the K10d I made a +120um adjustment in the Debug menu and got all my lenses including the manual to get sharp images. I guess the sensor was a little off. This is possible on the K-3 as well.

EDIT:

To clarify my thoughts; When looking through the OVF with a manual lens, focusing and seeing the object as in focus my K10d was way off when taking the image so I started to adjust in the debug mode until the image got sharp on the LCD/computer.

On the K-3 I find that what I see in the OVF is what I get so no adjustment needed. But with AF I have to adjust when using the 1.4x converter.

Last edited by Tjompen1968; 01-22-2015 at 03:29 PM.
01-23-2015, 08:16 AM   #15
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QuoteOriginally posted by jhmos Quote
Yes, thats right, "AF Fine Adjustment" "Apply All" does work for manual lenses and can be used via the green hexagon signal. In addition, its useful for Catch in Focus (as long as AF button customization is set to AF1). For my Samyang 85mm F1.4 lens, the available adjustment isn't quite enough though.

John.
This is what I thought. However I got off track for this post with my initial wordage. Im going to play with it a bit and see if I can find out more. Thanks.
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