In-camera lens compensation (pdf)

This article has been archived and is only available as pdf-document: In-camera lens compensation.

This article is also available in / Dieser Beitrag ist auch verfügbar in  German/Deutsch.

Advertisements

9 Antworten zu In-camera lens compensation (pdf)

  1. marc champollion sagt:

    Ich lese in ernstzunehmenden Testberichten immer wieder, wie stark die Schärfe (Definition in L/mm oder L/Bildhöhe) in den Ecken nachlässt, ohne, dass mit einem Wort erwähnt wird, ob mit oder ohne Korrektur gemessen worden ist. Jetzt aber beginne ich, zu ahnen, dass es gar nicht so einfach ist, zu wissen, ob diese kamerainterne Korrektur eingreift oder nicht. Es müsste also zuerst eruiert werden, wann diese Korrektur (bei Fuji z.B. heisst sie LMO) eingreift, und das kann recht zeitraubend sein. Bei starken Weitwinkelobjektiven, vor allem bei den billigeren, am schlimmsten bei WW-Zooms, ist u.a. schon die Verzeichnung so stark, dass sie wahrscheinlich immer intern korrigiert wird. Ausnahme: man benutzt z.B. ein Olympus Objektiv, wie das 9-18mm, an einer Panasonic, wie ich es mache, weil Panasonic kein so putziges UWW anzubieten hat (153 Gramm!). Ich habe dann über die stark gekrümmten Linien nicht schlecht gestaunt. Aber man kann diese Verzeichnung mit geeigneten Programmen am Rechner im Nachhinein korrigieren, genau, wie man stürzende Linien wieder „richtem“ kann. Nur muss die Elektronik in jedem Fall interpolieren, und das senkt die Schärfe beachtlich. Man kann Architekten und Bildbandfotografen also nur empfehlen, Objektive zu verwenden, die keiner Korrektur bedürfen, was natürlich schwer ins Geld geht, weil diese Objektive auf Grund der verschwindend kleinen Serien immens teuer geworden sind. Oder man greift auf frühere Objektive aus der guten alten, analogen Zeit zurück, wie z.B. das sehr gute Leica Elmarit-R 2,8/19mm, oder sogar auf die guten, letzten M-Objektive wie die letzten Versionen der 21mm, vorausgesetzt, sie lassen sich auf moderne Digitalkameras verwenden, was bei den Spiegellosen kein Problem sein sollte wegen der kurzen Schnittweite; sowohl die Fuji X- wie die Sony Alpha 24×36 haben sehr kurze Auflagemaße, die sogar deutlich kleiner sind, als dasjenige der M-Leica (27,8mm). Die Frage ist nur, ob die wenig telezentrische Konstruktion eines 21mm für die Leica M mit dem Sensor Probleme verursacht. Dann blieben nur noch die besten Retrofokus-Konstruktionen wie das schon erwähnte Leica-R 19mm, Zeiss Distagone und einige anderen von z.B. Nikon und Canon.
    Marc Champollion

  2. James Backer sagt:

    Not sure what software you are using where you cannot turn off the auto leans corrections? I have an A7r with FE 16-35 and have always had the ability to simply toggle On / Off any of the 3 lens correction options in Adobe lightroom or Adobe Camera Raw (ACR). This feature has worked since my Preordered FE 16-35 was delivered regardless of the new Sony lens firmware updates that became available recently. One thing to note is in Lightroom I import all my ARW files with auto lens corrections enabled and with Camera Calibration set to „Camera Standard“. To view the ARW image with lens correction for distortion „Off“ you must make sure that in the ‚Lens Correction‘ module that in both the ‚Basic‘ tab and the ‚Profile‘ tab that the „enable lens corrections“ checkbox is deselected. After the recent lens firmware updates from Sony I noticed a significant improvement in distortion correction at 16mm – 20mm

    In addition I have created a few ‚custom‘ vignette profiles for the FE 16-35 which improve the corners when shooting at 16mm – 20mm. I find setting the ‚Profile‘ tab ‚Vignette slider‘ to about 160 gives almost perfect corner exposure when shooting deep blue skies at 16-20mm. Note: Make sure that the ‚vignette‘ slider under the ‚Lens correction‘ Manual tab is set to ‚0‘ or it will apply both settings combined and seems to introduce more noise.

    • J. Haag sagt:
      Verfasser

      James, thanks for you comment. I am using Lightroom 5 with default settings which probably do more than 80 % of Lightroom users. I always import my pics with no profiles or templates applied to them, just to be sure to have as much control as possible.

      • James Backer sagt:

        I think you missed the main point of my comment above…. Distortion Correction IS built into all Sony ARW files as long as you activated the parameter for the lens ‚in camera‘. It CAN be turned ON or OFF for both ARW and JPEG files in both Lightroom and ACR and other compatible software. Your diagram and comment above is incorrect:

        „…that there is no correction of distortion in RAWs, no matter whether this parameter is activated. Lens-correction profiles can only be added to the camera with a new firmware.“

        Also the Sony Distortion correction profiles are built into Adobe Lightroom and ACR for all Sony native E-mount lenses. These corrections can be applied to ARW files easily in the Lightroom ‚lens correction‘ module. I think you may have somehow lost the connection in Lightroom that automatically links the Sony specific lens distortion correction profiles to the ‚Lens Correction‘ module.

        A simple way to verify that the distortion correction profiles are included with your ARW files is to simply open any ARW file in ‚Sony’s Image data converter 4‘ or „Capture One for Sony“ software and toggle the distortion correction on and off.

      • J. Haag sagt:
        Verfasser

        Yes, I missed your point and you are absolutely right.
        Thanks, Jörg

    • I think you’re mixing 2 different things. I believe Jörg’s diagram is correct.
      – LR takes its lens distortion correction from its database of lens-profile files. That’s what you’re applying in the „Lens Correction“ module.
      – However, Sony also embeds its own lens correction information in the ARW-file (SR2SubIFD tag 0x7982, mirrored in Exif SubIFD tag 0x7037 – it’s written independently of your off/auto setting for distortion correction), which LR then chooses to completely ignore. Interestingly, when you run the ARW through Adobe’s DNG-converter, it writes the information into an XMP-tag („LensDistortInfo“). Meaning, it does read the information but doesn’t use it.

      For CA, it’s the opposite. The equivalent tag in the ARW is always interpreted by LR, no matter your camera setting.

      I documented my findings on this a while ago at https://variousphotography.wordpress.com/ if anybody is interested in digging deeper.

  3. Pat Lopez sagt:

    This was a well written and thoughtful post. I greatly enjoyed it. Your point regarding the alternatives for image correction and their corresponding costs (in camera software correction vs. more expensive, and I would add heavier, lenses) is well made. I would also suggest third party software and post processing as another alternative that comes with it own costs (money and time). You frame the issue in a way that gives us all something to think about the next time we chose a new camera or lens. Thank you,
    Pat

    • J. Haag sagt:
      Verfasser

      Pat, thanks for your comment. Actually, I can’t tell what happens to pictures from Canon / Nikon or any other manufacturer when loaded into Lightroom. I think, that Sony is causing more issues and confusion than doing any good with either applying lens profile changes to the RAW or with „allowing“ Lightroom to apply these changes during import (if that is the case).

  4. Thomas sagt:

    Hi Jorg – very interesting test.

    I noticed this some time ago in Lightroom (4 and 5). I noticed that with the Sony NEX6 or A6000, the lens profile option „Chromatic Aberration“ had no effect at all on the images, and there was no sign at all of chromatic aberration in any image (which seemed impossible). Meanwhile, the „Distortion Correction“ option did have an effect on the images, straightening barrel or pincushion distortions. I was forced to conclude that either Sony lenses were exceedingly good (hahaha), or that chromatic aberration correction was being baked in to the RAW images.

    This was exceedingly obvious to me, because at the time I was also using a Canon 7D and several L series lenses in excellent optical condition, and ALL images from the Canon system benefited significantly from chromatic aberration correction in Lightroom.

    Clearly it was impossible that the cheap Sony 16-50 kit lens (which exhibited insane amounts of everything bad on my FS700 cinema camera prior to the lens correction firmware update for that unit) had absolutely no chromatic aberration while an expensive Canon L series had noticable amounts.

    Thank you for scientifically testing this, it is something that Sony do NOT clearly state in their documentation. It’s also a shame that the correction tables are not held in the LENS firmwware so that all future lenses were automatically compatible with existing Sony cameras. Sony do not have a great history for updating firmware on their cameras, and with the E-mount system still so young, it’s a sure bet that there will be many future lenses incompatable with cameras of today.

Ich freue mich auf Deine Meinung:

Trage deine Daten unten ein oder klicke ein Icon um dich einzuloggen:

WordPress.com-Logo

Du kommentierst mit Deinem WordPress.com-Konto. Abmelden / Ändern )

Twitter-Bild

Du kommentierst mit Deinem Twitter-Konto. Abmelden / Ändern )

Facebook-Foto

Du kommentierst mit Deinem Facebook-Konto. Abmelden / Ändern )

Google+ Foto

Du kommentierst mit Deinem Google+-Konto. Abmelden / Ändern )

Verbinde mit %s