1. What is Jaliko LensTool?

 

Camera and Lens Compatibility

  1. What cameras/lenses can be calibrated with LensTool?

 

 

Calibration and Correction

  1. How long does it take to calibrate a lens with LensTool?
  2. How many images should I capture for calibration?
  3. At which aperture setting should I capture calibration images?
  4. Some images have status 'skipped' after calibration is completed. What should I do?
  5. Some images have status 'pending' after correction is completed. What should I do?

 

Comparison with Existing Aberration Correction Software

  1. What differentiates LensTool from PTLens©?
  2. What differentiates LensTool from Adobe©'s lens correction tools?
  3. What differentiates LensTool from DxO Optics Pro©?

 

 

General

  1. Is LensTool available as a plugin to Adobe© Lightroom/Photoshop©?
  2. Can LensTool correct lens distortion in images captured with a fisheye lens?

 


 

  • What is Jaliko LensTool?

LensTool is a desktop software application for improving image quality by removing lens distortion and lateral chromatic aberration from digital images. It achieves precise corrections by 'learning' the aberrations specific to any individual lens through a calibration process. Once a lens has been calibrated in LensTool, any images captured with that lens can be automatically corrected in LensTool at the click of a button. The corrections are tailored to that specific lens for maximum correction accuracy.  

 

Camera and Lens Compatibility

 

  • What cameras/lenses can be calibrated with LensTool?

Camera Compatibility: Most digital cameras that output images in raw (mosaiced) format are compatible with LensTool. Exceptions are cameras whose image sensors do not use Bayer RGB filters. The vast majority of digital cameras use such Bayer filters with their image sensors (some Fuji cameras, e.g., those with X-Trans sensors, do not). Compatibility of your camera with LensTool can be verified by performing a calibration with any two images from your camera. A warning message will be displayed if the images are from a camera that is incompatible with LensTool.

 

Lens Compatibility: Calibration and Correction requires information about lens aperture and lens focal length. Most digital interchangeable lens cameras record this information in the image EXIF data, from which LensTool extracts this information. Cameras/lenses that do not record this information in the EXIF data cannot be calibrated or corrected with LensTool. Consequently LensTool cannot currently be used to calibrate manual lenses, as the lens settings are not recorded in the image EXIF data. LensTool also requires information about lens focus distance, however if this information is not included in the EXIF data LensTool will prompt the user to enter it manually.

 

It is recommended that you test your camera with the trial version of LensTool to ensure compatibility before purchasing.  

 

Calibration and Correction

 

  • How long does it take to calibrate a lens with LensTool?

Prime lens: a prime lens should be calibrated at approximately 6 different lens configurations. At each lens configuration the calibration chart should fill the entire field of view. In order to achieve this anything from 1 to 8 images may be required per configuration. Hence a good prime lens calibration typically requires between 6 and 21 images of the calibration chart to be captured, depending on the lens focal length and calibration chart size. Typically these would take less than 5 minutes to capture.

Zoom lens: a zoom lens requires more images than a prime lens due to the focal length variation. When calibrating a zoom lens with LensTool, images shot at approximately 36 different lens configurations are required. As with the prime lens calibration, in order to fill the entire field of view of the image at each lens configuration multiple images are required (typically between 1 and 8, depending on lens focal length and calibration chart size). Hence a zoom lens can require between 36 and 126 images to be captured. Typically these would take less than 30 minutes to capture.  

 

  • How many images should I capture for calibration?

Generally you should capture 5 to 6 images per aperture setting and per focal length setting, giving a total of 25 to 36 lens configurations at which images should be captured for a zoom lens, and 5 to 6 for a prime lens. Images should be shot at various focus distances by altering the distance from the camera to the calibration target. For small calibration targets and/or short focal length lenses, multiple images at each configuration may thus be required in order to fill the entire field of view. Hence between 21 and 126 images may be required, depending on the lens being calibrated and on the calibration chart size.  

 

  • At which aperture setting should I capture calibration images?

Shoot at the minimum aperture, the maximum aperture, and at 3 or 4 apertures between these two values. Shoot at approximately evenly spaced apertures, although the spacing should be smaller towards the larger aperture (small f-number) end of the aperture range. Please refer to Capturing the Images for Calibration for more detailed information on the calibration procedure.  

 

  • Some images have status 'skipped' after calibration is completed. What should I do?

This is typically a result of the calibration images being out of focus or noisy. Capture images under good lighting conditions and ensure that the grid target is in sharp focus. A good calibration can generally still be achieved with one or two ‘skipped’ images.  

 

  • Some images have status 'pending' after correction is completed. What should I do?

 

If this happens, perform the correction again with just the ‘pending’ images selected.  

 

Comparison with Existing Aberration Correction Software

 

  • What differentiates LensTool from PTLens©?

1. LensTool allows you to calibrate your lenses without depending on any third party. PTLens© does not allow you to calibrate your own lenses - images with straight lines (building facades are recommended) must be captured and sent to the PTLens© developer for calibration. Lenses that have already been calibrated in such a fashion are available through the PTLens© software.

2. LensTool performs automatic corrections for both lens distortion and lateral chromatic aberration. PTLens© performs automatic correction for distortion and provides manual adjustments for chromatic aberration.

3. LensTool enables corrections at the complete range of focus distances. PTLens© calibrations are only valid for 'distant' objects. As lens distortion depends on focus distance, images captured at short focus distances may not be corrected fully using PTLens©.  

 

  • What differentiates LensTool from Adobe©'s lens correction tools?

LensTool is an all-in-one calibration and correction tool - purchase of additional correction software is not required. Adobe©'s Lens Profile Creator (LPC) enables users to calibrate their lenses. However, image corrections that use this calibration information must be made using an Adobe© product (e.g., Lightroom©, Photoshop©).  

 

  • What differentiates LensTool from DxO Optics Pro©?

LensTool enables users to perform their own calibrations, thus corrections for images from new-to-market lenses can be easily made by the user in LensTool within a matter of minutes of acquiring the lens. DxO Optics Pro© supplies a database of calibration information for many existing lenses. In order to perform image correction, the lens used to capture the image must have been calibrated by DxO© and released in their database. With DxO Optics Pro© the user must wait for DxO© to calibrate the lens and then release the calibration information before corrections for that lens can be performed.

 

 

General

 

  • Is LensTool available as a plugin to Adobe LightRoom/Photoshop©?

No, LensTool is not currently available as a plugin.  

 

  • Can LensTool correct lens distortion in images captured with a fisheye lens?

For lenses that induce severe lens distortion, termed fisheye distortion, LensTool will not be able to perform complete correction. This is because the mathematical model describing fisheye distortion differs from that which describes non-fisheye distortion. It is envisaged that in the future a fisheye distortion model will be incorporated into LensTool so that it can perform accurate calibration and correction of fisheye lenses. Currently LensTool only incorporates the distortion model that describes non-fisheye lens distortion.  

 

 

 

 


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