R7 in camera lens correction?

da7329

I assume with all in camera lens corrections on the corrections are written to the raw file.  Using RF lens is best to use in camera corrections or DXO or ACR corrections when processing a raw file? ThanksDA


Gam3r01

The lens corrections in body are the same as the ones in DPP4, if you wanted to compare.I found on my RP and R6 that DXOs lens corrections were the best, especially for lenses like my 24-240 or 16mm which all require heavy software corrections.


koenkooi

da7329 wrote:I assume with all in camera lens corrections on the corrections are written to the raw file. […]It is unclear whether they are written to the CR3 as metadata or not, but we do know that DxO and ACR donotuse them. Both DxO and ACR create their own corrections, which is why it can take a few months or years for a lens to get supported.


Zeee

As stated only DPP recognises it and any in camera adjustments just slow things down.


drsnoopy

da7329 wrote:I assume with all in camera lens corrections on the corrections are written to the raw file. Using RF lens is best to use in camera corrections or DXO or ACR corrections when processing a raw file? ThanksDAThe corrections are not “written to the RAW file”. They are however written to the embedded preview jpeg (that you see in the EVF or in the rear LCD), and to the jpeg itself if you are recording JPEGs as well.The EXIF data identifies the camera and lens information, this is then used by the RAW processor to look up correction profiles from its own internal database.  Canon’s own DPP will apply identical corrections to the in-camera corrections when processing the RAW file. Similarly, Adobe ACR/LR will apply its own correction profiles which it has developed independently and are not necessarily the same as Canon’s. Likewise with DXO and others.  In my experience they can all differ, particularly with lenses that need more than modest correction.  I prefer DXO’s profiles; in my hands they give the best distortion and sharpness correction. Often the differences are fairly minor, and you will find varying opinions as to which are best.  It is worth checking that the software you are considering has the necessary profiles for your equipment.  It’s probably more important to choose software you find easy to use than to worry too much over the accuracy of correction profiles.


Kameratrollet

Zeee wrote:As stated only DPP recognises it and any in camera adjustments just slow things down.https://www.iridientdigital.com/products/ctransformer.html"Automatic lens corrections for distortion, chromatic aberration and vignetting. Corrections are based on native Canon lens information specified in their CR2/CR3 metadata. The lens correction stage is optional and lens correction information can also be passed on through DNG opcode metadata and left to later processing stages or ignored altogether. The lens correction processing in Iridient C-Transformer uses the same high quality resampling algorithms as Iridient Developer."Worked with RF 16/2.8.


Marceppy

drsnoopy wrote:da7329 wrote:I assume with all in camera lens corrections on the corrections are written to the raw file. Using RF lens is best to use in camera corrections or DXO or ACR corrections when processing a raw file? ThanksDAThe corrections are not “written to the RAW file”. They are however written to the embedded preview jpeg (that you see in the EVF or in the rear LCD), and to the jpeg itself if you are recording JPEGs as well.The EXIF data identifies the camera and lens information, this is then used by the RAW processor to look up correction profiles from its own internal database. Canon’s own DPP will apply identical corrections to the in-camera corrections when processing the RAW file. Similarly, Adobe ACR/LR will apply its own correction profiles which it has developed independently and are not necessarily the same as Canon’s. Likewise with DXO and others. In my experience they can all differ, particularly with lenses that need more than modest correction. I prefer DXO’s profiles; in my hands they give the best distortion and sharpness correction. Often the differences are fairly minor, and you will find varying opinions as to which are best. It is worth checking that the software you are considering has the necessary profiles for your equipment. It’s probably more important to choose software you find easy to use than to worry too much over the accuracy of correction profiles.So true, good advice.   One caveat on lens corrections, the correction can sometimes change the size of images, even by one pixel.  I found that in a stacking program, the optical change caused the stack to error.  After redoing the raw files without the lens correction engaged, it worked fine.


JohnMoyer

drsnoopy wrote:da7329 wrote:I assume with all in camera lens corrections on the corrections are written to the raw file. Using RF lens is best to use in camera corrections or DXO or ACR corrections when processing a raw file? ThanksDAThe corrections are not “written to the RAW file”. They are however written to the embedded preview jpeg (that you see in the EVF or in the rear LCD), and to the jpeg itself if you are recording JPEGs as well....I find the diffraction correction and correction for the low pass filter done by the camera or by DPP very valuable.I do not know what lens corrections are done by DXO or ACR. If they do diffraction correction and assume a circular aperture and a gaussian blur, then the only information needed would be the spacing of pixels on the sensor chip and the F number.DPP only does corrections for Canon lenses, so far as I know. If using a third party lens, then another program will likely be better than DPP. If the only corrections desired are distortion and peripheral illumination then other software is likely to be as good or better than DPP.A record of the lens corrections is written by the camera in the meta data in the RAW file, so in that sense it is written to the RAW file because it is in the file but it is likely in a form that can only be used by DPP. This information includes the amount of "digital lens optimization" chosen by the camera if it were enabled in the camera menus. When the raw file is opened in Canon DPP, one may see what amount of digital lens optimization the camera would have chosen. Setting digital lens optimization to high in the camera menus seems to me to slow down the camera, but in DPP one may double the amount chosen by the camera for "Standard" as an approximate starting point for "High".DPP permits one to choose among peripheral illumination, distortion, diffraction correction, color blur, and Chromatic aberation. If digital lens optimization were enabled in the camera menu, then some of those will be grayed out and unavailable until one disables digital lens optimizer in DPP.The digital lens optimizer seems to me produce similar results to a Richardson/Lucy deconvolution for small aperture diffraction blur. If there is much noise reduction, the digital lens optimizer seems to me to bring back the noise and the camera will have chosen a smaller amount for the digital lens optimizer. If the amount is set too high even with a low noise image then there may be some artifacts like ringing which can only be noticed when viewing at 100% or greater magnification.According to the manual for my camera (yours may differ):"Digital Lens OptimizerVarious aberrations from lens optical characteristics can be corrected, along with diffraction and low-pass filter-induced loss of resolution.If [Correction data not available] or [] is displayed by [Digital Lens Optimizer], you can use EOS Utility to add the lens correction data to the camera. For details, refer to the EOS Utility Instruction Manual.CautionNote"


koenkooi

JohnMoyer wrote:[...] I find the diffraction correction and correction for the low pass filter done by the camera or by DPP very valuable.I do not know what lens corrections are done by DXO or ACR. [...]DxO and ACR don't do diffraction correction, but the 'lens sharpness' slider in DxO does something that gives a very similar result. In LR you can then use the 'texture' slider in a mask to further improve things. Both DPP4 and DxO do fairly well with keeping the bokeh smooth, sharpening tools in LR/ACR tend to sharpen that as well, leading to very harsh and distracting looking backgrounds in my macro pictures.I replaced my EF85 f/1.8 with the RF85 f/2 and haven't needed DPP4 as much. I should revisit it and do a comparison before we leave on the family vacation this summer!


Zeee

Kameratrollet wrote:Zeee wrote:As stated only DPP recognises it and any in camera adjustments just slow things down.https://www.iridientdigital.com/products/ctransformer.html"Automatic lens corrections for distortion, chromatic aberration and vignetting. Corrections are based on native Canon lens information specified in their CR2/CR3 metadata. The lens correction stage is optional and lens correction information can also be passed on through DNG opcode metadata and left to later processing stages or ignored altogether. The lens correction processing in Iridient C-Transformer uses the same high quality resampling algorithms as Iridient Developer."Worked with RF 16/2.8.Wasn’t aware of that. Thanks  I remember how the buffer choked when I tried high noise reduction many years ago so I just shut everything in camera off just in case.


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