Export to DNG Denoise and Optical Corrections Only question

Reading through some of the forums I decided to try the idea of using ‘export to DNG (Denoise & Optical Corrections Only)’ as a way to work on my DeepPRIME denoised images. Two things surprised me:

  1. The export was very fast, much faster than a normal JPEG export with all of my corrections.

  2. The output file was larger dimensionaly than the raw file. For example a raw file that is 2620x1956 exports as a 5185x3888 DNG. In this example the image was shot with a 20MP sensor, and that is approximately the size of the resulting DNG.

So for those that understand these things could you give me a quick explanation (or a link to point me in the right direction) as to what is happening here? I’m guessing (and that’s all it is) that the original raw file (ORF in this case) has some type of compression that the DNG does not.

I’m happy to share more details if I didn’t provide enough information. Thanks in advance for answering.

Hi, Todd. If the image was shot with a 20MP sensor, how is the RAW file 2620x1956? The image wouldn’t have those dimensions unless it were cropped, and that info is not stored in the RAW file. If you mean that the DNG file is a lot bigger than the RAW file, then yes - that is to be expected.

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You are absolutely correct. The image software was reporting the file size of the ORF file incorrectly. The original and the DNG output are very close. I expected the file size to be larger so I don’t really have a question at this point.
Is there a way for me to delete the thread?

So after further experimentation I do have a follow up question. Other than the large file size is there any drawback to doing the raw to DNG conversion (loss of data in the shadows etc.)?

It seems like the DNG files are easier to work with in PL on a slow machine. It seems counterintuitive that the larger file would be more easier for PL to handle but it certainly seems to be. And the export to JPG is very quick since the denoise part was taken care of in the conversion. If there is no drawback that I am unaware of I am considering a change to my workflow to do the DNG conversion up front and all remaining edits on the DNG.

Since it is not documented yet, most people are not aware of exactly which tools are included in the Export as (Denoise & Optical Corrections only).

Besides HQ, PRIME and DeepPRIME denoising, this export includes the following features if they have been selected: Lens Sharpness (but not the Unsharp mask), Distortion, Vignetting, and Chromatic aberration . Additionally, if Viewpoint 3 is installed, Volume deformation is also exported. No other PhotoLab settings are included in this export.


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I’m thinking that you are seeing the dimensions of the embedded JPG in the RAW(2620x1956). There is no loss of information in the RAW to DNG conversion. You can edit the DNG as if it were the ORF. Even the white balance and color rendering is still in the sensor’s color space. I use this method almost exclusively. It’s a great way to edit!


As @mwsilvers wrote all lens based corections are also in there.
Chromatic Abberations are bount to white balance and if you use rawDNG the CA correction is set, done, fixed. So when you shift colors to much you will see new CA.

When you work in raw every change is causing a recalculating of optical module corrections and CA is one those who is constant changed when you change WB, exposure levels, saturation levels.
That’s why working in Raw is slower then working in DNG.

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