The process is reversed in the raw converter. The algorithm proceeds across all the columns in a row, then moves to the next row down, does it again, until it runs out of rows. Otherwise the step is 16.įor each of the remaining 14 pixels, the minimum value is subtracted, and the result divided by the step size, truncated (or rounded that’s what I did) and encoded as a 7-bit number which is stored. If the span is more than 512 and equal to or less than 1024, the step is 8. If the span is more than 256 and equal to or less than 512, the step is 4. If the span is more than 128 and equal to or less than 256, the step is 2. If the span is equal to or less than 128, the step is 1. Then a value called the step is calculated. The minimum is subtracted from the maximum to give a number that I call the span. and an even row would begin GBGBGBGBGB.įor each group of 16 pixels, the maximum and minimum 11-bit values are found, and the indices of those values recorded as two four-bit numbers. Odd and even are defined assuming that the first row is row 1.Īs an example, an odd row would start out RGRGRGRGRG. Because of the RGGB Bayer color filter array, that gives 16 green pixels in all rows, 16 red pixels in the odd rows, and 16 blue pixels in the even rows. The delta modulation extracts successive groups of 32 pixels within a single row. The tone curve applied to the 13-bit linear data is a linear interpolation between a curve defined by these input points: 0 1000 1600 2854 4058 8602, and these output points: 0 1000 1300 1613 1763 2047. CRAW is only capable of 13-bit precision. You can easily verify that by looking at some compressed raw single shot files with RawDigger. So the table Sony publishes (see link above) that says it is 14 bits is wrong. The CRAW compression algorithm throws away the LSB. Compressed single shot has a precision of 13 bits. Uncompressed, single shot has a precision of 14 bits. But, I was definitely using AF-C when in compressed during the first session. Honestly, I'm sure they were all ISO 100. Try using Rawdigger or FastRawViewer to see if you are clipping a channel. In single shot mode, no change in bit depth.ĭon't use fake ISOs. Anyway, curious what anyone thinks! I'm very competent in post and use C1 20 and the differences between the first session and the last were there. I'd bet the color bit depth would drop a bit with compressed, which might make for challenges with less even lighting (I'm always at ISO 64 or 100, FYI) like around Golden Hour. Ha, so I feel like this could be a compressed/uncompressed thing or something with the Sonnar 55, which would surprise me. Fast forward to a few days ago and where I did the same test (this time with the ART 50 in E-mount) and the files were virtually identical (differences in green, very correctable in post). In short, I found a few difficulties in skin (sort of splotchy, irradiated spots) under lower lighting conditions and the R4/55mmm. I took my R4 out for a paid session to try it out several weeks ago with a Sonnar 55. The image area within the fastrawviewer on my 4K monitor is approx 2590 x 1660. Post processing raw noise reduction can take a longer time to get a much better result. Note the quick Z6 noise reduction blur in the jpg. The raw is actually a bit wider than 14mm.) That crops off a little of the raw image to handle the barrel distortion. Note the wide angle distortion correction in the jpg. These examples have none of those enhancements.ġ4mm, ISO 6400, 1/15 second, f/4, -1.66 EV The viewer can show things like over or under exposure areas, contrast edges, shadow detail brightened, etc. This is the top left corner at 100% scale, screen grabbed from the fastrawviewer central view panel on my 4K monitor. The shortcut key "J" toggles to the jpg or back to the raw. I can Ctrl-Z to undo the last few deletes, or browse the rejected folder and move files from there as needed. It creates the folder at the first delete. I set it to use the Del key to move the current raw image and it's jpg to a _Rejected sub folder.
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