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Showing posts from January, 2022

Lossy DNG File Sizes by ISO.

Fairly recently I discovered the magic of lossy DNG's. My stock photo library is ever growing. Though JPG's might really be enough for my archive, I've been keeping my raw files. RAW files take up lots of space. And RAW files can't typically keep user generated EXIF data in the file. RAW files keep their keywords and other metadata in a sidecar, that is if you regularly save the EXIF data to file. So recently I've been converting all my RAW files to lossy DNG's. After testing the highest ISO setting on the new-to-me A7R IV, I converted the files to lossy DNG's only to find a surprise. The very high ISO lossy DNG's were much larger than the original Sony RAW files! Lossy ARW vs Lossy DNG full image sample So I thought it would be a good test to shoot from the lowest to highest ISO, convert to lossy DNG and see where the file size savings invert. Here's the data as seen in the above screen shot: ISO Lossy Sony ARW Raw file size (MB) Lossy DNG file siz

Negative scans with a new method

  For years I used a Nikon Coolscan to scan my slides and negs. Those scanners use a less-common Firewire connection (Apple sucks!) Now at the school lab I run, we use Epson V700 scanners. The quality of scans for 35mm especially leaves a lot to be desired!  Here's what I did...... Put my Sony A7rII with a macro (a real macro that can do 1:1) on a copystand Put a flat panel LED light box on the stand Put my negative in a negative carrier (I tried a few carriers, in this case the neg carrier is for a Besler 45) Put a couple of boxes (in this case 100' rolls of Kodak Plus X from the 1980's) to space out above the light box (prevents dust showing from on the lightbox) For comparison, I also scanned a set of negatives on the Epson V700. The results showed me that I shouldn't be scanning 35's on the Epson! Epson vs Camera Scan, overview Right off the bat, some of the exposures from the Epson in default mode looked pretty crappy. But I chose this Epson scan (on the left)