Put simply, Rawsie is software that reduces the size of your Raw files considerably, without any loss of quality in your raw file. It’s designed to free up space on your hard drives, make online back ups quicker and also to speed up your workflow.
I shoot with the Sony A1 cameras, and the files that come out of that camera are HUGE. They’re well over 100mb. After running them through Rawsie, they’re now in the 20-25mb territory.
I’ve loaded up both my Rawsie files and my original Sony Raws, and I cannot see any visible difference, even enlarged to 200%, on images where I’ve boosted exposure by 5 stops in Lightroom, which should really test it.
Here’s what Rawsie say on their website about their compression-`
“Rawsie takes this difference as the “leeway” for modifications to compress the image. There is potential for a small amount of information loss, and maximum information loss per pixel is 0.3 bits. This is equivalent to having a slight amount of increased noise, so, an image taken at ISO 100, after passing through rawsie will look as if it were taken at ISO 115. So, there is a small amount of loss, but it is ~10x less than JPEG / Lossy DNG, which also concentrates the loss in areas of high detail and makes images look less sharp.”