Scatterbrained wrote in post #18530352
Personally, I just export to TIFF for editing and use Lr to export jpegs for web or print. I don't bother deleting the TIFF files, I just buy a new drives as they fill up, 1TB at a time. I have a full ATX tower so there is plenty of room for SSDs in there.
digital paradise wrote in post #18530364
So you save and bring them back into LR for export? Yeah storage is so cheap these days.
Same here, if I need to go to Ps then I just keep the full 16 bit file, with layers, and use that to export my finished images to JPEG as and when needed. In my case though I use .PSD instead of TIFF.
One thing that I will add is that some time ago I did some tests to assess the results from using all of the 13 possible levels of JPEG compression, compared to the original image in 8 bit, saved as a TIFF. Yes it was possible to see a difference in the R, G, and B values for many pixels when using the top three levels of JPEG quality; 10, 11, and 12. So the results of encoding from the original in each case were different. What was interesting though was not the comparison between the different JPEG files, but the comparison back to the original uncompressed 8 bit data.
What really stood out was the fact that although the specific channel values were different in each JPEG file, the level of deviation from the original data was identical across all three levels of compression. The only thing that really changed between them was the specific pixel location for any variation. Most pixels would not normally have more than one channel with a variation, and most of the variations were either ±1. I don't think I could find any cases where the deviation from the original was higher than ±5 or 6.
Given the way that JPEG works, using a maximum value results in a file with no compression, so the file size is the same as the TIFF. If you move to level 10 though you get a significant reduction in file size, for no measurable increase in deviation from the original pixel values compared to using the highest quality setting. Using a setting of Q10 though will give you a file size reduction of between 40% and 60% depending on image content.
So if you are going to convert the image to JPEG you should use Q10 as your highest setting, since it is impossible to measure the difference between quality of that compared with a maximum quality setting file, but it could result in a file that is less than half the size! Needless to say you really cannot perceive the differences between any of the images from any of the files. I did it with images with both lots of very fine detail, and areas of very large smooth gradients.