how can i keep RAW dynamic range when processing images

[mudman]

yesterday i was looking at my images taken with my 50mm lens
i shot both RAW and JPEG, and noticed that the RAW images were up to 60 meg, while their JPEG images were 25 meg
so i thought, ' how can i process the RAW files, and save them to keep their dynamic range'
can anyone advise me please

[nardes]

I believe that with a RAW file, you can essentially generate multiple copies that displays the full dynamic range, but over those copies rather than in a single file. So, you may end up with new -1, 0 and +1 copies, or whatever combination gives you the DR you want.

You can then take these copies and merge them using a HDR application so the final HDR merge will display a more complete dynamic range than a simple JPG conversion.

This way, you keep your original RAW file (always a good idea) and can discard the multiple copies that fed into the HDR final shot.

Cheers

Dennis

[ameerat42]

yesterday i was looking at my images taken with my 50mm lens
i shot both RAW and JPEG, and noticed that the RAW images were up to 60 meg, while their JPEG images were 25 meg
so i thought, ' how can i process the RAW files, and save them to keep their dynamic range'
can anyone advise me please

About the file size difference: the jpeg stores less image data AND it is compressed (even if not much by being set to highest quality).
About keeping the same dynamic range: you can't at all if saving as jpeg. Hue and luminance info will get set to the nearest set bandwidths.
You might have a better go if you use a tiff with a close bit value to your raws, ie, a 16-bit tiff rather than an 8-bit tiff, the difference
being that it is lossless compared to the data loss due to compression in a jpeg.
And then: what's the color depth of your monitor? - And the program you're using to view it with?

But if you want: to show a fair representation of the tonal (and colour) values of the raw file then go along the lines that Nardes says.

[gcflora]

About the file size difference: the jpeg stores less image data AND it is compressed (even if not much by being set to highest quality).

Just a small nitpick: most raw files are also compressed, but it's lossless compression (like TIFF's LZW or ZIP compression modes). That's why raw files differ in size from shot to shot (for all Canon cameras anyway, and all Nikons that I've encountered).

Edit:
Interesting: "Most raw formats implement lossless data compression. [...] Several Nikon cameras let photographers choose between no compression, lossless compression or lossy compression for their raw images." (https://en.wikipedia.org/wiki/Raw_image_format)