So lately I have been entertaining the idea of using RAW+ as a mode for my cameras. There are however drawbacks to using that mode that I won't get into now, but it appears to me that it's possible if just simply shooting RAW for you to always derive the Jpg from the shot (complete with the Jpg settings used at the time of the shot from a couple of ways), either;
a) Use the camera itself and upon Playback>Downward Arrow Press>Raw Development
or
b) Use third party software, such as FastStone Image Viewer (FSIV) to somehow extract a decent copy of the Jpg preview file from the RAW DNG.
Here's what I have discovered thus far, but would appreciate some additional guidance from those with more know-how.
So Far
Ok, so to test things I took a picture in RAW+ mode, and generated an image with a DNG of 48.7mb and Jpg counterpart of 19.4mb (L, *** sRGB etc). I was using this as a kind of reference.
When viewing the DNG file in FSIV it actually shows the Jpg Preview, you can tell this easily with a test such as setting the camera settings Custom Image to being monochrome (BW), that's what you will see on FSIV, not the actual colour RAW file like how LR would present.
Now if I simply go 'Save As' in FSIV it will generate only a smallish file sized Jpg. From my 48.7mb DNG file it spat out a 5.77mb Jpg file (not quite the 19.4mb Jpg version the camera managed in RAW+ mode).
But what's this? There seems to be some additional Save Settings we can mess around with for the Jpg 'Save As' with the FSIV program, problem is I don't know what half this stuff means (see screen shot below).
Can You Help?
Look at the screen shot below and the variables we can change, and let's run through them all as they all impact the File Size of what the Jpg will end up as (actually trumping the 19.4mb the camera manages to generate for the Jpg in RAW+ mode!).
Ok let's first look at 'Quality', no brainer, we can slide that sucker up from 90 to 100. The new file size is now 14.4mb just from that tweak alone. Is it worth it? That's something else to consider... but we shall move on and look at the other settings.
Under Advanced we see 4 options, lets start with 'Photometric', it seems to be on 'YCbCr', perhaps this is default? Should I click the pull down menu I see the following options;
RGB
Grayscale
YCbCr
CMYK
YCbCrK
Changing to each of these gives the following new file size (provided we have still kept the Quality slider at 100).
RGB =
37mb
Grayscale =
10mb (image turned monochrome, durr)
YCbCr =
14.5mb
CMYK =
56mb! (um wat? this Jpg is now more mb than the RAW? lolwot)
YCbCrK =
38.5mb
Ok, cool... what does all this mean? I have my camera color space set to being sRGB, is that relevant to this area?
Ok we shall leave it as default YCbCr for now. Next up we have that little 'Progressive' box to tick, so tick it I shall. It has now reduced the file size from 14.5mb down to 13.4mb, ok I'm going to untick that
Across from that we have 'Optimize Huffman", it seems to be ticked as default, I'm going to untick that and see what it does to the file size. Ok, that pushed the file up to 17.6mb. So I'm guessing 'Progressive' and 'Optimize Huffman' are both some kind of compression? I think I shall leave them off for now.
Lastly we have 'Color Subsampling', it's default is set at 'High (Smaller File Size)' so lets change that, what options do we have?
'Disabled (Better Quality)' = 24.4mb image (if using this mode).
'Medium' = 18.7mb image (if using this mode).
Or
'High (Smaller File Size) = which gives us our aforementioned 17.6mb file.
So... that seems to be about it, but we can take DNG file and extract a hefty Jpg via FSIV, and we can do batch files Saves/Converts as well.
Would anyone like to weigh in with their thoughts on all this and the options and what we should perhaps set things at?
Summary
It might be that I decide to shoot RAW only and leave RAW+ alone, so that I don't hit possible buffer/write issues when on a job. Once the job is done I could always do a batch conversion of my RAW files and 'extract' those Preview Jpgs that the DNG's seem to have and get a size close to what the camera would generate. Then work on the Jpgs from editing perspective with RAW files still there if I need them. It's simply a case of how quickly I want those Jpgs, as I take the shot or at a later time at the computer and after I run a batch conversion.
Cheers,
Bruce