food ~ after the fact (and some tech stuff)
Monday, October 24, 2011 at 04:24PM 
Beets with goat's milk feta and a pork chop with sage ~ locally grown and raised / Au Sable Forks, NY - in the Adirondack PARK • click to embiggenI thought I would use this picture to mention some tech stuff, 2 items of which were asked in recent comments.
The picture with this entry raises an interesting question. It was made under "new" lighting conditions for which, to my knowledge, there is no in-camera (any camera) WB setting for the color temperature emitted by those newfangled energy efficient CFL light bulbs. CFL bulbs are advertised as fluorescent devices although, through the use of improved phospher formulations, they are claimed to have improved color perception characteristics such that some sources rate the best "soft white" CFLs as subjectively similar in color to standard incandescent lamps.
That claim is tempered (IMO) by the words, "perception", "subjectively similar", and "best" - words that mean nothing to a camera sensor. Add to that "fuzziness" the fact that different makers use different formulas and what you have is a veritable rat's nest of color temperature variations. Consequently, creating a "standard" CFL light source WB setting is neigh unto impossible at worst, ballpark-ish at best.
My solution is to set my WB for tungsten and then correct for the WB imbalance in my RAW workflow processing. If anyone knows a better way to deal with the issue, please let us know.
While we're on the subject of WB, on the civilized ku # 1151, John Linn asked:
You said "My camera WB was set to "CLOUDY"."... why is that relevant if you are working in RAW?
I use in-camera WB settings for a few reasons: 1) using the "correct WB setting allows the camera LCD to display my pictured referent with reasonable color accuracy, and 2) since color and color relationships are an important part of how I see (and therefore "compose"), viewing the proper color on my camera LCD is important to me, and 3) when the picture file opens in my RAW conversion software, it is, once again, displayed with a very close starting point from which I can make subtle adjustments (if needed).
On the same entry, "Chris" (no link provided) stated/asked:
How do you handle the lack of lens distortion correction in Raw Developer? Many MFT lenses have significant barrel distortion and chromatic aberration that's expected by the manufacturer to be corrected in software. The Olympus raw software, Lightroom/ACR, and Aperture/iPhoto all "understand" how to correct distortion.
I perform lens distortion correction using the Lens Correction filter in Photoshop. Chromatic aberration, which I encounter on only a small percentage of my pictures, is also handled as part of my Photoshop processing procedure. While other RAW conversion software may handle these issues "automatically", I still prefer the "film-like" files that I get from using RAW Developer. So I consider the additional work in Photoshop to be part of doing business with RAW Developer and, to be honest, that additional work is neither difficult nor time consuming.
gravitas et nugalis
Featured Comment: both "ausserirdischegesund" (no link provided) and Beau Comeaux left comments which suggested I make a custom WB setting for my CFL situational needs.
my response: Prior to making this entry, I considered that idea and promptly rejected it. As I mentioned in this entry, making a CFL WB setting seems to me to be a waste of time inasmuch as "ausserirdischegesund" pointed out - ... CFLs are typically labeled by colour temperature (and colour temperatures indeed vary wildly from 2700K to above 6500K) ...
IMO, unless one is using a specific / known / controlled CFL light source which remains constant, creating a custom CFL WB is exercise in futility.
gravitas et nugalis
Featured Comment # 2: Sven W (no link provided) wrote: "The light in this image looks very different to your usual indoor pictures. Perhaps the image is just a little too "high key" but it somehow looks "thin" or washed out, rather than "rich"."
• click to embiggenmy response: Sven - good catch. In the making of this picture, I was specifically attentive to my perception of the color and contrast of the CFL light. In the RAW conversion and subsequent PS processing, I attempted to faithfully capture that perception (even to the point of leaving the setup on the table and returning to it several times during my conversion / processing endeavors). The resultant look is more low contrast than high key which creates a rather muted color look.
After obtaining results I deemed to be "accurate", I reconverted / reprocessed the file to what might be called a more "normal" look (which essentially meant dialing in more contrast). That look is indeed "richer" (see picture in this update). Although, if pressed to choose one or the other for presentation, I am not certain (at this time) which one I would go with.
Reader Comments (4)
set a custom white balance in the camera and then shoot away
1. The light in this image looks very different to your usual indoor pictures. Perhaps the image is just a little too "high key" but it somehow looks "thin" or washed out, rather than "rich".
Of course, if this is the effect you were after then it worked just fine ;).
2. Are there any Windows PC based raw converters / editors that give a "film like" rendering? I'd love to try RAW Developer but it's only for Apple PCs.
[I currently use Canon's DPP product.]
I used to use CFLs for a specific project quite extensively, and unless I wanted an intentional colour-shift, I had the following workflow: I photographed a grey card with the CFL as the only light source, made a white balance by colour picker in the raw converter, and looked up what colour temperature and green factor the converter gave me (it is a number below the slider on my converter). I wrote down the numbers, and next time I could a white balance without any grey cards etc, just by using the numbers.
Also: In Europe CFLs are typically labelled by colour temperature (and colour temperatures indeed vary wildly from 2700K to above 6500K). Sometimes colour temperature is "encoded" in a colour code, e.g. 8*27* means 2700K. the "8" signifies the quality of colour reproduction (9 is better colour reproduction than 8, and 7 is garage lighting quality). These codes are most often printed on the CFL itself.
Can you do an in camera white balance by sampling a neutral object in your specfic lighting? Say using a whibal card for example.