Clarkvision: Digital Workflow Summarized

I found ClarkVision via Kotke, I've posted about both on Gordon's Notes recently. This ClarkVision description of workflow is noteworth because the author is an uber-Geek (MIT PhD planetary physics), an astronomer, and a super-serious photographer. The combination yields an almost unequalled knowledge of digital photography details.

I also like it because, it's consistent in many ways with my far more modest experience. I do a lot of these things, but I sacrifice quality for speed and portability. Also, use Aperture image editing, not Photoshop.

I don't agree with his approach to metadata (file names, nothing more), but I sympathize with the goal of avoiding lock-in. I'm making a calculated guess that the mass of photo geeks will provide a solution to save my metadata; until now iPhoto and Aperture both support writing applications that could extract most metada (if Aperture were able to export XML/XMP sidecars I'd be almost sanguine ... but, ominously, it doesn't).

Here are excerpts, the article is a great read ... (emphases mine with some inline comments]

Clarkvision: Digital Workflow

... I scan all my film at the full precision of the scanner. Good scanners are at least 12-bits/channel. The output file is 16-bits per channel TIFF images. I do the minimum processing at the time of the scan and save corrections for the photo editor where I have more control. Scan parameters include:

* Straight-line transfer curve.
* Brightness correction only.
* Little to no color correction...

... Digital Cameras. I do both jpeg and raw format output. Jpeg is only 8-bit, while raw on many cameras is 12 bit and a few now have 14-bit output. Raw files are converted to 16-bits/channel TIFF files... [jg. I use RAW in Aperture, no TIFF conversion.]

... In the photo editor

* 1) I only do 16-bit editing. If the starting file is 8-bit (e.g. jpeg), the first step is to convert to 16-bits/channel. [jg. If you work with RAW in Aperture this isn't an issue ...]

o Why? with integer math, there is always round-off error of 1 bit.... If you do multiple editing steps, added errors can result in poor intensity precision with an 8-bit file. This is called posterization. 16-bit editing provides enough precision so that posterization is not a problem....

* 2) Color Space. Check the color space and convert to a wide color space if not already there. I generally use Adobe RGB 1998.

* 3) Adjust Levels. First adjust the brightest portions of the image to your liking using the levels adjustment tool. For example, in a landscape image I might examine the brightest areas of the images, like clouds and adjust the levels adjustment slider so that the brightest parts just reach a value of 254 or 255 on the 8-bit scale typical of the slider tool. ... This levels adjustment is done on the entire image.

* 4) Curves Adjustment. The next step is curves adjustment using the curves tool. Never use Photoshop's contrast and brightness adjustment tools as they are additive. The curves tool, like the levels tool is a multiplicative tool. Multiplicative has the correct math to mimic changes in scene brightness, exposure, or f/stop changes. In the levels tool, the upper slider is used to derive the multiplier, and lower slider is an offset (a subtractive adjustment), and the middle slider changes the multiplier to a 2-part piecewise line multiplier.

* 5) Dodge and Burn selected regions. Select different regions as desired that may be at the limits of dynamic range and dodge and burn to bring them into printable range. For example, bring up shadow detail, or darken clouds. First select the area with one of the selection tools. Next feather it. Feathering makes the selection area a smooth transition to the rest of the image. Once feathered, adjust the level with one of the three following tools:
o Curves tool,
o Levels tool, or
o Shadow highlight tool.

* 6) Increase Image Size. If I'll be making larger prints, I'll interpolate the image to a higher pixel count. I usually use bi-cubic or bicubic smoother interpolation in Photoshop. [jg: this surprises me. It seems a bit magical, but this guy knows his stuff. This one item suggest how sophisticated modern Photoshop is ...]

* 7) "Sharpen." The main tool many use is called unsharp mask, a filter. But unsharp mask does not actually sharpen! The way unsharp mask works is that the image is blurred using a certain radius, and then the original image is differenced with the blurred image, and the result is added back to the original. The effect is to modify contrast around edges. The amount added back is usually controlled by the user (called amount in Photoshop). The effect is actually a change in acutance, not sharpness. But increased acutance gives the appearance of increased sharpness.

However, there are other methods that actually do sharpen. I use Richardson-Lucy image restoration. Photoshop currently does not have this tool.. [jg: Aperture has two sharpening tools, I use Edge Sharpen but I don't know how it works ...]

* 10) Save the file. Depending on my intended use, I save as a 16-bit/channel TIFF files, or convert to 8-bits/channel and save as jpeg. For best quality, 16-tiff files are necessary. I only save as jpeg at highest quality and only when I do not need highest quality. [jg. I never need his quality, so I always save as JPEG, highest quality, for maximal longevity. I work with RAW in Aperture and toss 'em when I'm done. (The Horror!]...

Flash picture with eyes open? Divide by 3

I think this rule applies to flash photography, but the idea is universally applicable. Flash is not long for this world ... fortunately.

Rule of thumb to avoid photographing people with their eyes... (kottke.org)

... to avoid photographing people with their eyes closed: divide the number of people by three (or by two if the light is bad). ... Jeff writes: 'Way back when we only used film I learned you could tell before looking at the photo whether someone blinked by asking them what color was the flash. If it was white or bluish white, then their eyes were open. If it was orange, then their eyes were closed and they had 'seen' the flash through their eyelids.'

Image Capture for Scanning: the 2nd most underestimated OS X application

Preview is probably the most underestimated OS X application, but Image Capture is close second. For years I've tinkered with a scanning workflow simple enough to outsource to my mother. I came close with Vuescan, but, really, it's still too tricksy.

Today I set my 8yo up with Image Capture, which I'd only recently realized is Apple's OS X scanning tool. He's keen to earn some Lego money, so I told him I'd pay 5 cents for each scan.

I plugged in my old Epson 1660* and Image Capture recognized it immediately. (Had I installed drivers years ago, honestly I don't recall. Most scanner manufacturer software is horrid, so I try to avoid it.)

The scanning worked like a charm. It was very fast at 300 dpi, a bit sluggish at 600 dpi (a new scanner would be faster, no doubt, with only a few bugs and missing features:

1. Image Capture won't remember settings between sessions, but it does remember them during each session.
2. If you keep the default name of "scan" it increments each scan with a number, but I don't think this works correctly if you change the default name. No matter, I used 'A Better Finder Rename' to embed date metadata in the file names. Keep the default.
   
3. The "auto" image improvement setting produced poor results. Manual has quite a few settings (similar to Preview's image editing tools) but I chose None since I was going to edit the lossless scans in Aperture and export archival JPEGs.
4. Don't use PNG. It works fine in Image Capture, but Aperture has trouble with PNG thumbnail creation. It's clearly a bug. I should have just used TIFF, I'm not keeping the TIFF anyway.
5. I had IC set up to launch Preview to view each scan, but sometimes it fails to launch. A bug, so I just turned off Preview. It slowed things down anyway and the confirmation wasn't necessary.
   

Ben's not used to real work, so he started to lose interest after the first 25 scans. Unfortunately I chose a pack that had pictures of his brother in it pre-Ben, I'd have done better with one that starred Ben. I know he wants a Star Wars Lego, so I'm confident he'll be back to his slave labor, though I may have to go to 7 cents/scan.

Here's Apple's blurb on Image Capture, note the reference to Apple's abandoned (they abandon a lot of their tech, it's surprising nobody calls them on this) "Services". iPhoto doesn't even show the Services menu, and Aperture shows it but doesn't support Services ...

Apple - Mac OS X - Image Capture

... Just plug in your digital camera or scanner and you can now directly import your pictures from any application that supports Services and Rich Text Format. All you have to do is choose Services in the Application menu and select Import Image. Image Capture lets you download all or any portion of the contents of your digital camera, crop images to a variety of sizes and delete unwanted pictures from your camera. And you can be sure that your captured images remain true to their source, because Image Capture embeds ICC profiles in the images you download or scan.

Want to share the bounty of your digital images? No problem. Image Capture lets others access the contents of your digital camera or scanner over a Bonjour network. Or create an Automator workflow to send photos to the parents.

The Automator workflow sounds interesting, but really there's not much to improve on from my point of view. It would be amusing if Image Capture were able to pull images off my despised Motorola RAZR phone via Bluetooth, but I loathe the phone to much to bother testing.

*Scanners aren't improving all that much, these are print scans, for the serious work I co-own a semi-pro Nikon film scanner.)

Repairing a corrupted home directory image

Apple tells how to repair a home directory image: Mac OS X 10.3, 10.4: FileVault - How to verify or repair a home directory image. I've never used this solution because it makes backup a mess, and it's one more thing to go wrong. Instead I keep a few key files in a small encrypted image. Still, it's good to know there are some fixes for image corruption.

BTW, if you use an encrypted image file, better be sure there's another admin account on your computer ...

Photo exposure tips

I used to know this stuff -- back when SLRs didn't have batteries. I'd forgotten most of it. The 1/ISO rule doesn't apply in the age of image stabilization ... (via Kotke)

Twelve Essential Photographic Rules - - PopPhotoSeptember 2007

1. Sunny 16 Rule
The basic exposure for an average scene taken on a bright, sunny day is f/16 at a shutter speed equivalent to one over the ISO setting...

2. Moony 11, 8, and 5.6 Rules [shooting the moon]
... full moon is f/11 at one over the ISO setting...

4. Anatomical Gray Card
... Hold your open hand up so it's facing the light, take a reading off your palm, open up one stop, and shoot...

5. Depth of Field Rules
When focusing on a deep subject, focus on a point about a third of the way into the picture to maximize depth of field...

7. Exposure Rules
..."Expose for the highlights, and let the shadows take care of themselves."...

11. Action-stopping Rules
To stop action moving across the frame that's perpendicular to the lens axis, you need shutter speeds two stops faster than action moving toward or away from you...

12. Sunset Rule
To get a properly exposed sunset, meter the area directly above the sun (without including the sun). If you want the scene to look like it's a half-hour later, stop down by one f-stop, or set exposure compensation to minus one.

Online identities: management and multiplication

FMH sent me to this post summarizing online identity management tools: 25+ Ways to Manage Your Online Identity.

Identities on the web add up quickly. Identity management is the "next big thing" and the gold rush has been underway for years. It's a fierce battle.

I currently have manged "major" identities at Amazon, faughnan.com, faughnanlagace.com, Google Gmail/Blogger, LinkedIn, and, yes, even Facebook -- and those are only the ones I can remember right now. I debated including my Yahoo! identity in the mix, but unless Yahoo does something remarkable with Zimbra that's just a front for spammers. I do have a Microsoft Passport (or whatever they call that now) identity as well, but I try to forget that one. I used to have a .Mac identity, but Apple's .Mac hasn't delivered much value for money so that one is in abeyance. There are a myriad of "unmanaged" lesser identities, and of course all my emails have some form of identity associated with them ...

None of these net identities belong to my banks, who own my rock-world identity. Ok, so I have a US Passport, and Canada probably still counts me too.

Eventually I'm going to put links to all the managed digital identities on my faughnan.com page, if only so I can keep track of what's publicly revealed on each profile. Amazon in particular makes it easy to unwittingly reveal information, fortunately my reading tastes are rather dull.

BTW, John Gordon, in case you can't tell, is a pseudonym.

Big google search improvement: date range

Matt Cutts tells us that Google's advanced search now offers real date range search -- but then tells the real secret -- how to craft URLs that embed time-based searches:

Useful Google feature: better date search:

...This little tweak is as handy as “&strip=1″ on cache: queries and “&filter=0″ on site: queries. Why? It’s an easy way to see new urls that Google has just discovered in the last few days.

For example, there’s been a lot of fast progress on iphone stuff recently. A query such as http://www.google.com/search?q=iphone+source+code&as_qdr=d1 would show all the new urls for the query [iphone source code] within the last day, because d1 stands for 1 day.

Suppose you wanted to see all the new urls that Google found on your site within the last 7 days. For the domain mattcutts.com, I’d use a query such as http://www.google.com/search?q=site:mattcutts.com&as_qdr=d7 to find those urls (remember, “d” stands for days and “7″ stands for, well, 7).

Previously, you could check whether Google had indexed a new url by (say) searching for content from that url, so this isn’t completely new, but it still simplifies life for site owners.

Honestly, this is big. The one thing I most wanted from Google search was date range information; many technical searches are frustrated by scads of outdated articles. The challenge will be to see if they can keep this working despite the best efforts of the usual parasites ...

PS. The iPhone source code example is cute.