Photo

Prints not-so charming

Ansel Adams wrote a celebrated series of photo instructional books. It is organized as a trilogy: The Camera, The Negative and The Print.

Of these, the camera business is still going strong, buoyed by sales of digital cameras and upgraders to DSLRs (although market saturation looms). Negatives are an endangered species as digital photography largely supplanted film. Prints are still going strong, whether using traditional silver halide, inkjet or offset printing, but that probably won’t stave off Kodak’s impending demise.

Last year, I wrote to X-Rite to complain that their software for the Colormunki color calibrator wouldn’t let me profile the full brightness range of my monitor, and limited it to an artificial ceiling designed around the limitations of print. Their response:

The ColorMunki software will not allow a range over 140cd/m luminance value.  This would basically defeat the purpose of using a device to measure luminance when you set the values this high.  While your monitor can be extremely bright however using a value of 300+ would allow your monitor to show you a brightness value that would negatively affect your prints and they would end up coming out so dark that you would be unable to see them.  The industry standard for photographic works is to use the luminance values setup at anywhere from 80 – 120cd/m.  That said, if your ambient light conditions are ranging very high then you should probably be using a value of 120cd/m which is the industry standard and what we recommend.

In the ColorMunki software there is an option to set the luminance according to your ambient light conditions.  This is a pretty high threshold in the software where as you have to read somewhere around 350-400 lux to get a target luminance above the 80 threshold.  If it does go above this value then you certainly will want to stay within the 120 range.  Anything below that will give you a target value of 80.

Implicit in this response is the assumption the only reason why you would want to calibrate your monitor is so you can make more accurate prints. Prints only have a 100:1 or so contrast ratio, compared to LCD monitors for which the static contrast ratio is closer to 1000:1, and plasma TVs go higher yet. This is why images on screen look more vibrant and punchy than prints, as did slides back in the day.

If Apple does indeed come up with the oft-rumored iPad 3 with double the resolution of current models, or 2048×1536 at 260ppi, you would have an easily portable display device with near gallery-grade resolution and massive storage capacity. At that point, prints would lose the last advantage they still hold over digital display technologies.

Image display on screen is the new normal, and X-Rite needs to get with the program. I want to see the full dynamic range and contrast of my images on my screen, not a Hobson’s choice between inaccurate color and crippling them with limitations from legacy print technology.

 

How prevalent is high-ISO photography?

Low light performance is one of the most important factors I consider when buying a camera. At one point I did an expensive switch from the Canon system to Nikon, when the D3 came out, for its amazing high-ISO performance (I returned to Canon when the 5DmkII came out).

On a popular forum for users of Micro Four Thirds cameras (which struggle beyond ISO 800), a poster recently questioned the rationale for high ISO performance, stating 99% of users will never shoot beyond ISO 800. I quickly looked at my statistics in Lightroom, and found over 54% of the photos I took in 2011 (to date) are at higher than ISO 800.

That begs the question: who is more representative, him or me? Flickr.com publishes statistics on popular camera models, but apparently not on other interesting EXIF metadata. I whipped up a quick and dirty Python script to sample recently uploaded photos from Flickr and collect the ISO speed from their EXIF tags, when available.

Of 3020 photos I sampled, fully 399 were shot at ISO higher than 800, or 13% (the 95% confidence interval is 12% to 14.4%). Thus significantly less than my proportion, but far higher than 1%.

Clearing custom crop aspect ratios in Lightroom

Lightroom’s crop tool allows you to constrain the aspect ratio to a proportion of your choice, e.g. to 4:3, defaulting to the same aspect ratio as the original. The last 5 or so custom crop aspect ratios are saved, but a minor annoyance is you are unable to clear the list.

Python on the Mac and SQLite to the rescue: this simple script  lraspect.zip will reset them. If you use a non-default name for your Lightroom catalog, you will need to edit it. To run it, quit Lightroom and run the script. It will back up your catalog for you just in case.

Needless to say, I cannot be held liable if this script corrupts your catalog or eats your dog (who ate your homework), use at your own risk.

#!/usr/bin/python
import sys, os, sqlite3

# edit this to point to your LR3 catalog if you do not use the default location
lrcat = os.path.expanduser('~/Pictures/Lightroom/Lightroom 3 Catalog.lrcat')

os.system('cp -i "%s" "%s.bak"' % (lrcat, lrcat))
db = sqlite3.connect(lrcat)
c = db.cursor()
c.execute("""select value from Adobe_variablesTable
where name='Adobe_customCropAspects'""")
crops = c.fetchone()[0]
print 'aspect ratios:', crops
c.execute("""update Adobe_variablesTable
set value='{}'
where name='Adobe_customCropAspects'""")
db.commit()
print 'Custom crop aspect ratios reset successfully'

Is this a Google Street View car?

Update (2011-05-12): the answer is no, it’s a Navteq 3D mapping car with a LIDAR array. Thanks to Darrell Kresge for the clarification.

As I was walking to lunch today, I caught sight of this weird contraption, and had just enough presence of mind to grab a few snaps of it.

One strange feature is a spinning white cylinder inside the arm canted at a 45 degree angle.

It doesn’t look like any of the Google Street View vehicles captured before, nor does it have the Google markings. The Michigan license plate is a bit odd as well. A prototype, perhaps? Or is some other company is getting into this racket, perhaps Microsoft?

First test roll from the Fuji GF670