Fri, 30 May 2008

New Hard Drive

Digital photography is a hard-drive consuming activity. When shooting in high resolution mode, my camera generates both JPG and RAW images for each exposure, the latter of which often results in files easily over 12MB each, which means with each photo session (and I make an excuse to get out and do something fun at least once or twice a month) generating up to 1-2GB of images, I was soon near 99% disk utilization.

So, I decided to upgrade my "100 GB" drive to a "200GB drive". Both the original and the replacement drive is a Seagate, and both carry the "Momentus" brand. The principal difference, outside of having double the capacity, is that the new drive is a 7200RPM model and the old one is a 5400RPM drive.

I agonized a little about having a higher RPM drive because the principal downside is that to spin a drive 33% faster presumably consumes at least 33% more power. Given that the hard drive is the most significant consumer of kinetic energy (DVD drives spin a substantially slower speeds), I have to imagine my battery time must suffer when using the disk heavily.

But the upside is, I've got a much faster hard drive, and given that it's the only routinely used mechanical device to get access to my data (everything else is solid-state), a 33% improvement in rotational hard drive platter speed is going to mean much faster access to my data. And frequently, the hard drive is the biggest bottleneck in a computer. RAM has access speeds on the order of "nanoseconds", whereas hard drives are on the order of "milliseconds"... or 1,000 times slower than RAM.

But not only is there a 33% improvement in rotational speed (meaning access time to your data), the new drive has a 16MB cache, twice as large as the old drive's 8MB. To try to quantify (somewhat simply I admit) the performance difference, I used the handy unix utility "time" to copy one of my larger files on my disk (112,419,532 bytes). Here are the results of three copies each with the old drive and new, for your perusal:
% time cp ~/Pictures/iPhoto LibraryLibrary6.iPhoto backup
0.001u 0.666s 0:11.31 5.8%      0+0k 0+99io 0pf+0w
%rm backup
% time cp ~/Pictures/iPhoto LibraryLibrary6.iPhoto backup
0.001u 0.652s 0:06.02 10.7%     0+0k 0+5io 0pf+0w
%rm backup
% time cp ~/Pictures/iPhoto LibraryLibrary6.iPhoto backup
0.001u 0.636s 0:05.57 11.3%     0+0k 0+1io 0pf+0w
%rm backup

% time cp ~/Pictures/iPhoto LibraryLibrary6.iPhoto backup
0.001u 0.367s 0:05.26 6.8%	0+0k 1+6io 2pf+0w
%rm backup
% time cp ~/Pictures/iPhoto LibraryLibrary6.iPhoto backup
0.001u 0.327s 0:02.01 15.9%	0+0k 0+0io 0pf+0w
%rm backup
% time cp ~/Pictures/iPhoto LibraryLibrary6.iPhoto backup
0.001u 0.326s 0:01.96 16.3%	0+0k 0+0io 0pf+0w
%rm backup

In short, the new drive is 2-3 times as fast in copying a 112MB file. The laptop feels a lot faster launching applications, in particular, so color me extremely satisfied.

Thu, 22 May 2008

For Point of Comparison (HDR vs. Non-HDR)

Here is the "standard exposure" of the photo I posted yesterday, so you can compare the detail that pops out of the dark and light areas of the exposure.

This image was only resized, sharpened, and saved as JPG, no other postprocessing was done. I've set it up so that mousing over the image shows the HDR version, and mousing out shows the standard exposure. These shots were taken hand-held (no tripod), hence the sense of motion as you mouse over/out of the image-- but this also illustrates how well Photoshop can compensate for movement between the various HDR exposures!

Notice the dark areas have better contrast, and you can make out finer details in the bright areas, like the detail of the stained glass, which are less washed-out in the HDR version I posted yesterday.

Name/Blog: Justin Akehurst
Title: looks great
Comment/Excerpt: A great HDR, that doesn't look too surreal or something out of a comic book.

Name/Blog: Maelyn
Comment/Excerpt: What a trip. The colors become so rich and the detail in the stained glass so apparent. I visited la Sagrada Familia a few years ago, thanks for refreshing my memories.

Mon, 19 May 2008

Sagrada Familia HDR Image

One of the things I'm glad I did during our June European vacation was to take the time to capture a few HDR-ready (high dynamic range) pictures. I've finally gotten around to processing these images with Photoshop.

The way to accomplish this effect is to use what's called the "Auto Exposure Bracketing" feature of a camera, which in sequence takes an under-, properly-, and over- exposed image. In post processing, software seams together the three exposures into one image.

Specifically, the darkest areas of the overexposed photo (which brings out the detail in the dark portions of the photo) are blended with the brightest areas of the underexposed photo (which preserves the detail of the bright areas), while the properly exposed photo's midtones are preserved.

The effect is like a supernatural flash, but without using flash... which has issues of adding false color, casting unnatural shadows, and illuminating closer things more than farther things.

My contribution to the blogosphere for today is an HDR image of three shots I took back in June at the Sagrada Familia in Barcelona. It's what I'd call a "neo-gothic" cathedral (begun in 1882, and still under construction), with very cool stained glass windows.

Name/Blog: Christine
Comment/Excerpt: Beautiful photo! Nice job.

Wed, 14 May 2008

Stores that check receipts

Some people clearly have nothing better to do with their time than to aggravate, and be aggravated by, receipt checking stores.

I'm talking about the guy ass that is behind this article (to any SEO people out there, yes, this link has a rel=nofollow param to avoid giving it search engine rankings by linking to it)...

Don't get me wrong, I'm far from one of those people who like walmart, not to mention one of those people who like shopping there! Rather, I agree with him. Receipt checking policies suck-- I find them offensive wastes of time and an insult to their shoppers.

But c'mon, acting like a prick with people who lack the intelligence to even comprehend why you're offended takes more time and creates more exasperation than grinning and bearing it... And if you just can't bring yourself to grin and bear it... (warning: novel concept ahead!) don't shop there!

I guess they deserve each other- Walmart and the stand-up-to-walmart guy... but where he really gets off base is when he turns his ire at Costco:
One problem with this receipt-checking system is that on busy days it forces customers to form long lines at the exit. On some of my visits, I decided to roll past this line with my items, now that I owned them, and head straight to my car.


As I suspected, there were about a dozen customers in line for “receipt review” at the exit. That represented about six extra minutes that I wasn’t being paid for, and so I rolled toward freedom. The employee “reviewing” receipts left the line and cheerfully said, “I’m going to have to see your receipt first.”

Adopting her happy demeanor, I replied, “And you are going to have to chase me in order to do so.” Sometimes it’s worth being an ass just to see the response on people’s faces. Not only was the receipt lady registering total bewilderment, but several customers in line for the same hassle appeared equally baffled. One woman glanced at me with what looked like total contempt. Her response was invigorating, although I’m not sure why. I continued toward my vehicle, where I was greeted by a man who looked and sounded like “security.”

“Was there a problem at the checkout, sir?” he asked.
“No, actually, checkout was great,” I said. “Very efficient. But leaving the store was a little shaky. In fact, there’s definitely a problem there.”
“What’s wrong?”
“Well, for openers, I don’t like being treated like a shoplifter.”
“Sir,” he solemnly stated, “No one is treating you like a shoplifter.”
“Really? Then why, exactly, am I having a conversation with store security, who just happened to reach my vehicle at the same time I did?”

But there's a difference between the likes of Best Buy and Walmart vs. Costco. Principally at Best Buy and Walmart, if you've paid for the goods, you're within your rights to walk right out of the store. It begs the question whether or not you really want to press your luck with your municipal, county or state laws that may or may not make this a legally defensible course of action... Choice A: Save yourself 5 seconds, spend your time and energy in such civil disobedience, potentially get accosted by security, make a scene, give a guy who makes minimum wage more grief than he's paid for, get law enforcement involved, and potentially even go to jail (maybe the cop is just as misinformed about your rights as the Walmart employee?). Clearly, if you must shop at these stores, I think you need to come to a realization that saving that $1.32 on that $599 TV by shopping at Walmart is the price of admission, which includes being accosted for your receipt at the door.

Why doesn't this apply to Costco? Well because at Costco, you agreed to that price of admission when you signed up for a membership! Right next to where you agreed that Costco has the right to "inspect any container, backpack, briefcase, etc., upon entering or leaving the warehouse", you also agreed that in order "[t]o ensure that all members are correctly charged for the merchandise purchased, all receipts and merchandise will be inspected as you leave the warehouse." Oh, and "Shirts and shoes are required" too.

If this rubs you the wrong way, I'm sure Costco will be happy to prorate your remaining membership refund.

Otherwise, I don't know why people don't realize that there is a law of cost conservation:
The paucity of your positive shopping experience is roughly proportional to the amount of money saved at said shopping establishment.

Wed, 07 May 2008

One thing every seasoned Internet user should know about mailing lists

Most email list software on the Internet today abides by a standards document called "RFC-2369". This document describes optional headers that mailing list software should use to help users and their mail clients alike handle "administrivial" requests such as how to get help using the list, how to subscribe/unsubscribe, how to post to the list, who owns the list, and where to find the list archive.

Internet mail is sent using a protocol called SMTP. You're somewhat familiar with this protocol if you've ever sent or received an email, because the "To/From/Subject/Date" values in each email are SMTP headers.

Most mail clients these days hide headers they don't recognize, including the ones from RFC-2369, but for seasoned users who are trying to figure out how to subscribe/unsubscribe or find list archives, they're there waiting for you.

Eventually, mail clients will begin to evolve (and some already have) and allow automatic built-in mail reader capabilities that let you subscribe/unsubscribe, etc. from a button in the mail client UI by using the features enabled by RFC-2369. But until the one you use provides that feature, here's how you can figure out how the mailing list experts "surf mailing lists".

The first step is to discover your mail client's "Long Headers" or "View Rich Headers" or "Raw Source" feature which will show you a wealth of SMTP protocol information for each message you've received.

Just about every mail client has such a feature. You may have to dig a bit to find it in your mail software, but it's probably there.

Once you're viewing the source of a list-generated email, you can verify the list you're subscribed to is RFC-2369-savvy if you see headers that look like the following:

  • List-Help
  • List-Unsubscribe
  • List-Subscribe
  • List-Post
  • List-Owner
  • List-Archive

These headers provide URLs or email addresses you can access to receive list help, to unsubscribe, to subscribe, reply-to/post, contact the admin, or access list archives, respectively.

There you have it... you never, ever have to ask anyone "how do I subscribe" or "how do I unsubscribe" to a list, ever again (so long as the list software you're using is RFC-2369 compliant anyway).

Khan Klatt

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