Archive for the ‘Technology’ Category

Dead Text

Friday, December 14th, 2012

During a presentation by a candidate for the directorship of our library, I mentioned that the real value of the library [ or more generally any library ] is not “as a repository of dead text, but rather in its subject specialists, research librarians, and special collections.”   Apparently this raised some eyebrows.   So what is this “dead text?”

Simply put, “dead text” is unsearchable text, unstructured data, or similar materials.   Unfortunately libraries are filled with these materials, left stranded by the digital tide.  The term has nothing to do with the relevance, ephemeral nature, or importance of the material itself.  I would assert that part of the mission of any modern library is to resurrect this dead text and make these materials discoverable and usable by its patrons.

Similarly, I argue that enabling global access to the unique collections and resources of any library is of paramount importance as we enter the digital millennium.   Historically the role of the library is as an archive, and the librarian as a gatekeeper and inventory control officer.   However the benefits of a modern library extend well beyond these rather limited roles.   This transformation from protector and gatekeeper to docent, contextualizer, and facilitator is under way.

The most successful and effective modern libraries are not those with the largest stacks, but rather the greatest capacity to facilitate it patrons to access the widest range of materials, irrespective of the physical location of either.   They teach patrons to be savvy customers of materials positioned on a spectrum of quality and depth.   They inculcate a sense of intellectual curiosity, and the skills required to act on that curiosity.






Pentax K5 In Camera Correction

Thursday, January 19th, 2012

The Pentax K-5 includes the ability to perform in-camera correction for geometric distortion and lateral chromatic aberration.  Here is an example of both enabled / disabled for the 18-55mm kit lens at 18mm where both distortion and CA are abundant.



The Myth of Solarization

Monday, December 26th, 2011

Solarization of modern films while in the camera is largely a myth.   Evidence for this is all around you if you have been shooting film. Look at the leader on ANY negatives you’ve had processed, which would have been exposed to the light since it was sticking out of the canister.   Its black.  Here is an example…

The negative on the left was handled in typical way, so perhaps 2-5 minutes of cumulative exposure to ambient light. The one of the right sat on a shelf in my office for 14 months, fully exposed to the sun for about 2 hours per day! There is no noticeable inversion, only a slight difference in light leakage past the felt.


Old Science

Monday, September 26th, 2011

I’ve been cleaning out my basement and unboxing huge amounts of my “science junk” that has been packed away since we moved a couple years ago.   There is a photo contest coming up that I occasionally enter, here are a couple test shots featuring some of my collection.

DIY Power Supply for Pentax K5 DSLR

Monday, July 18th, 2011

This is a follow-up to my prior post about a DIY DC to DC power supply for my FujiFilm S100fs camera.  I recently purchased a Pentax K-5 which I hope to use for time lapse work.   After doing some testing I found that the internal battery in the K-5 will power the camera for 3 hours and was capable of taking more than 10,000 6MP stills in continuous shooting mode.   However for longer term shooting, a DC power source is necessary.

The K-5 provides a strange DC-IN port labeled 8.3vdc.  This is the same port used on several of the K-series cameras and would normally be connected to Pentax’s D-AC50 AC power adapter.   But this would require me having an DC to AC inverter to power the AC to DC adapter.   This DC to AC to DC conversion would be very inefficient, requiring 5x the battery capacity.   So I built a similar DC to DC converter based on Dimension Engineering’s SWADJ-3 and D-SWADJ switching regulators.


CO2 Powered Pine Wood Derby Car

Thursday, July 14th, 2011

Live from TTP 2011 in Provo Utah…   one of our TTP members, James, entered his highly effective CO2 powered derby entry.

Homemade Helioscope – First Light!

Tuesday, June 14th, 2011

Our media services people were cleaning out the musty, dusty recesses of the campus and found a circa 1960′s opaque projector.   It was a high quality version with a very nice, huge, projector lens.   The lens itself has a whopping 4″ diameter clear aperture, and a 18″ focal length, and is well, but not perfectly, corrected for color.      It was designed to take a letter sized paper and project it on a 6 foot screen.    The lens forms a pea size image of the sun which basically vaporizes anything in its path.   Its not a toy.


Portable Power for Timelapse Rig

Wednesday, June 1st, 2011

I’ll be going out to Provo, Utah for the Novell ( Attachmate?  NetIQ?  SuSE? ) TTP Conference.   I’ve been in the habit of shooting time lapse series in the evenings and free time ( what’s that? ) while I’m out there – as its a very different place from the verdant rolling hills of Eastern Pennsylvania.    I normally use a portable AC supply, which is an integrated 12 volt 20 Ah battery + inverter.   So while the battery itself provides about 200 watt-hours, it can only power the camera for 12 hours.   It weighs about 20# – so not really something you want to carry around or take on a plane.   The underlying problem is that the camera needs 8.4vdc, which comes from the AC adapter, which is fed by the inverter, fed by the 12v battery.   So there is a lot of waste and inefficiency.   The camera itself uses only 4 watts, and the AC adapter uses 20 watts!   So already we are at 75% waste.   Also the power pack needs to be protected from the elements – and it uses house current, so dangerous when wet.  Other than that, its great!

So I built a DC-DC power supply using off the shelf components:   2000 mAh AA NiMH batteries, an 8 AA cell battery holder from Radio Shack, and a DC-DC switching power supply.   The DC-DC converter is a very cool.   It has a 20-turn potentiometer to adjust the voltage out, and decoupling capacitors on the output so no external caps are necessary.   Its about the size of a nickel.   And it accepts Vin up to 30 volts!   I created a harness so multiple DC-DC modules can be dialed in to the desired voltage and easily swapped out depending on the camera used.


Its Perihelion Day!

Monday, January 3rd, 2011

The Earth’s slightly elliptical orbit means that we are about 3% closer to the Sun in January than in July.   Today the Earth will again be at its closest point to the Sun, aka perihelion.   The seasonal changes caused the earth tilted axis of rotation overshadows the slight difference in solar radiation ( about 7% ) due to our elliptical path around the Sun.   Last July, I took a shot of the sun and made this side by side comparison with one form today.

Shot With My Fuji S100fs + Welder's Glass Filter

My camera rig is not really up to the challenge of capturing fine detail of the solar disk.  But you can still make out a sun spot at about the 10 o’clock position.   I set the S100fs to maximum zoom and use the 2x digital zoom with a green welder’s glass filter.   Then color corrected to give the sun a more natural appearance.

I, for one, welcome our new insect overlords!

Wednesday, December 29th, 2010

Change is Difficult

And the Attachmate – Novell merger is no exception.   There are two types of people who will emerge from this transaction.   The first is those searching for relevance in a changing environment:

One thing is for certain: there is no stopping them; the ants will soon be here. And I for one welcome our new insect overlords. I’d like to remind them that as a trusted TV personality, I can be helpful in rounding up others to toil in their underground sugar caves.

And the second being the rest of us, who hope that out of the chaos will emerge a vendor I still want to do business with, offering product I want to buy.   Or an an employee, to survive potential bloodshed, strife, and uncertainty.    Attachmate, playing the role of the ants, provided us with a glimpse of the future, in so much as is possible prior to “the close of the transaction.”