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Aug 03 2011

Pentax WG-1 GPS camera–too slow for scanning

I loved the Pentax WG-1 GPS camera when it first arrived.  It looked cool, had a non-extending lens, and offered the potential for GPS tagging our photos during flight – a feature that could be very time-saving for reconstructions.

But out of the box I quickly noted some major drawbacks.  The first was that the GPS only updates every 15 seconds.  At the average speed of 5 m/s of a Hexakopter, that meant that GPS logs would be something like 75m apart!  The unit also has a slower continuous shooting mode than the SD4000, about 1 fps.  The biggest drawback by far though was the lag, which I can only assume is a memory write lag.

I set up the camera to the maximum image quality settings, in continuous shooting mode, and with 15 second GPS refresh.  I was using a brand new Sandisk Extreme 16GB memory card, which would provide professional grade write speeds.  I strapped down the shutter button by lightly taping a plastic nut over the button and wrapping the unit with a velcro strap, just like we do with the SD4000s.  The Pentax WG-1 would take a continuous stream of about 30 photos then stop.  It would show the ‘number of images remaining’ counting down and just hung out.  After sometimes 10-15 seconds it would then resume taking photos continuously, but then repeat the same thing after another 30 photos.  The camera was not taking photos for 10-15 seconds while in continuous shooting mode.  At a flying speed of 5 m/s that means that for 50-75 meters in the air, no pictures would be taken!

I repeated this test with increasingly lower camera settings until I got down to the lowest possible settings of maximum compression and 640x480 resolution.  This time the camera took lots more photos  (~100 or so) but still had a long lag of no photos.

It was this that finally made us decide to send the Pentax WG-1 back.

Based on my research this GPS camera has the fastest GPS refresh time of any other point and shoot style camera, but the continuous shooting ‘lag’ was a deal breaker.

Nov 08 2010

Don't Forget to Backup!

Quick! Find the corrupt data!  

I had made the mistake of not being careful and meticulous with data backups a few months ago when I came in to the lab to find my primary data drive was toasted and some of my data was gone.  I do not think that that was a major loss, but I made sure to get my redundant backups up and running.  I have also been encouraging the practice with friends and loved ones ...  I don't think my parents have a clue what a Terabyte is though.

Out in the field I also backup data, mostly for fear of physically losing the media.  I have been in the habit of making a local copy of images collected during the day on the laptop and typically have enough SD card space to keep the originals on the cards.  This morning when I came in to dump the data from the weekend I kept getting an error that I couldn't transfer data from the card to my hard drive.  After some investigation I discovered what is seen in the image in one of the main image folders on a Sandisk Extreme 30MB/s 16GB SD card I had used during a flight.  In addition, Windows thought the card had 78GB of data on it!  I get the same results mounting the card in Windows and on my Macbook, and no problems reading other cards on the same Dynex card reader.  I also discovered that about 1000 photos were gone from the set and quickly panicked to find the laptop and confirm my backup copy was intact.  It was and I proceeded to transfer the good data over to the main system where we have nightly backups.

So do we wipe and reuse the card, perhaps also defragmenting, or is it time to find a replacement?  Considering the value of the data, it is probably time for another card.

Of course, the other explanation is that the card did some time traveling over night...