Hi mike
Thank you for replying so rapidly to my original post…… the World Wide Web is truly a thing of wonder ? I’m very sorry to hear about your current frustration with the new Pentax O-GPS1 GPS unit and it’s malfunctioning astrotracer function. I have never experienced photographing the sky at night, but if what I’ve understood so far about this device is accurate, it potentially opens up all sorts of serious possibilities for tracking and photographing the millions of stars and galaxies in outer space…..that is, when it works as advertised !!!
Living in London with it’s massive ‘light polution’ problem makes star-gazing particularly problematic here, but back in 2008 my wife & I spent 4 ½ months on a memorable world trip, stopping-off first at the cities of Chicago and then Seattle, before driving south via the beautiful Mount Rainier National Park to Portland. We followed the tortuous winding coastal route of Oregon through it’s giant redwood forests, eventually arriving at San Francisco.
The weather was astonishingly clear in SF during our stay and we were told at the time by locals that it was pretty unusual to be able to see so far, due to the prevailing mist or fog that often builds up and starts rolling across the bay, obscuring the view for unlucky tourists.
A further drive took us down to visit Hearst Castle, before flying from San Francisco onwards to Australia. There we spent a couple of months exploring significant areas of the ‘real’ outback and it’s myriad selection of charming Victorian towns and small settlements, whilst also taking in major cities such as Sydney, Cairns, Brisbane, Melbourne (family members), Adelaide, Perth and Tasmania. In between this period, we also spent six weeks in New Zealand and extensively covered both the north and south islands, before reluctantly heading back to Australia. From Perth we flew to Hong Kong, arriving back in London just in time for Christmas. Phew…..were we both totally knackered, but I’d been doing all the driving, don’t forget !
Anyhow, whilst travelling through the delightful island of Tasmania (it’s located a few hundred miles south of Melbourne) we found ourselves skirting along the east coast, but in a northerly direction, having left behind the remarkable city of Hobart. Outside the two main Tasmanian cities of Launceston (north) and Hobart (south), there are hardly any significant areas of population to talk of and therefore to all intents and purposes, in most areas at night there is virtually zero light pollution to speak of. By the time we had checked into our idyllic lakeside accommodation and had eaten a meal, it was absolutely pitch black outside and so I decided to have a short stroll to the edge of the lake to breathe in some clean fresh air. At which point I merely happened to look skywards for an instant and was utterly blown away with what I saw. I remained riveted to the spot and can honestly say I have never EVER before seen ANYTHING remotely like what I experienced that night……..it was as though the entire heavens was shimmering and sparkling above me as far as the eye could see. In fact I distinctly remember calling my wife over in great excitement and the pair of us just stood there for many minutes, gawping in total amazement at the billions of twinkling pinpoints of light……but oddly, there was no sign of the moon whatsoever ? Something to do with being in the southern hemisphere perhaps ?
I recall an occasion some years back when the SiRFstar III chip began to gain widespread acclaim in newer Sat-Navs, so I’m both surprised and disappointed to discover that the Pentax unit takes 3 or 4 attempts before it finally locks-on. I once experienced a strange anomaly when driving a hire-car through France for a few days and couldn’t understand why our usually brilliant Garmin Sat-Nav began announcing turnings or junctions virtually at the very last second. It transpires that most French cars now come fitted with heat-deflecting front windscreens as standard and this seriously degrades the signal strength to portable screen-mounted Sat-Navs. The only solution is to fit a wired sensor extension cable that’s mounted to the rear window, which is not made of heat-deflecting glass.
Prior to the meteoric popularity of the internet, I would not have considered a GPS feature in a camera to be a particular advantage. However, with popular photo-sharing sites such as Flickr widely accepted and Cloud servers gaining momentum, it’s clearly a neat feature allowing viewers to visit sights which grab their attention. Enabling others to follow in your footsteps sounds like a nice idea and Latitude, Longitude and Elevation seem pretty obvious requirements for this, but oddly enough, direction hadn’t actually occurred to me when plotting a location. Incidentally, glancing momentarily over that comprehensive ‘arsenal’ of lenses & Pentax DA’s that you’ve accumulated seems a mighty impressive collection……if I owned that much kit, believe me I doubt whether the wife & I would still be on speaking terms….which sometimes wouldn’t be a bad thing, if you catch my drift…….LOL !
Actually I find it quite interesting that you have acquired BOTH the DA 10-17mm and the Sigma 10-20mm……..any particular reason ? I would have thought that to some extent they more-or-less overlap each other’s territory ?, but I can only comment about the Sigma, which still gives me slight goose-bumps every time I frame an image through the SLR viewfinder. Without a shadow of a doubt, it’s an astounding optic and it has earned my respect. Mentally you simply need to visualise ‘when’ and ‘how’ to exploit it’s innate ability and I often use the versatile ‘zoom’ function’ to precisely frame a shot, rather than needing to walk either forwards or backwards some considerable distance. Admittedly a full frame lens it is not, but I can live with that compromise, until Pentax/Ricoh finally pull their ‘proverbial’ finger out and begin manufacturing a full-frame DSLR…..does the term ‘Hell freezing over’ spring to mind !!!!
Now, in reply to interested_observer, I can’t imagine it’s not possible to incorporate a smaller device inside a Pentax DSLR, as they must do so in the case of the Optio WG-2 GPS D.C. ? Battery life need not prove a problem, assuming that an on/off button were provided and a separate battery compartment incorporated in the main camera body ?
As you correctly observed:
Quote:“If it is going to record direction pointing, it needs to determine where it is within the earth's magnetic field, and that is the reason for the somewhat complex calibration across the three axis.”
I believe this is absolutely true and may well have some bearing on the overall size and design of the Pentax O-GPS1 GPS unit.
Quote:“ The actual GPS signals from the satellites are very weak and can not go through a lot of material. That is why you need a direct line of sight to the satellites. The same thing happens under trees and within deep city canyons with tall buildings. That is why GPS is also coupled with accelerometers and gyros in a lot of applications, so that you can have continuous coverage”.
This is more-or-less precisely why my 5-Series BMW has a sensor fitted to each ABS-hub and actually tracks my progress in real time when for example I drive under the Dartford Tunnel, which crosses the River Thames some miles upstream east of central London.
Quote: “It records the data, however a lot of the mapping software uses the same data in a different format. Its a case of ddd.ddd vs DMS (degrees, minutes, seconds)
Here I naturally bow to your greater knowledge and experience, as I have very little useful comment to add to the subject.
Quote: “In deep city canyons, you can also get a lot of multipathing of signals - this is the reflection of the GPS signals off the walls of the buildings - an indirect path vs a direct path. The positioning is all done on a time basis. If the signal is reflected, (time triangulation) there is additional time taken for this and it will throw off the position, or create a position that does not make any sense”.
Well, I was sort of aware of the “spitching” phenomenon which tends to badly affect both analogue and digital radio signals, so no real surprises there !
Lastly:
Quote: “It never achieved signal and position lock in Seattle, hence it still thought it was in Chicago”.
Having had time to reflect properly on this, had I not been so knackered from the tiring flight and all that this entails, I should have considered activating the Garmin whilst outside our low rise hotel rather that attempting to do so surrounded by loads of tall buildings ! Lesson learnt the hard way !
Thank you both for your valuable contributions
Best regards once again
Richard