[john mood]

I am in the market to buy the O-GPS 1 for my K-5. I'd like to hear comments on normal geotagging and operation from anyone who has used it for awhile?
Some specific questions:
Do you get elevation data? If you take the unit off to use the flash, does it have to be recalibrated or is that just when the battery depletes? How well does it do in forest
vs. up to date hand-held devices?

Any non-astro oriented comments would be most appreciated. If the manual is as crappy as previously mentioned, LOL.
I've always used a hand-held unit, but if this works well, it would be more convenient in plotting positions for botanical field work. I hope to use it on an upcoming
India/Thailand visit. Thanks.

[jbinpg]

I have used it mostly in astrotracer mode but can answer one of your questions. Yes, elevation is burned to the exif. The definitive online manual is here:

Calibration | GPS UNIT O-GPS1 | PENTAX

Jack

[elho_cid]

1- yes, elavation data is available once you get enough satellites triangulated.
2- No problem to remove for a short while, it has own power source so it catches up very quickly when returned to camera.
3- I do not know about forest, but in the city I got few untagged pictures. But vast majority was tagged correctly.
4- calibration is only necessary for compass. It has nothing to do with coordinates.

[DAZ]

The manual is by far the worst part of the unit. I have used it for months now and have used it to tag all my photos. You do get elevation data like any other GPS data. Like any other GPS unit the HDOP is about 1.5 times worse then the PDOP but I have had elevation in feet so that is good. The calibration is for the compass part so if you don't need that data then you don't need to calibrate. If you want maximum compass accuracy then you should calibrate at every location as it is magnetic. It takes so little effort to calibrate that I tend to do it just because. Under a tree canopy it works as well as any hand held unit I have used.


Now that your questions are out of the way on, to information you will need but don't know you do.


All GPS units work best when there is an open sky. Most know that but what a lot don't know is that if the sky is not open it can take longer to get the first fix. Once you have the first fix the unit can keep tracking even when the sky is not open like under trees. What this means is it is best to get a good fix and not turn off the unit. If you leave it on all the time you are out it will do much better.


I see you are going to India/Thailand. Good for you not so good for GPS data. The reason for the not good for GPS as there is no GPS augmentation systems (SBAS Space based augmentation systems) over your location. Augmentation lets you get PDOP down to less then 3 meters, possible less then 1. With out it you get about 10 meters if the sky is open (possible better but that is what is promised). The less sky the worse it will get. This is for all GPS units not just the O-GPS1. The O-GPS1 can use any of 3 augmentation systems WAAS (over North America), EGNOS (over Europe) and MSAS (over Japan). As you can see not over India/Thailand so this limits the accuracy if you are going to return to a location. You can overcome this by taking more photos. What you do is not just take the photo of the “flower” but things around and the location a little back from the site. This way you can get close with the GPS and then use the photos to get the exact spot. One other thing about the SBAS. If you can see one it takes a few minutes to get the data down. When you do as long as you leave the unit on it will just update the data when it get new data. If it can't the data is good for about a day so if you can't get updates that is OK. The problem with the O-GPS1 is it won't let you know when is has the data. You just have to assume it got it if you are in an area that has a SBAS. This is one of the few problems I have with the unit.


Next the unit reports in WGS 84 as its datum. Now for most modern maps this is not a problem as most new maps are in this datum but you could get maps in India/Thailand that use a different datum. Not a problem for something like Google earth but could throw you if you don't know about this.


I have used it with flash. You can do this in multiple ways but if you are not look for that I will skip it. If you need more info on flash just let me know.


DAZ

[DAZ]

One additional thing. You must wait about 5 seconds from when it wakes up until you take the first photo. A little longer then the SR indicator. If you don't on the first photo you will not get any data. All of the next photos will have it. Just focus, and count to 5 then take the photo. You can look at the data on the camera to verify it is there if you like. If there is a photo in the camera that has data you can even use it to have the camera navigate back to that place.




DAZ

[john mood]

Great information and makes me more comfortable in buying the unit. I've used Garmin handheld units since they were avail. to the general public and in the military way before that. My last two I gave to my Thai and Indian students, so need a replacement for this trip. Actually in Assam and Thailand, Sat coverage is quite good, though you are right, the accuracy is not to bomb with as there would be a lot of collateral damage. Concerning the jungle reception, I've found what you said to be true. We always take a good fix before we enter forest cover and hope for the best after that--just not as accurate as my old Boeing 737-700 dual GPS, but a lot better than LORAN (opps, dating myself). Thanks Daz, others.

[DAZ]

Please don't confuse GPS satellite coverage (they are every were) with SBAS. SBAS are only for some locations to improve the accuracy/reliability of air craft GPS systems. This is one of the reasons your Boeing 737-700 dual GPS was more accurate.


I know LORAN and I also used one of the earliest civilian GPS units that used the GPS 1 satellites. We are now using the GPS IIF and soon the GPS III satellites. It was so dumb that you had to tell it where it was and the time before you could start the system. It would only look at 1 satellite at a time. When you started driving (it was the size of a bread box and had to be on a vehicular) it would count the wheel turns and use a magnetic compass to estimate where you were. After about 10 miles you need to stop so it could get a new fix. If you were on a open desert you could get to about 300-600 feet from the spot you were looking for. Most of the time I could do a lot better and faster with just a map!


DAZ

[Col]

Personally I find the O-gps1 a real pain for day to day work. I bought it after my gps logger failed to hold a charge for longer than 3hours. Yes its convenient to have the data written direct to the image. But until they produce a hot shoe hub I'm stuck without geotagged images every time I'm using the ring flash.

I'm hoping that gps becomes inbuilt soon, or you could geotag the first shot and the camera could be told to use that info until a new reading in taken.

[Gimbal]

One additional thing. You must wait about 5 seconds from when it wakes up until you take the first photo. A

Or you wait for the blue LED on the o-gps1 to stop blinking.

[DAZ]

Personally I find the O-gps1 a real pain for day to day work. I bought it after my gps logger failed to hold a charge for longer than 3hours. Yes its convenient to have the data written direct to the image. But until they produce a hot shoe hub I'm stuck without geotagged images every time I'm using the ring flash.

I'm hoping that gps becomes inbuilt soon, or you could geotag the first shot and the camera could be told to use that info until a new reading in taken.

You can use both a flash and a O-GPS1 at the same time you just need more parts to connect it all together. This is because the system is a bus so if you have the connectors and cables it will work. You could still find it is a pain but that is a different problem then you can't use flash. Incidentally you could just take the first photo with the unit getting the GPS data and for the next photos use software like you do with a GPS logger and add the data to the rest of the photos.


Soon (2-4 years) this unit and just about any GPS unit is going to be obsolete as Galileo GPS and GPS III with the new channel will be coming on line. These new systems will allow these new units to get and keep a lock with much more covering the sky. They will also be more accurate. If the GPS is built into the camera the only way to get this would be a new camera. With a unit exterior to the camera (like the O-GPS1) you can just get a new GPS when they come out.


DAZ

[john mood]

All great information on GPS-like info. I've been considering this situation for 24 hrs. and came up with a $4 solution. If you have an IPhone, buy the Theodolite Pro app. I did and it is really
great. Here's what it does. First take a picture with the phone and it attaches all the data to the top left of the pic. Take a pic with the mail button and it turns it into an email you can
add notes to and send to yourself back home. It also has all kinds of angle gizmos and ties in to google maps. It also does track. But most important, it gives you lat./long in about 6 different formats plus elevation (m or ft.) along with the current corrections. So if you are at a site ready to take serious pics with the K-5, simply take a mail pic first with the iPhone, make your notes when its convenient and press into the forest. When you are back out, put the pic sequence nos. in the email and send. Or spend another $196 plus shipping and tag all...if it works at the moment and you don't want to use your attached flash and its not raining like a cow wizzing on a flat rock. This app uses cell phone inputs (when avail.)
flash.