Pentax O-GPS-1 and Pentax Flashes

The O-GPS-1, is a GPS (Global Positioning Service) unit that attaches to the Hot Shoe of certain Pentax Cameras. As of this writing (July 23, 2011) there are only three Pentax Cameras that can use the O-GPS-1. The Pentax K-5, K-r and the 645D. I own the K-5 and I wrote this within the first week of Pentax shipping the unit to North America. I have no doubt that the O-GPS-1 is an accessory that is going to be a standard purchase for owners of Pentax cameras that can use it.

First, some compulsory pictures of the O-GPS-1.

Here is my unit straight from the box. Yes, the top of the device is a glossy black and mine had some swirl scratches. I'm not too concerned about the swirls as I imagine it was from the packaging that might be part of the first batch. I am happy to get the O-GPS-1 as it is. Maybe a "Camera Weenie" would want their money back from the little swirls, but I am going to use my Pentax gear, not admire it or polish it.

The Battery door with a battery inside.

The Battery compartment without a Battery. I love the weather sealing.

Another view of the weather sealing and Battery Door compartment.

The back of the unit. Battery level and GPS signal and power. Notice that the "fix" lever is to the left. As you move the lever to the right, the whole bottom of the mounting moves and makes for a perfect connection. The mechanism works perfectly.

The bottom of the GPS unit. You can see my serial number. I wonder what my production run was?

On the Hot Shoe part, all of the contacts are spring loaded - even the orientation pin. In the image below, the orientation pin is the larger pin in the upper left.

This is an extreme close up of the bottom of the O-GPS-1, with the electrical contacts and the orientation pin.

The K-5 has the recess on the Hot Shoe for accessories that have an orientation pin.

Having the O-GPS-1 pins spring loaded, is good thinking on the part of Pentax, as not every Hot Shoe accessory that Pentax makes, has the recess in the hot shoe to accept the orientation pin of the O-GPS-1.

With the O-GPS-1 connected to the K-5, I quickly realized a usability issue concerning the O-GPS-1.

When the O-GPS-1 is on the camera - the built in flash can't be used. The internal flash, hits the O-GPS-1 when the flash pops up

If I were to use the O-GPS-1 with my K-5 and walk around and take pictures, it would perform exemplary. However, there are several scenarios that involve using a flash or using other accessories on the K-5 Hot Shoe while I am using the O-GPS-1. There are times when I would like to use a "Fill Flash" when I am out and about or maybe I would like to put an external microphone on the Hot Shoe.

External Flash with the O-GPS-1

What about using an External Flash while I use the O-GPS-1?

I can remedy my concerns using a matrix of various Pentax flash accessories.

YOU SHOULD BE CAREFUL!

Potentially you *could* damage something on YOUR Camera/O-GPS-1/Flash

What I am about to demo/try out has been tested with a Pentax AF330FTZ and AF540FGZ flash. However, all the pictures are taken with the AF330FTZ.

Here are the pin assignments for the K-5.

As you can see in the image below - of the underside of the O-GPS-1 - there is NO Trigger contact with the O-GPS-1, so there is no trigger voltage.

Digital, Ready, Mode, and Ground are used.

Since Pentax makes flashes that have the ability to be daisy-chained, it made sense that there could be more than one digital device connected to their Cameras. There are flash accessories that can place the O-GPS-1 off the Camera's hot shoe, however none of the adapters come with the Orientation Pin recess. Since the Orientation Pin is spring loaded, there is no problem!

Here is an image of the adapter(s) without the Orientation Pin recess.

To use my O-GPS-1 off the Camera Hot Shoe, I used a combination of an existing Pentax AF400T bracket with a custom insert, a Manfrotto 482K Head, and off-the-shelf Pentax Flash components.

I used a 2 Pentax Hot Shoe Adapter F and a F5P flash cord.

In the image below, are two Hot Shoe Adapters. The Hot Shoe Adapter F comes in TWO versions. One with contacts on the bottom, and one with a 1/4-20 socket (Tripod Socket). The Pentax Stock Numbers are 31046 - for the Tripod one, and 31022 - for the contacts one. The one with the tripod socket is usually more expensive.

Note: I hope I don't have the Pentax numbers reversed!

The tops are identical.

The bottoms show the differences.

You connect these adapters via a F5P cord.
You can also use the Hot Shoe Adapter Fg if you just want to use the O-GPS-1 off the camera and connect it to a bracket of some sort.
In the image below, I have the Hot Shoe Adapter Fg, connected to a Hot Shoe Adapter F (31046) via a F5P cord!

In the image below, I am getting ready to use both F Hot Shoe adapters, to connect both my flash, and my O-GPS-1.
The Hot Shoe adapter Fg is still connected to the F5P cord, and the two versions of the F adapters are next to each other.

YOU SHOULD BE CAREFUL!

Potentially you *could* damage something on YOUR Camera/O-GPS-1/Flash, but I did not.

Here is everything connected!

Here you can see the mechanism of connecting the O-GPS-1 and the Pentax flash accessories.

From below.

Here you can see my custom Pentax AF400T bracket insert. It's connected to the Manfrotto 482K.

Here is the set-up from behind.

Another view. Potentially, I could reverse the locations of the Flash and the O-GPS-1 unit.
I originally made the AF400T bracket insert so that I could position my flash on a mini-head or put a microphone there.
Either way works.

Here are some images of the custom Pentax AF400T bracket insert. It's 6061-T6 Aluminum that I made on my metal lathe.
Yes, it's over built. I might make another version that is lighter.

How did it work?

YOU SHOULD BE CAREFUL!

Potentially you *could* damage something on YOUR Camera/O-GPS-1/Flash, but I did not.

Since the O-GPS-1 doesn't have a Trigger pin, it made sense that the O-GPS-1 could co-exist with Flashes. In the case of the AF-330-FTZ it appears that it works! I turned on the O-GPS-1 unit, it got a fix on satellites and the electronic compass continued to work as I walked around taking pictures with the flash! The AF-330-FTZ has limited interactions as a P-TTL/TTL flash with the K-5, so I am using the flash in "manual" mode. For me, the important thing is that the O-GPS-1 didn't get damaged, nor did the flash or camera.

One interesting bit, was that the AF-330-FTZ and AF540FGZ DO have a data link to the K-5, and have auto-zoom capability. As I zoomed my Pentax DA 18-135 WR lens, the AF-330-FTZ zoomed as did the AF540FGZ!

It appears that the O-GPS-1 can send/receive data to the K-5, while a flash can do the same, and therefore the O-GPS-1 and Pentax flashes can work with the K-5 simultaneously!

Conclusion

Some things you should know or think about before you try this yourself.