[Dale H. Cook]

I have debated getting an O-GPS1 for geotagging field photographs. The problem is that it monopolizes the hot shoe and for some field photography where I want geotagging I also need to use my wireless flash trigger for one or more off-camera speedlights. My Pentax K-70 body does not have a flash jack - it it did I could use the wireless trigger off the shoe with the supplied cable. Has anyone found a work-around? The wireless trigger is not smart, it just needs the two basic dumb hot shoe connections. I am fully capable of (and well equipped for) hacking a flash jack onto the O-GPS1, but I would prefer not to void the warranty on a $150 GPS.

[deus ursus]

Yeah, it would be nice if there was a hotshoe on top of the O-GPS1 unit, so you could use a flash with it.

[ThorSanchez]

Probably not the answer you're looking for, but several Pentax cameras have GPS built in and don't need the O-GPS1. K-3ii, for example.

[RGlasel]

I am fully capable of (and well equipped for) hacking a flash jack onto the O-GPS1, but I would prefer not to void the warranty on a $150 GPS.

Ithink the problem you will run into is that the circuits for triggering a flash are used for communicating with the O-GPS unit, so there is no way the camera can do both at the same time (and even if you bypass the wiring to operate a flash trigger, the camera's processor won't provide the functionality you want). My suggestion is cheaper than getting a camera with built-in GPS, but more expensive than the the O-GPS1; unless you already have a separate GPS unit with logging and a copy of Lightroom, in that case Lightroom will import your GPS log into its database and match it to the timestamp of your photos. To be honest, unless you want to use Astrotracer, buying the O-GPS1 is probably not worth it, in my opinion.

[Pentax Syntax]

I think you can use this if you can find one :
Pentax Hot Shoe Adapter F for Extension of the Camera TTL Hot Shoe AND Off-Camera TTL Flash Capability - Requires Off-Camera Shoe Adapter F & F5P (or F5PL) Extension Cord (Not Included) | ShaShinKi Malaysia First & Largest Online Camera Shop

It’s the hot shoe adapter F. It allows you to use a cable to add a hot shoe adapter and still allow a pass through on the camera hotshoe.

A little hard to find now.

[aslyfox]

. . . It’s the hot shoe adapter F. It allows you to use a cable to add a hot shoe adapter and still allow a pass through on the camera hotshoe.. . .

here is a couple of reviews for it

PENTAX Hot Shoe Adapter F reviews - Pentax Camera Accessory Review Database

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Keh.com says they have a used one:

https://www.keh.com/shop/pentax-dedicated-ttl-hot-shoe-adapter-f-231646.html...%20Accessories

and B H video has new ones:

https://www.bhphotovideo.com/c/product/41177-REG/Pentax_31022_Hot_Shoe_Adapter_F.html

[Dale H. Cook]

... and even if you bypass the wiring to operate a flash trigger, the camera's processor won't provide the functionality you want

I don't want any flash functionality from the camera. I am using modified vintage Vivitar 283 flashes with manual strobe duration setting as off-camera flashes for photographing old gravestones. All I need from the camera is the shoe base and center pin to trigger the wireless flash transmitter. Everything else, including many of the camera settings such as ISO, f-stop, and shutter speed, is set manually.

I want to use the GPS to geotag shots. There are days when I visit multiple graveyards in a day, and geotagging will let me pull up my laptop map program, into which I have already entered graveyard locations, and allow me to enter the coordinates - that will take me directly to the pre-entered graveyard on the map showing me where that photo was taken.

---------- Post added 05-24-19 at 02:45 PM ----------

Probably not the answer you're looking for ...

Right - not the answer I'm looking for as I am retired and I pretty near had to break the bank to buy my K-70 a year ago.

[stevebrot]

It’s the hot shoe adapter F. It allows you to use a cable to add a hot shoe adapter and still allow a pass through on the camera hotshoe.

A little hard to find now.

The Hot Shoe Adapter F is easy enough to find, just expensive. The same is true of the dedicated cable and the Remote shoe Adapter F. I own all three and they are on my "glad I got an amazing deal, cuz I woulda felt ripped off otherwise" list. I can also affirm that they may not work as expected with a mix of flash.*

However, your suggestion got me thinking. How about something like a universal pass-through adapter with PC sync out?

Vello Universal Hot Shoe Adapter - PC Connection + Top HSA-PSU Edit: Illustration is not accurate, provides hot shoe passthrough + PC only. A different adapter with pass through and PC would work, however.

The PC sync would work for the wireless TX and the pass-through shoe for the O-GPS1. All this assumes that voltage across the main contact/PC pin will not mess with the O-GPS1, but perhaps worth looking into. Edit: The O-GPS1 uses the three data pins and ground rails only and does not have a pin for the hot shoe's main contact. It should work with a pass-through shoe.

Addendum: The official Pentax solution will cost a fair amount of money due to the need to buy all three components (proprietary fittings). A less expensive third-party option would work just as well:

Amazon.com : Vello Off-Camera TTL Flash Cord for Pentax Cameras (3') : Camera & Photo


Steve

* Quite off topic, but mixing speed lights and P-TTL flash on the same circuit may not work well.

[Dale H. Cook]

Ithink the problem you will run into is that the circuits for triggering a flash are used for communicating with the O-GPS unit ...

I doubt that. Any dumb flash, like my modified early Vivitar 283 flashes, can be triggered by the camera connecting the center pin to the hot shoe base. The communication between the camera and a TTL flash, or between the camera and the O-GPS1, are almost certainly using the three other pins on the shoe, perhaps with the shoe base as ground. Pentax probably used a readily available GPS chipset that sends serial data, perhaps in NMEA format, to the body. Communications go in the other direction with the flash, the camera body telling the flash what it needs to do, also probably in serial format. I strongly suspect that the center pin plays no role in either.

---------- Post added 05-24-19 at 03:09 PM ----------

I think you can use this if you can find one ...

That is the sort of thing that should work - I will look around and see what is available.

---------- Post added 05-24-19 at 03:17 PM ----------

How about something like a universal pass-through adapter with PC sync out?

That should work but the pin pattern does not appear to match that of the K-70 hot shoe, so the O-GPS1 probably would not work with it.

... mixing speed lights and P-TTL flash on the same circuit may not work well.

I will not be mixing them. The idea is to use the GPS and my wireless off-camera flash trigger transmitter at the same time (the transmitter can be mounted off of the hot shoe and cable-triggered from a standard flash sync jack). The off-camera flashes are dumb and manually set - no TTL involved.

---------- Post added 05-24-19 at 03:19 PM ----------

Thanks for all of the ideas, folks. That's why I asked here - to get ideas on what to look for and where to look at it.

[stevebrot]

That should work but the pin pattern does not appear to match that of the K-70 hot shoe, so the O-GPS1 probably would not work with it.

The item had a bad illustration and does not do TTL pass through (shows the top of the Canon version that does). That being the case, there may be other adapters that do.


Steve

[Pentax Syntax]

I doubt that. Any dumb flash, like my modified early Vivitar 283 flashes, can be triggered by the camera connecting the center pin to the hot shoe base. The communication between the camera and a TTL flash, or between the camera and the O-GPS1, are almost certainly using the three other pins on the shoe, perhaps with the shoe base as ground. Pentax probably used a readily available GPS chipset that sends serial data, perhaps in NMEA format, to the body. Communications go in the other direction with the flash, the camera body telling the flash what it needs to do, also probably in serial format. I strongly suspect that the center pin plays no role in either.

---------- Post added 05-24-19 at 03:09 PM ----------


That is the sort of thing that should work - I will look around and see what is available.

---------- Post added 05-24-19 at 03:17 PM ----------


That should work but the pin pattern does not appear to match that of the K-70 hot shoe, so the O-GPS1 probably would not work with it.


I will not be mixing them. The idea is to use the GPS and my wireless off-camera flash trigger transmitter at the same time (the transmitter can be mounted off of the hot shoe and cable-triggered from a standard flash sync jack). The off-camera flashes are dumb and manually set - no TTL involved.

---------- Post added 05-24-19 at 03:19 PM ----------

Thanks for all of the ideas, folks. That's why I asked here - to get ideas on what to look for and where to look at it.

I just confirmed that the pass through to the the O-GPS1 on my K-3 works with the Pentax adapter I linked to ( Hot Shoe Adapter F). It would provide a way to do what you want. I have used with wireless flash with the 360FTZ and 540 FTZ flashes.

[stevebrot]

I just confirmed that the pass through to the the O-GPS1 on my K-3 works with the Pentax adapter I linked to ( Hot Shoe Adapter F). It would provide a way to do what you want. I have used with wireless flash with the 360FTZ and 540 FTZ flashes.

Yes, it definitely will work for the GPS; though a Sync Cord F 5P and Off Camera Adapter F would be needed to fire the wireless trigger. I acquired my set of those while looking to support a wireless TX in combination with a P-TTL flash to work with my K10D. The setup works, but it was fairly expensive and would have been so much easier had there been some way to run a simple sync from the Hot Shoe Adapter F. Even better would be a third-party pass-through adapter with PC out.


Steve