Solmeta GMAX-GD GPS BDS Dual-Positioning Geotagger & Bluetooth Shutter Release for Nikon D5, D810, D800, D4s, D4, D500, D3, D700, D300S.with 4GB Flash,1900mAh Li-ion, Altimeter, eCompass, LCD.

The Solmeta GMAX geotagger is a solid choice for anyone wanting an advanced GPS device to use with Nikon cameras. I'd been using Solmeta's Pro 2 model, but needed something sturdier with more reliable connectivity between the geotagger and camera. The GMAX is the answer.Compared to the earlier Pro 2, the GMAX is significantly larger and heavier. The GMAX sits higher in the camera's hot shoe, partly because it has a lockdown mechanism lacking in earlier models. A second advance over earlier models is the cable connecting the GMAX to the camera, both ends of which can now be tightened down for extra security while shooting. Finally, a rechargeable lithium battery provides considerably longer lasting power to the GMAX, All these new features are welcome improvements over earlier models.In use, the GMAX rapidly acquires a satellite signal and has provided very accurate positioning data. It is reasonably customizable, though at times this process seemed awkward in the absence of clear translated instructions. A power saving setting lets the GMAX sleep when the camera is turned off, but wake when the camera is turned on. The GMAX remains linked to the satellite even when shut down, so there is no delay in data transmission when powering back up.Like other commenters here, I wish Solmeta had provided a dedicated remote for the GMAX rather than relying on a cell phone app. This omission is the reason for four stars rather than five. It's a pain in the patoot to fumble with a cell phone while shooting, especially under changing conditions. Moreover, landscape photographers can find themselves shooting often enough where cell phones can't get a reliable signal, rendering the app useless.The GMAX is not cheap, especially given the lack of a dedicated remote, but on the whole its functionality and solid build make it a worthwhile investment.

This is a somewhat tentative review, as I haven't had the chance to really use & abuse this yet. I'm optimistic that I'll revise my rating upwards in time, once I get that chance.In summary:Pros:• Seems to work very reliably.• Seems to be accurate.• Certainly has lots of capabilities, many unique.• Built-in battery enables much more accurate tagging, especially if you take photos without warning often.Cons:• Pretty heavy.• Very pricey.• Doesn't support all the positioning systems that competitors support.In [much] more detail:The first thing to note is that it's *big*. Much bigger than I expected. I don't know what it is about the various product photos, but they just did not convey to me nearly how big this thing is. It's bigger in volume than my phone, by far. Probably two or three times the volume. It's *big*.It's not super heavy, but it's not light by any means. If you're used to having speedlights (or similar) in your hotshoe, this will be no problem in comparison, but if this is the first thing you've put in the hotshoe, you're going to notice it in regular use, for a while.GPS acquisition isn't exceptionally fast - and certainly slower than a typical smartphone, which has the benefit of wifi & other assistances - but isn't unusually slow, either - about the usual sixty seconds or so, in most cases.I haven't tested it rigorously, but thus far I haven't noticed any GPS accuracy issues. It's infinitely better than Nikon's SnapBridge tagging mechanism, which is ridiculously flawed and will misplace you as miles and miles away from your real location.The heading functionality is a little squirrelly, though - as with pretty much all electronic compasses, it's not all that accurate out of the box. Calibration is fairly simple, but of course requires you to have a more accurate compass to begin with (or some other kind of accurate means for determining true north). I haven't really checked the real-world results yet, but in some in-home testing I saw it often reporting the wrong heading. Again, though, certainly no worse than a typical smartphone's electronic compass, so it all depends on your expectations.It's got a *lot* of config options, most of which are truly optional, so you need only worry about them in certain edge cases (or if you're just geeking out on them).The user interface isn't as awkward as I expected. It is of course a bit limited, with only a couple of buttons and that "old fashioned" LCD display, but it actually works quite nicely once you get a little used to it. And it is nice to have the display visible to you at all times - I use a Cotton Carrier chest harness for my camera, which is a very nice combo with this since I can just glance down at my holstered camera to read my GPS coordinates, my heading, the current time - whatever I choose to have displayed on there. If you're actually out navigating by GPS it's actually a really convenient setup.I have not yet explored it's off-camera capabilities, nor its built-in GPS logging function (other than to check it out once, just to see that it was working & recording something). It's a nice to have for me, but I typically have my phone recording my travels already. It will be interesting to compare them for accuracy and reliability at some point, though.The built-in battery is nice. It allows me the peace of mind to just set it to always-on and thus always get accurate GPS stamps in my photos. The alternative, which is basically your only practical option for any GPS dongle that doesn't have an independent battery supply, is to have the GPS attempt to rapidly reacquire signals when your camera starts metering (e.g. half-press of the shutter button). But if you're doing wildlife photography, as I usually do, you might go from holstered to snapping away in literally two seconds, which is simply way too fast for GPS reacquisition and position updating. So I fully expect this, in its always-on mode, to be dramatically more accurate in those situations in particular. But again, I haven't enough experience with it to judge, yet.Lastly, there's the price. It is about the most expensive GPS dongle you can get, short of Nikon's official ones. And nobody should ever buy Nikon's official ones, because they're insanely expensive for what they do - this one is far more capable, but with the aforementioned trade-offs in weight & size etc, so maybe not the right one for you if you just essentially want a cheap version of Nikon's, but there are several other manufacturers that make much smaller ones that have all the same functionality as Nikon's, at an order of magnitude less cost.

Works very well. The only reason I am not giving it 5 stars is because of not having a better solution for a remote release. Using the phone as a remote is just about useless because of the bulk of the phone. What needs to be done is like they had set up with the previous GPS unit that was a small wireless remote shutter release that came with the unit & worked OK. The biggest problem the previous unit had was the cable connection to the unit which always kept coming off which is why I returned 2 of them but this one is designed much not only does it have a threaded connection to hold the cable securely to both the camera & the GPS unit but it hasd a locking unit that holds it securely to the camera hot shoe. Make a small wireless remote release for this unit that has at least a 75' range and I will be completely satisfied

I've been impressed at how simple it is to use and yet how geeky it is with tons of info.The battery is pretty good before it starts sucking the battery life from the camera.NOTE: if you deplete the battery on the gps too much it won't even turn on even when connected to the camera.And because i lost the charger and am ordering another i am not presently able to use it.But that's my fault so obviously still 5 stars.I used the nikon gps for many many years and this is way better... as long as you don't mind the larger size.I actually think the camera looks better with it on, for what that's worth

While a bit bulky this unit quickly acquires signal in most areas and only slightly longer in mountain canyons and heavy forest. Images are tagged with coordinates with no post processing necessary. Accuracy appears to be less than one meter in open areas and within three meters in heavily forested areas and mountain canyons if allowed a little more time to obtain sufficient satellite input. Usually, this is about the time it takes to set up my tripod etc. The additional wireless remote works perfectly although very basic in functionality.