I have a lovely Gitzo series 1 traveler tripod - (GT1544T) I bought this for the light weight and low profile. It is expensive, but worth it. Also, the center post is removable and the legs can spread out to get to ground level. With the center post, this is about as low as it can go.
The legs can spread out further, but with the center post it'll only go about another 2 inches down.
At the time of purchase, I didn't realize I'd need a "ground level kit" to get it down to ground level. The center post is easy to remove, just unscrew the bolt/hook from the bottom of the post, and pull the post out. But then you are left with an empty center pole and no bolt on the top to mount a head. Once I realized this, I started poking around for the kit online and found it to be priced around $100 - reviews complained that you don't get much for the money... (this is it)
Take out the center post, replace it with this bolt/disc combination.
... so I thought I'd wait for a coupon, or to see if the price would come down.
By the time I had a sale coupon to use, the ground level kit was difficult, if not impossible, to find.
I checked back around the internet every few months with no further luck, the price came down but it was perpetually "out of stock, check back". Last week I found it on Adorama "In stock online, may take 1-2 days to process" and the price was down to about $55, so I ordered it.
Almost immediately my order went to "backordered" status, even though the website still showed it to be in stock.
In the meantime, I was researching my tripod online to see if there might be an alternative way to get lower. I researched spare parts and discussions pertaining to the Series 1 traveler. The center post can actually be reversed - once you take the bottom bold and center post out, simply put it back in upside down... then your hook/bolt is on the top and the camera mount disc is on the bottom. But shooting this way is impractical and not as stable as being on a platform. Still, I thought I would try to set it up that way, and in removing the bolt/hook, I realized that it looked awfully familiar...
Huh... that hook/bolt part looks a lot like the "ground level kit", just without the disc on top.
I wondered if I could remove the top disc from the center post and just connect it directly, but alas the top disc does not have a threaded bolt underneath it to connect directly to the hook/bolt.
Back to the internet, to seek out a replacement disc. B&H photo had this:
Gitzo GS1320D Series 1 Aluminum Adapter Disc for Center Column
The is used to attach a head to the bottom of Gitzo series 1 tripods with threaded center columns. It features a reversible 1/4"-20 and 3/8"-16 stud for camera mounting, and is an ideal solution for upgrading to the latest version of aluminum discs and bolts.
The description does NOT indicate that this can be used to make the tripod work at ground level. In fact, I think the description means to say that you can use it to attach a camera to the bottom of the center post - as in... instead of the hook that is already there. Or maybe I am supposed to remove the current disc from the top of the center post and replace it with this one so that the center bolt can be reversed? It is unclear to me. However at a glance it looked like this could work with the hook/gasket part that I already had. And at about $35, it was worth it to order it just to check it out.
This is how it comes, the center bolt can flip over depending upon which size you need. The smaller side is actually two sizes of thread,
By flipping the bolt so that the smaller side was down, I was able to put the hook/bolt part underneath the center and screw it into the disc on top
Leaving the larger threaded side on the top to connect my ball head to
and now the tripod goes all the way to the ground, and the ball head can tilt to any angle necessary to get the shot. Also, this disc is larger than the original or the "ground level kit", which makes it even more stable.
In my review of the product on B&H, I suggested that they include this capability in their description of the disc, as I'm sure I can't be the only one out there with a Series 1 Tripod trying to remove the center post. Had this been in the description a few months ago I would have bought it immediately!
My Adorama order, by the way, was till on Backorder so I had to email them to cancel it. When I checked back this morning, the "ground level kit" part was labeled as "temporary backorder" instead of "in stock".