According to the blurb, the Manfrotto/Bogen MDeVe 756XB, of which I have the 756CX3 carbon fibre version:

"The tripod has an easily removed centre column provided with a 50mm leveling ball and spirit level that can be used horizontally or vertically. This option allows the column to be converted into a horizontal arm in seconds, providing the tabletop and overhead camera positioning that are impossible with standard tripods."

This may seem like a really dumb question, but, how? The tripod didn't include any instructions (other than a safety guide) and I'm a little baffled.

If anyone with a 756XB or 756CX3 could shed any light on the method, it would be appreciated!

I don't have one of these, never even played with however we do have a similar boom pole / stand thingy. If your tripod is anything like that you have to pull the centre column all the way up then you can turn it on it's side.

Bob, thanks for the reply. Manfrotto have a similar design; pull the centre column all the way up and then it hinges sideways to create a horizontal boom... but not on this tripod. There's no hinge and if you pull the centre column all the way up, it just comes out (and is a real bear to put back in again).

I think I'll have to E-mail them and ask what this "convert in seconds" stuff is all about.

I've found two images of your tripod on the web!
The one on the Manfrotto site certainly does not look like it'll do what you bought it to do.
The image here: Manfrotto 756XB MDeVe Aluminum Video Tripod (http://www.video-direct.com/accessories/manfrotto/manfrotto-756xb-image.html) looks like it would. In that image you can see the extra ears on the ball that would hold the column horizontally.
Manfrotto make a lot of great kit. We mostly buy it off a showroom floor as from their catalogues it's hard to know exactly what you'll actually get.

Bob, thank you for finding that link. Here's a picture from the same site of the tripod I actually have: Manfrotto 756CX3 MagFiber MDeVe Tripod (http://video-direct.com/accessories/manfrotto/manfrotto-756cx3-image.html)

That's got the mount and column arrangement that I've seen quickly converted to the horizontal, but that's not what my tripod has. The images on the Manfrotto site of the 756XB (the aluminium version) depict what I have:

Manfrotto 756XB - MDEVE ALU TRIPOD BLK WHB (http://www.bogenimaging.co.uk/Jahia/site/biuk/pid/15913?kindOfProductCollectionRequest=productDetail&productCode=756XB&productDescription=MDEVE%20ALU%20TRIPOD%20BLK%20WHB&curBrandId=MAN&market=MKT1)

...and of course, they don't match the description!

All very confusing. You're right about the websites too, the parent Manfrotto site is still displaying models that have been replaced.

If this is the same design as mine, (don’t have the numbers with me), the leveling screw on the bottom of the column unscrews completely off the column allowing you to lift the column all the way out of the vertical slot. You then insert the column into the horizontal slot and screw the level screw back in. Not quick, but it is the only way I’ve been able to do it.

Sean, thanks for the reply. I can unscrew the level tightening screw/handle and remove the centre column, but there is no horizontal slot whatsoever.

I have attached a photo (apologies for the colour of the background in this impromptu shot) and unless I'm missing something really obvious, there's no way to mount the centre column horizontally.

So I finally spoke to a helpful chap at Bogen in the UK, who had forwarded my E-mail to Manfrotto.

Turns out to be an error in their catalogue, neither the 756XB nor the 756CX3 can do what it says about turning the centre column into a horizontal boom. It's not possible.

They thought the image at Video Direct wasn't entirely legit as they didn't have any tripod that fit the image and description. The closest thing they could come up with was a 190CXPRO3: tripods, heads, monopods, light stands, camera supports, lighting supports, professional tripod 190CXPRO3 - 190 MAG FIBER TRIPOD 3 SCT (http://www.manfrotto.com/Jahia/site/manfrotto/pid/16519?livid=68&lsf=68&child=2) - with the suggestion being that the levelling function shown in the Video Direct image didn't belong.

I got my Mdeve 756b off ebay it must be a difference in the 756xb and the 756b because unexpectedly ine has the horizontal option which works great.

I was pleased because having read this thread I thought I would be getting a tripod without that capability.

The one I have is here and though the picture is smallish you can see the place where the center column can be placed horizontally.

Manfrotto MDeVe 756B review (http://www.filmalley.com/articles/Manfrotto%20MDeVe%20756B/)

Hope this helps because it's great to have the horizontal solution and the ball leveller in one package.

http://www.chengseng.com.tw/catalog/images/Manfrotto756B.jpg