You will find the answer and what you need here.

http://www.studio1productions.com/lanc-sa.htm

Rant = On.

You will also find the reason why I will no longer buy a Sony camera in the future. Sony has foolishly gone out of their GREEDY way to prevent people from using third party accessories! I have had many Sony cameras over the years and this problem has been growing like a cancer.

I have a camera light that I bought for their proprietary hot shoe that I can no longer use because SONY changed things making it obsolete!

They cause you to have to buy their odd-ball junk only to make them obsolete so you will have to buy more of their odd-ball junk later on.

Oh yea, a number of more recent cameras from Sony did not have the needed threads for filters. Need a filter to make the video better? FORGET IT!!!

Sony knows how to loose a dollar trying to make a dime...

Rant = Off.

I bought this one for my AX100 and can reuse my old LANC controller.

@VidMus
I get where you're coming from with the "Proprietary" thing.. I am seeing that the more I learn about digital videography the more I need to bring to the table, in terms of devices and any other hardware to enhance my ability to get that "Money Shot".. Therefore there will be more forethought when I buy cameras.
The HDR cx900 is an awesome Digital Eye worthy of shooting modest budget video projects, which is what I do with it along with 3 x B and cutaways cameras. (HDR cx330).
I guess what I'm trying to say is I own the cx900 so I have to make the best of it.
Your displeasure of Sony's business practices is thoroughly shared by many ,I'm sure.

@OldSmoke
The Amazon pops up with the 3 items needed to operate the cx900's zoom , focus and record.. I see that the multi mini jack on the camera should achieve what I want with the Lanc controller..
I would also most definitely need an extension for crane use as well.
I believe you have the big brother AX100 and if it works on your unit then it should work out fine for me.
Once again your help is much appreciated.

@FPP

I also have the HDR-cx900 and am using my LANC controller with it.

@VidMis
How's that working out for you?
And is there an affordable unit minus the clicking issue in the zoom toggle switch?

"@VidMis"

Vid-Who? LOL! Just so you know, 'Vid' for video and 'Mus' for music.

Anyway, if you use the original link I gave you, they have controllers that are quiet and do not make the annoying 'clicks'. I am not sure if they are what you would consider 'affordable' or not but they are not overly expensive.

I am using a cheep, cheap and cheep 'click' controller that lets me dial the zoom speed. My hands are not steady enough to push the zoom buttons just so for a steady and slow zoom. My hearing is too poor to hear the clicks so that does not bother me. LOL, so much for others around me.

Seriously, my limited budget says what I can and cannot afford to get. I have to balance what I need vs what I can get to best achieve the results.

http://www.studio1productions.com/lanc-sa.htm

As for how the cx-900 is working out for me, I almost returned the camera the second time. The first one I had was awful with auto-focus even with the first firmware update. The second one was much better but still much too slow. The second firmware update made the biggest difference. It is still a bit below par on auto-focus but is now to a certain extent acceptable. I would not use the it for run and gun!

I set the 'agc' limit to 24 db. The max gain has too much noise. I set the exposure off-set to -1. Like all Sony consumer cameras, it tends to over-expose.

With any camera, you have to learn what it can and cannot do. I have done a lot of test videos in a number of different situations to see what its limits are. So when it comes time for the real deal, I know what it can and cannot do so I do not loose a one time shot guessing with it.

Anyway, get yourself a controller that meets your needs. If a cheep one does then get it, if not, get a higher priced one. The cheep ones are throw away types and they click and clack.

Happy videoing!

And is there an affordable unit minus the clicking issue in the zoom toggle switch?

B&H has another Lanc controller, a Revo, which is quite cheap ($20). Don't know if it clicks, but the reviews, though few, are good. Plus, B&H is very good about returns if you're not happy. I'm still using an old Giottos lanc conroller that is no longer available. No clicks.

wwaag

@VidMus
Please accept my apology on the finger slip.. No harm intended.
I know all to well about budget priced hardware, especially when it comes to a camera maker not offering the peripherals specifically designed for it's product.. It seems very dicey when it comes to converting this and that.
It looks like I can get a decent one at around $50- $125 US .
And while I am editing... Let's drop the E from Lance as clearly everyone knew what I was posting about..
Keep me posted if you see a great deal out there.

@wwaag
Thanks for the lead.. I often use B&H and may have overlooked their offering on this item.

I am cheating. I bought a used Sony VCT-80AV Tripod of eBay just to get the LANC controller and fixed that to the AX100 with the adapter cable and made an adapter to fit it to my trusted tripod. Was a bit of work but that on works very well; no clicking and has variable zoom speed to.

By the way, this should work too. I bought it for my wifes RX100iii and it works just fine.

@OldSmoke
I believe I'll give this one a a go(Sony VCT-VPR1 Compact Remote Control Tripod)..
I just need the remote portion.
Unfortunately no remote focus.o