Zoom/focus controller for Steadicam

A

Alan Dague-Greene

Active member
I bought a Varizoom Stealth-PZFI focus/zoom/iris controller when I got my HVX. It's a pretty nice gadget, but the problem is that the cord is too thick for Steadicam work. It is impossible to orient the cord in a way such that it does not affect the sled balance.

Can anyone recommend a controller with a really thin wire? I know that wireless would be the best, I'm just not sure I want to invest that kind of money right now. I really just want focus and zoom, iris would be a bonus but I'm not sure I can keep track of that much at once.

Thanks,
Alan
 
At this time there are only 3 commercial Focus controllers for the HVX (that I know of)
The Varizoom PZFI
The BeBob FOXI - a Focus & Iris unit, probabaly too big gimble mount. It uses a coiled cord.
The Chroziel (sp?) Digi-Fox. A Privy but very high quality wireless FF system that has been adapted to control the HVX too.


... You could always build your own controller, it's just a couple of potentiomiters. :) After all, you did build the rest of the rig. :thumbsup:

- Mikko
 
Thanks for the vote of confidence, but anything electronic is a long shot for me. I could barely muster the knowledge to get the right batteries for my monitor.

The Digifox looks something like a BFD, where the focus is controlled by an assistant. As you've guessed, I need something that's gimbal-mounted.

Peter Abraham mentioned he has something with a thin wire, but couldn't remember the name of it. I'll pick his brain again.

Thanks for the help, Steadi-Guru!
 
I would mirror Mikko's comments about making one. I tried out the Varizoom and couldn't get it to fly at all and ended up making my own. The circuit for the HVX is dead easy and you can get everything you need from a supplier like Jameco.com.

Bob
 
Hey! good thing here.

I build my zoom-rec controlled but could not build the Focus.iris.

Do you have plans for it?

Thanks Bob
 
wire extension

wire extension

I have the same controller for my hvx on Steadicam Flyer. Just build a wire extension from more flexible cable. To be as flexible as possible, only lead the focus signal over. Mount the controller on the hade. Tie the controller cable to the arm. Make a U-shaped cable shape from handle to front of post. No problem. Particularly if you weigh the camera down with extra stuff and/or junk metal ;-)
Oh, and I have successflly mounted the controller beneath the post also, keeping the isolation betwen arma and post. Less good for controlling the Flyer, though, as your post arm needs to do several things, which may bump things abit. It is possible, though!
 
I'll post up a schematic for both the Zoom/Rec and Focus/Iris circuit. They are just 20K pots and a momentary switch. Look for something later this evening.

Bob
 
Here are two schematics for what I made initially. It lets me switch between multiple fixed focus and iris points with a switch. Please ask questions if you don't understand anything. I built these with parts I had laying around but Jameco.com carries everything that you would need. I'll see about putting together a parts list.

Bob Hill


1161028349.jpg

1161028413.jpg
 
Bob Hill said:
Here are two schematics for what I made initially. It lets me switch between multiple fixed focus and iris points with a switch. Please ask questions if you don't understand anything. I built these with parts I had laying around but Jameco.com carries everything that you would need. I'll see about putting together a parts list.

Bob Hill
Click to expand...

Why the DP4T and the DPDT switches?

You only need a SP4T and an SPDT for this application. No need to add to the complexity and costs.
 
Mikko beat me to it. The schematic is for a unit with multiple presets. I made a simple one as well but I tend to use the one with the presets more. As for the pots they are all 20K.

Bob Hill
 
The fact is that you only need to switch one side of the "pots" not both, so there is zero need for a DPxT switch in either of these applications.

Let me expand on switch terminology.

DPDT is a double pole, double throw switch. SPDT is a single pole, double throw switch. The same for the 4 throw switch. The schematic shown can be simplified (read less expensive to execute) without any resultant lose in function by only using a single pole switch for both the iris and focus control sides.
 
I concure.

Now someone (Barry?) correct me if I'm wrong, but you could use momentary switches, pushbuttons, in place of a selector and it woudl still set focus to the marks and then leave it, right?

- Mikko
 
Mikko, I tried momentary switches but you have to hold them down until you get to the focus point and once you release the focus stays set. However, if you release them too early you don't get the correct focus. For me they weren't as idiot proof as I needed them to be when I was flying my rig . As for the DPDT switch, you and khmuse are right about using a SPST swtich. I wrote the schematic based on what was on my bench not what would be the best case, sorry my bad.

After having slapped together a few controllers I have to say that I have only used 2 settings for the focus or iris so having more is probably pretty useless. Also, I would highly recommend some form of strain relief when using either of the controllers. Those connections can easily be damaged if you are not careful.

Bob
 
Hi Bob,

I had a question. Would it be possible to buy the Foxi and take it to a model shop and have the guys there make it wireless? there is a model shop in my area that is all about hellicopters and big boys toys.
 
You can hook up a servo to the pot and use it to control things. I am playing with a rig right now that can work wirelessly but I am also making it able to handle focus control on a 35mm adapter as well. I'll post up as soon as I get something decent working.

Bob
 
You must log in or register to reply here.
Back
Top