Focus/Iris controller

[Bob Hill]

Hi all,

I have been meaning to post up these pics and information for quite some time but kept forgetting it so here it is. The picture is of one of my controllers that I use on either my camera stabilizer or shoulder mount and I also included again the wiring diagram for the controller.

http://www.dvxuser6.com/uploaded/14894/1185463687.jpg
http://www.dvxuser6.com/uploaded/14894/1185463716.jpg

[Kholi]

Whoa! Bob that's crazy. How much did that cost to build?

DOes it work really well?

[Bob Hill]

Hiya Kholi,

Lets see I think the whole thing was around $15. I found the surplus slide pots for $1.50 a piece which really helped. I really like how it works as well. When paired with a good monitor HD focusing and Iris control is dead easy.

Bob

[Kholi]

That's insanely crazy. LoL. Does the Record and Pause button control the camera as well?

Wow man... that's some serious DIY.

[Bob Gruen]

What size are the jacks on the camera? Focus / Iris seems to be a standard 1/8th stereo jack (but I don't like the way the plus feels as it snaps in) and the other is a bit smaller.

Bob

[Bob Hill]

There is an 1/8" stereo and a mini stereo jack. I highly recommend using some sort of strain relief if you are using a wired remote. You do not want to put undo strain on your jacks.

Bob

[Bob Gruen]

Actually, I am going to make a set resistance plug for the focus to lock in back focus for my RR Micro35. Won't be any wires at all...

[mikkowilson]

Actually, I am going to make a set resistance plug for the focus to lock in back focus for my RR Micro35. Won't be any wires at all...

Now *that* is a smart idea! :thumbsup::thumbsup:


- Mikko

[Kholi]

Now *that* is a smart idea! :thumbsup::thumbsup:


- Mikko

Seriously, though. Even when gaffed down if you bump the focus it seems like it still slips.

Very good idea.

[Bob Hill]

Such a good idea that I am going to have to make up one. I'm thinking a ten turn trim pot mounted right to the plug would be the ticket then. Very useful.

[Ted Spencer]

It would seem that a very inexpensive follow focus could also be built this way. Imagine a 20K pot in a large-ish box (maybe 6" x 6") with a big pointer-equipped knob and a white dry-markable surface. A 10' cord (or any length, really) could make it very easy for a focus puller to work it at a convenient distance. I bet it could be bulit for real cheap. Might try it myself actually...

One question: what wattage value should the pot be?

[Barry_Green]

Check out the Bebob Foxi, it's a remote follow focus which is basically exactly what you're talking about.

[Ted Spencer]

Check out the Bebob Foxi, it's a remote follow focus which is basically exactly what you're talking about.

Right, but for $465. If a 20K pot is all that controls it, I could probably build a follow focus box for under $20 from parts at Radio Shack.

Could someone plase inform me what exact wattage value the 20K pot needs to be? Then I'll go ahead and take a shot at building the sucker...

[marketmd]

Finally! I knew someone would come up with a plan to avoid those absurdly overpriced remote units. $300! $400! Ridiculous.

[mikkowilson]

"finally" ?

These simple spec has been open information from day one.

In fact I saw this article: http://www.dvxuser.com/articles/remote/ AGES before I ever actually read of joined DVXuser.


- Mikko

[Bob Hill]

Watt load on the pot is terribly low. I ended up using 1W pots because that is what I could find easily but I'll have to meter the thing to see what the actual load is if no one knows off the top of their heads.

[Ted Spencer]

Watt load on the pot is terribly low. I ended up using 1W pots because that is what I could find easily but I'll have to meter the thing to see what the actual load is if no one knows off the top of their heads.

Thanks Bob. Sounds like a 20K consumer line level audio pot should do it. I'm gonna give this project a shot and will report back when I do.

[Bob Hill]

Ted,

Make sure you get a linear pot not an audio taper. An audio tapered pot changes resistance logarithmically which wouldn't work very well at all.

[Ted Spencer]

Ted,

Make sure you get a linear pot not an audio taper. An audio tapered pot changes resistance logarithmically which wouldn't work very well at all.

Thanks for the heads up on that!

Ted

[Angus_Findlay]

"finally" ?

These simple spec has been open information from day one.

In fact I saw this article: http://www.dvxuser.com/articles/remote/ AGES before I ever actually read of joined DVXuser.


- Mikko

The one I'm hoping to see is the digital control spec. There's tons of information on LANC online, but nothing about the digital control mode on the HVX. Anybody care to prove me wrong?

[mikkowilson]

What "digital control spec" for the HVX?

- Mikko

[Bob Hill]

Like Mikko said. All the controls are analog not digital.

[mpbstereo]

Sweet, I've been building one of these myself, and then came across this site in hopes of looking for a way to incorporate Auto/Manual iris Toggle, which I can't seem to figure out... I've got it figured out for Auto/Manual Focus, just a matter of setting the camera to Autofocus, and closing the circuit that leads to the Focus pot (if that makes any sense, I know jack about electrical engineering, I'm just kinda flying by the seat of my pants here).

I deduced that I'd need a jack with 4 connectors (3 rings), soldered some wiring to it (USB cable whose ends I'd cut off) and thus far have been just testing to see which wire does what, with a 20K pot (though, I find it a little sensitive, really). Focus was easy enough to figure out, but I cannot figure out how to switch between Auto/Manual Iris, which would be frickin' great.

Any suggestions?

[markjs]

Would this unit work with the DVX100B as well?

[mikkowilson]

Yes. It will work with the HVX-200 and the DVX100B


- Mikko

[faultygoblin]

Good job Bob,
thanks for posting. Would like to see some pictures of the rig in action.

[Neal Buconjic]

Any status updates?

[Jason Miller]

I have a couple questions, are the pots controlling power to the ports in the camera, or does the input to the camera flow power both ways and the pot is controlling the compleation of the current?

Jason

[Bob Hill]

Jason,

When you plug in your controller you are completing a circuit where the camera is providing the power. The pot just varies resistance in the circuit.

[Jason Miller]

Thanks Bob, so for example, the focus iris cable, its basicly a head phone cable, so the right ear bud pos and neg will go to one pot for one of the "focus/iris, and then the pos and neg of the left side ear bud wil go to the other pot?

This is great I'm going to build one with servo controlled pots, so I can make it part of my moco rig.

thanks
Jason

[Bob Hill]

Thats basically it and since it is just a pot it is very easy to hook up a remote controlled servo to turn a pot and remotely adjust the focus and iris.

[Jason Miller]

wow, I'm really shocked that these people charge 300 and up for a couple of pots and some headphone cables. i thought for sure there would be some micro computer involved.


so your 1w pot works fine? does it have much play?

I'mm be heading to my local radio shack this weeked.

Thanks
Jason

[Jason Miller]

one more question, for the power loop for the record I'm assuming its a simple 1:0 at one is there enough power to also run a small red led?

[EDIT-XTREEM]

Anyone know the best places to get the pots?

[Jason Miller]

I have to say I think this is one of the most worthwhile diy projects I've seen on this board, I think this should be a must for any hvx-dvxb user out there tac this in with a lanc controller and I think we have the most important sticky on the year.

Jason

[Bob Hill]

I haven't looked at it to see if the circuit will support an LED. My first guess would be no however I will look at it. As for getting pots, Jameco.com, Mouser.com, etc. are the usual places.

[Jason Miller]

I'm having a hell of a time finding a 20ko 1 watt pot, i'm finding a lot of 10ko, and or 25ko 3 watt pots, where did you find yours?

[Bob Hill]

You could use something like this:

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=241656

Not the greatist but it would work.

[Jason Miller]

2 watt isn't to large?

[Bob Hill]

No 2 watt isn't too large. When I said they aren't the greatest I was referring more to their physical size and relative precision.

[Capt Quirk]

Hey Bob, can you make one of these to work with a Fuji lens? I would love to have something like this for the pan bar when using my JVC HD100.

[Jason Miller]

how preicise are they? would a lower watte or lower kohm make them more so, or would a larger watt/ohm make them more so?

or is 20k the requirment? would 10k ot 25k work?

Jason

[Al MacLeod]

If I understand this discussion correctly, a potentiometer wired in series to the focus plug on a hvx200 can control the focus settings.
Does this mean that, given a range of say one to ten, one representing the clockwise extreme and ten representing the counterclockwise extreme of travel in the pot, that each discrete point in between, two, three and so on will represent a specific point of focus on the lens?

[Jason Miller]

so I got the stuff to build this and I hyave two quick questions, I'm hoping you'll this this and answer tonight.

the two jacks, the stereo and sub mini, both have 3 wire intakes two + and one ground, I'm assuming both pots are hooked to the ground and one to each of the poss.

question two, the record button, does it go into the second intake of the zoom plug? or do I need to rig up a third plug for it. and if so once again, + to + on each then each to the ground?

thanks
Jason Miller

[Jason Miller]

never mind both those questions are answered by just taking the time to look at your diagram, my bad,

the answer to both questions is yes

thanks
Jason Miller

[Jason Miller]

I'm not sure about the focuse yet, but I know that is true for the iris, and it is not true for the zoom, the zoom, pot works like the toggle on the camera, the harder you push it the faster it goes, same with the pot, the more you turn it the faster it zooms, but at what ever seep it keeps zooming untill you turn the pot back to 0 I was hoping for a turn zoom ratio that was repeatable. I still may be able to make it work with the moco, with timing rather than points in space. will find out soon enough I guess.

Jason

[Jason Miller]

finished mine tonight, it works great, not sure if i can use it with the moco, as the pot controlls the zooms speed rather than possition, however i can controll the focus with a servo as it and the iris corrispond with the pot. will post images and maybe a video of it soon. looks like something out of the world of tomorrow.

Jason

[mjjason]

Anyone have a detailed parts list for this?

[Prodigi Pictures]

Anyone have a detailed parts list for this?

You raise a great point, one that has frustrated me lately. When I post something I tell other people how they can do it too.

Lately, the DIY section feels more like show and tell. "Hey, look what I made!" What we all need as filmmakers is to SHARE OUR KNOWLEDGE.

I share just about everything I've learned. Something like this thread only has value if you're willing to share how you did it.

[Jason Miller]

everything you need is in the photos and diagram, its pretty easy, pots botton box, wires, and connectors.

[Prodigi Pictures]

everything you need is in the photos and diagram, its pretty easy, pots botton box, wires, and connectors.

I owe you an apology. I confused your post with a different one I saw yesterday. Your post is more detailed than 90% on the thread.

I think it would help to add:

1.) A parts list
2.) A step-by-step instruction guide

But, at least you show the inside of your device. Many of the recent DIY posts are simply "Look at what I made!" The entire point of the DIY section is to educate other filmmakers so we spend less money on gear.

[mjjason]

everything you need is in the photos and diagram, its pretty easy, pots botton box, wires, and connectors.
Yeah, after posting I realized the iris/focus control were connected to a separate jack. The one thing that is still confusing me is in the diagrams he list auto/manual switches but for the life of me I can't seem to see them or even understand why they are there.

[StayNuts]

Yeah, after posting I realized the iris/focus control were connected to a separate jack. The one thing that is still confusing me is in the diagrams he list auto/manual switches but for the life of me I can't seem to see them or even understand why they are there.
Have same kind of issues.... the FOCUS switch I can understand, put the camera on A/F and when you push this button, it will override the A/F... nice :beer:

The IRIS and ZOOM switches have only the ON/OFF function. For the ZOOM I don't mind, if it is on the right position, turn it off and it is secured. I do miss the function between the AUTO IRIS and MANUAL IRIS. Of course I prefer to use the MANUAL IRIS but sometimes it can be handy to swap back to AUTO IRIS. Don't know or it is possible with a DVX, should be nice :Drogar-Dum(DBG):

[chadarthur]

is anyone interested in selling me one of these??