Using LANC to control camera and DOF adaptor operation?

[Toenis Liivamaegi]

I`ve been thinking that it might be possible to control DIY DOF adaptor with LANC cotroller for simultaneous operation of camcorder and adaptor, just like the mini35 does.
What we need to know is the exact specification of LANC cotrol and some other unknown electronics stuff?
How would lanc activate and deactivate a 1.2V vibration motor for example?

Thanks in advance,
T

[Wayne Morellini]

Don't know about Lanc, but good idea.

Also there is a Canon SLR lens control module out there that has full controls. It might be worth looking at for hints. Another camera device that uses remote control, is security camera lens, if it can be adapted to SLR lens control mechanism, then there's another avenue to look at. Converting Lanc signals to control these is another thing, but keep looking.

[Frank Hool]

LANC is serial protocol designed basicly to drive remotely DV camcorders. So it has special keywords for camcorders main operations.

I'm not sure You're about to extend this protocol or use it strictly as it is.
Most likely second case - so customer can just purchase LANC remote device and connect it to 35mm adapter instead of connect it to the camcorder.

LANC: http://www3.nbnet.nb.ca/dmeed/sony_lan.html

[Wayne Morellini]

Pic like micro-controller boards (for down to $30) is the sort of things you would use to receive and interpret Lanc information, and control hardware. You can do it cheaper with controller chip and proto board, but a lots of hassle. Somebody is doing a freescale arm based controller at the moment for around $30. The last Circuit Cellar Journal I got had a number of different ones.

It's not going to be completely easy, somebody has to do the mechanical electronics and programming.


Thanks

Wayne.

[Frank Hool]

Originally Posted by Wayne Morellini

It's not going to be completely easy, somebody has to do the mechanical electronics and programming.

Implementing LANC part is as it is just straight code behind certain events. Headache starts with lens. I haven't found any respectable documentation about lens driving. As it's been long time one of my interrests build up programmable remote for slr lens and use them with 35mm adapters.

[Frank Hool]

Viktor Carlquist gives in another dvinfo thread excellent sources for DIY LANC. There are even source codes for programming PIC available.

[Toenis Liivamaegi]

Thank you all very much.

So it seems that actually everybody who`s camcorder has LANC control can simultaneously turn on and off a camcorder hooked to DOF adaptor via regular male to male 2.5mm streo cable as LANC puts out +5..8v when camera is turned on.

I really don`t know why this isn`t used widely already?

Another interesting thing is that even the little Panasonic GS series camcorders put out ca 2.4v from the "Magic Wand" wired remote socket. But it needs that custom plug.

So I think that for camcorders with LANC socket the DOF adaptor power problems will be over soon - more testing to come.

Our PRO/rental fleet for XHA1 will have that infinite synchronized power option for sure. Hell, it even saves manufacturing costs.

Cheers,
T

[Frank Hool]

Originally Posted by Toenis Liivamaegi

I really don`t know why this isn`t used widely already?

One possible reason might be that given current is limited for such applications. I'm pretty sure that pic uses fraction of power that use those vibramotors.

[Toenis Liivamaegi]

I`ll test that but it works with LED and resistor when camera is turned on. Our vibros for example use as little as 40mAh @ 1.2v.
The two upper pins of the pin-header are ground and +5V (when camera is on).

Cheers,
T

[Frank Hool]

ELFA says for PIC16F8X max current 10mA, some current for service circuits(say another 10mA) and some overhead. So it may reach to 40mA.
You may succeed but certainly You need there matching circuit for voltage.

[Wayne Morellini]

I thought there were pics with a small fraction of that power requirement.

Originally Posted by Frank Hool

Implementing LANC part is as it is just straight code behind certain events. Headache starts with lens. I haven't found any respectable documentation about lens driving. As it's been long time one of my interrests build up programmable remote for slr lens and use them with 35mm adapters.

I don't assume people know about programming.

[Frank Hool]

Originally Posted by Wayne Morellini

I don't assume people know about programming.

I'm sorry, i made things confusing here.But i ment under programmable remote, a remote with few memory cells for focus positions. So for instance if to shoot dialog You can memorize few focus positions and access them with 2(or 3) different speeds. Usually You won't need more than three positions to memorize. While shooting You just touch pressure sensitive button(one of those 3 of 4 so called memory buttons). Memorizing while setting scene up should be simple as well: You just have two position switch(setup/shoot) in setup mode. Now You dial dreamed focus and press memory button. Exacly that button which You wish to use later to access that focus position. Thats all programming what should do user of that thing.

As i said earlier biggest problem by building such prototype is unpublic documentation. Even worse: http://en.wikipedia.org/wiki/EF_lens_mount
says:

Third-party EF lenses

Third-party lenses compatible with EOS electronics are manufactured by Sigma, Tamron, and Tokina. The manufacturers of these lenses have reverse engineered the electronics of the EF lens mount. The use of these lenses is not supported by Canon. However, many users find these lenses to be cheaper, and sometimes superior alternatives to Canon lenses.

[Frank Hool]

Wooow! You got me going again. Found something to start from: http://www.birger.com/Merchant2/merc...een=ef232_home . But i would skip LANC part from this but just use dedicated remote for such lens. Just to implement the lerning/one-touch-focusing idea.

[Wayne Morellini]

Yes, that looks like the one I was talking about.

When you say remote, do you mean adapting a normal programmable remote control (for TV/DVD) to learn and send Lanc signals instead? Sounds like an enterprising idea, but can it get away with not having an interactive feedback mechanism between lens and remote?

[Frank Hool]

Originally Posted by Wayne Morellini

When you say remote, do you mean adapting a normal programmable remote control (for TV/DVD) to learn and send Lanc signals instead?

I actually ment to build dedicated remote controller for given purpose especially. It means to make changing focus and FL etc. for cam operator as easy as possible while shooting.

There comes out some min. requirements for such device:

1. it must have two position switch for dial - learning and shooting mode.
Learning mode is used for memorizing those focus position which You will need later shooting in that specific scene. You can dial focus manually right on lens and make remote ask lens focus position.

2. it must have at least 3(maybe 4 is ok) pressure sensitive buttons for memorize/access focuspoints. You can choose different speeds to achieve desired focus by varying pressure on sensitive button. Those speed may be limited amount say 2-3 if it makes architecture and useage of such controller easier. Memorizing is like car radio channel memorizing - after choosing right focus hold few seconds one focus button down - of course in learning mode.

3. additionaly it may have one predefined pressure sensitive button for infinity

So 4-5 pressure sensitive buttons, AD- converter to determ their state, one switch for choosing contoller mode and PIC for keeping Motorola SPI connection between controller and lens.