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Possible to create a lens controller/override?
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hystavito



Joined: 14 Jan 2008
Posts: 9

PostPosted: Sun Apr 05, 2009 6:35 am    Post subject: Possible to create a lens controller/override? Reply with quote

With all the 5D Mark II owners wanting to control the aperture, I was thinking that it might be not so difficult for someone who already has so much expertise with the control and protocol for Canon lenses.

Maybe something on a flat ribbon cable that sits on the contacts between the lens and the body and wouldn't physically interfere. Even very basic like two buttons, one that sends the aperture increment command and the other decrements. This would be much easier if the lens itself has the ability to prevent the aperture from being moved too far either way, and I would guess it does but of course I'm no expert. It doesn't even have to pass the data back to the body, it can just report a fixed aperture of say 2.0 like those chipped AF confirm adapters do.

This would be applicable to any Canon lens, converted Contax or others. I have seen something like this on the web, well I don't think it had controls on it. I think it was for using EF lenses on a video cam, and it might have just been a physical adapter that gave the serial out connection, I can't remember.

Of course maybe I'm way off and it's way too hard but I just thought I'd post this and see what you think.
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conurus
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Joined: 15 Aug 2006
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PostPosted: Sun Apr 05, 2009 11:21 pm    Post subject: Reply with quote

I will order a 5D mark II next week to look into video. Hope it is in stock and if it is will take about a week to arrive.

What I am thinking is, the 28-80 and 70-200 Zeiss lenses are equipped with an AF/MF switch and that frees up the aperture ring to do whatever we want, such as manually controlling the aperture. However I will have to look into whether this is possible to begin with. For example if the camera powers off the lens during video shooting there is nothing we can do. The last time I speculated about how a 5D mark II worked it led to quite a bit of confusion and misunderstandings and I hope I am not repeating the mistake this time. I will really purchase the camera this time, and look into it, and let you all know.

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hystavito



Joined: 14 Jan 2008
Posts: 9

PostPosted: Mon Apr 06, 2009 2:23 pm    Post subject: Reply with quote

From some other posts I thought you already had the camera Smile.

Regarding the power issue, that is something I didn't even know about. By power down, do you mean not send power to the lens until the very moment it needs to? Moments such as autofocus and aperture changes?

Oh, IS works while recording, so there has to be some way to provide constant power.

Anyway, I realize until you have the camera this is just kinda useless chat heh, but I thought discussing it might bring up ideas and such. Maybe some other people will join in to at least express interest.
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conurus
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PostPosted: Mon Apr 06, 2009 5:55 pm    Post subject: Reply with quote

A fellow Vancouverite generously let me try out his 5D mark II (and in return he tried out the 17-35/2.8 and a few others).

Just placed my order with cameracanada.com... Smile

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conurus
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PostPosted: Tue Apr 14, 2009 5:38 pm    Post subject: Reply with quote

Canon Canada is raising the price, forcing me/giving me the excuse to purchase the camera right now. Buying from CameraCanada was a great experience. They threw in a Lexar 233x 8G CF and I got them to waive shipping charges. The camera arrived last Thursday and I have been making good progress. I am not finished yet and as such I cannot make any promises but if I succeed this is going to be an exciting feature of our upcoming firmware release.

"Why bother? I can put on any adapted manual focus lens on a 5D2 and have direct aperture control," you may ask. This is however the best of both worlds. AF/AE or manual control, the choice is yours, in both still and video modes.
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conurus
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PostPosted: Wed Apr 22, 2009 9:58 am    Post subject: Instructions Reply with quote

The aperture ring of the lens now serves double-duty as both the AF/MF switch and LiveView Aperture Control.

Normally, the lens is set to manual focus if the aperture ring is set to the minimum aperture, and autofocus at any other aperture (except for 28-80 and 70-200, which have dedicated AF/MF switches).

The lens will automatically detect if the camera is in LiveView mode or not. To enter LiveView Aperture Control mode, all of the following conditions must be satisfied.
  1. Your camera supports movie recording.
  2. The camera is in LiveView mode.
  3. You rotate the lens' aperture ring at least a little bit. You are now in LiveView Aperture Control mode.

You may now begin movie recording and use the aperture ring to directly set the desired aperture.

To exit from LiveView Aperture Control mode, either
  1. use "Quick AF" in LiveView (not during movie recording), or
  2. press the DoF preview button, and release it (not during movie recording), or
  3. exit LiveView mode.

Note: the lens remains stopped down after you stop movie recording. Do one of the above to reset the aperture diaphragm to wide open.

With a variable-aperture lens, the aperture indicated on the aperture ring is valid only at the shortest zoom position. For example, with a Vario-Sonnar 24-85/3.5-4.5 lens, if you zoom to 85mm, you may use the aperture ring to set the aperture from f/4.5 to f/32. The aperture you will use is one stop slower than the value indicated on the aperture ring. This behaviour is the same as a manual focus zoom lens. This design choice is made so that, although a variable-aperture zoom's aperture changes as you zoom, the aperture diaphragm does not change so as not to produce an obtrusive click noise or cause a sudden exposure change in the footage.

This new feature is developed for and tested on a 5D mark II. The minimum firmware version required is v2.95. Existing customers may send their lenses in for a firmware update to the latest version. We are not sure if this will function on the upcoming Rebel T1i 500D. If you have a chance to try it on that new camera please kindly let us know if it works.

Any comments or feedback concerning the user interface of this new feature is greatly appreciated. The rules sound elaborated but in practice it is simple, intuitive and effective.
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hystavito



Joined: 14 Jan 2008
Posts: 9

PostPosted: Wed Apr 22, 2009 2:32 pm    Post subject: Reply with quote

Wow, this is pretty awesome, nice work Smile.

If I send my lens in, how long do you think it will take? I am in Canada. Just a rough estimate would really help me to decide if I should send it now or wait. Thanks.
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conurus
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PostPosted: Thu Apr 30, 2009 12:26 am    Post subject: Reply with quote

I received a number of questions lately from the cinematography/video community. There is much interest in us because of our knowledge of the Canon EF lens protocol.

Thank you for your questions and suggestions. They mostly fall into 2 categories and I will explain our position on both.

Some of you are looking for a generic way to control all EF lenses on the 5D mark II, such as follow focus and aperture control. While electronically we are capable of doing so, mechanically there is no room to insert something between the camera and the lens. This seems an insurmountable problem to us.

Some of you are looking for a DOF adapter for your video camera. We would like to refer you to Redrock and their product is capable of controlling an EF lens electronically:

http://www.redrockmicro.com/lensadapter/index.html

To summarize, sometimes the registration distance/lack of room gets in the way, and in other cases other vendors have already been offering the video product that you are looking for.
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CP



Joined: 17 May 2007
Posts: 15

PostPosted: Wed May 27, 2009 5:59 am    Post subject: Reply with quote

http://www.dpreview.com/news/0905/09052701canon5dmarkiifirmware.asp

Canon will have the similar control fro 5DII on Jun 2.
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conurus
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PostPosted: Wed May 27, 2009 6:38 am    Post subject: Reply with quote

Yikes! This is the second time something like this happens to me! In 2007, we shipped the AF micro adjustment feature a few months ahead of Canon.
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Y M WAN



Joined: 30 Jan 2009
Posts: 10

PostPosted: Thu May 28, 2009 6:19 am    Post subject: Reply with quote

So, should we install the Canon's new firmware, or wait for your advice. What I mean is that would the Canon's conflict with yours in the converted lens.
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conurus
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PostPosted: Thu May 28, 2009 1:06 pm    Post subject: Reply with quote

Hi Mr Wan,

No conflict is expected. We will find out for sure on June 2, and in any case, there is an undocumented switch to disable the lens' aperture control feature.

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conurus
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PostPosted: Tue Jun 02, 2009 6:47 am    Post subject: Reply with quote

UPDATE: I downloaded Canon's own implementation of movie aperture control. There are no conflicts between the Contax N lens' LiveView Aperture Control and Canon's own that I can find.

If you use the lens' aperture ring first, the camera's aperture control will not function. Conversely, if you use the camera's aperture control first, the lens' aperture ring will not function. The two aperture control functions will never fight with each other. Whoever gains control to the aperture first will disable the other.

There are no surprises here, and everything is as designed.

There is still an important reason why you would want to control the aperture of your movie using my feature instead of Canon's, if your lens is a variable aperture zoom. If you use Canon's aperture control feature, the lens will mimick a constant aperture zoom by changing the aperture diaphragm as you zoom. For example, if you set your movie aperture at f/8.0 at 24mm, the diaphragm will open up by 1 stop as you zoom to f/5.6, resulting in some click noises and some sudden changes in brightness to your footage.

Using my aperture control feature built into the lens, the aperture diaphragm doesn't care, and your actual taking aperture will go from f/8.0 to f/11 as you zoom from 24mm to 85mm. The exposure will gradually become darker and there is no aperture click noise.
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Y M WAN



Joined: 30 Jan 2009
Posts: 10

PostPosted: Wed Jun 03, 2009 12:22 pm    Post subject: Reply with quote

Thanks a lot.
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hystavito



Joined: 14 Jan 2008
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PostPosted: Sat Sep 19, 2009 5:14 pm    Post subject: Reply with quote

Just thought I'd revive this thread because of the new micro 4/3 cameras.

With all that extra space between the body and a Canon EF lens, would there now be enough room to supply power (from the body I guess) and also include aperture control?

I have no idea if there is a sufficient market, just wondering if you think it's technically possible.
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