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Old December 11th, 2003, 07:35 AM   #1
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Multiple Iris Controls

When using the Mini 35, you then have two iris controls, one on the camera and one on the film lens. Is there also one on the Mini 35 itself? What do you do?
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Old December 11th, 2003, 08:43 AM   #2
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No, there is the aperature on whatever 35mm lens your using. Then the XL1s version of the mini35 system also has a 7-stop iris on the relay lens which connects the XL1s to the mini35 adapter.

The camera itself doesn't have any iris controls.

so in answer there isn't an iris control on the camera only on the lens and the P+S image converter relay lens.
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Old December 11th, 2003, 10:30 AM   #3
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That applies to the XL1 version, but not to the other (fixed-lens) cameras. On the PD150/VX2000 and the DVX100 version (and presumably on any version for a fixed-lens camera) there is no secondary iris control on the mini35, instead you use the camera's built-in iris control.
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Old December 11th, 2003, 11:49 PM   #4
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Iris control

Craig,

When you say the camera itself does not have any iris control, do you mean it's disabled when the 35 is attached?
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Old December 13th, 2003, 04:33 PM   #5
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yeah the XL1s doesn't have an electronic iris. the Iris on thier video lens is controlled by the camera body but it's still a physical iris on the lens.... so no iris control on the camera body...

U can control light by adjusting the shutter speed on the camera body.

Further there are a bunch of things that the XL1s will do if the video lens is attached but will not do if the video lens is not attached... for example custom white balance settings will not be retained if the power on the camera is cycled without the video lens, which is kinda a piss off..

However instead of screwing around setting white balance over and over again I chose either the indoor or outdoor setting that most closely resembles the look I'm going for then make color temperature adjustments in post which is super easy and yeilds great results (I use discreet stuff for color correction by the way).

Similarily the shutter speed will return to it's default everytime you cycle the power as well, so if you want 1/30 and the camera outta the box is set at 1/60 it will return to 1/60 everytime the camera is powered on or off...... I haven't tried putting it into standby because Canons standyby mode makes me nervous...

if you know you wanna shoot at 1/30 or some other shutter speed most of the time attach the video lens set the shutter speed then power off... reconnect the camera body to the mini35 rig and it should default to 1/30 everytime.
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Old December 13th, 2003, 05:49 PM   #6
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James:

I'm guessing you were also wondering when and how to adjust the iris on the taking lens (the film lens) vs exposure control elsewhere (the relay on certain versions of the Mini35, or shutter speed as Craig mentioned, or other options as detailed below).

The setting on the film lens should be done first, as this will determine the depth of field of the shot. There are many considerations to make on where to set the iris. Many users automatically will set it wide open to minimize the depth of field--after all, isn't that why we are spending all that money on this setup? However, wide open creates some potential issues. Most motion picture lenses are not optimized for this; they will resolve the image better stopped down slightly (you don't want to work with the lens fully stopped down either, which can cause other problems). Plus it may be too difficult to maintain focus with super shallow depth of field. Or you may be looking to match the degree of softness in the background between two shots of varying focal lengths; stopping down the longer lens shot will help maintain the look.

Once your taking lens has been set, you can bring the actual exposure of the system down by the means mentioned above: iris on the relay lens if available, iris control on the camera body or built-in lens, adjusting the gain on the camera, or altering the shutter speed. To me, adjusting exposure with the shutter speed or gain control should only be done as a last resort as it is not a transparent effect; i.e. this will cause a difference in the appearance in the footage. I prefer to decide when I want a shutter speed other than 1/60 and adjust the exposure accordingly, not the other way around. In other words you are introducing a different look which may cause the audience to perceive the scene in a different way.

Another way to control the exposure is with glass ND filters up front, certainly a more cumbersome and time-consuming way to work. With the latest version of the Mini35 on an XL1s, this would be the only transparent way to go. It's a bit of a pain considering one is using a video camera (and there was another option available on the earlier Mini35's, as well as in the current PRO35), but then again this is the protocol one follows when shooting film, so it's not that outrageous a demand.
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Old December 14th, 2003, 01:39 AM   #7
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Order of operations

Thanks Craig. I am/was aware that the iris control is on the camera body. It just seems like a lot more to fool with with three settings such as the film lens, 35 adapter, and then the camera iris to set. When you said "the camera itself doesn't have any iris controls", that's what confused me. I still don't understand why you said that. If you meant it was disabled when the 35 was attached, that makes more sense.

Charles. So when using the 35, just attach it to the camera body, then attach the film lens and then turn on the camera. Leave the camera body's iris alone until you set the film lens and the 35's settings (if any) and then adjust the camera body's iris last. Is this correct?
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