View Full Version : Whu have "CLOSE" as an option for Iris?
Shannon Rawls December 19th, 2005, 01:07 PM Messing around here with my camcorder. I see the aperture can be "CLOSED". Will someone please explain why on earth I would want it in "CLOSE"? Everything goes totally black. I pointed it at the sun...still black.
What is this used for? Please let me know so I can sound like a professional when someone else asks me. *smile*
- ShannonRawls.com
Mathieu Ghekiere December 19th, 2005, 01:08 PM Maybe so you could tape some black screen for a timecode?
Don't know sure, only reason I can think of on this moment.
You could do that with the lens cap too, I don't know.
Ashley Hosking December 19th, 2005, 02:55 PM Probably to protect the ccd in situations were you may not have the lens cap... True black needs to have a sync pulse of 0.3 volts so I doubt it would be for putting black on the tape, although it could be used for it... not really a rule you have to go by inless your going to give a TV station the tape.
I'll look through my notes from college back in 2002 later on as I am sure I asked the same question.
You already sound like a pro Shannon ;-)
Chris Hurd December 19th, 2005, 03:09 PM Do-it-yourself fade outs.
Nick Hiltgen December 19th, 2005, 04:27 PM I perfer the do it yourself star-wipes...
I'm not positive because we didn't get into it yesterday, but on the 900 there is something called "black balance" I don't know if the canon has it our not but it's used to give the camera an internal reference to what absolute black is. So maybe that's the reason?
Anthony Marotti December 19th, 2005, 10:09 PM Messing around here with my camcorder. I see the aperture can be "CLOSED". Will someone please explain why on earth I would want it in "CLOSE"? Everything goes totally black. I pointed it at the sun...still black.
What is this used for? Please let me know so I can sound like a professional when someone else asks me. *smile*
- ShannonRawls.com
It protects the image block from burn ins... in case you lost the all important lens cap.
Ashley Hosking December 19th, 2005, 11:05 PM Thought so :-)
Probably started back in the days of tube cameras
Jon Bickford December 20th, 2005, 12:47 AM like chris said it's for in camera fade outs/fade ins, there is a considerably more beautiful look to fade outs/ins done with the aperture becaue as it fades, thqt last moment before it closes everythin is getting deeper and deeper depth of field, of course it's even better to do your fade ins/outs with the lighting there's a lot of that in The Aviator and citizen kane
Anthony Marotti December 20th, 2005, 06:24 PM Hello,
JMHO
You may use it like that for certain, but its functional utility is to protect the CCDs. I am not sure, but I believe I ran across it in the manual during one of my read-throughs. I always keep a lens cap on the lens when the camera isn't running to protect the CCDs and the lens at the same time.
Personally I can't imagine locking my footage into a particular effect. I would never use a fade in-camera, it totally limits your editing options.
Ashley Hosking December 20th, 2005, 06:57 PM Hello,
JMHO
You may use it like that for certain, but its functional utility is to protect the CCDs. I am not sure, but I believe I ran across it in the manual during one of my read-throughs. I always keep a lens cap on the lens when the camera isn't running to protect the CCDs and the lens at the same time.
Personally I can't imagine locking my footage into a particular effect. I would never use a fade in-camera, it totally limits your editing options.
If I was editing footage that was shot by a camera op that had done that I'd kick his b*tt! *Smile*
Not to mention it would be very hard to make the fade a constant speed from start all the way to finish
I think Chris was joking...
Anthony Marotti December 20th, 2005, 07:38 PM Me Too, or at least he had Joke Overtones :-)
Steven-Marc Couchouron December 21st, 2005, 05:20 PM The problem with the Canon XL-H1's iris is that it is incremental. Meaning you can't do any smooth exposure adjustments or fades. It is really a shame they haven't implemented a smooth iris on this camera.
Ron Pfister December 23rd, 2005, 10:42 AM The problem with the Canon XL-H1's iris is that it is incremental.
Is this still so? What an absolute shame! I've thought this to be one of the most significant limitations of the XL 1/2. Can't believe they didn't change this!!
Shannon Rawls December 23rd, 2005, 11:37 AM Is this still so?
Not so... the iris incrememntally and smoothly changes from f-stop to f-stop on the XL-H1. It's kinda fast, but surely not a hard switch. And atually, you COULD use the closed option to fade to black like Chris said.
- ShannonRawls.com
Ron Pfister December 23rd, 2005, 11:44 AM Well, the XL-1s does change the iris 'smoothly', too, but with distinct increments. There's no way to *really* smoothly/slowly adjust the iris w/o the viewer noticing. In post, it's pretty much a cut (or luminance tweaking) whenever the iris was changed in the footage. Suxx big time! Can you confirm or deny whether this is clearly the case? You have an XL-1s around, Shannon, correct? If so, could you compare the behavior of the two cams? That'd be great!
Thanx a bunch - and don't let Santa ruin those nice red candles in your fireplace! ;)
Cheers,
Ron
Shannon Rawls December 23rd, 2005, 11:54 AM One step ahead of you. I pulled out the XL1s to see for myself after I replied.
The XL1s switches a tad-bit harder then the XL-H1, but not by much.
and get this...
it's smoother then the Z1U going to "closed".
- ShannonRawls.com
Ron Pfister December 23rd, 2005, 12:05 PM Shannon, thanx for checking this! Are the increments (in f-stops) the same as in the XL-1s?
Steven-Marc Couchouron December 23rd, 2005, 06:12 PM It seems to me you would definitely still notice small luminance jumps if you tried to adjust the iris during a shot.
The stops go 1.6 (when wide), 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.2, 3.4, 3.7, 4.0, 4.4, 4.8, 5.2, 5.6, 6.2, 6.7, 7.3, 8.0, 8.7, 9.5, CLOSE
Anthony Marotti December 24th, 2005, 12:29 AM Hello Guys :-)
JMHO This is useless... do it in post and use the iris for what it is designed to do... adjust for DOF and lighting conditions.
Now if you shoot in automatic mode, which I never do, I can see that you would want smooth iris changes when moving from a light scene to a dark one, or vise versa, but I can't see the value in manual mode.
Now I must admit that I don't do events and all of my shots are planned, so my light is right from the get go and I don't require any Fstop changes during a take, so I am no authority when it comes to live events.
If I ever find myself shooting a natural scene, I would rehearse my moves and take a reading from my darkest to my lightest extreme and choose the most appropriate setting so that I wouldn't have to change it in the shot. I can see how you would use auto mode for ENG.
Merry Xmass and all that!!
Jon Bickford December 24th, 2005, 02:48 AM i just went out with my H1 and did a bunch of iris tests on christmas tree bulbs, it is incremental but quite smooth, if you roll the dial smoothly and consistently you can get very clean fades
Ron Pfister December 24th, 2005, 02:57 AM The stops go 1.6 (when wide), 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.2, 3.4, 3.7, 4.0, 4.4, 4.8, 5.2, 5.6, 6.2, 6.7, 7.3, 8.0, 8.7, 9.5, CLOSE
Thanx for posting this info! So it's the same as the XL-1s, but the latter adds 10, 11, 12, 14, 15, 16 and then goes to CLOSE. Did they omit f/13 to steer clear of bad luck? ;)
Cheers,
Ron
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