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Old January 23rd, 2005, 02:43 AM   #1
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I think I found how how to lock manual

not really but a sort of:

I aim at something with the right light conditions and I set the frame rate at 60 for example, the camera will pick the appropriate aperture. If you don't move the camera you cycle (so happened to me today at least) until the fps/apertura indication goes away and immediately after you lock the iris pushing for a few seconds the iris weel. I got my camera locked with the exposure I wanted and the fps were for sure 60. I panned, I used it, I moved it around I didn't get that annoying change of brightness on the video that make things brighter and darker automatically. It was really cool (finally after 1 year). Anybody did a similar test?

I remember a review critisizing the HD10/HD1 a lot since he was panning and he was getting all the brightness fluctuation. May be I discovered nothing new but at least it is new for me.

Gabriele
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Old January 23rd, 2005, 10:17 AM   #2
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Yes, pushing and holding the jog wheel will lock the exposure. The trick is to set the iris, then fool the camera to a desired frame rate and then lock the exposure. The problem is that there's no feedback what the frame rate actually is so you need to guess by looking the screen or viewfinder.
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Old January 23rd, 2005, 11:54 AM   #3
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Yes, I was capable to replicate it at will but I was doing the other way around,lock the frame first and then lock the iris. I'm very happy with the results, there is no display of the setting (idiots at jvc) but from the result I can see, the frame/second is what I usually use in those situations.
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Old January 23rd, 2005, 01:13 PM   #4
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Gabriele - As soon as you lock one you LOOSE the lock on the other. If your light levels are consistant you will probably be fine, but what shutter are you in then 1/30 or 1/60? Thats the problem. In your situation this is probably fine if it is giving you the look you like. Just know that your shutter isn't locked.
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Old January 23rd, 2005, 01:55 PM   #5
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Ken, I also have the AGC disabled btw but no, I can't put my camera against the sun or toward a dark room and exposure doesn't change a bit, I came back to the shutter speed and it was where I left it 1/60 . Please try yourself. In any case doesn't make any sense that my exposure doesn't change and the camera keep changing aperture and shutter trying to keep the total exposure unchanged, the camera is really locked.
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Old January 23rd, 2005, 02:25 PM   #6
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That is because the exposure is locked. You can not rely on what the shutter speed says as it is not locked.
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Old January 23rd, 2005, 02:39 PM   #7
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normally changes in shutter speed will change also the global exposure setting, this is usually compensated byt the iris opening and closing . Explain to me how can the iris be locked, there are NO CHANGES in my exposure moving the camera even toward very strong sources of light (I get overexposed pictures) and the shutter speed is changing.
Explain also why I leave the shutter speed at 1/60 and I find it at 1/60.
But listen a question. Did you spend 2 minutes? Did you try?
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Old January 23rd, 2005, 02:51 PM   #8
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I must admit that I am having a hard time following your english.

"Explain to me how can the iris be locked, there are NO CHANGES in my exposure moving the camera even toward very strong sources of light (I get overexposed pictures) and the shutter speed is changing."

To me that sounds like you have already locked it. "L" on the read-out. You are admiting that your shutter speed is changing.

"Explain also why I leave the shutter speed at 1/60 and I find it at 1/60"

If it is not locked it can do what ever it likes. You can not go by what it says when it is not locked. You just admitted above that your shutter speed keeps changing when you change lighting.
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Old January 23rd, 2005, 02:53 PM   #9
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<<<-- Originally posted by Ken Hodson : Gabriele - As soon as you lock one you LOOSE the lock on the other. If your light levels are consistant you will probably be fine, but what shutter are you in then 1/30 or 1/60? Thats the problem. In your situation this is probably fine if it is giving you the look you like. Just know that your shutter isn't locked. -->>>

I'm pretty sure the press-and-hold lock will lock the shutter and iris. Look at it this way, in the manual mode, if you dial the iris to a certain value, it will stay there no matter what, right? Why would it be then necessary to take the extra step to press and hold to lock it down if the shutter will remain in the automatic mode anyway?

I've been using the exposure lock many-many times and know for sure that it locks both the shutter and iris. The tricky part, like I said earlier, is to fool the iris or shutter to a certain value and then lock it there.

This was one of the first tests I did with the camera after I bought it. I set the shutter to 1/30, pointed it to a dimly lit room to make the iris open all the way, locked the exposure and pointed the camera to a very bright light and waved my hand in front of the lense to caputure the motion characteristics. Next test: shutter 1/30, no lock. Pointed the camera to a bright light and and immediately the iris kicked in. Next: manually set the iris to wide open and pointed the camera to the light. Moving the hand in front of lense immediately revealed that the shutter was running faster than 1/30. So my conclusion was: in the exposure locked mode, if either the iris or shutter would have taken priority to keep the exposure at the set level, I would have seen either the higher shutter speed motion characteristics or less changes in scene exposure due to iris kicking in. Unless I couldn't distinguish 1/30 from 1/60 or F-stops from eachoter, the conclusion I drew was that the press-and-hold lock locks the iris and shutter.

Unfortunately I don't have the camera anymore to put this theory under testing.... sold it on eBay few weeks ago =(
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Old January 23rd, 2005, 03:18 PM   #10
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Sten

Sorry, english is not my mother language but I was saying exactely what you said. I've to admit that I was not saying that it is tricky to lock into the iris/shutter relation that you want. In his posts Ken gave the impression that doing what I was doing the shutter isn't locked. This was the source of my disagreement and probably misunderstanding. There are tricks to lock the shutter though. Do this test:
1) You se the camera in the "sport" pre-setting. The shutter will be forced at 1/250
2) lock the iris

DOing so the shutter will be locked at 1/250 I tested this 100 times and the iris will be locked at what is the right exposure according to the 1/250. From now on nothing will move exposure-wise and your shutter will stay at 1/250. This is just an example but there are other combinations in order to regain some flexibility with this camera. We all agree the manual mode kind of suck but having 2 or 3 options like this cover a good range of applications in my opinion.
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Old January 23rd, 2005, 03:23 PM   #11
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<<<-- Originally posted by Gabriele Sartori : Sten
Sorry, english is not my mother language but I was saying exactely what you said.-->>>

No need to apologize to me, English is not my native language either. I read you just fine.
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Old January 23rd, 2005, 04:06 PM   #12
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Sten, I can see you are from SD, where are you from? I'm in Carmel Valley.
BTW, did you sell the camera to buy the FX1 or you just got rid of it?, if yes why? I was very close to the FX1 swap but then a few features didn't make me too happy, CCD upscaling and interlaced mode only were the showstoppers for me, so I decided to "invest" the money in the Nikon D2X as soon as it become available in volume. About the JVC (I've just the HD1) although some limitations are big, I'm very happy with it and I got great memories out of it. It is some of the best money I spent in this field, now I wish something serious but it has to be progressive.

Gabriele
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Old January 23rd, 2005, 08:42 PM   #13
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"my conclusion was: in the exposure locked mode, if either the iris or shutter would have taken priority to keep the exposure at the set level, I would have seen either the higher shutter speed motion characteristics or less changes in scene exposure due to iris kicking in. Unless I couldn't distinguish 1/30 from 1/60"

It can be hard to judge between 1/30 and 1/60 especially in quick tests. It also depends how intense the lights you were using were. It may have sat at 1/30 the whole time, or fluctuated between the two. The fact is you can't lock both at once. Not a huge problem though as it isn't a run and gun cam. You set up the shot for what is needed. Shutter or aperture priority, use a few cam settings/filters and light it like film.

I don't want you guys to get me wrong. I am a huge (biggest) fan of the cam, but fact is fact. I would suggest both of you go through past threads. Search for "manual control" in this forum and read what has been discussed by many smarter than me.
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Old January 23rd, 2005, 11:22 PM   #14
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I see both sides of this debate.

Gabriele's point is well taken, that if *exposure per se* is truly locked, then for shutter speed to be changing, aperture must change with it, or exposure is not locked. So what sense would it make to simultaneously be juggling shutter speed and aperture with a locked exposure?

To understand Ken's point, I would ask Garbriele or Sten to consider what would happen if they locked the exposure on "-3"?

Since I think these are 1/3 f-stops, then setting the exposure lock to -3 would appear to maintain an underexposure by 1 f-stop to whatever the scene lighting was, whether dark or light it would be underexposed by 1 f-stop. If true, then some combination of shutter and/or aperture is being manipulated to maintain the 1 f-stop underexposure as the scene lighting changes. The salient question is, why would it be any different if exposure was locked on "0"? Locking the exposure on "0" would thus logically be assumed to be locking to the correct scene exposure, neither under or over exposed, which is confusing because that's what it should be doing if it wasn't locked at all.

My own quick and unscientific test raised more questions than yielded answers. What I did was point the camera at a bright window, and lock the exposure on "0".

When I panned the camera to a darker area of the room, the image appeared dark and underexposed. But when I pointed it back at the bright window, it appeared darker than when I locked the exposure.
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Old January 24th, 2005, 12:08 AM   #15
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I'm glad this topic has come up (again) ... as my experience has been the same as Gabriele's. So I've always felt a bit confused about these "unable to lock" discussions.

For example, I point the camera at a scene, select 1/60 and then press again ..... the camera locks on f5.6. Then I press again (so that there's no reading is on the screen) and then double-press the exposure button (so that "L" appears besides the +0). I can then move the camera through varying light levels without the exposure fluctuating.

OK, so now back to the exact same scene. This time I select 1/250 and press ... the aperture now locks on f2.8. I press again to clear the screen and double press to lock exposure.

As far as I've been able to tell, my shutter ends up locked at 1/60 in the first example, and 1/250 in the second, regardless of the ambient light levels once I start I wandering around.

As long as the light doesn't change while shifting from shutter lock to aperture lock, it is my impression that the shutter maintains its initial setting (otherwise why would the camera settle on two different f-stops in the above two examples?). The next step then appears to lock both shutter and aperture (I've never gotten the impression that they are moving in tandem).

If I get time tomorow I'll test this properly using a spinning disk with constant motion so that I can confirm what I'm saying about the shutterspeed.
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