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Old September 28th, 2003, 07:11 PM   #1
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1/30 lock??

I just noticed that the AGC is disabled while the shutter speed is locked.

I heard it recommended that the shutter be locked at 1/30? What is the danger? Will the camera shoot at 1/15??

I preparing for a overseas documentary - it will be three weeks of run and gun - some dark locations.

What do you guys recommend? Maybe just release the shutter lock when the AGC is needed?
Some pratical tips would be appreciated. I have been practicing since I got the camera two weeks ago. The camera has its limitations - but the image is incredible - might do justice to Africa!
Please any info on "general" to "run and gun" shooting as far as the AE settings. ("bring your vx-2000" is not acceptable)

-Steve
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Old September 28th, 2003, 07:37 PM   #2
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My advice, lock the exposure at 1/30, f2 (point at darkness and it will automatically adjust to that setting). Than use the necessary ND filters (and/or polarizer if you shoot outside) to have the image you need. I know it is teedious but it works very well. One other thing: do disable automatic gain control, even if you do run and gun, you better control the overall image, not let it automatically adjust. This camera reacts very badly to sudden changes, it is better that you evaluate prior to the shoot your needs in terms of exposure. Better to underexpose a bit with this camera. The LCD gives a very good idea of your image, get used to it and use it as much as possible. I did extensive followups of people in different environnements and a controlled exposure gives much better results anyway you put it. There are no secrets, experiment with it while you have some time. This camera can produce outstanding images but rarely in any automatic mode.

Of course, it's my methodology, this is to be experimented by you to see if it fits...

Good luck,
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Old September 28th, 2003, 08:29 PM   #3
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Ericís the man!

If you shoot into a bright area the shot then it tends to crush like crazy. Here is an example of what we are talking about.

http://www.advancedcomputerdesigns.com/vette.m2t

Notice as the car move into bright area it almost completely washes out. I have yet to workout how to get around this but I still not ready to give up and I am going to give some of Eric's tips a try.

If it were me: I would go out and shoot a tons of footage under different lighting conditions prior to your trip. After you shoot your footage load them up on a PC and check out on a large monitor. The build in LCD just does not hack it for analyzing shots under outdoor conditions. If your shooting outdoors pray for overcast or avoid conditions like above.

As Eric said be sure you should stock up on is a good set of ND filter and a polarizer. Go out and shoot a LOT of footage prior to your trip and get comfortable with the camera.


Good Luck!
Mike
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Old September 28th, 2003, 09:15 PM   #4
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<<<-- Originally posted by Eric Bilodeau : My advice, lock the exposure at 1/30, f2 (point at darkness and it will automatically adjust to that setting).
-->>>

If you lock exposure--it can't adjust. It will be wide open at 1/30th. Yes, you could now use ND to get an image--but no one would work that way. Especially in the field!

He asked a simple question. If it's dark, the shutter-speed will be 1/60th or under. So no need to lock shutter speed. Hence he can use AGC to increase image brightness.

Now he can use the exposure control to lock exposure.

Most of all he needs my Shooting Guide.
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Old September 28th, 2003, 09:47 PM   #5
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If it is dark as Steve Mullen suggested it is true that the shutter won't go up so no need to lock it. I still would not use AGC though but it is my point of view.

The exposure lock works, all the images I posted where locked AE at 1/30 f2 or 1/60 f2. Of course if you go from a basement without light to the outside it won't be a good idea, I guess you figured out by yourself but the auto adjustment still won't make it much better, there will be a "in between" zone where image will be a wash out before it adjusts.

When you shoot field images you have to make a statement: do I want washed out areas and comfortably visible dark ones or nice bright areas with darker areas where you might not discern everything. you cannot have a perfect both without sacrificing image (unless there is not much difference between the two areas of course). Mike's example is a good one, the corvette becomes washed out but notice that the leaves and ground where already washed in the bright area. I love high contrast so dark areas don't bother me, I prefer to have control over the bright areas since the wash out (combined with the edge artefacting) will look much cheaper than darken shadows with a good overall balance. Once again this is my feeling of it, I don't pretend to know "the way", I just go my way...
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Old September 28th, 2003, 10:20 PM   #6
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<<<--Most of all he needs my Shooting Guide. -->>>
Are you putting it on sale by itself?
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Old September 28th, 2003, 11:00 PM   #7
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<<<-- Originally posted by Eric Bilodeau : The exposure lock works, all the images I posted where locked AE at 1/30 f2 or 1/60 f2. -->>

What do you mean by Exposure Lock? You are holding the EC control for 2 seconds while keeping the camera in the dark? That's the only Exposure Lock possible?

Or do you mean you lock the Shutter-speed? If so, that's not an exposure lock. You are simply setting shutter priority mode. The AE is still active and setting the exposure.
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Old September 28th, 2003, 11:01 PM   #8
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<<<-- Originally posted by Jose Cavazos : <<<--Most of all he needs my Shooting Guide. -->>>
Are you putting it on sale by itself? -->>>

Yes. It just went on sale. See my site.
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Old September 29th, 2003, 01:04 AM   #9
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Eric pretty much nailed it in his original post. Use ND filters to force the shutter speed down to 1/60 or 1/30, then lock the exposure by holding that button down until the "L" comes on.

If the shot is low contrast, you should be fine at 0. As the image gets more contrasty, start putting in some bias to underexpose, I use -1 to -3 depending on how bad the ratio of darkest to lightest is.

Remember, once a highlight blows out, it is gone forever and nothing in post can recover that detail. However, as crushed as the blacks look on this camera, there is still detail in those shadows that can be brought up later.

I am not crazy about video gain, but the AGC circuit on this camera is pretty quiet. I wouldn't leave it on, because you don't want some automatic function mucking up your project. But I would switch it in on a "as needed" basis. I did a project for the Air Force JAG, and shot some tests of a night scene. I did them with and without gain, and I actually preferred the shots with gain.

Jay
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Old September 29th, 2003, 12:41 PM   #10
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<<<-- Originally posted by Jay Nemeth : Eric pretty much nailed it in his original post. Use ND filters to force the shutter speed down to 1/60 or 1/30, then lock the exposure by holding that button down until the "L" comes on.

If you understand HOW the camera works you'll realize that the firmware is such that you can't really force shutter under 1/60th FOR SURE. Depending on the current light level it may alter either iris or shutter -- or both-- to get a new exposure. You don't know what it does.
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Old September 29th, 2003, 04:34 PM   #11
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<<<-- Originally posted by Eric Bilodeau : When you shoot field images you have to make a statement: do I want washed out areas and comfortably visible dark ones or nice bright areas with darker areas where you might not discern everything. -->>>

I prefer the latter well - you still say lock 1/30 and F2 + ND is the best way get this result?

Cant get the "L" on -- whats the procedure?
So you can still bias the AE with it locked??
If so, I see the advantage to exposure lock.

-Steve
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Old September 29th, 2003, 07:59 PM   #12
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I think folks need to be more specific in what they describe.

I think the Exposure Control (with Lock) is being confused with setting Shutter Priority Mode.

I can't follow what Eric is saying.
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Old September 30th, 2003, 12:01 AM   #13
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<<<-- Originally posted by Steve Mullen : If you understand HOW the camera works you'll realize that the firmware is such that you can't really force shutter under 1/60th FOR SURE. -->>>

Well I understand HOW my camera ( HD1 ) works, although I have no direct experience with the HD10. Yes, the camera has a mind of it's own when it comes up with a shutter, aperture combination, but my camera will always give me a 1/30th with anything a 5.6 or lower. For example, if I light a scene or put in enough ND to give me a 1/30th and f2, and then I add some light or remove ND, it will iris down all the way to 5.6 BEFORE it will let me have 1/60 as a shutter.

This was somewhat problematic during our short since I really wanted to shoot at 1/60. If the camera came up with 1/30 and an f4, I would go into shutter priority and switch to 1/60, and the camera would now open up a stop to f2.8. I would exit the shutter/aperture priority mode and then lock the exposure. Momentarily cycling through shutter/aperture mode I could see that the camera held 1/60 and 2.8. BUT......after a few minutes, another check showed that even with LOCK "on" the camera had changed back to 1/30 and f4, completely imperceptibly to those watching the monitor.

Trust me Steve, my living is based on an artistic and scientific understanding of HOW light and optics and mechanics intermingle to create images on various media. It doesn't take long between testing and real world use to see the personality of this camera.

I can for sure, make shutter settings of 1/30 anytime in any situation. On the contrary, I can not get 1/60 on a regular basis.

Jay
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Old September 30th, 2003, 12:44 AM   #14
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First, for one of the posters--you cannot set both speed and aprture at the same time.

Second, you can't SEE both speed and iris readouts at the SAME time. So all these references to 1/30th AND f/2 -- may or may not be valid.

I too tried the "cycle through the modes" trick to see if I could get BOTH readings. HOWEVER:

You only see a reading when you ENTER either Shutter Priority OR Aperture mode. And, the very act of entering either mode may or may not change what the settings were before you entered the mode. And as you step through the modes, entering each one in turn.

The uncertainty prinicipal is at work here.

Moreover, the aperture varies continuosly from 1/30th upward. And the f-stop varies continuously. A tiny change in light can flip the readout from one whole number to the other. And it's hard to press a button without bumping the cameraand causing a tiny light change.

And, as you found it slowly re-adjusts while shooting!

Of course, I also spent time by myself and with JVC trying figure it out. Then JVC contacted Japan and got the algorithm. Once I had it, I realized there was little point in playing games with ND filters and button pressing.

That's what the data from your experiment is telling you. If your theory worked 100% you would be able to get 1/60th--which is the speed I prefer and you wanted. You are getting a result at a limit condition. And, I suspect that is what Eric is doing by too--although exactly what he's doing isn't clear to me.
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Old September 30th, 2003, 01:03 AM   #15
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Steve,

I never claimed anyone could set both, this is my single biggest complaint about this camera. What I described is a way, on my HD1, using ND filters and the exposure "lock" button to always get a 1/30th shutter speed.

And it is possible to "see" both values when using the "priority" mode. It is very simple to set one item and "look" at the other. Enter Shutter mode, it flashes for a moment then the display turns solid. You can now adjust the shutter to what ever you like, let's say 1/60. Now push the shutter/aperture button again to switch to Aperture. It too will flash, now quickly read this value, this is the other setting the camera had to "compute". Do not let the display turn solid, or you will now have entered the Aperture priority mode!

In this 1.5 seconds while you are looking at the flashing aperture, you still have the shutter locked. Now quickly press the button again and nothing will be displayed, DO NOT WAIT OR YOU WILL LOSE YOUR SHUTTER SETTING! Press the button once more, and you will be back to the solid display of your shutter, which has remained locked.

That button has three modes, full auto, shutter pri., and aperture pri. You are simply stepping through these without waiting long enough for one to take over.

You can do the same with the aperture priority, set an f stop and push the button twice to step through "full auto (no display) and then shutter. Quickly look at the flashing value the camera computed for the shutter, but don't look very long or it will switch priority. Press the button again to return to the solid f-stop setting.

This process is a huge pain in the a** and it's comical that JVC has us jumping through hoops like circus dogs, but this method absolutely works for knowing what the other value is.

A full set of NDs is the only way to get close to the shutter / aperture values you want. I agree with you, it isn't 100 percent accurate due to the camera drifting when using the exposure "lock" button versus one of the priority modes.

Jay
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