View Full Version : I think I found how how to lock manual


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Graham Hickling
March 12th, 2005, 08:20 PM
>>>We need to beg. plead, force JVC to give us a firmwear that allows 1/60 lock.

YES!!! How frickin' hard could that be...

Tom Roper
March 12th, 2005, 09:31 PM
<<<-- Originally posted by Graham Hickling : >>>

..... it's really starting to seem that our two cameras are behaving differently. Once I have the "L" showing, neither shutter nor aperture ever vary from that point on - regardless of whether I'm pointing it at bright sun or deep shadow - and I can cycle (quickly)through S and A whenever I need to confirm that they are both still where I want them to be.-->>>

Put the camera on a tripod, and point it at a bright scene. Give it a minute to warm up and stabilize. Cycle quickly through S and A. If the scene is bright enough, the default shutter should be around 1/250. Next put it in shutter priority mode, and use the menu wheel to turn the shutter down to 1/60. Now turn on Exposure-Lock, and watch what happens in the viewfinder after about 20 seconds.

Graham Hickling
March 12th, 2005, 10:57 PM
I've only tried what you asked a couple of times, but ... to get the camera to set its initial shutter at 1/250 I found the scene had to be bright enough that the corresponding f-stop was around f16. So I couldn't then dial down to 1/60th because there wasn't a small enough f-stop available for the camera.

From an earlier post: >>> Yep, that's an additional complication. When you first lock the shutter, it has to be at a speed where the camera can achieve correct exposure with an available f-stop (i.e. somewhere between f1.8 and f22). In that situation, the method we've been discussing [seems to] work.

I'll try some other combinations in the morning (it's 11:57pm..)

Graham Hickling
March 12th, 2005, 11:10 PM
By the way, Tom, I can see I've been kinda missing your point for the last few posts. I've been saying how the camera WILL stay put at the shutter speed and aperture it gets locked at (and that we can check both settings by toggling S/A).

Whereas you are saying (I think) that the shutter speed the camera locks at sometimes is not the speed we intended, and indeed not the speed visible in the viewfinder at the point in time when the lock button gets pushed.

Tom Roper
March 13th, 2005, 12:00 AM
<<<-- Originally posted by Graham Hickling : I've only tried what you asked a couple of times, but ... to get the camera to set its initial shutter at 1/250 I found the scene had to be bright enough that the corresponding f-stop was around f16. So I couldn't then dial down to 1/60th because there wasn't a small enough f-stop available for the camera.
-->>>

At around 5:30 pm, just before twilight under a partly cloudy sky, the lighting was flat, with non-distinct shadows.

When I first turned the camera on and cycled the S/A button, the shutter was 1/60 and the aperture was f11-f16. But after about a minute of warm-up, that changed. I cycled the S/A button again, but now the shutter was 1/250 and the aperture was f5.6. This was with the camera on a tripod, not having moved it. But with the flat averaged light, it really didn't much matter where the camera was aimed. 1/250 at f5.6 was where it wanted to be, whether aimed down at my brown lawn or across the street.

I had the requisite exposure latitude for shooting at 1/60 without overexposing. Earlier in the day when it was bright and clear, I used 4x ND. So I acknowledge your point about the camera having to be within the range of exposure latitude for 1/60, i.e. f-stop less than f16-22.

Tom Roper
March 13th, 2005, 12:17 AM
<<<-- Originally posted by Graham Hickling : By the way, Tom, I can see I've been kinda missing your point for the last few posts. I've been saying how the camera WILL stay put at the shutter speed and aperture it gets locked at (and that we can check both settings by toggling S/A). -->>>

And on that we agree, the camera WILL stay put at the shutter speed it gets locked at, if you use that method you described earlier, of aiming the camera at an averaged scene that just happens to give you 1/60 shutter when cycling fast thru the S/A.

But what I'm saying, is that if the scene you're composing doesn't just happen to give you 1/60 when cycling fast thru the S/A, then if you attempt to force 1/60th by turning down the "Menu" dial, it WON'T STICK once you go to Exposure Lock.

Even weirder, is if you had turned the shutter down to 1/60 and it had been at 1/250 before, by the time you get the exposure lock "L", you cycle fast through the S/A and it reads 1/100, so you think you're locked there at 1/100th, but you're not. It will keep on slowly changing all the way back to the default 1/250 over the course of about 20 seconds, and the viewfinder will gradually go darker at the same time. Once it finishes this slow ramping, the exposure is locked, but not with the correct exposure for the scene and not at the shutter speed you hoped for, 1/60. But truly locked thereafter it will remain, whether you put the lens cap on or point it at the sun.

Also, if you just turn the camera on and don't give it a minute or so warm-up, when you cycle fast thru the S/A button, it will likely show you 1/60 shutter. But leave it aimed on that exact same scene for more than a minute and try again. It will likely have changed the shutter speed to something faster, in my case today it was 1/250.

Graham Hickling
March 13th, 2005, 12:55 PM
>>>If you just turn the camera on it will likely show you 1/60 shutter. But leave it .. for more than a minute .. it will likely have changed to something faster.

OK, you are indeed correct. I think the above statement explains what has been going on - my camera often ends up powering-down while I'm fiddling around without filming, and consequently a lot of my S/A toggling has been within a few moments of it powering up again, so I usually got it locked onto 1/60th without realizing why that was actually a bit of a "fluke".

(One has to wonder what drugs the JVC firmware dudes were on when they were setting up this camera .)

Ken Hodson
March 13th, 2005, 07:28 PM
This must be the same thing I am finding with my variable ND trick. As I stated in my last post, I would increase ND levels untill I could get a 1/60 S/A. I would then lock the exposure only to cyclr through and find it at 1/30 soon after. I am going to try to go slower with the variable ND's and see if I can get it to fully settle on 1/60 befor I lock.

Les Dit
March 15th, 2005, 12:22 AM
So JVC obviously didn't want this camera to lock exposure.
What if I so a little mod to the lens assembly and *physically* lock the f stop while the camera is set to 1/60 sec.
I wonder if the firmware would decide that the camera is defective (and error out ) as it frantically trys to alter the fstop ?
I've taken apart cameras before, but it is a risk the first time on a new model.

-Les

Ken Hodson
March 15th, 2005, 01:58 AM
In a way I can't figure out why JVC hasn't offered a firmware update for this issue. With the HD100 on its way it would be a good PR move to show that they stand behind their products.

Gabriele Sartori
March 15th, 2005, 09:19 AM
<<<-- Originally posted by Ken Hodson : In a way I can't figure out why JVC hasn't offered a firmware update for this issue. With the HD100 on its way -->>>

May be that is the reason, with a full manual capability the HD10 would be "too dangerous" for the rest of the future product line..

Tom Roper
March 15th, 2005, 10:46 AM
...but really and truly, just setting the camera to shutter priority 1/60th with ND works fine for many lighting situations, and assures you of perfect exposure wherever your subject is.

Gabriele Sartori
March 15th, 2005, 10:52 AM
<<<-- Originally posted by Tom Roper : ...but really and truly, just setting the camera to shutter priority 1/60th with ND works fine for many lighting situations, and assures you of perfect exposure wherever your subject is. -->>>

I agree 100%. I do most of my stuff setting the shutter at 1/60th and depending on the situation with or without ND. When I need to pan and there are different light sources that may trick the exposure, I find a spot where I naturally get 1/60th and then I lock the iris. It is not perfect world but honestly it works well enough and I'm too happy with the camera to change. I'm quite a gadget freak and I was ready to jump on the Sony but some of the features there (interlaced, up-scaling) turned me off. The multiple shots I saw with the Sony having a bit of cromathic aberration were the deal killer.

Gabri

Tom Roper
March 15th, 2005, 10:58 AM
The JVC zoom lens is very good glass, fast...totally absent of barrel distortion/pincushion, and has the same speed (f1.8) at maximum zoom that it does at wide angle. That's a hallmark of a great zoom lens.

Graham Hickling
March 15th, 2005, 03:54 PM
I'm totally sold on progressive. I dont see myself ever being tempted now by a 1080i camera, regardless of its other features.

As an aside - I find the JVC is great for copying old super-8 films. I have a rheostat on the projector so I can tweak its speed, then I just plunk the JVC in front of the screen, film it, resize it with a few filters and get a great-looking flicker-free DVD. I NEVER managed to get a flicker-free result when I tried the same thing with an interlaced DV camera.

Ken Hodson
March 15th, 2005, 09:41 PM
So were back to square one? Whats your opinion Gabriele, do we just need to get better at finding the right light level to get 1/60th befor we lock?
The program AE has some interesting options. I know that the "spotlight" gives an exposure -3. And sports 1/250. (why they couldn't make a "Usefull" and set it at 1/60!. Anyone know exactly what "snow" and "twilight" set to?

Ken Hodson
March 15th, 2005, 09:58 PM
http://videosystems.com/ar/video_jvc_jyhd/index.html

This article by Steve Mullen writen just when the cam cam out has some interesting details on the problems we are having. Scroll down half-way to JY-HD10 Performance.

Tom Roper
March 16th, 2005, 12:33 AM
Interesting that you mentioned snow, Ken. We still have some on the lawns and roof tops that hasn't melted, yet with clear streets making for some interesting contrasts, and some mixed findings on the HD1.

Yes, I did try the "SNOW" setting in the program menu, and on brief observation it looked like it maintained the same exposure, but increased shutter speed from 1/250th on Auto to 1/500 on snow, and opened the aperture by 1 f-stop. Before I read your post about spotlight dropping exposure by -3, I wanted to try that to see if I could get the shutter speed going the other way.

It's square one as far as I'm concerned, or maybe square 2 being optimistic.

My result shooting the snow was oh-so close, but another typical HD1 non-manual shooting problem.

I started with 4x (.6) ND, and a really good polarizer, white balance on "fine." I put the camera in shutter priority and set it to 1/60th. The attendant aperture worked out to about f16. The result was a very sharp, nicely saturated picture with one flaw...it was about an f-stop too dark overall. I had an idea, try the backlight button, but as HD1/10 history would have it, that doesn't work either in shutter priority.

With the camera warmed up, I was never able to lock 1/60 manual using Gabriele's trick. The one time I did, a check revealed it had switched itself to 1/30th. In any case, the camera needed to have its metering working and not lock the exposure because it's too easy to blow the highlights or lose shadow detail when panning from the street to a snow covered lawn.

But again, just like a SLR, the exposure metering gets tripped up by the snow, metering to the highlights and underexposing the shadows means you need a working backlight button, or you have to increase the exposure +1 or +2 on the dial, either of which affords no control of the shutter speed.

What I want to do some more tests on, is to see how much of the choppiness is really caused by the lack of motion blur with fast shutter speeds, and how much is possibly caused by the optical image stabilization, which seems sub-par.

There's something I don't like about panning at 1/60th, almost seems like the tops of trees or pointed shapes seem to "bend" for a lack of a better way to describe it.

The camera needs a tripod to cope with some of the shortcomings. I do use one, but point and shoot is sometimes the only way I'm going to get the shot, expecially for candids.

Tom Roper
March 16th, 2005, 12:37 AM
I should mention that while I continue to struggle with some outdoor situations, I think the camera is underrated for what it does indoors in ambient lighting. I had some incredibly good results with indoor industrial photography in factories, using the ambient lighting they have, flourescent, mecury vapor etc. For that, nothing seems required, just point and shoot in auto.

Ken Hodson
March 16th, 2005, 10:29 PM
"With the camera warmed up, I was never able to lock 1/60 manual using Gabriele's trick. The one time I did, a check revealed it had switched itself to 1/30th. "

I unfortunately have found the exact same thing. Now that I know the "quick" cycle through trick, I can check. My cam always seems to revert to 1/30th indoors. I try to spoof it by aiming directly at a light source. It will read out 1/30 f22. Argh!
If I raise the shutter it will go back. If I lower the f-stop the shutter will rise only to revert to 1/30 once exposure is locked.
Locking the shutter at 1/60 then using ND's seems to be the only way if auto exposure won't fit the situation. Otherwise it is lock the exposure and expect a 1/30 shutter.

Maybe JVC would be very interested in a petition thread(s) complaining about a lack of a very deserved firmware update the day the HD100 is announced?
We have very little leverage to get JVC off their butts. Some well deserved criticism that lets future JVC HDV customers know how little the company stands behind you after you buy, just might be that leverage.

Ken Hodson
March 18th, 2005, 03:16 AM
Any one have any insite with the 480p60 mode as far as shutter goes with that?
I am going to test it out tommorow. If it defaults to less than 1/60, that would just be sad.

Patrick Jenkins
March 18th, 2005, 08:09 AM
<<<-- Originally posted by Ken Hodson : Any one have any insite with the 480p60 mode as far as shutter goes with that? I am going to test it out tommorow. If it defaults to less than 1/60, that would just be sad. -->>>

It defaults to 1/60. I was trying it the otherday to test something, but ultimately my test didn't work.

Ken Hodson
March 18th, 2005, 01:08 PM
1/60 is what I have found as well. 1/30 HD , 1/60 SD.