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Old January 24th, 2005, 01:13 AM   #16
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Okay, I overlooked the "L".

So if I was -3 on the exposure, it's tracking at minus 1 f-stop as the scene lighting changes, but if I was -3L on the exposure, it's locked at 1 f-stop below whatever the scene lighting was when I locked it.

If I lock the exposure at "0L", and shine a flashlight into the lens, it can be seen that the aperture (iris) does not stop-down, therefore the exposure is locked, and so is the shutter.

The question is, at what shutter, what aperture?

You can hope that by toggling the A/S button, with the display reading out your preferred shutter speed and aperture in the manner of the spoofing as described by Garbriele and Sten, that it will remain so upon entering the exposure lock mode. And further if you are convinced to your own satisfaction that the exposure is locked at 1/60 by waving your hand in front of the lens in the manner described by Sten, then I would probably agree that you have succeeded in locking the shutter *and* the aperture.
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Old January 24th, 2005, 01:26 AM   #17
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One problem I had though, was demonstrated when I was practicing this in the kitchen with incadescent lights.

If I toggled the A/S button to shutter, it would display 1/30. If I changed this to 1/100, the viewfinder/LCD would get dark.

If I toggled the A/S button to aperture, the viewfinder/LCD would get bright again. I could toggle it to the aperture that existed when I had the shutter set to 1/100, and the viewfinder/LCD would again get dark.

But in order to use the exposure lock, I had to toggle the A/S button once more until neither the shutter speed or the aperture was displayed.

Then I could enter the exposure lock mode, but the viewfinder/LCD would return to bright.

So without some of Sten's handwaving, or Gabriele's trickery, I can't really get assurance that I have preserved the desired shutter speed or aperture upon entering the exposure lock mode.
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Old January 24th, 2005, 03:04 PM   #18
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<<<-- Originally posted by Tom Roper :
But in order to use the exposure lock, I had to toggle the A/S button once more until neither the shutter speed or the aperture was displayed.

Then I could enter the exposure lock mode, but the viewfinder/LCD would return to bright.

So without some of Sten's handwaving, or Gabriele's trickery, I can't really get assurance that I have preserved the desired shutter speed or aperture upon entering the exposure lock mode.
-->>>

Tom, you've made some good points. The results I got most likely resulted from the dimly lit room so the shutter locked at 1/30 and iris wide open (F2.8?) thus I drew the incorrect conclusion that the camera locked the values I had manually set prior to locking.

In my mind this is still what the evidence points to: the exposure lock does lock the shutter and iris, but you cannot be sure what the values end up being.

Just for the record, the camera I used was HD10. Unlikely, but could there be a difference in this regard between the HD1 and HD10 since the camera Gabriele uses is HD1?
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Old January 24th, 2005, 03:18 PM   #19
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<<<-- Originally posted by Gabriele Sartori : 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, in these days I stay in Temecula but a few years back I lived near your neighbourhoods... Carmel Mountain Rd just off the i-15. At the moment, though, I'm visiting my homeland in EU.

I sold the camera since I don't do much shooting in winter time and it really was the utmost time to still get a reasonable price from the camera.

I hear you, I want progressive as well, since all of my footage ends up in the computer. I'm sick and tired of dealing with deinterlacing and all the extra steps required to make the footage look artifact free. I'll wait for the next batch of HDV cams, progressive, couldn't care less for the 24fps, though.

Back to the regular programming...
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Old January 24th, 2005, 06:39 PM   #20
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>>If I toggled the A/S button to shutter, it would display 1/30. If I changed this to 1/100, the viewfinder/LCD would get dark.

>>If I toggled the A/S button to aperture, the viewfinder/LCD would get bright again. I could toggle it to the aperture that existed when I had the shutter set to 1/100, and the viewfinder/LCD would again get dark.

-----------------------------------------

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 will work.

However ..... if you lock on a shutter speed that requires a non-available f-stop, the shutter WILL shift when you then lock the aperture (presumably because the camera detects the incorrect exposure and decides to do something about it).
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Old January 24th, 2005, 11:43 PM   #21
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Quote:
In my mind this is still what the evidence points to: the exposure lock does lock the shutter and iris, but you cannot be sure what the values end up being.
I agree.

Quote:
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 will work.

However ..... if you lock on a shutter speed that requires a non-available f-stop, the shutter WILL shift when you then lock the aperture (presumably because the camera detects the incorrect exposure and decides to do something about it).
I agree also.

Bottom line, I think Gabriele's method, when it's possible to achieve correct exposure with an available f-stop, has a strong likelihood of being a usable workaround to the lack of manual control.
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Old January 25th, 2005, 12:51 AM   #22
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To everybody

I think that now we have more agreement than disagreement here. I did a few more tests, bottom line I found this:

1) When "L" is active & locked, both iris and shutter get locked, I did some DOF test and it never changes even with strong changes in light hence they are both locked but it seems that now everybody agree on this. I'm 110% positive on this. Frankly before fiddling with this I had the impression that locking both was impossible now I observed otherwise and I'm frankly very happy. Magazine wrote articles saying that locking was impossible, evidently they wrote articles but they didn't study the camera well. One editor said that he was having problems with the camera since the brightness of the scene was changing while panning, he didn't even know about the iris lock wheel evidently.

2) Ken is totally right, it is very hard to guarantee aperture and shutter locking at will. I probably had some fortunate coincidence. After extensive test however I found that I can repeat these situations:
A) If I want fast shutter I go in sport mode than I lock the iris. The shutter will never be slower than 1/250 even if I disable the sport mode as long as I keep the iris locked "L"
B) I aim at something with average light I fiddle with the shutter/iris just to check if they are more or less what I want (I.E. 1/60 or 1/100 in order to minimize the strobe effect) than I lock them, everything will stay locked at that aperture/shutter speed.

Naturally these are dirty tricks and the FX1 folks will laugh at them but all thing considered the camera is quite usable in manual. Unless someone want intentionally underexpose or overexpose (there are functions like the iris wheel to accomplish that however) we can do the following:

1) Lock the shutter and have cinematic like or more TV like type of result. We can maximize light sensitivity or fluidity.
2) Lock the aperture and have better or worse DOF
3) Lock everything with just a little ability to choose (although some ability) and doing so avoid "pumping" in the brightness of the scene if someting moves, changes or with zooming or panning.

It is not perfection but it is enough manual mode for me. We still have zero control over audio. Someone ever tested how an external controller works with that? BTW, on video the AGC (gain up) OFF/ON setting is indicated in the Automatic menu but it influences also the manual mode (it is another factor that changes more frequently the iris/shutter)

I don't know you guys but after about one year I decided to keep this camera for a longer period of time. THe FX1 doesn't make me happy, I like progressive and I don't like interpolation, I like real resolution.

Thanks to everybody
Gabriele
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Old January 25th, 2005, 12:55 AM   #23
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For Sten

Temecula, not too far however. Give me a buzz when you are back, may be we go for a coffee together and we can talk about toys. Have a nice trip in EU, I miss it butnot in this season. San Diego is a much better place for me now. Last week we got about 30 degree Celsius (better than the summer)

Gabriele

email: myfirstname@gmail.com
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Old January 25th, 2005, 08:59 AM   #24
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>>Naturally these are dirty tricks and the FX1 folks will laugh at them

Perhaps, but these are nevertheless very 'do-able' tricks that can be easily be incorporated into day-to-day shooting. Heck, how hard is it to press a button three times?

Besides, with the street price for a new GR-HD1 approaching $1500, the FX1 and Z1 users are definitely paying (more than double!) for their better features.
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Old March 1st, 2005, 11:56 AM   #25
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I’ve never used the camera, but I’m curious: if you wanted to shoot outdoors in 30P, wouldn’t it work fine if you locked the shutter speed at 30fps, put a heavy ND filter on the front of the lens, and then let the camera adjust the rest of the exposure automatically? I’ve done that with the Canon Optura Xi, which has a similar setup, and it worked well that way.
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Old March 1st, 2005, 11:09 PM   #26
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That's how most people do it Kevin, but you can overdo it with too much ND will cause blacks to drift toward a dark green cast, sort of a reciprocity-like failure.

My $0.02 is that 60fps is more natural than 30fps shutter speed which helps also.

My rule is to not apply more than 3 f-stops of ND filters. You can try Gabriele's spoofing trick, or choose aperture priority in combination with the ND filters, with some reasonable assurance that if you don't get exactly 60 fps shutter speed, it'll be close enough.
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Old March 4th, 2005, 02:09 PM   #27
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I just wanted to throw in my $.02... I've been able to reproduce this shutter & iris locking method and it does apparently work. I also did some comparison (eyeballing it, but tried to be as scientific as possible - same settings, same subject, lighting, etc) on some repeatable panning and dollying using both the built in 1/60 shutter (non locked; 1/60 is on the screen, exposure is all over the place, etc) and Gabriele's method of locking to 1/60 (everything locked) and though there's no on screen display confirming it, I'm getting 1/60 locked.

Way to go Gabe!
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Old March 4th, 2005, 03:22 PM   #28
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This good news guys. Thanks for pushing forward on this topic Gabriele, we seem to be making headway. I will be doing some more testing of my own this weekend using some software that allows variable zebra monitoring that will help detect any exposure flux.
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Old March 4th, 2005, 07:44 PM   #29
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Well I've been lame and not done the testing I promised to do weeks ago.

But...if any of you ARE testing this weekend and have the time - try the following. Go through the steps indicated in this thread to lock the shutter and aperture. Now, cycle through the settings again QUICKLY (i.e. less than a half second before each push of the button) until you get back to the starting-point.

The impression I have - and feel free to prove me wrong - is that as you do this the display will report the current settings - such as 1/60 and f2.8 - but will NOT attempt to alter them them. That is, each setting stays fixed as you cycle on to the next setting.

If I'm correect about this, it means not only can you lock f-stop and shutter, but you can ALSO get visual confirmation of what settings you've locked them at!
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Old March 6th, 2005, 12:35 AM   #30
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<<<-- Originally posted by Graham Hickling :

The impression I have - and feel free to prove me wrong - is that as you do this the display will report the current settings - such as 1/60 and f2.8 - but will NOT attempt to alter them them. That is, each setting stays fixed as you cycle on to the next setting. -->>>

I got the very same impression in a few instances but I wasn't 100% sure. Guys I can't wait to see your results !

Gabriele
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