HD100 Lightmeter at DVinfo.net

Erik Walth · February 27th, 2006, 12:16 PM

Have been trying to find som info regarding the build-in light meter.
JCV manual and JVC PRO homepage.

Does the lightmeter measure center spot or average acros the frame or ..??

Wouldt be nice to know especially when the Zebra starts running...

Thanks in advance.

Erik

Efrain Gomez · February 27th, 2006, 01:08 PM

Hmm... I've never heard of the built-in light meter on the HD100. Maybe i skimmed over that part in the manual?

:: efrain ::

Erik Walth · February 27th, 2006, 01:31 PM

Quote:

Originally Posted by Efrain Gomez

Hmm... I've never heard of the built-in light meter on the HD100. Maybe i skimmed over that part in the manual?

:: efrain ::

Well, lets call it something else then.
If you put the camera to full auto it figures out the F stops right. My question was where the camera measures the amount of light ? When I go manual and try to light my shoot the best I can, I would just like to know where the measure point is ?
Ok, better like this ?

regards
Erik

Tim Dashwood · February 27th, 2006, 01:31 PM

Erik is referring to auto-iris.

I don't really have a definitive answer to your question Erik because I've never used auto iris. I always manually set my exposure, sometimes based on the programmable zebra bars.

However, I would imagine that the auto-iris is not centre-weighted, but instead responds to average exposure over the whole frame.

Efrain Gomez · February 27th, 2006, 01:45 PM

oh right. Auto-Iris function. sorry. i never use that.

i'm just a newbie, but i agree with Mr. Dashwood. It seems like it's overall exposure in the frame and not based on the center.

:: efrain ::

Erik Walth · February 27th, 2006, 01:49 PM

Thank you Tim.

Fast and to the point as always.

One more for you Tim. Do you use 60-70% or 70-80% as standard setup for Zebra. Or..?

Regards

Erik

Tim Dashwood · February 27th, 2006, 01:55 PM

Quote:

Originally Posted by Erik Walth

One more for you Tim. Do you use 60-70% or 70-80% as standard setup for Zebra. Or..?

Actually I use "OVER 100%" and then I know exactly which bits will clipped. This helps me expose properly to squeeze as much dynamic range out as possible.

Erik Walth · February 27th, 2006, 02:01 PM

Well I am just afraid that my whites will be blown out. Have to do some testing on that one.

Thanks Tim

Regards

Erik

Tim Holtermann · February 27th, 2006, 07:47 PM

No matter what you set your Zebras at you will eventually teach your eye to know when something will blow out beyond saving. If you use 80% and a good portion of your sky has zebras you probably will have ok highlights but you won't have as much in the dark areas of the frame. At 100% you can stretch more out of your image but you will need to be much more critical with your eye on where the zebras show up.

It's just a matter of getting use to a setting and sticking with it so that you start to pick up on the areas without even thinking about it.

Steve Mullen · February 27th, 2006, 09:20 PM

Quote:

Originally Posted by Efrain Gomez

oh right. Auto-Iris function. sorry. i never use that.

Used correctly it is VERY accurate.

John Mitchell · February 28th, 2006, 07:57 AM

Well I guess in essence the zebra is the lightmeter in video cameras as it measures the exposure on highlights in the frame. I would say that the same circuitry that measures and displays zebra also controls the auto iris.

Constantin Marin · February 28th, 2006, 09:35 AM

Quote:

Originally Posted by Tim Dashwood

Erik is referring to auto-iris.

I don't really have a definitive answer to your question Erik because I've never used auto iris. I always manually set my exposure, sometimes based on the programmable zebra bars.

However, I would imagine that the auto-iris is not centre-weighted, but instead responds to average exposure over the whole frame.

You can adjust in the menu the exposure for auto iris. It's the menu named:
CAMERA OPERATION - and you have to adjust AE LEVEL from -3 ...o..0...+3 value.

Efrain Gomez · February 28th, 2006, 12:10 PM

okay, now i'm a little confused. in traditional photography, i've used the AE levels, but I'm a little unclear as to how the AE -/+ levels work on the HD100....

Does the AE-/+ levels work in conjunction with the Auto Iris function on the HD100?

Tim Dashwood · February 28th, 2006, 12:43 PM

Quote:

Originally Posted by Efrain Gomez

okay, now i'm a little confused. in traditional photography, i've used the AE levels, but I'm a little unclear as to how the AE -/+ levels work on the HD100....

Does the AE-/+ levels work in conjunction with the Auto Iris function on the HD100?

Yes, you are just shifting the bias of the Auto Exposure system. It is the same as "exposure compensation" (in EV) in SLR photography.

Efrain Gomez · February 28th, 2006, 12:48 PM

oh okay cool. that makes sense. so whatever the auto iris adjusts to, the AE adds or takes away a little, right?

:: efrain

February 27th, 2006, 12:16 PM	#1
Erik Walth Regular Crew Join Date: Jan 2006 Location: Hesselager - Denmark Posts: 27	HD100 Lightmeter Have been trying to find som info regarding the build-in light meter. JCV manual and JVC PRO homepage. Does the lightmeter measure center spot or average acros the frame or ..?? Wouldt be nice to know especially when the Zebra starts running... Thanks in advance. Erik

February 27th, 2006, 01:08 PM	#2
Efrain Gomez Regular Crew Join Date: Feb 2006 Location: salinas, california Posts: 41	lightmeter in hd100? Hmm... I've never heard of the built-in light meter on the HD100. Maybe i skimmed over that part in the manual? :: efrain ::

February 27th, 2006, 01:31 PM	#4
Tim Dashwood Wrangler Join Date: Aug 2005 Location: Toronto, ON, Canada Posts: 3,637	Erik is referring to auto-iris. I don't really have a definitive answer to your question Erik because I've never used auto iris. I always manually set my exposure, sometimes based on the programmable zebra bars. However, I would imagine that the auto-iris is not centre-weighted, but instead responds to average exposure over the whole frame. __________________ Tim Dashwood

February 27th, 2006, 01:45 PM	#5
Efrain Gomez Regular Crew Join Date: Feb 2006 Location: salinas, california Posts: 41	ohhhh... oh right. Auto-Iris function. sorry. i never use that. i'm just a newbie, but i agree with Mr. Dashwood. It seems like it's overall exposure in the frame and not based on the center. :: efrain ::

February 28th, 2006, 12:10 PM	#13
Efrain Gomez Regular Crew Join Date: Feb 2006 Location: salinas, california Posts: 41	HD100 auto iris and AE +/- levels okay, now i'm a little confused. in traditional photography, i've used the AE levels, but I'm a little unclear as to how the AE -/+ levels work on the HD100.... Does the AE-/+ levels work in conjunction with the Auto Iris function on the HD100?

February 27th, 2006, 01:49 PM	#6
Erik Walth Regular Crew Join Date: Jan 2006 Location: Hesselager - Denmark Posts: 27	Thank you Tim. Fast and to the point as always. One more for you Tim. Do you use 60-70% or 70-80% as standard setup for Zebra. Or..? Regards Erik

February 27th, 2006, 02:01 PM	#8
Erik Walth Regular Crew Join Date: Jan 2006 Location: Hesselager - Denmark Posts: 27	Well I am just afraid that my whites will be blown out. Have to do some testing on that one. Thanks Tim Regards Erik

February 27th, 2006, 07:47 PM	#9
Tim Holtermann Regular Crew Join Date: Feb 2006 Posts: 184	No matter what you set your Zebras at you will eventually teach your eye to know when something will blow out beyond saving. If you use 80% and a good portion of your sky has zebras you probably will have ok highlights but you won't have as much in the dark areas of the frame. At 100% you can stretch more out of your image but you will need to be much more critical with your eye on where the zebras show up. It's just a matter of getting use to a setting and sticking with it so that you start to pick up on the areas without even thinking about it.

February 28th, 2006, 07:57 AM	#11
John Mitchell Contributor Join Date: Jul 2005 Location: Sydney Australia Posts: 873	Well I guess in essence the zebra is the lightmeter in video cameras as it measures the exposure on highlights in the frame. I would say that the same circuitry that measures and displays zebra also controls the auto iris.

February 28th, 2006, 12:48 PM	#15
Efrain Gomez Regular Crew Join Date: Feb 2006 Location: salinas, california Posts: 41	cool. oh okay cool. that makes sense. so whatever the auto iris adjusts to, the AE adds or takes away a little, right? :: efrain