asa? at DVinfo.net

Leslie Wand · December 12th, 2010, 04:13 PM

anyone one know the approximate asa / iso speed of the z5?

Jeff Harper · December 14th, 2010, 07:41 AM

I have not heard of ISO being applied to a camcorder, but I could be wrong. What is asa?

ISO is used when discussing still photography.

Brian Drysdale · December 14th, 2010, 10:24 AM

ASA is film speed, the rating is the same as ISO.

People use ISO with camcorders so know the sensitivity of the camera, it's especially useful when you're lighting. It's also a specification used when comparing different cameras for use on a production. You often need to test a camera, because the internal menu's curve settings can change the ISO.

Colin McDonald · December 14th, 2010, 02:17 PM

It's a bit like Farenheit and Centigrade. I can still think in ASA and judge accurately without a meter what exposure to use for the old Kodachrome 25 or Ektachrome 100 (outdoors of course!) I was never quite been able to think in DIN to the same extent. The "film speeds" on digital cameras nowadays are so much higher it is still hard for some of us old timers to quite believe them.

Jeff Harper · December 14th, 2010, 02:29 PM

http://www.bhphotovideo.com/c/product/582905-REG/Sony_HVR_Z5U.html
Look at the specs...

Adam Gold · December 14th, 2010, 03:29 PM

Jeff, where did you see any reference to ISO in the specs? I couldn't find them anywhere... No mention of it in the manual either.

I, too, have never heard of ISO being applied to a camcorder, only still cams. I'm wondering if you could derive this by setting up the Z5 next to a still cam, and then dialing in the ISO on the latter until the exposures matched. I may have to try this with my Alpha next to a Z5.

Jeff Harper · December 14th, 2010, 04:11 PM

No, Adam. Like you I've never heard of ISO being applied to a camcorder...maybe they use ISO for larger cams.

Greg Laves · December 14th, 2010, 07:44 PM

Occasionally you will here people refer to the ISO (ASA) of a video camera. But it is pretty rare. I am sure Sony does not include any such information in any of their specs. I guess you could try to match settings with the Z5 and a good still camera. If you match the settings of the two cameras (shutter & f-stop) and match the look by setting the ISO of the still camera, you could get a good idea what the native ISO is of any video camera. I think it would be pretty high. And maybe that is why we see the grain we get.

Adam Gold · December 14th, 2010, 08:37 PM

I don't know that you could match it by eye; at least I know I couldn't, and much would depend on the brightness of the LCD on the Camcorder, even if you were only looking through glass on the still cam. I'd suspect the best way would be to lock the still cam at a shutter speed of 1/60th and, making sure neither cam had any form of ND engaged, play with the ISO on the still cam until both cams showed the same f-stop. I'd guess WB would be an issue too, although perhaps not a critical one.

I think that might get you into the ballpark, at least.

Leslie Wand · December 15th, 2010, 01:12 AM

according to adam wilt - it's between 400>500 asa or iso.

very useful to know if lighting a scene and taking incidental meter readings......

btw. many years ago i worked with some world class cameramen (who usually worked features), and every one of them knew the asa (ok, iso) rating of the video camera they were using / hiring so they could light scenes for the best possible 'balance'. i can say that editing their footage was a joy, the blacks were black, the whites were white and everything in-between exposed to perfection.

Chris Duczynski · December 16th, 2010, 05:02 AM

There's some stuff here

What Is... ISO - Digital Photography Tutorial - Photoxels

When I used film, ASA or ISO it was relative to graininess of the negative - the higher the ASA the more grain you got but you could shoot at a faster shutter speed in low light. The zone system by Edward Weston combined shutter, exposure, development to maximise detail in the blacks and whites.
With digital I think it's all down to sensor size and after that it's just dialling in the db's and noise and not really relevant or important.

Brian Drysdale · December 16th, 2010, 12:55 PM

Quote:

Originally Posted by Jeff Harper

No, Adam. Like you I've never heard of ISO being applied to a camcorder...maybe they use ISO for larger cams.

It's a rating that camera people workout for themselves by doing camera tests, With the RED One and Arri Alexa, the manufacturers themselves give ISO recommendations.

For sensitivity the video camera manufacturers tend to use 89.9% reflectivity at 2000 lux and a f stop. However, that's pretty useless if you need to light something and you need to plan your lighting. It also can change depending how you set up the camera's curves, hence the reason for testing.

There was quite a bit of discussion in the past about the ISO of cameras on the JVC HD 100 and HVX 200 threads, possibly because people were using them for drama shoots. Also in camera comparison tests.

Dale Guthormsen · December 25th, 2010, 04:13 PM

Merry Christmas,

I know where this is coming from!!!

Using a standard light meter to set exposure exactly where you want it, or at least know if you are ball park.

I use a light meter with my cameras, particularly the canon xlh1.

To see what Din/ Asa your camera is at try this:

use the auto exposure. If the camera comes in at say 1/500th at f 5.6, then

set your light meter so that these two values match up, then

go to the din setting and see what it reads.

this will give you what the camera reads on Auto.

I have found that both the sony fx 1000 and the xlh1 will give me good exposures with a din of 17.

That would be an ASA of approximartely 50!!!

With my canon it is always slightly overexposed on automatic, so I adjust my aperature one stop smaller for the canon.

I have found this particularly of value as I use a black and white view finder. IF ONE OF THE ADJUSTMENTS GETS BUMPED AND I GO BY "LOOK" I CAN BE WAY OUT!!!

It is also a good check for the fu 1000. Set the exposure and then adjust the brightness on the view finder so it looks like I think it should!!!

My light meter is about 30 years old, so I do not know if it is even up to standard these days, but it works for me!

Hope someone will find the aforementioned useful.

Leslie Wand · December 25th, 2010, 11:28 PM

I have found that both the sony fx 1000 and the xlh1 will give me good exposures with a din of 17.

That would be an ASA of approximartely 50!!!

interesting - adam reckons between 400 > 500 asa (iso?). my own, rather limited experiments confirm this, though i will go back to the drawing board with my light meter and nikon after the family leave.....

Greg Laves · December 26th, 2010, 08:41 PM

That is an interesting number Dale. I wish I had a good light meter to do the testing. That seems like it would be a good way to test. My testing is much less scientific and based on shooting with a Z7 and a 5D MK II. When I set up interview type lighting for a shoot, on my Z7, my shutter speed is always 1/60 sec and my f stop is usually in the f2.4 - f 3.5 range. With the 5D MK II and using similar lighiting, typically I wind up with an ISO of 640. My f stop is usually in the similar range as the Z7 and I typically wind up with a slightly slower shutter speed. That is why I would have guessed that the base ISO of the Z7 (and Z5) would be in the 640 or 800 range. Hmmmm.

December 12th, 2010, 04:13 PM	#1
Leslie Wand Trustee Join Date: Mar 2004 Location: upper hunter, australia Posts: 1,410	asa? anyone one know the approximate asa / iso speed of the z5?

December 14th, 2010, 07:41 AM	#2
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	I have not heard of ISO being applied to a camcorder, but I could be wrong. What is asa? ISO is used when discussing still photography. __________________ "The horror of what I saw on the timeline cannot be described."

December 14th, 2010, 02:29 PM	#5
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	http://www.bhphotovideo.com/c/product/582905-REG/Sony_HVR_Z5U.html Look at the specs... __________________ "The horror of what I saw on the timeline cannot be described."

December 14th, 2010, 03:29 PM	#6
Adam Gold Inner Circle Join Date: Jan 2007 Location: Woodinville, WA USA Posts: 3,467	Jeff, where did you see any reference to ISO in the specs? I couldn't find them anywhere... No mention of it in the manual either. I, too, have never heard of ISO being applied to a camcorder, only still cams. I'm wondering if you could derive this by setting up the Z5 next to a still cam, and then dialing in the ISO on the latter until the exposures matched. I may have to try this with my Alpha next to a Z5. __________________ "It can only be attributable to human error... This sort of thing has cropped up before, and it has always been due to human error."

December 14th, 2010, 04:11 PM	#7
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	No, Adam. Like you I've never heard of ISO being applied to a camcorder...maybe they use ISO for larger cams. __________________ "The horror of what I saw on the timeline cannot be described."

December 14th, 2010, 10:24 AM	#3
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	ASA is film speed, the rating is the same as ISO. People use ISO with camcorders so know the sensitivity of the camera, it's especially useful when you're lighting. It's also a specification used when comparing different cameras for use on a production. You often need to test a camera, because the internal menu's curve settings can change the ISO.

December 14th, 2010, 02:17 PM	#4
Colin McDonald Trustee Join Date: Dec 2007 Location: Glasgow, Scotland Posts: 1,546	It's a bit like Farenheit and Centigrade. I can still think in ASA and judge accurately without a meter what exposure to use for the old Kodachrome 25 or Ektachrome 100 (outdoors of course!) I was never quite been able to think in DIN to the same extent. The "film speeds" on digital cameras nowadays are so much higher it is still hard for some of us old timers to quite believe them.

December 14th, 2010, 07:44 PM	#8
Greg Laves Major Player Join Date: Nov 2007 Location: Corpus Christi, TX Posts: 640	Occasionally you will here people refer to the ISO (ASA) of a video camera. But it is pretty rare. I am sure Sony does not include any such information in any of their specs. I guess you could try to match settings with the Z5 and a good still camera. If you match the settings of the two cameras (shutter & f-stop) and match the look by setting the ISO of the still camera, you could get a good idea what the native ISO is of any video camera. I think it would be pretty high. And maybe that is why we see the grain we get.

December 14th, 2010, 08:37 PM	#9
Adam Gold Inner Circle Join Date: Jan 2007 Location: Woodinville, WA USA Posts: 3,467	I don't know that you could match it by eye; at least I know I couldn't, and much would depend on the brightness of the LCD on the Camcorder, even if you were only looking through glass on the still cam. I'd suspect the best way would be to lock the still cam at a shutter speed of 1/60th and, making sure neither cam had any form of ND engaged, play with the ISO on the still cam until both cams showed the same f-stop. I'd guess WB would be an issue too, although perhaps not a critical one. I think that might get you into the ballpark, at least. __________________ "It can only be attributable to human error... This sort of thing has cropped up before, and it has always been due to human error."

December 15th, 2010, 01:12 AM	#10
Leslie Wand Trustee Join Date: Mar 2004 Location: upper hunter, australia Posts: 1,410	according to adam wilt - it's between 400>500 asa or iso. very useful to know if lighting a scene and taking incidental meter readings...... btw. many years ago i worked with some world class cameramen (who usually worked features), and every one of them knew the asa (ok, iso) rating of the video camera they were using / hiring so they could light scenes for the best possible 'balance'. i can say that editing their footage was a joy, the blacks were black, the whites were white and everything in-between exposed to perfection.

December 16th, 2010, 05:02 AM	#11
Chris Duczynski Major Player Join Date: Feb 2010 Location: sydney Posts: 304	There's some stuff here What Is... ISO - Digital Photography Tutorial - Photoxels When I used film, ASA or ISO it was relative to graininess of the negative - the higher the ASA the more grain you got but you could shoot at a faster shutter speed in low light. The zone system by Edward Weston combined shutter, exposure, development to maximise detail in the blacks and whites. With digital I think it's all down to sensor size and after that it's just dialling in the db's and noise and not really relevant or important.

December 25th, 2010, 04:13 PM	#13
Dale Guthormsen Inner Circle Join Date: Jun 2005 Location: Saskatchewan Posts: 3,048	Merry Christmas, I know where this is coming from!!! Using a standard light meter to set exposure exactly where you want it, or at least know if you are ball park. I use a light meter with my cameras, particularly the canon xlh1. To see what Din/ Asa your camera is at try this: use the auto exposure. If the camera comes in at say 1/500th at f 5.6, then set your light meter so that these two values match up, then go to the din setting and see what it reads. this will give you what the camera reads on Auto. I have found that both the sony fx 1000 and the xlh1 will give me good exposures with a din of 17. That would be an ASA of approximartely 50!!! With my canon it is always slightly overexposed on automatic, so I adjust my aperature one stop smaller for the canon. I have found this particularly of value as I use a black and white view finder. IF ONE OF THE ADJUSTMENTS GETS BUMPED AND I GO BY "LOOK" I CAN BE WAY OUT!!! It is also a good check for the fu 1000. Set the exposure and then adjust the brightness on the view finder so it looks like I think it should!!! My light meter is about 30 years old, so I do not know if it is even up to standard these days, but it works for me! Hope someone will find the aforementioned useful. __________________ DATS ALL FOLKS Dale W. Guthormsen

December 25th, 2010, 11:28 PM	#14
Leslie Wand Trustee Join Date: Mar 2004 Location: upper hunter, australia Posts: 1,410	I have found that both the sony fx 1000 and the xlh1 will give me good exposures with a din of 17. That would be an ASA of approximartely 50!!! interesting - adam reckons between 400 > 500 asa (iso?). my own, rather limited experiments confirm this, though i will go back to the drawing board with my light meter and nikon after the family leave.....

December 26th, 2010, 08:41 PM	#15
Greg Laves Major Player Join Date: Nov 2007 Location: Corpus Christi, TX Posts: 640	That is an interesting number Dale. I wish I had a good light meter to do the testing. That seems like it would be a good way to test. My testing is much less scientific and based on shooting with a Z7 and a 5D MK II. When I set up interview type lighting for a shoot, on my Z7, my shutter speed is always 1/60 sec and my f stop is usually in the f2.4 - f 3.5 range. With the 5D MK II and using similar lighiting, typically I wind up with an ISO of 640. My f stop is usually in the similar range as the Z7 and I typically wind up with a slightly slower shutter speed. That is why I would have guessed that the base ISO of the Z7 (and Z5) would be in the 640 or 800 range. Hmmmm.