Z
Zoomforce
Guest
Re: ASA rating for the DVX 100
thats why the ASA doubled form the normally tested 320 to 640.
thats why the ASA doubled form the normally tested 320 to 640.
ASA rating for the DVX 100
- Thread starter Cope
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Barry_Green
Moderator
Re: ASA rating for the DVX 100
I used 1/1000 because that's what it took to get readings outdoors that didn't require ND filters. Under normal circumstances, to use 1/50 or 1/60, I'd have to put it on ND2, then back-figure how fast it really was, or find two ND.3 filters to stack in front of the spotmeter, etc. Using 1/1000 as a consistent setting between the camera and the meter *should* deliver the same results.
I used 1/1000 because that's what it took to get readings outdoors that didn't require ND filters. Under normal circumstances, to use 1/50 or 1/60, I'd have to put it on ND2, then back-figure how fast it really was, or find two ND.3 filters to stack in front of the spotmeter, etc. Using 1/1000 as a consistent setting between the camera and the meter *should* deliver the same results.
Re: ASA rating for the DVX 100
I guess. It seems to me though that the DVX isn't more sensitive then 400 speed film. Again just a guess, but as I've shot 400 for so many years and without flash alot, it seems to me the DVX is maybe just a tad less sensitive then 400. But purely instinctive, you know it's that "feels like stuff" ;D
I would like it to be up around ASA 640 though.
-Rodger
I guess. It seems to me though that the DVX isn't more sensitive then 400 speed film. Again just a guess, but as I've shot 400 for so many years and without flash alot, it seems to me the DVX is maybe just a tad less sensitive then 400. But purely instinctive, you know it's that "feels like stuff" ;D
I would like it to be up around ASA 640 though.
-Rodger
Barry_Green
Moderator
Re: ASA rating for the DVX 100
Okay, so you had me thinking, so I went and verified some more indoor tests. 1/60th shutter on both. The DVX is absolutely, positively, unquestionably, 640 ASA.
Okay, so you had me thinking, so I went and verified some more indoor tests. 1/60th shutter on both. The DVX is absolutely, positively, unquestionably, 640 ASA.
Z
Zoomforce
Guest
Re: ASA rating for the DVX 100
Barry are you shooting in 24p or 60i? I ask because if you are shooting 60i is it possilbe your gain is jacked up?
Like Rodger, I have a very hard time accepting that the DVX is that sensitive.
Barry are you shooting in 24p or 60i? I ask because if you are shooting 60i is it possilbe your gain is jacked up?
Like Rodger, I have a very hard time accepting that the DVX is that sensitive.
Re: ASA rating for the DVX 100
[quote author=Barry_Green link=board=news;num=1078944734;start=0#23 date=03/18/04 at 16:45:05]Okay, so you had me thinking, so I went and verified some more indoor tests. 1/60th shutter on both. The DVX is absolutely, positively, unquestionably, 640 ASA.[/quote]
All I can say is I absolutely, positively, unquestionably hope you're right
-Rodger
[quote author=Barry_Green link=board=news;num=1078944734;start=0#23 date=03/18/04 at 16:45:05]Okay, so you had me thinking, so I went and verified some more indoor tests. 1/60th shutter on both. The DVX is absolutely, positively, unquestionably, 640 ASA.[/quote]
All I can say is I absolutely, positively, unquestionably hope you're right
-Rodger
Barry_Green
Moderator
Re: ASA rating for the DVX 100
Gain was set to off. Both 24P and 60i. Same readings.
The meter is accurate to 1/10th of a stop. The DVX is calibrated to half-stops. So, technically there could be up to 4/10 of a stop of variation, but the readings were so consistent over the course of maybe 20 test shots, that I have no doubt. The good ol' DVX is equivalent to 640 ASA.
Gain was set to off. Both 24P and 60i. Same readings.
The meter is accurate to 1/10th of a stop. The DVX is calibrated to half-stops. So, technically there could be up to 4/10 of a stop of variation, but the readings were so consistent over the course of maybe 20 test shots, that I have no doubt. The good ol' DVX is equivalent to 640 ASA.
J.R. Hudson
Spirit Animal
Re: ASA rating for the DVX 100
Now can you explain to me (us) what that means and how it affects us?
(My brain is ready)
Now can you explain to me (us) what that means and how it affects us?
(My brain is ready)
filmmaker58
Well-known member
Re: ASA rating for the DVX 100
...not that I would ever doubt Barry, but I've shot a lot of 500 ASA film (although it's been a while) and I would have guessed the DVX was around 320 ASA also. I'm shooting with Barry on Monday and I'll bring my spot meter to see for myself.
...not that I would ever doubt Barry, but I've shot a lot of 500 ASA film (although it's been a while) and I would have guessed the DVX was around 320 ASA also. I'm shooting with Barry on Monday and I'll bring my spot meter to see for myself.
Z
Zoomforce
Guest
Re: ASA rating for the DVX 100
man if Barry is right like he usually is I gotta rethink everything.. I always shot under the impression it was close to 400 ASA...
Damnit.. im off to do my own tests. And im gonna aproach it in a different way.
man if Barry is right like he usually is I gotta rethink everything.. I always shot under the impression it was close to 400 ASA...
Damnit.. im off to do my own tests. And im gonna aproach it in a different way.
Barry_Green
Moderator
Re: ASA rating for the DVX 100
Hey, I'm all for testing, nobody has to take my word for it -- I'd love some backup testing to either tell me I'm crazy, or verify that it's accurate.
But I'm telling you... light up a white sheet of paper. Zoom in on it to fill the DVX screen. Set your spotmeter to the same shutter speed and shift the ASA dial around to where you get the same f-stop reading on both the camera and the light meter. It'll read 640.
One thing that bugged me, why was I getting the same readings on progressive and on interlaced? Everything I know says that that shouldn't be so: the interlaced should be about a stop brighter, due to the line-pair summation of adding the fields together (which would make the 60i rating at around 1280 ASA!) That seems nonsensical.
So I've been playing around with it more, and I think I know why -- seems like if you change from interlaced to progressive, and you have a fixed shutter speed set, that shutter speed will change as well. i.e., if you're on 1/1000 in progressive, and you change to interlaced, your shutter will now be 1/2000. I guess I hadn't noticed it before.
When setting the camera to use "shutter off", it does read a stop faster in interlaced -- but progressive still reads at 640. Which means I'm showing 60i at 1280 ASA. And I just verified it again -- set to F1, stock settings, white wall, soft light, spotmeter set to 1280 ASA, shutter off, zero gain: f/8.0. And f/8.0 on the spotmeter.
I guess my meter could be "off"... I'll calibrate it against Pat's on Monday. Until then, if I'm crazy, somebody verify it and let me know!
Hey, I'm all for testing, nobody has to take my word for it -- I'd love some backup testing to either tell me I'm crazy, or verify that it's accurate.
But I'm telling you... light up a white sheet of paper. Zoom in on it to fill the DVX screen. Set your spotmeter to the same shutter speed and shift the ASA dial around to where you get the same f-stop reading on both the camera and the light meter. It'll read 640.
One thing that bugged me, why was I getting the same readings on progressive and on interlaced? Everything I know says that that shouldn't be so: the interlaced should be about a stop brighter, due to the line-pair summation of adding the fields together (which would make the 60i rating at around 1280 ASA!) That seems nonsensical.
So I've been playing around with it more, and I think I know why -- seems like if you change from interlaced to progressive, and you have a fixed shutter speed set, that shutter speed will change as well. i.e., if you're on 1/1000 in progressive, and you change to interlaced, your shutter will now be 1/2000. I guess I hadn't noticed it before.
When setting the camera to use "shutter off", it does read a stop faster in interlaced -- but progressive still reads at 640. Which means I'm showing 60i at 1280 ASA. And I just verified it again -- set to F1, stock settings, white wall, soft light, spotmeter set to 1280 ASA, shutter off, zero gain: f/8.0. And f/8.0 on the spotmeter.
I guess my meter could be "off"... I'll calibrate it against Pat's on Monday. Until then, if I'm crazy, somebody verify it and let me know!
Barry_Green
Moderator
Re: ASA rating for the DVX 100
[quote author=Jarred Land link=board=news;num=1078944734;start=25#29 date=03/18/04 at 22:30:45]I gotta rethink everything.. I always shot under the impression it was close to 400 ASA...
[/quote]
Keep in mind the difference from 400 to 640 is barely over half a stop... it's not that much, and since the DVX's meter is marked in half-stops (even though the iris is free-moving) you may have been actually up to a half-stop off and not even known it. In other words, 400 may have been working perfectly fine for you...
[quote author=Jarred Land link=board=news;num=1078944734;start=25#29 date=03/18/04 at 22:30:45]I gotta rethink everything.. I always shot under the impression it was close to 400 ASA...
[/quote]
Keep in mind the difference from 400 to 640 is barely over half a stop... it's not that much, and since the DVX's meter is marked in half-stops (even though the iris is free-moving) you may have been actually up to a half-stop off and not even known it. In other words, 400 may have been working perfectly fine for you...
Barry_Green
Moderator
Re: ASA rating for the DVX 100
[quote author=John Hudson link=board=news;num=1078944734;start=25#27 date=03/18/04 at 18:47:41]Now can you explain to me (us) what that means and how it affects us?
(My brain is ready)[/quote]
As a practical matter, it doesn't really mean a thing. If you're not using a light meter for your setups now, then whether the DVX reads at 640 or 320 or 1280 really doesn't affect you at all. All it means is it's one great performer, with excellent low-light sensitivity.
If you were the type who carries a light meter on you, and scouts locations with a light meter in hand, etc., then you'd want to know what the ASA equivalent of the camera is. But since the camera is, in and of itself, a light meter, most video shooters don't bother with 'em, so it won't really have an effect on anyone.
The only real effect it could have is it could prove that I'm either
a) crazy,
b) a fool who doesn't know how to use his own gear,
c) owner of a defective light meter, or
d) none of the above, and the DVX is one fast little camera...
(I'm hoping it's not "C", and I'm afraid it could very well be either "A" or "B", but it'd be nice if it was "D"!)
[quote author=John Hudson link=board=news;num=1078944734;start=25#27 date=03/18/04 at 18:47:41]Now can you explain to me (us) what that means and how it affects us?
(My brain is ready)[/quote]
As a practical matter, it doesn't really mean a thing. If you're not using a light meter for your setups now, then whether the DVX reads at 640 or 320 or 1280 really doesn't affect you at all. All it means is it's one great performer, with excellent low-light sensitivity.
If you were the type who carries a light meter on you, and scouts locations with a light meter in hand, etc., then you'd want to know what the ASA equivalent of the camera is. But since the camera is, in and of itself, a light meter, most video shooters don't bother with 'em, so it won't really have an effect on anyone.
The only real effect it could have is it could prove that I'm either
a) crazy,
b) a fool who doesn't know how to use his own gear,
c) owner of a defective light meter, or
d) none of the above, and the DVX is one fast little camera...
(I'm hoping it's not "C", and I'm afraid it could very well be either "A" or "B", but it'd be nice if it was "D"!)
Z
Zoomforce
Guest
Re: ASA rating for the DVX 100
First shot is a still camera with Leica 2.8T Lens set to 5.6f shutter 1/60 ISO400.
Second shot is the DVX with 5.6f shutter 1/60.. ISO ???
Damn you. Someone give Barry a cookie.
First shot is a still camera with Leica 2.8T Lens set to 5.6f shutter 1/60 ISO400.
Second shot is the DVX with 5.6f shutter 1/60.. ISO ???
Damn you. Someone give Barry a cookie.
Re: ASA rating for the DVX 100
I suppose everyone notices when we "argue" with Barry, we all sortof do that Japanese half-bow with our wordage and tone ;D. This is exactly the reason why.
Good job Barry and thanks to Jarrad for confirmation.
I guess I now know why I like my low-light shots so much now.
-Rodger
I suppose everyone notices when we "argue" with Barry, we all sortof do that Japanese half-bow with our wordage and tone ;D. This is exactly the reason why
.Good job Barry and thanks to Jarrad for confirmation.
I guess I now know why I like my low-light shots so much now.
-Rodger
Z
Zoomforce
Guest
Re: ASA rating for the DVX 100
LOL... yeah I really had a hard time believing that the DVX was that sensitive, not that its that big of a deal, but I think its because way back when Sony users use to use the sensitivity as thier only attack against the DVX.. after hearing it so many times I started to believe it
LOL... yeah I really had a hard time believing that the DVX was that sensitive, not that its that big of a deal, but I think its because way back when Sony users use to use the sensitivity as thier only attack against the DVX.. after hearing it so many times I started to believe it
J.R. Hudson
Spirit Animal
Re: ASA rating for the DVX 100
Thanks Gurus!
Thanks Gurus!
Barry_Green
Moderator
Re: ASA rating for the DVX 100
Well, at least I'm not crazy... thanks for reassuring me on that! ;D
Also, another thing to keep in mind, if you do your own tests: the 24P presets have the auto-iris set at -3. That'll cost you somewhere around half a stop -- which will put the sensitivity back around 400 or so. So to test the true sensitivity, be sure to set the auto-iris to 0 in your scene file settings.
Hey, maybe this means my light meter isn't broken either! We'll still double-check it on Monday though.
Well, at least I'm not crazy... thanks for reassuring me on that! ;D
Also, another thing to keep in mind, if you do your own tests: the 24P presets have the auto-iris set at -3. That'll cost you somewhere around half a stop -- which will put the sensitivity back around 400 or so. So to test the true sensitivity, be sure to set the auto-iris to 0 in your scene file settings.
Hey, maybe this means my light meter isn't broken either!
We'll still double-check it on Monday though.
Z
Zoomforce
Guest
Re: ASA rating for the DVX 100
yeah.. since things seem to be working out for me Im just gonna continue shooting with the implication that im shooting at 400iso.. if its not broke dont fix it.
I dont use auto iris, unfortunately.
yeah.. since things seem to be working out for me Im just gonna continue shooting with the implication that im shooting at 400iso.. if its not broke dont fix it.
I dont use auto iris, unfortunately.