Cinematography? Aperture? at DVinfo.net

Jun Tang · October 16th, 2004, 03:21 PM

Okay ASA of DVX is 640 ASA. Right?

If you had a light meter, and it said to put it an apeture at F 4.8, would that be equivalent if you shot it with Film?

If so, what kind of film stock would it be most similar to? Anyone do any test yet? Barry???? :)

I hear Cinematographer say that if a film stock is 600 ASA, they treat it like 500. Meaning that treat it slower so that more light can hit the film. Which means more saturated colors? Which typically means, prettier pictures.

Now, since DV doesn't really have emulsion like film, is saturation non-existence in digi world?

So is opening the apeture all the way open, the better way?

Charles Papert · October 16th, 2004, 07:10 PM

<<If you had a light meter, and it said to put it an apeture at F 4.8, would that be equivalent if you shot it with Film?>>

Presuming you set your meter at 640 (and if it was a digital meter, it would likely read 4 and 5/10's rather than 4.8), then yes, it would deliver the same results as film rated as 640 ASA.

<<If so, what kind of film stock would it be most similar to? Anyone do any test yet? >>

DV's exposure curve and look (any video, really) is so dissimilar to film in general that I couldn't say that it resembles one emulsion more than another. It's probably closer to reversal stock (such as Kodak 5285) in terms of highlight management, but arguably more resembles the lower-contrast 5229 in the shadow areas. But that's forcing the issue. They just aren't really comparable.

<I hear Cinematographer say that if a film stock is 600 ASA, they treat it like 500. Meaning that treat it slower so that more light can hit the film. Which means more saturated colors? Which typically means, prettier pictures.>>

Many feel that Kodak's method of rating negative film stocks is a bit generous and that overexposing by 1/3-2/3 will deliver a fatter negative and thus richer tones. Thus an emulsion with the "boxtop" rating of 500 ASA is often exposed as (i.e. meter will be set at) 400 ASA (1/3 exposure adjustment) or 320 ASA (2/3 adjustment).

However, motion picture reversal film, just as slide film in the photographic world, has less latitude in the highlights and thus is usually exposed dead-on. The classic school of thinking is that with negative film, you expose for the shadows; and with reversal, you expose for the highlights. This is very similar thinking to the way many approach digital video. Stop down until you are able to maintain detail in the highlights as much as possible without crushing the rest of the image. This will tend to increase saturation anyway, but of course that can be tweaked within the camera and again in post if necessary.

<<So is opening the apeture all the way open, the better way?>>

Not quite sure what you mean by this...the best way is to expose properly...! And what "properly" means varies according to taste.

Tom Hardwick · October 17th, 2004, 02:57 AM

Good reply Charles. And Jun - you've got a few things twisted here. DVX is much more likely to be nearer 350 ASA, but why worry about that? The opportunities for taking incident light meter readings are so few and far between in movies, you're much better off using a grey card if you're unsure about what aperture to set for any given lighting. As with reversal film though - if you have the opportunity to bracket (take the same shot three times at three different apertures) you'll really appreciate it come the edit. Tape is pretty intolerant of exposure errors and blown highlights generally are pretty unacceptable.

If film stock is 600 and you treat it as 500 you'll be over exposing it by 1/3rd of a stop. Harmless to colour negative, but could be death to reversal.

Shooting at wide open aperture does indeed have its advantages. If I know I'm going to continue in the bright sunshine I prefer to add an ND8 (absorbs three stops) because this means I can shoot wide open at full tele yet at the flick of a switch I can delete the internal NDs for shooting the same faces backlit, for instance. Modern camcorders are superb wide open, and footage shot this way has much more of a film look simply because of the dof control offered you. The individual frames are vignetted slightly, but that won't worry you unless you're into stitching panoramas out of individual frames. And if this
doesn't mean anything to you, forget that I mentioned vignetting at all.

tom.

Barry Green · October 17th, 2004, 02:10 PM

Quote:

DVX is much more likely to be nearer 350 ASA

In progressive mode, the DVX ranges between 400ASA under the lowest-light conditions, to 1000 ASA under the brightest-light conditions. The exposure curve isn't linear, and for most of the f-stop range, the DVX responds as 640 ASA. But in darker conditions (where you'd want to use f/2.8 or less) it goes responds at 400, and in very bright conditions (f/11 or higher) it responds at 800, and in the brightest (f/16) conditions it responds at 1000. Which means that using an external light meter is nearly impossible, to get accurate exposure, unless you change the light meter's ASA according to the overall light level... and who's going to do that?

It's infinitely superior to use the zebras and a calibrated production monitor.

Bogdan Apetri · October 21st, 2004, 04:26 PM

If you shoot with a film camera (35mm, super16mm etc)...

...and you have a DVX with you in the field (set)...

...is there any way you could theoretically preview the exposure of the film with the DVX camera (not exact results, but at least give you an approximate idea).

Barry Green · October 21st, 2004, 06:29 PM

Well, not really. The DVX is going to have a lot narrower latitude than film will (unless we're talking about Kodachrome or Velvia film!) And the exposure curve is very different.

In film the tried-and-true advice never changes: test, test, test, test, test until you know for yourself how the exposures will come out.

Not much else you can do, really, other than extensive spot-metering of a scene and reading up on the exposure characteristics so you know how the film will respond...

Charles Papert · October 21st, 2004, 08:41 PM

Some DP's will use old Polaroid Land cameras (the ones that use the peel-off backed film) to evaluate their lighting. I personally find them a bit too contrasty to be of real use (you have to extrapolate the characteristics of the stock you are using to shoot the movie with).

What Barry says is apt. Experience is the main factor in being able to "see" the scene the way the film will record it

Bogdan Apetri · November 8th, 2004, 12:12 AM

Well, I understand.

But... I don't wanna beat a dead horse here. F1.8 is the same wether on video or on film. Of course, DVX doesn't have the same latitute as film. But middle grey is middle grey on both formats. A grey card should be exposed the same on a film or video camera, if exposed correctly, of course. Naturally, on film you would see more into highlights and shadows, and on the DVX you will not.

So I'm just asking theoretically, you try to see if you nailed the exposure (just the stop that interests you, so to speak), can you preview it on your DVX? Not how the overall picture is exposed, but just the tone of the face skin.

I don't know, correct me if I'm wrong.

Bogdan

PS Assuming that you would (again theoretically) use a 640ASA film stock.

Charles Papert · November 8th, 2004, 12:16 AM

I guess, sort of, in theory...

I think a much more handy way to do this would be with a good digital still camera. In fact I've done just that.

Milt Lee · November 9th, 2004, 05:10 PM

Back in the day, when I was a full fledged photographer, and had not fallen into the easy life of video ( no flaming please), I had lots of meters but they are all gone.

What do you folks like? Seconic? Gossen?

And how do you use them? Spot? Incident?

Thanks - I look forward to a spirited discussion about the best method for really getting the shot.

Milt Lee

Bogdan Apetri · November 9th, 2004, 05:32 PM

We use both incident and reflected. It always depends on the situation. Normally you would use the incident for the precision and assurance that you will get what you want. Spot meters have their good use, too, in certain conditions (many, but the main two would be when you cannot reach the subject physically or - because of their ability to measure a tight angle - when you want to select just small portions of what you see and do light level comparisons).

As far as meters are concerned, check the Sekonic 508 (both spot and incident, plus you can add accessories), I believe there is a newer model which is THE meter to have currently but it is pretty expensive. 608? I need to check.

Read THE EXPOSURE METER BOOK (Gerald Hirscfeld, Bob Shell, Martin Silverman and Jim Zuckerman). It has a neutral card attached which you would need for the spot meter, usually.

Milt Lee · November 12th, 2004, 01:48 PM

Thanks - I've been lookiing at the Sekonic 558 - It has a combination spot incident meter that looks fine. I'm excited about both options .

I was also wondered what you might think about filters, and using them with the dvx100a? I'm wondering about getting some more Neutral Density filters than what's built in - and wondered it there were other filters that have a nice effect. Also if there are significant Brand Differences.

Thanks again,
Milt

Tom Hardwick · November 13th, 2004, 04:10 PM

Extra ND is always useful as you can switch the internals in and out at will while leaving the ND8 (3 stops) on whenever you're out in the sunshine. That way you'll get great film-like differential focus shots because the camera will be working at or near maximum aperture.

The better names (Hoya, Tiffen etc) will mean the neutrals are more neutral. I had a cheepie once that wasn't neutral at all - but rather deep purple.

tom.

October 16th, 2004, 03:21 PM	#1
Jun Tang Regular Crew Join Date: Sep 2004 Location: West LA Posts: 135	Cinematography? Apeture? Okay ASA of DVX is 640 ASA. Right? If you had a light meter, and it said to put it an apeture at F 4.8, would that be equivalent if you shot it with Film? If so, what kind of film stock would it be most similar to? Anyone do any test yet? Barry???? :) I hear Cinematographer say that if a film stock is 600 ASA, they treat it like 500. Meaning that treat it slower so that more light can hit the film. Which means more saturated colors? Which typically means, prettier pictures. Now, since DV doesn't really have emulsion like film, is saturation non-existence in digi world? So is opening the apeture all the way open, the better way? __________________ www.tangfilms.com

October 16th, 2004, 07:10 PM	#2
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	<<If you had a light meter, and it said to put it an apeture at F 4.8, would that be equivalent if you shot it with Film?>> Presuming you set your meter at 640 (and if it was a digital meter, it would likely read 4 and 5/10's rather than 4.8), then yes, it would deliver the same results as film rated as 640 ASA. <<If so, what kind of film stock would it be most similar to? Anyone do any test yet? >> DV's exposure curve and look (any video, really) is so dissimilar to film in general that I couldn't say that it resembles one emulsion more than another. It's probably closer to reversal stock (such as Kodak 5285) in terms of highlight management, but arguably more resembles the lower-contrast 5229 in the shadow areas. But that's forcing the issue. They just aren't really comparable. <I hear Cinematographer say that if a film stock is 600 ASA, they treat it like 500. Meaning that treat it slower so that more light can hit the film. Which means more saturated colors? Which typically means, prettier pictures.>> Many feel that Kodak's method of rating negative film stocks is a bit generous and that overexposing by 1/3-2/3 will deliver a fatter negative and thus richer tones. Thus an emulsion with the "boxtop" rating of 500 ASA is often exposed as (i.e. meter will be set at) 400 ASA (1/3 exposure adjustment) or 320 ASA (2/3 adjustment). However, motion picture reversal film, just as slide film in the photographic world, has less latitude in the highlights and thus is usually exposed dead-on. The classic school of thinking is that with negative film, you expose for the shadows; and with reversal, you expose for the highlights. This is very similar thinking to the way many approach digital video. Stop down until you are able to maintain detail in the highlights as much as possible without crushing the rest of the image. This will tend to increase saturation anyway, but of course that can be tweaked within the camera and again in post if necessary. <<So is opening the apeture all the way open, the better way?>> Not quite sure what you mean by this...the best way is to expose properly...! And what "properly" means varies according to taste. __________________ Charles Papert www.charlespapert.com

October 21st, 2004, 04:26 PM	#5
Bogdan Apetri Regular Crew Join Date: Oct 2003 Location: New York, USA Posts: 117	theoretical question If you shoot with a film camera (35mm, super16mm etc)... ...and you have a DVX with you in the field (set)... ...is there any way you could theoretically preview the exposure of the film with the DVX camera (not exact results, but at least give you an approximate idea).

October 21st, 2004, 08:41 PM	#7
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	Some DP's will use old Polaroid Land cameras (the ones that use the peel-off backed film) to evaluate their lighting. I personally find them a bit too contrasty to be of real use (you have to extrapolate the characteristics of the stock you are using to shoot the movie with). What Barry says is apt. Experience is the main factor in being able to "see" the scene the way the film will record it __________________ Charles Papert www.charlespapert.com

November 8th, 2004, 12:12 AM	#8
Bogdan Apetri Regular Crew Join Date: Oct 2003 Location: New York, USA Posts: 117	again about checking your exposure with DVX Well, I understand. But... I don't wanna beat a dead horse here. F1.8 is the same wether on video or on film. Of course, DVX doesn't have the same latitute as film. But middle grey is middle grey on both formats. A grey card should be exposed the same on a film or video camera, if exposed correctly, of course. Naturally, on film you would see more into highlights and shadows, and on the DVX you will not. So I'm just asking theoretically, you try to see if you nailed the exposure (just the stop that interests you, so to speak), can you preview it on your DVX? Not how the overall picture is exposed, but just the tone of the face skin. I don't know, correct me if I'm wrong. Bogdan PS Assuming that you would (again theoretically) use a 640ASA film stock.

October 17th, 2004, 02:57 AM	#3
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Good reply Charles. And Jun - you've got a few things twisted here. DVX is much more likely to be nearer 350 ASA, but why worry about that? The opportunities for taking incident light meter readings are so few and far between in movies, you're much better off using a grey card if you're unsure about what aperture to set for any given lighting. As with reversal film though - if you have the opportunity to bracket (take the same shot three times at three different apertures) you'll really appreciate it come the edit. Tape is pretty intolerant of exposure errors and blown highlights generally are pretty unacceptable. If film stock is 600 and you treat it as 500 you'll be over exposing it by 1/3rd of a stop. Harmless to colour negative, but could be death to reversal. Shooting at wide open aperture does indeed have its advantages. If I know I'm going to continue in the bright sunshine I prefer to add an ND8 (absorbs three stops) because this means I can shoot wide open at full tele yet at the flick of a switch I can delete the internal NDs for shooting the same faces backlit, for instance. Modern camcorders are superb wide open, and footage shot this way has much more of a film look simply because of the dof control offered you. The individual frames are vignetted slightly, but that won't worry you unless you're into stitching panoramas out of individual frames. And if this doesn't mean anything to you, forget that I mentioned vignetting at all. tom.

October 21st, 2004, 06:29 PM	#6
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Well, not really. The DVX is going to have a lot narrower latitude than film will (unless we're talking about Kodachrome or Velvia film!) And the exposure curve is very different. In film the tried-and-true advice never changes: test, test, test, test, test until you know for yourself how the exposures will come out. Not much else you can do, really, other than extensive spot-metering of a scene and reading up on the exposure characteristics so you know how the film will respond...

November 8th, 2004, 12:16 AM	#9
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	I guess, sort of, in theory... I think a much more handy way to do this would be with a good digital still camera. In fact I've done just that. __________________ Charles Papert www.charlespapert.com

November 9th, 2004, 05:10 PM	#10
Milt Lee Major Player Join Date: Jan 2004 Location: Cass Lake MN Posts: 221	So...what light meters do you folks like? Back in the day, when I was a full fledged photographer, and had not fallen into the easy life of video ( no flaming please), I had lots of meters but they are all gone. What do you folks like? Seconic? Gossen? And how do you use them? Spot? Incident? Thanks - I look forward to a spirited discussion about the best method for really getting the shot. Milt Lee __________________ Professional website - http://manykites.com Personal - http://mrdogsblog.com

November 9th, 2004, 05:32 PM	#11
Bogdan Apetri Regular Crew Join Date: Oct 2003 Location: New York, USA Posts: 117	We use both incident and reflected. It always depends on the situation. Normally you would use the incident for the precision and assurance that you will get what you want. Spot meters have their good use, too, in certain conditions (many, but the main two would be when you cannot reach the subject physically or - because of their ability to measure a tight angle - when you want to select just small portions of what you see and do light level comparisons). As far as meters are concerned, check the Sekonic 508 (both spot and incident, plus you can add accessories), I believe there is a newer model which is THE meter to have currently but it is pretty expensive. 608? I need to check. Read THE EXPOSURE METER BOOK (Gerald Hirscfeld, Bob Shell, Martin Silverman and Jim Zuckerman). It has a neutral card attached which you would need for the spot meter, usually.

November 12th, 2004, 01:48 PM	#12
Milt Lee Major Player Join Date: Jan 2004 Location: Cass Lake MN Posts: 221	and further more - filters Thanks - I've been lookiing at the Sekonic 558 - It has a combination spot incident meter that looks fine. I'm excited about both options . I was also wondered what you might think about filters, and using them with the dvx100a? I'm wondering about getting some more Neutral Density filters than what's built in - and wondered it there were other filters that have a nice effect. Also if there are significant Brand Differences. Thanks again, Milt __________________ Professional website - http://manykites.com Personal - http://mrdogsblog.com

November 13th, 2004, 04:10 PM	#13
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Extra ND is always useful as you can switch the internals in and out at will while leaving the ND8 (3 stops) on whenever you're out in the sunshine. That way you'll get great film-like differential focus shots because the camera will be working at or near maximum aperture. The better names (Hoya, Tiffen etc) will mean the neutrals are more neutral. I had a cheepie once that wasn't neutral at all - but rather deep purple. tom.