Thinking of getting an F3 and want to get your hands some S-Log un graded footage? Here is your chance download this ProRes HQ 10 bit clip SLog NOT GRADED.mov (http://www.mediafire.com/?t7zd1yg5qn2rlhm)

Here is Apple Color Graded version SLog GRADED COLOR.mov (http://www.mediafire.com/?n5xw8l246vm2bh7)

Enjoy

Nice one. what lens did u use?
cheers.

How did you set your exposure Douglas? It looks just a little over exposed to me, mid grey should be 38% and white 68%. Over exposure effects the linearity of the mid tones and highlights which makes it harder to grade.

Nice one. what lens did u use?
cheers.

Hi Koravik. I used the never used on a paid job Tokina 11-16mm f2,8

How did you set your exposure Douglas? It looks just a little over exposed to me, mid grey should be 38% and white 68%. Over exposure effects the linearity of the mid tones and highlights which makes it harder to grade.

Hi Alister. I used my trusty light meter of about 20 years with a flat surface (not the dome). The dome is for average light setting and that is why people change the ISO rating. Wrong tool.
I measure direct sun light (highs) and under the shade (lows) facing where the reflected light was coming from. Then I split the difference and set my lens to that. I this case since the ratios were about 6 f-stops and I have no absolute way of determining f-stop on the Tokina I used the VF to set the iris +- to my meter reading.
As I told you on your xdcam-user.com forum, I don't use charts or waveforms for production, but I use scopes on post and everything is within 0-100 IREs. I can set my highlights, middle and lows where ever I want in post, I just like my white clouds to be white with detail.
As far as mid gray at 38% and whites at 68% since I don't use the waveform or the meter in the camera, I can't tell you I if agree or not with those finding. What I have found on my testing is that I like the way I can correct or improve over exposure better than I can under exposure.
See the simple test I did just opening and closing the Iris one stop at a time 14 f-stops.

Sony PMW F3 S-Log Usable F-Stops Test on Vimeo

The problem with S-log is that it is log. So while you do get a greater dynamic range to play with, correct exposure becomes more critical than with a standard gamma. With a standard gamma, which can be considered as "near linear" it really doesn't matter where you place your picture information provided it is neither overexposed or under exposed as all parts of the range can be considered equal. With S-log (and Cinegammas and Hypergammas to a lesser degree) the higher up the exposure range you go, the more compression gets applied to the image prior to recording. As a result brighter parts of the image are more compressed than darker parts and contain less brightness and contrast information. Typically this isn't an issue as our own visual system is tuned to mid tones, faces etc and we tend not to notice anomalies in the brighter parts of a scene.
However when you start grading your image if you are over exposed you'll find it much harder to recover the best possible image. You want to expose so that those important mid tones are within the more linear part of the exposure range which is below 50%. Typically faces, plants, foliage etc should be below 50-60%. White should be around 65-70%. This then gives you a generous overexposure range to cope with direct light sources such as the sky, clouds and reflections. It's not really good enough to simply keep everything between 0-100%, you need to carefully manage your mid tones and place them in the S-log sweet spot.

It's really, really easy to use a grey card with an F3. Simply use the F3's spot meter to measure the exposure. Much faster and more accurate than a light meter. Grey cards cost very little. If you don't have a grey card then a white card at 68% will be very close. These numbers were not simply grabbed from thin air. They are the design parameters for the S-Log curve and correspond to the LUT's and gain settings used in most grading suites. I strongly recommend that you use them for S-log.

A face exposed correctly at around 40-50% will have considerably more subtle texture information than a face recorded at 65-70% where the extra compression due to the logarithmic signal reduction reduces the amount of data required to record each successive stop. S-Log does not behave like film, nor is it like a standard gamma curve. In many respects it is the opposite to film. With log your most useful part of the exposure range is the low range, this is where your best detail and contrast will be so you need to make the most of it by exposing accordingly. With film, if anything you would favour a slight overexposure rather than under. S-Log is the opposite. Don't expect to be able to see everything that's going on in the shadows correctly on a standard monitor. The gamma miss-match between log and most monitors means that you won't see the full range of subtle tones captured in the low range until you grade or correctly apply a look up table.
There is a lot of miss understanding about the way S-Log works and how to get the best from it. The assumption (incorrect) is that because it has greater dynamic range you can be more relaxed with your exposure, but this is simply not the case. You must be just as careful and you must learn to hit the sweet spot for the best results. It also helps to use a grading tool that supports log gain instead of linear gain. If you grade using tools designed for standard gammas you will get unnecessary noise increases as you adjust the log curve. You must either de-log the clip first and then work in standard gamma space or use the correct log gain setup. If you don't do this your highlights and brighter parts of the image will have a tendency to blow out and become excessively bright whenever you try to lighten the image. I don't know about color but certainly resolve has a specific log mode and the difference is night and day.

It sounds so complicated. I don't even have to bring the camera out until I'm ready to shoot.
If you don't understand light meters, use what you do know. A light meter also read a reflexion off of a white disc. The only difference is that it is not affected by things like glare, differences in color, scratches, dirt, etc. I have a Kodak gray/white card,,, somewhere. I use to use it for white balance with cameras that didn't have adjustable Kelvins.

Why would anyone need ISO rating if a waveform doesn't use the ISO for reference only a lightmeter does. A waveform only measures a percentage of reflection within the range that the camera sensor can see and it is affected by the reflectance of the surface being measured.

I haven't seen a video of the 38"/61" theory to see how it holds up when graded. I want to see an open and closing of that iris 14 stops like I did on my test. Theory is good, but what counts is actual footage wish is what I get paid for.

All the tests that I have seen are of a couple f-stops difference and poorly graded right on an NLE.
I used Apple Color because it is a powerful tool that can bring the highs into detail the same as lows without affecting the rest of the image. Just look at my 14 f-stop test split screen before and after simple grading and make you own conclusions.

I'm sticking with my lightmeter. It works for me and my clients like what I do. They can care less what I use or how I use it.

Sorry, but I don't understand why you would prefer to use a light meter when you can use the cameras built in tools for 100% accurate measurement of the actual recorded image.

In my mind it's like using a dip stick to work out how far the fuel in a car will get you when you have a modern car with a trip computer that will tell you exactly how far you can go. Times change, technology moves on. I'm not convinced your method is working as your clip appears to be rather overexposed. But as you say, it's your choice and if you feel it's working for you then carry on.

There is more than one way to skin a cat. I have been getting the results I want my way for over 30 years and it still works for me.

Tell me what you find wrong with the 14 f-stops test I did. It is not theory it is fact.

Everything changes once you do your own grading on a qualified grading tool like Resolve, Apple Color, etc. Adding an S curve plugin to FCP, Premier won't do it.
There is more in the 10 bit highs than what you see on you monitor. The same happens with the lows, but they brake up sooner in grading and looks really noisy and pixelated as you can see in my test.

I know this is a F3 forum but was reading your comments Alister and found them to be in line with my experience in relation with Clog on the C300.

I have been using a Canon C300 in C-log mode and have found getting correct exposure is a bit tricker than at first thought. Skin tones I'm finding need to be exposed lower than I have been doing on the Sony 500.
I'm also finding it's a fine line between under and over exposure in log mode.

I'm also finding it's a fine line between under and over exposure in log mode.

The whole idea of Log is the wide range of exposure latitude. What do you mean by a fine line between UNDER & OVER?

What that means to me is one f-stop difference between under & over.

Yeah that didn't sound right when I put that down, what I meant was skin exposure to my eye compared to hyper-gamma from a 2/3rd inch camera.

Log gives us more latitude, but the majority of the extra latitude is in the shadows. But because the images are no longer correctly displayed directly on a standard gamma monitor you can't easily directly see a lot of the extra latitude when you shoot. As a result there is a tendency for many to over expose instead of shifting the exposure range down to take advantage of the increased low end latitude. It's why the EI modes in the F3 only go up in ISO and not down, shifting the exposure range lower down the log curve.

It's only when you go to a camera with 12 or 14 bit linear recording, like the F65 that you can really afford to place your exposure range wherever you want it.

We will continue to agree to disagree.

You may have a crystal ball that gives you the Lotto numbers, but you still have to buy the ticket and the numbers have to actually come out.

The only proof you think you have is a scaling gray chart perfectly expose where you say it shows more detail on the dark area of the chart than bright area of the chart. If done that way I will concede since I haven't really checked or care to check.

My concern is actual exposure since that is what we shoot, not a back lit charts.

I specially like how Zacuto did the test in their Camera shootout 2, Minute 4:34. This was a camera comparison and not an F3 under and over comparison but all you needed to do is change f-stop to see how it resolved at different exposures.

Hey what do they know? They were only famous ASC cinematographers conducting the test.

The Great Camera Shootout 2011: Episode 2 ~ "Sensors & Sensitivity" on Vimeo

See what they used to determine exposure at minute 4:03

https://vimeo.com/24334733#

The method I use to measure dynamic range and latitude using a back lit dynamic range chart and waveform monitor is one of the standard methods for measuring the actual dynamic range and latitude of a video camera. The measurements I make are done in accordance with ISO standards. The same charts can also be used with film. It's very accurate and when done correctly repeatable time and time again. It is not subject to issues such as changes in lens flare with aperture, aperture or ND filter inaccuracies, personal interpretation, monitor issues or other vagaries.

It's almost exactly the same method the Andy at Abel Cine uses. You can view videos about how he does it here:
S-Log and the Sony F3 – Part 1: On the Charts | CineTechnica (http://blog.abelcine.com/2011/08/04/f3-s-log-part-1-on-the-charts/)

And surprise surprise, Andy came up with the same results as I did. If you think we are both wrong, and the majority of other people that have measured and plotted the DR of an F3, then that's up to you, but I stand by my measurements and my advice on how to expose and use S-Log. It's not film, it doesn't behave like film and as a result you should modify the way you use it if you want the best results.

The method I use to measure dynamic range and latitude using a back lit dynamic range chart and waveform monitor is one of the standard methods for measuring the actual dynamic range and latitude of a video camera. The measurements I make are done in accordance with ISO standards. The same charts can also be used with film. It's very accurate and when done correctly repeatable time and time again. It is not subject to issues such as changes in lens flare with aperture, aperture or ND filter inaccuracies, personal interpretation, monitor issues or other vagaries.

It's almost exactly the same method the Andy at Abel Cine uses. You can view videos about how he does it here:
S-Log and the Sony F3 – Part 1: On the Charts | CineTechnica (http://blog.abelcine.com/2011/08/04/f3-s-log-part-1-on-the-charts/)

And surprise surprise, Andy came up with the same results as I did. If you think we are both wrong, and the majority of other people that have measured and plotted the DR of an F3, then that's up to you, but I stand by my measurements and my advice on how to expose and use S-Log. It's not film, it doesn't behave like film and as a result you should modify the way you use it if you want the best results.
I am not looking at who is right or who is wrong. I am doing my test my way because that is what I trust.

You don't understand my test, that is fine. I don't think that anyone that uses TV tools will. I didn't post it for or mention you in it. You have taken my test personal for some reason. This test is not intended to proof you right or wrong. Most likely you can arrive to same exposure as me using your tools and me using mine.

All I can tell you is that my test is not 100% useful to everyone else and I heven't seen your test clips, so can't even comment on them.

Anyone else that saw the 14 f-stop test you can do what I do with most of the tests I see. Use what you can and do your own test. If you don't have the camera download my free clip. It is the only free S-Log ProRes HQ 10 bit clip in the internet that I know of that you can download. The camera with and without slog is awesome.

True! It is the only clip that you can download for free. Before I purchased the s-log upgrade and began recording to an external recorder (ProPres422, 10Bit, 220Mbps etc) I searched painstakingly for hours to find an example, so well done, Douglas.

As it turns out, your clip looks pretty much exactly what my clips look like before grading. I don't use any measurements to calculate the correct exposure. If it looks alright through the view finder, then I assume it should be alright. Sometimes I get it wrong, but most of the time the finished product looks great.

I am however always mindful of what Alister says about over exposure, but on location I'd go crazy if I kept worrying about that.

Alister reminds me of the teacher who will always push you to get the better results. Nothing wrong with a good teacher.

Alister reminds me of the teacher who will always push you to get the better results. Nothing wrong with a good teacher.
Nothing wrong with that.
I read daily what other people say about things that interest me including Alister Chapman, Andy, Timur Sivan, Philip Bloom, etc. That is why I bought the F3 for a feature I directed, filmed and edited last October ("The Awakened") that required shooting with very little lighting. The camera was a heaven sent. Even before S-Log I was able to shoot a whole movie inside an small house with 7' sealing. Not a lot of room to hide lights there.

True! It is the only clip that you can download for free. Before I purchased the s-log upgrade and began recording to an external recorder (ProPres422, 10Bit, 220Mbps etc) I searched painstakingly for hours to find an example, so well done, Douglas. .

Of course, you could have saved yourself hours of painstaking searching and just bought 126 clips (50GB of raw unadulterated footage) for about a hundred bucks. I don't know what your time is worth to you, but $100 doesn't even cover an hour of my time. :-)

PMW-F3 S-LOG & External Recorders Test Drive (http://www.vortexmedia.com/F3_TEST_DRIVE.html)

By the time I got serious with this type of craft it was too late for a career change, so I need to do the painstaking stuff to avoid spending more money.

Alister,
Thanks for the explanation. I have a bunch of tests I've run as well, but i tend to be too damn lazy to post them. In fact sometimes to even look at them as carefully as I did when shooting. I think the first S-log I ever shot may have been overexposed and that would explain why I was not happy with the grading.

I for one agree completely about using the viewfinder readout and or waveform & for setting exposure, but I guess everybody has there own ways of doing things.

There are clips and S-Log frame grabs on my bog for download. They have been there since October last year.


Canon C300 and Sony F3 footage to download. | XDCAM-USER.COM (http://www.xdcam-user.com/2012/02/canon-c300-and-sony-f3-footage-to-download/)

More Codec and Gamma Tests. | XDCAM-USER.COM (http://www.xdcam-user.com/2011/12/more-codec-and-gamma-tests-444-rgb-has-greater-dynamic-range/)

Convergent design Gemini S-Log frame grabs. | XDCAM-USER.COM (http://www.xdcam-user.com/2011/10/convergent-design-gemini-s-log-frame-grabs/)

There are clips and S-Log frame grabs on my bog for download. They have been there since October last year.


Canon C300 and Sony F3 footage to download. | XDCAM-USER.COM (http://www.xdcam-user.com/2012/02/canon-c300-and-sony-f3-footage-to-download/)

More Codec and Gamma Tests. | XDCAM-USER.COM (http://www.xdcam-user.com/2011/12/more-codec-and-gamma-tests-444-rgb-has-greater-dynamic-range/)

Convergent design Gemini S-Log frame grabs. | XDCAM-USER.COM (http://www.xdcam-user.com/2011/10/convergent-design-gemini-s-log-frame-grabs/)
Hello Alister,

I downloaded the folder F3-C300 Clips with the F3 recorded to the internal recorder at 1080p/25, 8 bit 4:2:0. Is there a 10 bit I can download so I can grade?

No, 8 bit only but the only difference in the grade would only be possible additional banding and a bit more noise. In terms of the look you can create it will be essentially the same.

The 8 bit file has been downloaded about 300 times and I simply can't afford the bandwidth for full 10 bit RGB files. That's why I normally provide frame grabs or single DPX frames. The grading is then identical to working with a clip, just limited to a single frame. I did have a 3 second long RGB DPX file on the site, but after over 100 downloads (45Gb) and only one paypal donation I decided enough was enough and removed the clip.

No, 8 bit only but the only difference in the grade would only be possible additional banding and a bit more noise. In terms of the look you can create it will be essentially the same.

The 8 bit file has been downloaded about 300 times and I simply can't afford the bandwidth for full 10 bit RGB files. That's why I normally provide frame grabs or single DPX frames. The grading is then identical to working with a clip, just limited to a single frame. I did have a 3 second long RGB DPX file on the site, but after over 100 downloads (45Gb) and only one paypal donation I decided enough was enough and removed the clip.

Got it.

The clip for download is in the 4-5 f-stops (10%-87% waveform). Do you have any single frame DPX frame with a range over 0-100%?

It's only when you go to a camera with 12 or 14 bit linear recording, like the F65 that you can really afford to place your exposure range wherever you want it.

And Sony recommends with the F65 to expose Caucasian faces at 33% not 38%. My tests with that camera bear this out. When you get down in exposure that much (33%) you can't see the faces all that well so having a good LUT working on a monitor goes a long way towards nailing exposure - you just can't use the monitor as a final arbiter of it.

I have a suggestion for Douglas, why not do another test with the same setup, but this time shoot with your light meter style and another identical shot using the simple viewfinder middle box percentage at 38% on a grey card? I would like to download those two and compare them in Resolve using the Log settings.

BTW, Resolve Lite is a free download and will do up to 2 nodes of HD 1920x1080 without watermarks.

Bruce, why don't you do that test and tell us what you find out? :-) I'm finished doing any testing for public consumption. I have already come to my own conclusions, best practices, and methods and I have no interest in explaining and/or defending my findings any further.

And not only that, I completely agree with Alister that using a light meter is not nearly or easy or fool-proof as the camera's own built-in exposure tools. Sure, my light meter is a good tool for some purposes, but is a lousy alternative to newer technology for setting the overall exposure. The F3 ain't no film camera.

And not only that, if you exceute both of the methods correctly that you propose testing, the results would be the same, wouldn't they? I am a firm believer that there can only be one correct exposure, regardless of what method(s) you use to find it.

Roger all of that Mr, Jensen, but I was directing that suggestion to Mr. Villalba who started this thread - you both have similar first names.

I agree with Alister and you that reflective metering via the camera is the very best method of determining the exact light level the sensor is seeing, but as a long time DP & HD DIT I have shepherded many a film DP into the gaping maw of digital motion photography and can understand how abandoning a light meter is like throwing one oar overboard in the middle of a vast ocean.

I too have no need or necessity to conduct additional tests of processes that I know are accurate and true.

And Sony recommends with the F65 to expose Caucasian faces at 33% not 38%. My tests with that camera bear this out. When you get down in exposure that much (33%) you can't see the faces all that well so having a good LUT working on a monitor goes a long way towards nailing exposure - you just can't use the monitor as a final arbiter of it.

I have a suggestion for Douglas, why not do another test with the same setup, but this time shoot with your light meter style and another identical shot using the simple viewfinder middle box percentage at 38% on a grey card? I would like to download those two and compare them in Resolve using the Log settings.

BTW, Resolve Lite is a free download and will do up to 2 nodes of HD 1920x1080 without watermarks.

I would think that the Douglas is me, the one that posted my test.

First you have to understand the test.

The test is to determine what happens to the surrounding areas that may be over or under exposed when you expose your subject using what ever method you use.

Example that comes to mind right now:

In an establishing shot you have inside a building someone spying through a window (- 6.5 - f 0.7). Across the street two actors under the shade of a building. Behind the two actors a car with gunmen is approaching (direct sun light)(+ 6.5 - f 64). Where do I want my pivoting point? what f-stop?

Look Bruce regardless of how I came up with my exposure you have 14 1 f-stop Bracketing clips. You can easily see the max under & over. If I had used a rear lit gray scale card and change f-stops like I did to determine actual latitude I had to come to the same conclusion.

If you need any ProRes HQ original clip, let me know which one and I will upload it so you can open it in Resolve. I've got resolve light, but I know how to use Apple Color better.

Good references:

A Simple Explanation of F-Stop Numbers (http://www.petapixel.com/2012/04/02/a-simple-explanation-of-f-stop-numbers/)
Sunny 16 rule - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Sunny_16_rule)
Accurate Exposure with Your Meter (http://www.kodak.com/cluster/global/en/consumer/products/techInfo/af9/index.shtml)

And Sony recommends with the F65 to expose Caucasian faces at 33% not 38%. My tests with that camera bear this out. When you get down in exposure that much (33%) you can't see the faces all that well so having a good LUT working on a monitor goes a long way towards nailing exposure - you just can't use the monitor as a final arbiter of it.

I have a suggestion for Douglas, why not do another test with the same setup, but this time shoot with your light meter style and another identical shot using the simple viewfinder middle box percentage at 38% on a grey card? I would like to download those two and compare them in Resolve using the Log settings.

BTW, Resolve Lite is a free download and will do up to 2 nodes of HD 1920x1080 without watermarks.

My previous answer was started long before you reply, but it took me a long time to finish. Sorry.

The clip for download is in the 4-5 f-stops (10%-87% waveform).

That's not correct this is log and 10-87% equates to 8 to 9 stops.

The S-Log curve is as follows:

0-10% 3 stops (If trying to use 8 bit this means each stop represented by only 8 grey shades, 10 bit is 30 grey shades per stop)
0-20% 5.5 stops
0-30% 7 stops
Middle Grey 38%
0-40% 7.5 stops
0-50% 8.5 stops
0-60% 9.5 stops
0-70% 10 stops
0-80% 11 stops
0-90% 12 stops
0-100% 12.6 stops
0-104% 13 stops

Arguably the first stop above black is going to be quite noisy so is unlikely to be of any significant use in a real world image, so measured dynamic range is 13 stops but latitude 12 stops.

Roger all of that Mr, Jensen, but I was directing that suggestion to Mr. Villalba who started this thread - you both have similar first names.

Sorry, my mistake.
Ever since I created the 126 test clips I referred to in post #18, I have been deluged by requests from people to do further testing as well. I mistakenly made the assumption you were suggesting the same thing. Sorry.

That's not correct this is log and 10-87% equates to 8 to 9 stops.

The S-Log curve is as follows:

0-10% 3 stops (If trying to use 8 bit this means each stop represented by only 8 grey shades, 10 bit is 30 grey shades per stop)
0-20% 5.5 stops
0-30% 7 stops
Middle Grey 38%
0-40% 7.5 stops
0-50% 8.5 stops
0-60% 9.5 stops
0-70% 10 stops
0-80% 11 stops
0-90% 12 stops
0-100% 12.6 stops
0-104% 13 stops

Arguably the first stop above black is going to be quite noisy so is unlikely to be of any significant use in a real world image, so measured dynamic range is 13 stops but latitude 12 stops.

That is why I did a test that is useful to me.

My brain can't compute that for example from 40% up every 10% increase is 1 full stop then from 60-70% it is only 1/2 stop and then from 70-80% it goes back to 1 full stop all the way to 90%. My brain can compute a Log slope, but a sharp drop in the middle middle, I can't.

Can't get any easier to see what an f-stop difference does than opening and closing the iris one stop at a time.
You can stop trying to convince me to trust your theory. It will never happen.

The anomaly around 60-70% is due to rounding of the exposure to the nearest 0.5 stop. I suggest you take a look at any of the published curves or S-Log curve plots on the web and make your own assessment of the exact numbers.

S-log curve image by hingsberg on Photobucket (http://media.photobucket.com/image/s-log%20curve/hingsberg/Abelcine-SLOG-curve.jpg)

It's not theory it's fact. Fact that is borne out by every other correctly done S-Log measurement that's been done. I suggest you read the Sony S-log white paper or watch the Abel Cine tests etc.
If you don't like the facts that's your choice but don't keep telling me I am wrong and only your test is right. I don't agree with your test results of a 9 stop range or that 10-87% is only 4-5 stops because that's not the case and that isn't opinion or speculation, it's stone cold fact.

Your test obviously has value to you, it may have value to others as well, your exposure method is obviously one you like, but statements such as 10-87% only being 4-5 stops show that you do not fully understand the curve and it's exposure range, either that or you are talking a different language to everyone else. In that case don't expect us to understand you.

It's not theory it's fact. Fact that is borne out by every other correctly done S-Log measurement that's been done. I suggest you read the Sony S-log white paper or watch the Abel Cine tests etc.

I understand Theory like this.
Wilkipidia: "Theories are analytical tools for understanding, explaining, and making predictions about a given subject matter."
In order for ME to be fact, you have to show me an actual situation (Zacuto shootout scene video) with a range over 7 stops. Less than that I find S-Log totally useless and just an extra step that 709 can handle even at 8 bits 4:2:0 straight out of the camera.

If you don't like the facts that's your choice but don't keep telling me I am wrong and only your test is right.

I don't remember saying that you are wrong or that my test is the only test that is right. I said and I repeat, My test is the only one I have seen that shows ME the facts that I wanted to see.
I have only use your name to praise the work that you have done.

I don't agree with your test results of a 9 stop range or that 10-87% is only 4-5 stops because that's not the case and that isn't opinion or speculation, it's stone cold fact.

I shouldn't even call what I did a test. All I did was to shoot a video that SHOWS ME what happens to the under or under expose areas in 1 F-STOP increment.

statements such as 10-87% only being 4-5 stops show that you do not fully understand the curve and it's exposure range, either that or you are talking a different language to everyone else. In that case don't expect us to understand you.
The 10-87% came from just dropping your clip on the Apple Color Timeline before any grading. I am sure if you do the same you should get the same result unless different waveforms read differently. I only use the waveform in post to make sure that my whites don't go over 100% and my blacks don't go bellow 0%.
When I said that the clip was in the range 4-5 f-stops, I guessed. I don't know how anyone could use a waveform to determine accurately f-stops. I used experience on similar lighting situation and the Sunny 16 Rule. Again I was just asking you if you had a one frame clip of a 13+ f-stops shot.

I thought of doing one with a single light until I did the math.

I order to do it I had to place the 1st object 3' from the light...
3' = 0 f-stop under
6' = 1 f-stop under
12' = 2 f-stop under
24' = 3 f-stop under
48' = 4 f-stop under
96' = 5 f-stop under
192' = 6 f-stop under
I can only do 5 f-stops in my living room ;-)

If your guessing about exposure ranges then don't make statements:
The clip for download is in the 4-5 f-stops (10%-87% waveform). Do you have any single frame DPX frame with a range over 0-100%?

It's fine to guess or estimate, I haven't got a problem with that, I do it. But you stated the range was 4-5 stops and it felt like a criticism that somehow I was trying to short change people with a restricted dynamic range clip. I suspect your waveform readings are correct, and that makes it 8 to 9 stops.

If you know the gamma you are using then of course you can use a waveform monitor to measure latitude or F-stops. As I tried to explain earlier a video camera is no different to a light meter. You have a sensor and a voltage output. By measuring the output you can figure out the amount of light falling on the sensor or as it has a lens different parts of the sensor. That's all a light meter does. It has a sensor and you measure the voltage output of the sensor and from that calculate the the light levels. So if you know the characteristics of the gamma curve you can very accurately measure the exposure in f-stops. With a waveform monitor not only can you measure the average levels but the minimum and peak levels, all at the same time at any point in the image, something simply not possible with a light meter.

Frankly that's something I rarely do other than when testing a camera. Once I know the characteristics of the curve and how best to use it all I need to do is ensure my exposure range falls in the correct voltage range using either the spot meter built into the F3 or a waveform monitor. Most half decent monitors have a built in waveform monitor these days. Certainly my TV Logic and Transvideo's do. The waveform monitor is the best tool for setting accurate exposure with a video camera. Not always practical, especially for run and gun, but a waveform monitor is much more accurate than a light meter for measuring actual exposure.



The scene in the new Zacuto shootout has a 12 stop range.

If your guessing about exposure ranges then don't make statements:


It's fine to guess or estimate, I haven't got a problem with that, I do it. But you stated the range was 4-5 stops and it felt like a criticism that somehow I was trying to short change people with a restricted dynamic range clip. I suspect your waveform readings are correct, and that makes it 8 to 9 stops.

If you know the gamma you are using then of course you can use a waveform monitor to measure latitude or F-stops. As I tried to explain earlier a video camera is no different to a light meter. You have a sensor and a voltage output. By measuring the output you can figure out the amount of light falling on the sensor or as it has a lens different parts of the sensor. That's all a light meter does. It has a sensor and you measure the voltage output of the sensor and from that calculate the the light levels. So if you know the characteristics of the gamma curve you can very accurately measure the exposure in f-stops. With a waveform monitor not only can you measure the average levels but the minimum and peak levels, all at the same time at any point in the image, something simply not possible with a light meter.

Frankly that's something I rarely do other than when testing a camera. Once I know the characteristics of the curve and how best to use it all I need to do is ensure my exposure range falls in the correct voltage range using either the spot meter built into the F3 or a waveform monitor. Most half decent monitors have a built in waveform monitor these days. Certainly my TV Logic and Transvideo's do. The waveform monitor is the best tool for setting accurate exposure with a video camera. Not always practical, especially for run and gun, but a waveform monitor is much more accurate than a light meter for measuring actual exposure.



The scene in the new Zacuto shootout has a 12 stop range.

I hope that you understand that my "test" is not about how to measure light or reflection. Your way or mine. It just shows what the camera can register when light hits the censor at different intensity in a 1 f-stop variations. I even used a still lens to get the full click in between f-stops.

The discussion we have about light meters and waveform has nothing to do with my test.
We will never agree on this because I am interested on light landing on the subject regardless of its reflectance value and you are interested on the light reflecting off of the subject. They are both useful, just different and we each feel more comfortable with our different tools.

In Andy's test the light landing on the chart is even. Therefor there is no difference in exposure on the chart. The same amount of light is landing on that black as it is landing on the whites and all the way through.
Now the reflectance of chart varies in the shades from black to white and that is what the waveform is seeing.
Are you still with me on this?

Do you really think I don't understand the difference between incident and reflected light or how a grey scale chart works. Don't insult me. Andy's tests were done with a transmissive chart by the way.

If you think that waveforms are irrelevant when measuring exposure or assessing latitude then I'm leaving this now pointless discussion.

I'm leaving this now pointless discussion.

Good idea.