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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

9 1/2 stops...

Also it's not right to judge the noise on a still image. On the move the noise will seem a little less anyway!

Obviously keep the shots up purely to show the amazing amount of information in there.
Jeez tough crowd in here Jim! :sarcasm:
 
Noise can be less to the eye on moving images IF it's completely random. If not, it can be more annoying. That's where I hope that build 16 will show improvements.

Regards,

Uli
 
www.DANCAD3D.com said:
Best to shoot for the lowest comman denominator since if you don't you will need to tie your shoes...
Click to expand...

DANCAD3D, even if anyone asks, please don't explain that statement... I need something to reflect on:usd:
 
Graeme Nattress said:
First, are we talking dynamic range, the difference between the brightest and darkest thing you can record and still retain detail? Or are we talking lattitude which, to me, is by how much you can under or over expose an object and not clip or crush it.

8 stops lattitude, ie, 4 over and 4 under, for a real world object, is quite reasonable. 8 stops dynamic range is not.

Graeme
Click to expand...

Graeme, I am a little confused.

First I see: finally someone tries to define the difference between dynamic range and lattitude. The source of many misunderstandings.

Then you go on to make a totally unreasonable claim in your next post.

Are you claiming that you can pull up a normal subject that has been underexposed by 4 stops and pull down a subject that has been overexposed by 4 stops also? I don't think so. 1 1/3 underexposed and 1/2 stop overexposed is more like it imho.

Let's make the definitions again to clarify:

-Dynamic Range is the mediums ability to capture differences between lightest and darkest object within the frame and retain detail.
-Lattitude is the mediums ability to be under/overexposed and brought back to normal in printing or digital post manipulation and retain detail.
-Both of these measurements are subjective: How much grain/noise is acceptable to you and what do you consider retaining detail for the specific look you are going for.

A lot of times - as with Stouffer charts - the combination of Dynamic Range and Latitude are measured. This is mainly for marketing purposes and has little real life value to someone creating an image.

Where is the discrepancy between our definitions?
 
Let's take a real world example of a macbeth chart. The greyscale on that is say a 5 stop range, so we have an object under test that has it's own DR of 5 stops. Say our camera, for instance (not being specific to any camera here) is good for a 10 stop dynamic range. Therefore, your exposure lattitude for that chart on that camera would be +-2.5 stops. Or 5 stops of lattitude in total. You may even be able to get more on the bottom end with the expense of some noise. The most exposed image without clipping will have the best image though.

Graeme
 
Graeme Nattress said:
Let's take a real world example of a macbeth chart. The greyscale on that is say a 5 stop range,
Graeme
Click to expand...

Ah that's where we are off. I consider a real life subject with a "normal" tonal range to be about in the seven stop range...
 
A scene will surely have >7 stop range, but objects within that scene will usually be less. That's why I was specifically talking about exposing an object, rather than exposing a scene. Moving to a specific object like a Macbeth with known dynamic range is helpful here.

But a scene could have still a greater dynamic range. At that point, your lattitude is close to, if not zero as there would be only one perfect exposure, if you're lucky, that can take in the entire scene.
 
florianstadler.com said:
Ah that's where we are off. I consider a real life subject with a "normal" tonal range to be about in the seven stop range...
Click to expand...

7 or 5 is immaterial, basically what Graeme is saying is that:

Dynamic range (on camera, in stops) = number of stops from pitch black to the darkest tone in the scene + number of stops for the scene + number of stops from the highest highlight in the scene to the max the sensor can have.

Therefore,

tonal range (scene) = number of stops for the scene = number of stops between highest highlight in the scene and darkest tone in the scene.

Latitude = number of stops from pitch black to the darkest tone in the scene + number of stops from the highest highlight in the scene to the max the sensor can have.

So, if latitude > 0 (i.e., the tonal range in the scene is less than the full dynamic range on the camera), then you have that wiggle room to move your tonal range up and down the dynamic range as a slider, with some consequences, of course.
 
Precisely! Latitude is totally scene / object dependent, as well as dependent on your noise threshold / preference.

Graeme
 
Joofa,

the aspect you are not taking into account in your explanation is the display medium. All this extra information you have at your disposal has to be squeezed into a bottle like a genie before it gets to the viewer (color correction!)...

With film your print could replicate a 7-8 stop range linear. It was a known quantity. For TV broadcast a 7 stop range would be more normal. That's why I "randomly" picked that 7 stop range and why it matters...

That's why some people say there's 7-8 stops of DR plus and 2-3 stops of latitude while others define it as 9.5-11 stops of "dynamorangeitude":nerd: (dynamic range & latitude).

It's a matter of definition. I think we're all talking about the same thing and all I'm trying to do is define what we're talking about so that ultimately we would understand each other.
 
Usually, for a grade to look "good", on an average display you need to squash the range to nearer 5 or 6 stops though. However, this is in no way related to what or how you shoot, because if the range you shoot is much greater than those 5, 6 or 7 (whatever) stops, you have to get into secondaries to correct it so all the information you want the viewer to see lies within that limited range. I don't see how that relates to either dynamic range or latitude of the capture device, just that you're going to have to do some grading afterwards for best results.

Graeme
 
Florianstadler,

I understand what you are saying. I think partly the confusion is arising that the word "dynamic range" is being used for both:

(1) Full range of the sensor i.e., 12 bits
(2) the tonal range of the objects in the scene, that may or not may not occupy the full 12 bit range. If it does not then the difference is latitude.

We need to stick with one meaning of DR. However, there is no clear consensus that should DR mean (1) or (2) as far as definition is concerned. Though, as mostly happens, one typically knows by context that by DR one is referring to (1) or (2), and then some of confusion gets eradicated.
 
Graeme Nattress said:
I don't see how that relates to either dynamic range or latitude of the capture device

Graeme
Click to expand...

It relates to the testing you do before you start a film where you test your entire IMAGE CHAIN in order to come up with the best way to expose and light your Negative (be it digital or not) to achieve the look you are after.
 
florianstadler.com said:
With film your print could replicate a 7-8 stop range linear. It was a known quantity. For TV broadcast a 7 stop range would be more normal. That's why I "randomly" picked that 7 stop range and why it matters...
Click to expand...

A perfect film in an average cinema (with 'Exit' lamps and enough diffuse lighting to identify your popcorn) can reproduce about 10 stops at max.

Some home theaters could reproduce more than 14 stops these days, if you paint the walls black, have black velvet seating and wear something black while enjoying images graded for a JVC DLA-HD100.

Hard to find a camera with a 14 stops sensor…

A TV in an ordinary living room (not a Pioneer plasma in the home theater described above) will be proud to reproduce 5-6 stops!

A scene can have any contrast from 2 stops in dense fog to nearly infinite when filming straight into sunset/sunrise.

The art of shooting plus the art of grading – hopefully two versions, one for cinema and one for TV – is finding the best compromise to make any of those scenes look convincing for the audience.

Regards,

Uli
 
Graeme Nattress said:
Precisely! Latitude is totally scene / object dependent, as well as dependent on your noise threshold / preference.

Graeme
Click to expand...

Hi G:

Instead of just saying dynamic range, what about Recordable Dynamic Variation. This would take into account that Silcon is much more linear than film. A recordable change in the level grey for the medium would be a Recordable Dynamic Variation. For example, film doesn't have shaddow detail while silicon does. Maximum Dynamic Range would be better fitted to film. Here's an example of what it could look like:

Red:
RDV 12 bit (12 stops)
MDR 12 bit (12 stops)
Film:
RDV 10 bit (10 stops)
MDR 16 bit (16 stops)
 
I think that might add a whole new layer of confusion. I know what you mean though....

Graeme
 
To Be less confusing, it could be simplified into a ratio. For each shade of grey, it represents how much on average is recorded.

MDR/RDV= MLR

Media Linear Ratio:

Red: 1.0

Film: .625
 
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