9 stops! (Canon EOS 1D M.II)

[Tito948]

"The dynamic range of the EOS-1D Mark II sensor is approximately 9 stops."

Can someone explain real briefly what are/is stops. I have an idea what it is and I read about it, but can someone break it down to a nice decent explanation about it.

Thanks,
Tito

[-Bill-]

When you increase or decrease exposure by double or half the value, you are changing it by one stop. So, if you go from a shutter speed of 1/100 of a second to 1/50", you are doubling the time the sensor is exposed, so are increasing exposure by one stop (all other things being equal). The same holds true when going from f/11 to f/8.
So 9 stops means 2x2x2x2x2x2x2x2x2, which translates to 512. That means that the camera can handle a scene in which the brightest part is 512 times brighter than the darkest part. Quite an accomplishment !

[cgratti]

When you increase or decrease exposure by double or half the value, you are changing it by one stop. So, if you go from a shutter speed of 1/100 of a second to 1/50", you are doubling the time the sensor is exposed, so are increasing exposure by one stop (all other things being equal). The same holds true when going from f/11 to f/8.
So 9 stops means 2x2x2x2x2x2x2x2x2, which translates to 512. That means that the camera can handle a scene in which the brightest part is 512 times brighter than the darkest part. Quite an accomplishment !

So, in other words....

One fish, Two fish, Red Fish, Blue fish?

LOL...

Suess Rules!

[DaveG]

"The dynamic range of the EOS-1D Mark II sensor is approximately 9 stops."

Can someone explain real briefly what are/is stops. I have an idea what it is and I read about it, but can someone break it down to a nice decent explanation about it.

Thanks,
Tito

"Stops" are the universal constant in photography. The film or sensor wants ONE amount of light to hit it. That is the holy grail, the "correct exposure". In order to do that we must control the light.

First off we must know how sensitive the film or sensor is and we use ISO (International Standards Organization) who cheerfully gives us numbers to rate the sensitivity. The higher the number the greater the sensitivity, as in saying that "ISO 400 is more sensitive than ISO 100". A series of ISO numbers could be written ... 100, 200, 400 ... and so forth.

You should be able to easily see a pattern forming and the next number higher than 400 will be? Right, 800. ISO 400 is 100% more sensitive than ISO 200, and that makes sense. But how much less sensitive is ISO 100 to 400? It's make you crazy to figure that out so they've made it easy. The difference between each of these numbers is one "stop". ISO 400 is one stop more sensitive than ISO 200. ISO 100 is two stops less sensitive than ISO 400.

So if the Mark II is sensitive across NINE stops (which I highly doubt) it would be able to handle a range of light from ISO 100 to ISO 51,200. Another way of putting it would be: if you had this nine stop range of light and you exposed in the middle it would accept an overexposure of four stops and an underexposure of five stops! Since I'd guess that the 10D is sensitive across maybe three stops that's big jump.

I'd like to hear other people's opinion of this claim of nine stops since that kind of latitude is something I miss from colour neg film - not that colour negs had nine stops of latitude either. But since digital capture is similar to colour slides in latitude, I'd welcome some relief in this area!

[CyberDyneSystems]

10D is "sensitive" to (or has a range of) 6-6.5 stops.

[theflyingkiwi]

It is all nice to say that the Canon 1D mkII has a total of 9 stops, I am just wondering to myself how this compares to film.

It just seems to be that the cmos sesor in the camera might(?) be more sensitive than film?

I have never had a film camera, and as such I have never learned the fine art of how to use film.

or perhaps I am wrong in saying that this 9 stops has anything to do with film.

[CyberDyneSystems]

I do not remeber exactly,. but I think film.. the film not the print.. is around 9-11 stops?

Slides more like 7.. very similar to the 10D...

Something like that,. anyway,. I know film was better than the 10D and most digitlas,. good digitals were similar in dynamic range to slide film,. etc.

[theflyingkiwi]

then in that case does the number of stops change with the speed of the film being used/

eg does ISO 100 have less no of stops than say a ISO 400 speed film

[nosquare2003]

I do not remeber exactly,. but I think film.. the film not the print.. is around 9-11 stops?

Slides more like 7.. very similar to the 10D...

Something like that,. anyway,. I know film was better than the 10D and most digitlas,. good digitals were similar in dynamic range to slide film,. etc.

I remember Ansel Adam's zone system from Zone 0 to Zone X. There are 11 stops including the pure black and pure white. Therefore there are 9 useable zones (stops) in negative. (I assume the paper will have about 5 stops and will depend on their qualities.)

[iwatkins]

Some speciality B&W films have a 14-16 stops coverage.

Cheers

Ian

[ron chappel]

As many have said-a stop is either double or half and is used in measuring light in photography because of the huge numbers involved.
The great thing is that shutter speeds,apertures,filters,films,etc are all rated in stops so are TOTALLY interchangable
-yes aperture numbers don't look like they work the same way but they do .
The next thing to know is that films or sensors (or our eyes) can only 'see' a restricted range of light.

Digital sensors and slide film see only about 5-6 stops so they tend to look very contrasty

colour film can see more-about 7-8 stops which looks a little bit closer to what our eyes see

apparently there is something called black and white film that can see even more but never seen those myself........lol

and 9 1/2 stops does indeed sound like alot from a digital sensor! I'll be interested to see if that proves to be true in everyday use.

[DaveG]

then in that case does the number of stops change with the speed of the film being used/

eg does ISO 100 have less no of stops than say a ISO 400 speed film

Stops are just "units" of measurement. ISO 100 film is two "units" less sensitive to light than ISO 400 film. In photography we speak of these units as "stops", so ISO 100 film is two stops less sensitive than ISO 400 film. So I guess you could say that ISO 100 film has two "fewer" stops of light.

But before you think that you get less when you use ISO 100, there's also a trade off that I didn't mention; and that's that the lower the sensitivity (and therefore the lower the ISO) the finer the grain in film, or the lower the noise in digital capture. So don't think that ISO 100 film is somehow flawed because it's "missing" those two stops of sensitivity over ISO 400.

[DaveG]

It is all nice to say that the Canon 1D mkII has a total of 9 stops, I am just wondering to myself how this compares to film.

It just seems to be that the cmos sesor in the camera might(?) be more sensitive than film?

I have never had a film camera, and as such I have never learned the fine art of how to use film.

or perhaps I am wrong in saying that this 9 stops has anything to do with film.

The problem with film or digital capture is with your brain. Your brain, with help from your eyes see an amazing range of light, from shadows to bright highlights. No film or capture exists that sees this kind of range so we play all kinds of games to manipulate either the film or even the light to let the image appear to have greater range.

Colour negative film has the greatest "latitude" of all films. It is especially forgiving to over exposure. I don't know how much range it has in stops. But if a pro gets into a too contrasty situation (outside in the bright sun) then they will still need to use fill flash. Fill flash uses the ambient light but also pops some flash into the shadows. This removes the racoon eyes from people outside. But in reality you are reducing the contrast between the highlight and shadow.

Black and white film has also a lot of latitude but one of the things that extends the latitude of b&W film is that you can use the development of the film to modify the range.

Ansel Adams and other would use a technique called Zone where the would measure the highlights and shadows of a scene and would expose the film based on a the difference's between the highlights/shadows. If it's a sunny day you will notice a huge difference in exposure between the sun struck part of the scene and the shadows. On an overcast day the difference between the shadows and highlighs aren't so much.

Then they would go into the darkroom and mess with the development. They could underdevelop and that would lower the contrast (sunny day) or they could increase the development to increase the contrast (cloudy day). There are a few other development techiques but I'll leave it there, but basically they would modify the negative to "extend" the latitude. Even then when they got the negative into the darkroom they'd darken local areas of the print (burning in) or lighten other local areas (dodge).

By the way I know of no special B&W film that has any more range than any other.

Colour transparencies or slides have the least latitude of the three films. A pro using transparency film would almost always bracket their exposures to make sure that one was correct. Transparency film also has almost no tolerance for over exposure. If you blow out your highlights then there's no fixing that picture. Does that sound familiar? Although thanks to the histogram there's no real need to bracket, transparencies and digital capture are very similar in their lack of latitude.

So blame it all on what our wonderful brain sees and how film and digital capture struggles to keep up.

[Man-Fai Wong]

Thanks Dave for the well-written posts and (for me) additional insights.

For others still not quite clear on all this stuff, you might want to check out this article from Luminous Landscape:

http://www.luminous-landscape.com/tutorials/understanding-series/understandexposure.shtml

It might help put things into better perspective, especially if you need some pictures and actual examples/figures to help visualize things.

And yes, I too am skeptical about the 9-stop meaning (for the 1DMk2) as I said in the original thread. Would be a huge leap forward and make the 1DMk2 THE killer DSLR -- perhaps far more so than most anyone has thought prior to that "tidbit".

_Man_