digital iso's

[corkymiller]

Why is all the emphasis on higher and higher iso's but no one offers lower and lower iso's for very bright situations?

 

[IgsEMT]

NOT ALL

 

[KmH]

Film has grain.

Digital has image noise.

In general and assuming a correct exposure, digital image noise at ISO 100 is less noticable than the grain in ISO 100 film.

Additionally exposure is approached differently with digital than it is with film.
Film is exposed for the shadows and the highlights take care of themselves.
Digital is exposed for the highlights and the shadows take care of themselves.

 

[480sparky]

I, for one, miss the 'old days' of slow film. RIP, Kodachrome 25.

 

[Overread]

I suspect the pressure for higher and higher ISOs is because a large number of people in the industry are working in darker conditions in need of good shutter speeds - sports, journalists, wedding photographers etc... Thus there is more market demand for more sensitive sensors and better, clean high ISO (plus marketing pressure also helps increase the perceived demand).

Plus you can use filters to block out light so for those after slower shutter speeds or working in brighter conditions there is the option to use ND filters.

 

[Garbz]

It's a conspiracy to boost money to filter manufacturers.


No the real reason is simple. Attaining a higher ISO is a technical marvel involving loads and loads of research and millions of R&D dollars to allow people to use cameras in low light scenarios which they otherwise would not be able to use.

Where as attaining low shutterspeeds in bright lights is solved quite simply with a ND filter on the lens as it has been for the past 60 years, a $50 expense for those who want it.

 

[EchoingWhisper]

Is it more expensive to make cameras less sensitive to light or is it more expensive to make cameras more sensitive to light?

 

[chaosrealm93]

i guess its cuz people see the camera as more important than the lens. more people will rave over how many megapixels and how high the iso can go to for a camera and spending their money that way instead of getting good glass for hundreds and thousands. maybe the lens has less appeal to them..

 

[Trever1t]

not at all and that's quite silly.

It's plainly simple to make the allow less light to reach the sensor but immensely difficult to do the opposite eh? Even with the best glass there are time when there's just not enough light to get the speed you need.

 

[EchoingWhisper]

If an image's quality degrades when ISO is increased (because of digital noise), will an image's quality degrade too when ISO is decreased? I have always heard that lower ISO often mean lower amount of digital noise, but will other artifacts be introduced?

 

[Josh66]

If an image's quality degrades when ISO is increased (because of digital noise), will an image's quality degrade too when ISO is decreased? I have always heard that lower ISO often mean lower amount of digital noise, but will other artifacts be introduced?

Any time you deviate (up or down) from the native ISO of the sensor (usually either 100 or 200), you're going to be adding noise. How much noise depends. Cameras are getting better with every release, so the acceptable noise level is getting farther and farther from the native ISO.


edit
The same is true with film. Pushing (under exposing, over developing) or pulling (over exposing, under developing) film will alter the grain and contrast.

 

[Garbz]

Is it more expensive to make cameras less sensitive to light or is it more expensive to make cameras more sensitive to light?

Define expense. As mentioned earlier light can be cut by something as simple as a ND filter on the sensor. But also it's much easier to make a sensor that is less sensitive to light. The issue with that is quality. Typically cameras with high sensitivity (D700 for instance) end up having truly astounding dynamic range at ISO100. My point and shoot however goes to ISO80 and the image quality is balls.

If an image's quality degrades when ISO is increased (because of digital noise), will an image's quality degrade too when ISO is decreased? I have always heard that lower ISO often mean lower amount of digital noise, but will other artifacts be introduced?

Camera sensors have a base ISO where the sensor extracts the maximum amount of dynamic range. This is usually the lowest ISO setting, however as the base ISO has crept up to 200 some manufacturers have added settings to make the sensor appear less sensitive. This results in a reduction of dynamic range. Nikon call this "Lo" ISO, not sure if other manufacturer's have something similar.

 

[c.cloudwalker]

The emphasis on higher ISO comes from the average camera buyer who doesn't really want to learn photography. Flash is scary to some people, complicated as hell, so a higher ISO quality let's you avoid learning how to use a flash.

I have heard the world is getting warmer but not that it is getting darker. Reading some people who have never known anything but digital, I really wonder how in hell we managed to get usable photos back in the days of film.

 

[Garbz]

I really wonder how in hell we managed to get usable photos back in the days of film.

I disagree. In film we had those as well, I loved Ilford Delta3200 for the ability to shoot in low light situations. It's not so much a fear of flash but an expanse of what we are now capable from. Sure you can make your own light, but some times the light that is already there is what we wish to capture and goddamn the fact that I left my tripod at home. The fact that it's easier is just a coincidence to the fact that many people want to capture what they see rather than create something they can't (my opinion anyway)

 

[Neil S.]

Camera sensors have a base ISO where the sensor extracts the maximum amount of dynamic range. This is usually the lowest ISO setting, however as the base ISO has crept up to 200 some manufacturers have added settings to make the sensor appear less sensitive. This results in a reduction of dynamic range. Nikon call this "Lo" ISO, not sure if other manufacturer's have something similar.

This.

They cant just make ISO lower and lower, as they are doing with higher ISO.

The reason is because it is "base ISO" meaning that it is the "native ISO" of the sensor, and produces the finest image quality possible. The problem is that as conditions darken, you will reach the limit of your lenses ability to gather the necessary light. This is where raising the ISO comes in, which allows for proper exposure.