Jump to content

Noise philosophy?


Recommended Posts

Dear All,

 

We mostly know the perception of DX to FX equivalent in focal length and pixel size. Is there noise equivalent available?

 

We know bigger px. sensor produces less noise. But how much less, countable?

 

Your idea please.

 

Cheers,

Blurrist

Link to comment
Share on other sites

I guess it varies continually. In the sense that the technology keeps getting better, so today you for sure can get DX cameras with a lot better noise performance than older FX models. According to some (like e.g. Ken Rockwell) the ISO performance of today is so fantastic that you can forget all about using flash, because you'll never need it. I do not quite agree about that...
Link to comment
Share on other sites

  • 2 weeks later...
I guess it varies continually. In the sense that the technology keeps getting better, so today you for sure can get DX cameras with a lot better noise performance than older FX models. According to some (like e.g. Ken Rockwell) the ISO performance of today is so fantastic that you can forget all about using flash, because you'll never need it. I do not quite agree about that...

 

I think I 99.9% agree.

 

Before digital, I used mostly Ektachrome 100, and often flash for indoors.

 

With the D70s, I believe up to ISO 1600, I pretty much never used flash, except for unusually dark places, or unusually bad lighting.

 

I now have a (bought used) D700, which goes even higher, especially with the + (higher than indicated number) ISO.

I think I have never used flash with that one.

 

Film has an amazing amplification, where a few photons make a (on the atomic scale) large grain developable.

 

Digital doesn't have that built-in amplification.

 

There is a thermal noise limit, which depends on the sensor (absolute) temperature.

Cooled sensors will have a condensation problem, so are not normally used in cameras,

but often are for laboratory experimental systems.

-- glen

Link to comment
Share on other sites

Unless you are printing really big or doing heavy cropping sensor noise on newer cameras might as well not exist anyways. If it does chromatic noise is likely what you are seeing because it's pretty ugly.

 

There are plenty of times flash is desireable because ambient light, even though 'grain free' just isn't pleasing. I used to shoot wedding receptions and other informals with my 35mm Nikon gear and used a SB-16B which had the ability to bounce and fill flash at the same time with dead on exposure. With a 8-10' white ceiling I'll take those shots over straight ambient regardless of grain/noise anyday.

Link to comment
Share on other sites

From your comments, I would say there is relative noise to sensor size but it depends on technology which I suppose a so-called‎ algorithm conversion from analog signal to digital signal, less and less electron diffraction produced.‎

For me, I experience that high ISO noise made in highlight (for example to increase speed in shooting BIF daylight) is much more comfortable than lowlight (in the dusk, for instance). What is the root cause here?‎

Link to comment
Share on other sites

For me, I experience that high ISO noise made in highlight (for example to increase speed in shooting BIF daylight) is much more comfortable than lowlight (in the dusk, for instance). What is the root cause here?‎

 

I'd say that most likely your "lowlight" shots have unbalanced amounts of the three colors - reddish, greenish, and bluish light. (In daylight, each of these colors are roughly equal in strength, and a typical digital camera sees them as such.)

 

Try looking at the individual color channels of your low-light noisy images. I'd guess that you'll find that most of the noise is in one of the individual color channels. If you're under tungsten light, it will be the blue channel - the relative strength of the bluish light is only about 20% of what it would by in daylight, meaning that the blue amplifiers have to be turned up higher to counteract that.

  • Like 2
Link to comment
Share on other sites

I'd say that most likely your "lowlight" shots have unbalanced amounts of the three colors - reddish, greenish, and bluish light. (In daylight, each of these colors are roughly equal in strength, and a typical digital camera sees them as such.)

 

Try looking at the individual color channels of your low-light noisy images. I'd guess that you'll find that most of the noise is in one of the individual color channels. If you're under tungsten light, it will be the blue channel - the relative strength of the bluish light is only about 20% of what it would by in daylight, meaning that the blue amplifiers have to be turned up higher to counteract that.

Really informative comment. I think it will help me in future processing.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...