Canon 40 D, and noise at low iso ratings

[Bags]

I purchased a Canon 40D about 5 years ago and shortly after they discontinued this body. I find that this camera produces lots of noise at low ISO 100. can anyone help me with this? Was this possibly the reason the camera was shor lived? Help

[Donald]

I think the 40D was and remains one of the most highly regarded of the series of xxD Canon cameras. I've never ehard of it having a noise problem such as you describe.

Has this always been a problem? Have you ever had it checked by Canon or at one of its authorised service centres?

[rpcrowe]

I still use the 40D and, although I never shoot at exceptionally high ISO levels, I have never been troubled by noise at alower ISO.

Noise is often dependent on exposure with under-exposed areas showing the most noise. However, even so, shooting at the lowest ISO at which the camera can shoot - noise certainly should not be a problem.

I shoot at 400 quite often outside when I need a fast shutter speed and smaller f/stop and have had no problems.

I will not shy away from ISO 800 when I need it...

1/25 second, f/2.8 at ISO 800

[Squidgy]

I've had a 40D for a long time and have always had great pictures with no noise issues, especially at ISO100 - Why not post a few pictures so we can get a better idea of your problem.

[Tygart]

I still use the 40D and, although I never shoot at exceptionally high ISO levels, I have never been troubled by noise at alower ISO.

Noise is often dependent on exposure with under-exposed areas showing the most noise. However, even so, shooting at the lowest ISO at which the camera can shoot - noise certainly should not be a problem.

I shoot at 400 quite often outside when I need a fast shutter speed and smaller f/stop and have had no problems.

I will not shy away from ISO 800 when I need it...

1/25 second, f/2.8 at ISO 800

Thanks for the info I have trouble noise too.

Does a long exposure cause noise? For those underexposed areas that show noise, would shooting in RAW and correcting the exposure form there take it away or am I stuck with just the noise reduction software?

Also does aperture effect the visibility of noise?

[Donald]

Does a long exposure cause noise?

Yes, if you don't get the exposure right.

For those underexposed areas that show noise, would shooting in RAW and correcting the exposure form there take it away or am I stuck with just the noise reduction software?

There is no substitute for correct exposure at time of capture. The idea that you can capture at any setting and 'fix' it in post-processing is quite wrong. Ensuring proper exposure is one of the skills of photography and this is an example of why that is so important

Also does aperture effect the visibility of noise?

Not in itself. It's an element in the setting of exposure. So, to that extent, it does.

As Richard suggests, if there is a noise problem, the first thing to be checking is the exposure of the captures.

[Tygart]

Thanks Donald

I have a lot of practicing to do.

[Bags]

Thank you everyone for you helpful feed back. My noise issues are not constant, so I will experiment as I believe it may be my exposure deficiencies.

Bags

[Glenn NK]

Thank you everyone for you helpful feed back. My noise issues are not constant, so I will experiment as I believe it may be my exposure deficiencies.

Bags

I concur with the previous comments by Donald and Richard, and might add that a check of the histogram of your existing images may reveal the problem.

Don't know what post processing software you are using, but any decent one will have a histogram. And if the unprocessed histogram isn't close to the right, then the chance of noise rises considerably.

This does not imply that a well exposed image won't have noise - an example might be a bride and groom photo - if one exposes for the bride's dress (to capture detail), there is a good chance that the groom's dark suit will be problematic. I don't do wedding photography, but this is probably a good common example of balancing the range of light levels. Night photography is also difficult as frequently there will be a bright point source of light and the dynamic range will be too large to capture with one image (and noise will almost certainly be present).

Glenn

[Tygart]

Speaking of Histograms

Understanding Histograms Pt 1 & 2
https://www.cambridgeincolour.com/tu...istograms1.htm
https://www.cambridgeincolour.com/tu...istograms2.htm

I need to read this again.