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View Full Version : Help - what's the problem here?


minnesotamom
Apr-22-2008, 08:15 PM
Recently, my photos have been coming out with something that looks like noise in the shadows (even at 100 ISO) but isn't across the entire photo. Anyone experienced this before or have any idea if my sensor might be going bad? Thanks for any help!



ISO 100
1/160 at f/4.0
Canon 300D
70-200mm f4L
tripod

ziggy53
Apr-22-2008, 08:24 PM
Did you have to increase the Exposure or Brightness or Levels in CS2/ACR?

minnesotamom
Apr-22-2008, 08:26 PM
Yep. I increased exposure and brightness a little bit. Is that bad?

Seymore
Apr-22-2008, 08:42 PM
Well, I would suggest you get a print of this good shot and I suspect you'll not even see the "noise" or worry about it. :thumb

Let us know if the print shows this... :wink

ziggy53
Apr-22-2008, 08:44 PM
Yep. I increased exposure and brightness a little bit. Is that bad?

It's not "bad" but it does tend to increase visible noise, especially in shadow areas. You might try increasing the ISO instead of pushing the exposure and brightness.

A good noise reduction software can reduce the problem with little reduction on overall sharpness or detail.

Tee Why
Apr-22-2008, 11:34 PM
If you underexpose a shot and try to increase brightness in post processing you will always get chroma noise (color noise) from the shadows.

You can use noise reduction to reduce the noise, but proper exposure will ensure minimal noise levels.

minnesotamom
May-02-2008, 10:16 AM
Thanks for the tips everyone.

Tee Why - I guess that means that with my camera I might want to over-expose? I shot in manual and according to the little toggle button in my viewfinder my exposure was dead center. If I had over-exposed, would that have given me the look I wanted?

Thanks again for your help!

ziggy53
May-02-2008, 10:41 AM
Thanks for the tips everyone.

Tee Why - I guess that means that with my camera I might want to over-expose? I shot in manual and according to the little toggle button in my viewfinder my exposure was dead center. If I had over-exposed, would that have given me the look I wanted?

Thanks again for your help!

The exposure information in the viewfinder can only estimate the exposure, depending on the mode.

Look at the histogram and the highlight "blinkies" to try to get your exposure somewhat "to the right" in the histogram without too many blown highlights.

A pretty good explanation here:

http://www.luminous-landscape.com/tutorials/expose-right.shtml

PS, I wouldn't call this technique "overexposure" because that implies information is lost in the highlights. Let's call it "high exposure" instead.

JGD
May-08-2008, 12:02 PM
Thanks for the tips everyone.

Tee Why - I guess that means that with my camera I might want to over-expose? I shot in manual and according to the little toggle button in my viewfinder my exposure was dead center. If I had over-exposed, would that have given me the look I wanted?

Thanks again for your help!

This is why the use of a hand held light meter is prefered to using an "in camera" light meter.

It's not that you need to overexpose your shot. It's that the light meter in your camera is easily fooled into underexposure.

Use the histogram after the shot is taken to take note of what it looks like and then what you have to do to "fix it". A little experience and you will get the hang of it.

The best thing about digital is the ability to take many exposures with different settings. With the EXIF info available it becomes a piece of cake to get the hang of your metering.

There is a great book called "The Hand Exposure Meter Book" by Jim Zuckerman et al.
it is published by the Photo books division of Mamiya America Corp. 8 Westchester Plaza Elmsford, NY 10523

This book really tells it like it is as far as exposure is concerned.

I have no connection with this book, it's just in my libary.

jim

swintonphoto
May-08-2008, 07:41 PM
Well, I would suggest you get a print of this good shot and I suspect you'll not even see the "noise" or worry about it. :thumb


:agree