Why does this photo look so noisy at ISO 400: http://img213.imageshack.us/img213/... ?

Question

Why does this photo look so noisy at ISO 400: http://img213.imageshack.us/img213/... ?

Answer 1

I realy like that picture! Did you take it? Good job! What do you mean noisy?This is not noise. These are JPEG artifacts that ruin this image. You took a 6 megapixel photograph and compressed it down to 315 kilobytes. What else could you expect? I am not sure if your camera compressed it this way, or you did that later with Photoshop (looks like you passed it through Photoshop before uploading). But since JPEG is a lossy format, it can compress files down to tremendously small sizes, but that will be at cost of quality. The way JPEG works, it doesn't save every individual pixel, but some reference points and methods to recreate the adjacent pixels. The higher the compression level, the fewer reference points will be saved, hence more chances of seeing things weren't in original picture (called artifacts). In particular, shots that have sky, water and similar objects are hard to compress. This file should have been at least 2-3 megabytes in size in order to preserve most details. Not 300KB!

Make sure your camera is set to lowest level of compression (fine, or whatever they call it), and when you photoshop do save it with compression level of 12 - that's the highest quality.

s****. Doo-

Answer 2

This is not noise. These are JPEG artifacts that ruin this image. You took a 6 megapixel photograph and compressed it down to 315 kilobytes. What else could you expect? I am not sure if your camera compressed it this way, or you did that later with Photoshop (looks like you passed it through Photoshop before uploading). But since JPEG is a lossy format, it can compress files down to tremendously small sizes, but that will be at cost of quality. The way JPEG works, it doesn't save every individual pixel, but some reference points and methods to recreate the adjacent pixels. The higher the compression level, the fewer reference points will be saved, hence more chances of seeing things weren't in original picture (called artifacts).  In particular, shots that have sky, water and similar objects are hard to compress. This file should have been at least 2-3 megabytes in size in order to preserve most details. Not 300KB!

Make sure your camera is set to lowest level of compression (fine, or whatever they call it), and when you photoshop do save it with compression level of 12 - that's the highest quality.

LEM.

NOTE TO s****. DOO:

Please remove my answer from your reply. This is called plagiarism and not only it is not nice, it is illegal under copyright laws.

Answer 3

I am not so sure that this is just jpeg artifacts.  A quick look in an editor shows that the exposure is off by about -1/3 of a stop. This would cause noise in the darker parts of the photo.  

Answer 4

That appears to be JPEG artifact, not sensor noise. The file that downloaded had about 72:1 compression, while my JPEGS typically run about 6:1. So I'd guess either you have your picture quality set too low or you have compressed the picture in postprocessing.