New to RAW - noise question

[crockny]

I shot some evening pictures at 800 with sky, moon and clouds ... I seem to have a lot of noise and am wondering if RAW gives you even more noise than jpgs? Yes I know 800 is high but didn't have a choice ...



Canon EOS DIGITAL REBEL XSi
Exposure 0.01 sec (1/100)
Aperture f/5.0
Focal Length 91 mm
ISO Speed 800

[RLucas]

Unfortunately, I can't see the pic in question( work filter), but as a general rule, if you are looking at a RAW image in the converter, depending on what the defaults are, you will see more noise. This is because you are looking at the image before any in camera adjustments are made. When shooting RAW you have to make these adjustments yourself, including noise reduction. You can minimize the noise effect while shooting some times by slightly overexposing,and pulling the exposure back in post. Then you can use less post noise reduction which increases softness in the image. It's a nice little balancing act, but once you get it, it will be easier to manage.

[crockny]

So you can overexpose in RAW and unlike a jpeg the data is still there to recover?

[RecurrentNerve]

Not exactly. It's more of a signal-to-noise ratio thing. Have a look at this, pretty much explains it all.

[RLucas]

Originally Posted by RecurrentNerve

Not exactly. It's more of a signal-to-noise ratio thing. Have a look at this, pretty much explains it all.

Great article! The "try to avoid clipping at all costs" thing I don't necessarily agree with, but still a good read!
Thanks.

[RecurrentNerve]

First one that came up on Google when I entered 'Overexposing RAW'.

Crockny, remember you can set your camera (I assume, my D5000 allows it) to take both a RAW and a JPEG simultaneously. It uses more space but if you're not confident with reducing the noise yourself you have the best of both worlds.

[crockny]

Tried that - can't stand the lag ... I'm playing with RAW when I have time to spare and shoot jpeg when I need fast results ... will check out that video ...

[teaking]

A lot of RAW shooters use the expose to the right rule, which pretty much means they push the exposure as if you were over exposing but they try not to clip highlights (using an RGB histogram is better as individual channels may clip but may not be apparant on a value histogram) The idea is that more detail is captured in the highlights than the shadows. The draw back is in any format blown out pixels are dead pixels you can use saturation masks to make it less obvious although blown out hightlights are not always un welcomed they can work well.

[AdrenoJunkie]

Ok, from my simplistic amateur point of view, seems like the best solution would be (if you plan on taking these kind of shots regularly) to invest in a tripod. Then you could drop your shutter speed down, which means you could lower your ISO, thus reducing noise. I have that same camera and I also get alot of noise when shooting at that high of an ISO.

[teaking]

An high ISO will increase noise and lowering it will reduce noise, how ever the amount of noise in a RAW file compared to a JPEG file will usualy appear higher as stated by "RLucas" earlier, when processing RAW files noise reduction is left to the user in most cases where as in JPEG noise reduction can be applied by the camera