Where does noise come from in my workflow?

[Bend The Light]

I sometimes have problems with noisy images, and I can't quite get to the bottom of it. So, this is what I might do with a typical picture...where might noise be creeping in...where might I be better doing something else?

Shoot at ISO 100 wherever possible, try to have good light.
Copy RAW files into Bridge...sort through good and bad, and delete the bad.
Open an image in Adobe RAW...
Check for burnt out, or blocked up blacks on the histogram...adjust exposure, recovery if burnt out, slight increase in clarity. Tend to leave all other bits alone...
Open image in Photoshop.
May do a curves adjustment (on adjustment layer) if necessary, nothing fancy...S-curve mainly. May adjust saturation (again, on adjustment layer).
Usually add sharpening with unsharp mask, typically radius is around 1 max. Slide up until it looks ok, but not oversharp.
Crop to 10in x 8in x 300ppi.
Save as PSC and then as JPEG, quality 12.

Anyhting in there a problem, you think?
I wonder about cropping...if I crop to 10in x 8in 300ppi, am I adding pixels, or deleting some? If I crop with nothing in the size boxes I will get non-standard crop sizes, but will I then not be extrapolating pixels, or something?

I welcome all ideas to avoid noise in PP.

Thanks

 

[Overread]

Noise typically comes from or is shown up more so by a few thigns:

1) Underexposure - any areas in your photo that are underexposed will naturally have a more noisy appearance than those that are well exposde. I should also point out that it is not essential with every photo to have every point correctly exposde - many photos and scenes will have naturally shadowed and darker areas.

2) Adding light to underexposed areas - boosting the exposure in editing - adding light to the shadows and selective brightening as well as adjustments to the Curves and Levels. All these can brighten dark areas in a photo and when done, will show up that noise which is present there.

3) Boosting contrast - increasing the contrast can help give present noise a more defined appearance. This combined with increasing the saturation can also lead to banding (esp in background areas) when taken too far.


In the end I suspect that your curves and increasing of the exposure in editing are both contributing to the increase in noise that you are seeing in your photos. I would encourage you to keep an eye on your exposure as if you correctly expose a photo at a higher ISO you'll have less noise than if you incorrectly expose at a lower ISO and then boost up the lighting in editing.

 

[Bend The Light]

Thanks, Overread for that informative response. I will bear those things in mind and endeavour to get it righht in camera...I think there is a tendency to not have blocked in blacks, or blown whites but they could be present and make the photo work. So I can ease off on the adjustments in some cases...

Cheers

 

[Bend The Light]

Well, here's an image that people have said is noisy...


jumping spider 1 by http://bendthelight.me.uk, on Flickr

And the RAW is hosted here...

_MG_8811.CR2

If anyone wants to have a go and process this anyway they like, THEY CAN. Any help in my processing would be appreciated.

 

[Edsport]

This is your jpg and i used neat image on it. Incase you didn't realize, you shot this at ISO 400.

This is the raw without any noise removal. You are adding noise somewhere because this isn't as noisy as yours...

 

[Bend The Light]

Thanks, EWdsport.

Yes, I was aware of the ISO 400...I was trying to raise the shutter speed...this guy was tiny, about 5mm long, and halfway up a wall. I was shooting manual with a vivitar 90mm macro lens (hence the f1.8 in the EXIF...I didn't shoot at 1.8, that's what it shows). I was struggling to get a well lit shot (no flash with me...on board flash doesn't clear the end of the lens in 1:1 macro mode...leaves a semicircular shadow),.

All in all, tricky to shoot...

I don't think the 400d works so well at ISo above the basic 100, 200. Shame really.

 

[Overread]

You should be able to get ISO 400 very usable from the 400D - at ISO 800 things do dip down more noticeably