RAW files noisy and blotchy

[cian]

Hi There,

 

I should post a picture here but havent the access through my computer

currently, but i have some pics taken very early morning at iso 400 and 800 on

a 350D RAW, and they are very very noisy and the colours are all blotchy,

unuseable! Any ideas what the problem may be??

I have tried opening them in various programs, bridge, iphoto.. so its

something in camera i'm guessing..

 

Thanks

[muirne81]

Please post pics when you can and we can better diagnose.

 

Noise is pretty commonplace in digital at higher ISOs. I would expect quite a bit of noise at 800. If your exposure wasn't spot on, the problem would only be compounded (correcting exposure, even in RAW is going to make it much more evident).

 

Have you shot at higher ISOs with this camera, without the problem occuring?

[cian]

Hi,

 

Yes i have shot at 1600 with much better results, different light and situation entirely but...

i'll try and post a pic.

thks for reply

[cian]

http://www.flickr.com/photo_zoom.gne?id=358933421&size=l

this is a jpeg copy, and its been much much improved from the raw version, but you can see

the colour blotchiness and the noise..

any clues?

[eugene_scherba]

Sometimes an underexposed shot at ISO 400 is noisier than a properly exposed shot at ISO 1600, so nothing unusual here. Make sure you "expose to the right" side of the histogram, and you should be fine.

[ronaldo_r]

Looking at your sample it appears quite typical for such a uniformly dark-lit scene... Would've been much better if there was a bright part somewhere, but here the whole scene is kind of underexposed, hence "noisy".

 

Question: is this the way it was exposed or did you adjust its "exposure" in RAW by increasing brightness? If so, try shooting "brighter" in-camera next time (search for "exposure to the right" techniques). I'd also use ISO 200 on a tripod for such static scenes.

 

Also, shooting ISO 1600 on a bright day will show a lot less "noise" than in darker conditions. Apples & oranges. I laugh when I see "look - no noise!" examples shot in bright sunlight. Of course it'll have little noise. Conversely, an underexposed ISO 100 shot can have awful noise. More light => less noise.

[cian]

Thanks for tips, yes it has been brought lighter very slightly with exposure, and a tripod is

going to have to be used nxt time..

[muirne81]

Just an experiment:

 

If you're going to go back out with a tripod, try lowering your ISO to the lowest possible (50, if you can, or 100 if that's as low as you can go) and shooting a longer exposure. If you go out during the "magic hour" -- dawn or dusk -- and lock your shutter open you'll get some beautiful mirroring from the movement in the water. The sky might pop a bit more for you too. Clouds will look lovely.

 

See this example (copyright Gary Shrimpling):

 

<a href="

[muirne81]

Sorry, that's:

 

[john_davids]

Or consider making your next lens an IS one. Shots you would have taken @ iso800 can now be done @100 with the same shutter and apeture with a 3 stop IS lens.