[matt34 (Matt)]

Originally Posted by ourkind

Hi Matt,

in my opinion the first of the 4 images looks best, the large single image whilst the noise reduction is effective it seems as though some of the stars on the top right half are suffering chromatic aberration.

I use the "Noise Reduction on long exposures" setting on my camera, then in Photoshop RAW I apply "lens correction" and "luminance" approx 20%. Afterwards if image still appears grainy I will sharpen and guassian blur.

Carlos thanks for your thought/opinion, I think with the current lens (24mm f1.4 II that CA is tough to deal with in the corners when the lens is wide open even stopped down to f2.0 isn't enough)

Do you know much about how the in camera noise reduction works? I played with it a couple of years ago But should do "new testing" my understanding was that it takes a dark frame and subtracts the noise from the image frame, my questions around that are does it save that to the RAW? Does the camera do it the a jpg version? will the "subtraction" only be done in the cameras only RAW reader (like canon's DPP)
I think I remember it didn't seem to do alot to the shots I was processing but that could have been the RAW viewer. Time for another test

Originally Posted by gregbradley

Long exposure noise reduction only. If there is any residual noise I use Adobe Lightroom as its noise reduction is fantastically efficient and does not damage the rest of the image much.

Ideally none. All noise reduction seems to damage the fine stars to some degree. Sometimes I use Noise Ninja plug in which is like selective noise reduction in that it only smooths dim noisy areas and leaves bright less noisy areas alone.

Greg.

Thanks Greg, do you know how the in camera NR works? I've heard Noise Ninja is good.

Originally Posted by philiphart

Love a good test. Nice work.

The first two images have dark halos around the stars which I would be trying to avoid.. the de-fringing has been taken too far with those settings.

I would be really interested to see the Digital Lens Optimisation applied to corners of an image where the star shapes are not 'stars' anymore and see if it can improve those.

Phil

Hi Phil

I hadn't spotted the halo's until you mentioned it. Ill look out for that in processing in future. I'll have to look at the default DPP settings to see if the haloing exists. I'll also grab the DLO shots of the corners to compare to see if it helps the stars look more like stars. More test data to come, I just have to recover from a PC crash first


I also like the more colour in the stars in the last 2 shots, not sure if thats the Lightroom processing or how the stars looked, but it seems the higher DPP processing removed some of the orange/pinky colour in some of the bigger stars.