M8: @ ISO 1250: DNG noisier than JPG

[arthury]

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Hello Everyone,,

 

At ISO 1250, if I shot it in DNG, the image is, at least, 10-20% noisier than when I shot it in JPG. Looks like the firmware's Noise Reduction(NR) cleaned up the noise quite a bit.

 

I use PS/CS2 ACR3.6 to process the DNG and looks like even cranking the Color NR and Luminence NR up did not help much.

 

How did you guys handle noise in DNG above ISO 640? Please throw in some light. What are your post-processing? Did you set up anything else on the camera?

[ptomsu]

Looks like the in camera NR for JPEG is not too bad :-))

[adan]

As you say, the combination of noise reduction and the anti-moire processing in jpegs knocks the noise down quite a bit (both are "blurring" functions). And also seem to even out the noise between the shadows and highlights. They do nibble away a bit of resolution, however.

 

.dngs have more obvious noise, but are a bit sharper.

 

As to processing in ACR, it varies some from shot to shot. I do different things when the lighting was really bad (sodium vapor or extreme tungsten) than I do for "daylight" or full-spectrum lighting.

 

I usually do NOT use ACRs luminance noise filter - it does more damage to the details than it does to the noise, and adds that "painterly" look that was so obnoxious with the Digilux 2 @ 400. I DO use the color NR. None for 160/320, about 25 points for 640, and about 50 for 1250/2500.

 

Under those nasty yellow lights I fiddle with the blue saturation (under calibration) to make the noisy blue channel blend better with the red and green, in color shots. I also often use the channel mixer in PSCS to remake the blue channel as 65% blue, %35 green - which transfers some of the clarity of the green channel to the messy, blotchy blue channel.

 

For B&W under tungsten: 1) don't try to white-balance the .dng - it just transfers blue noise into the green channel. 2) Simply turn down the saturation in ACR to zero, or open the shot "yellow" in PS/CS2 and use just the green channel, which is often substantially less noisy by itself.

 

For any residual little "flecks" in the shadows at 1250 or 2500 I run a "Dust and scratches" filter at pixel size 1, threshold from 35-60 as needed for the best balance of retained detail and speck removal.

 

This shot is 2500 with the 15mm Cosina (f/4.5) under halogen-like street lights, from .dng processed more or less as above. Except for a bit of yellow patchiness it looks, on average, about like scanned ISO 100 color neg film when printed. Surprised even me!

[adan]

Here's a 100% crop, since the small version both accentuates and hides the noise in different places.

[rosuna]

The best solution is Noise Ninja or Neat Image. These applications have specific profiles for each model of camera and ISO. You will reduce the noise lossing only a bit of sharpness.

[Riley]

is this a consistent issue

or just a few frames ?