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06-12-2010, 03:46 PM   #1
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K-7 ISO3200 Advanced NR Case Study

I'd like to thank ASammet from the community for taking the time to take this image(along with others) and submitting them for none other than to help.
So a big thanks to you my friend for caring enough to follow through.


~

Before I begin, I'd like to say that the following image was underexposed by 1.45 stops. Which really works against us with regards to image noise. Therefore... I was not able to draw a solid conclusion as to how the K-7 performs at ISO3200 with this sample alone. Though I will say, that the K-7 does exhibit noise characteristics that make it a little more challenging to work with than it's predecessor. Which I beleive plays a part in many of the reasons people tend to hold back from shooting at such levels.

The good news however... is that the K-7 can be managed to produce full size images(as can be seen here) without compromising on color or detail. However, doing so, does call on a level of expertise with respect to image noise and the NR methods applicable in doing so.

The following image was taken with a K-7 at ISO3200(f/4.5 1/60) with a deficiency of an -1.45 underexposure. Which resulted in what I would call premature low frequency noise patterns(color blotching). Which is quite possibly one of the most difficult noise types to manage within a scene or image. Which is why I classified this image as a 8/10 on the difficulty side of things. IOW. it required a few extra steps over that of a properly exposed image.

META: K-7, ISO3200, 1/60, f/4.5
WORKFLOW: ACR 6.2, CS5, Dfine, Topaz Denoise 4.1
NOTABLE: - 1.45 EV
DIFFICULTY: 8/10
OUTPUT: 1:1
IMAGE COURTESY OF: ASammet

Click on the image to view it in a larger size




ASammet provided me with four ISO3200 samples to work with, and so I am happy to report that this one was the most challenging ones of the set. The other three range from "very good" to "excellent", and so I look forward to publishing them shortly.
Thanks for looking and keep shooting!

...the end


Last edited by JohnBee; 06-12-2010 at 05:54 PM.
06-12-2010, 11:11 PM   #2
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With respect to Asammet's contributions, here is the second sample of this set. Plenty of shadow regions and DR demands in this scene.

META: K-7, ISO3200, 1/1600, f/10
WORKFLOW: ACR 6.2, CS5, Dfine, Topaz Denoise 4.1
DIFFICULTY: 8/10
OUTPUT: 1:1
IMAGE COURTESY OF: ASammet

Right click > view image to see full size preview



...the end
06-17-2010, 07:04 PM   #3
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Thats some incredible noise correction work... most impressive! Have you defined work flow parameters for this process? and are you willing to share?
06-18-2010, 01:02 AM   #4
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QuoteOriginally posted by ivoire Quote
Thats some incredible noise correction work... most impressive! Have you defined work flow parameters for this process? and are you willing to share?
Thanks very much(you are most encouraging).
The answer to your question is "absolutely" I've been working on a video tutorial of the workflow(with these images) and I plan on posting the results here.

However, I've had allergies lately and the last time I tried to record a chapter, I sounded really weird due to the nasal congestion(lol). So imagine for a moment that we already find out own voice uncofort5able and multiply that by a factor of 10x

Anyways, the allergies are clearing up and I will be back at it soon. Hopefully it will be ready for viewing over the weekend.

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