Nikon Df - what is causing this effect?

<p>I have been on a photographic trip - which I really enjoyed - however some of my photos when edited in Lightroom (brightened) show a posterisation effect. I was using 14 Bit RAW, ISO 100.<br>

Is there any other setting I can make when taking photos that would reduce this effect?<br>

Thanks for any input - I am not sure what is causing this so am at a loss.</p><div></div>

<p>And a crop</p><div></div>

<p>You've got 16.2 MP. You can do a lot with that (I use a DF) but there is a point, in a tiny crop from a full frame, even at low iso, that is just going to show "grain". I was having similar frustrations with bird photos. My answer was using a longer lens or getting closer so that the subject becomes a larger scale presence in the image. Less enlargement is required, problem reduced / solved.</p>

<p>Complete guesses: The blocks look like the size of JPEG blocks, which suggests maybe some of the channels are saturating during output? Maybe you're running out of dynamic range in blue even if you're not in the other channels? If it's definitely there before you save the file to JPEG, I might ask if you're using "compressed" as opposed to "lossless compressed" raw - I'm not sure what Nikon's compression algorithm is, but I could believe this might be a corner case that's becoming visible. Good luck; I'll be interested to know what others have to say. If it was more clearly clipping then I'd suggest colour spaces might be relevant and that something in the input is running out of dynamic range, but the blockiness suggests something digital is happening.</p>

<p>Thanks Sandy and Andrew - and it was your comment Andrew that had me check everything again only to find that this one photo was a JPEG only - not RAW. So I was editing a lossy image. Now, since everything was shot as RAW this was a real one off and I don't know what happened. I can only say that instead of adjusting aperture I may have also pressed the QUAL button and adjusted the file type. Well I'm glad that's sorted - and just to prove it here is a crop of the processed RAW file - no posterisation.</p>

<p>Thanks for the help - it helped and made me look for something I would not have otherwise.</p><div></div>

<p>Yeah, I agree with Andrew. I've got a D4, which is the same sensor, and I've never had problems like that with RAW files.</p>

<p>Glad you got it sorted. That Df is a nice camera.</p>

Phew! Glad to help. :-)

<p>BUT while I'm glad you worked it out, there is a limit to resolution on any given camera. If you crop (blow up) any image far enough at some point you will encounter degradation of the image through pixelation, and many other perfectly normal technical processes.<br>

In film days, the limit was the grain (e.g., on Kodachrome 25, magnification in scanning above ca. 4000 ppi didn't make much sense.)<br>

For a 16.2-MP sensor, there are similar limits beyond which you do not gain any additional information.<br>

(BTW, if something like the Nikon Df had been available when I went to digital in 2005, I'd still be a Nikonista today. )</p>