D7100 'streaking'

Started Apr 7, 2013 | Discussions thread
_sem_
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Re: Streaking = Smart IQ
In reply to mosswings, Apr 13, 2013

mosswings wrote:

_sem_ wrote:

mosswings wrote:

_sem_, Andrea Dawn's sunset rock shot (dsc0066.nef) is probably not a good candidate for this discussion.  There is a sun-aligned lightening of the shadowed rocks on the left, but it appears to be part of a constellation of sun rays and possibly a lens flare. I count at least 13 rays at all angles. The line artifacts seen there appear to be nothing more than regular deep shadow banding.

I'm afraid it is a candidate. Not as a most obvious example to examine the phenomenon, but as one that shows it may matter in real life for HDR-like processing of sunsets. For instance, if one'd want to make a bright image and light up the rock on the left: open in LR4.4, set Highlights -100, Exposure +3, Shadows +50 (push Shadows and Blacks further to make it more obvious). Streaking is noticeable in the upper half of the rock (practically the whole upper half). There is the sunstar and some lens flare but I don't think it these can be confused if you look in the leftmost third of the image (away from the sun). There is regular banding in the lower half of the rock. I guess 'streaking' may become noticeable in practice, when pushing shadows heavily, a stop or two earlier than regular banding. In other words, not really much more pushing possible than with the D90 when it occurs.

I can see where the horizontal ray of the sun star appears stronger and of longer extent than the others, but I notice that the rays leading towards the lower left of the image are almost as strong. Certainly when you back off and look at the entire image with this heavy processing, the horizontal ray stands out - but I don't see a effect that extends any further than the most intense region of the sun disk. Still, streaking could very well be present underneath all the other stuff.

I'd kindly ask you to look again and closer. Look at the banding pattern in the lifted rock at the left of the image, where the sun rays are no longer strong. Notice there is an "edge" in the banding pattern; "regular" banding below and more intense banding or "streaking" above it. The edge is in the horizontal level of the sea and sun reflections in it. I think it is less pronounced than in the window samples, but enough to state that this isn't uniform banding.

If we think about your statement a bit it would suggest that D7100 images really can't be pushed much at all...perhaps 1 stop for ISO 100. ...

I didn't say that at all. Banding shows up evident when pushing 6 or 7 stops, streaking a stop or two less than that.

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