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03-31-2010, 02:26 PM   #1
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Highlight / Shaddow correction

Disclaimer: Newbie here and I have read the manual, searched the forums, read the suggested forums before starting this thread.

I have a K-x and I am trying to figure out/understand Highlight Correction vs Shadow correction and should they be used, how can the adversely affect the picture. Obviously highlight correction makes the bottom ISO 400 but if I turn on expanded sensitivity it restores that to 200. I guess the question in a nutshell is how do these three interact, what are recommendations on these settings, and what is the downfall to using them? Thanks

03-31-2010, 03:07 PM   #2
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Isn't the bottom ISO with highlight correction on 200, not 400? And it goes to 100 with it off and Expanded Sensitivity on?

I don't use it for various reasons, although I do have shadow adjustment on at the minimal level, which will overexpose those areas a little to bring them closer to correct mid-levels and they're not just dark mud.

From what I've read, and based on the ISO restrictions when Highlight Correction is on, I prefer to not let the camera do this processing.
03-31-2010, 07:02 PM   #3
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yes with expanded iso on the bottom iso is 100 and when you turn on Highlight correction the bottom becomes 200, but with expanded ISO turned off the bottom ISO is 200 and with Highlight correction on it goes to 400. I was looking for anyone who may be able to list pros and cons of the various configurations so I could understand the pluses and minus of using them
03-31-2010, 07:08 PM   #4
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One thing that confused me: The corrections also influence the RAW file, not just the jpeg. This almost scared me, because i always thought no settings whatsoever directly influence the RAW file.

It does work to some extent, but my question would be how this effect is achieved? Can i get the same results in an RAW processing programme? If not, then the correction would almost seem necessary to get that last bit of dynamic range out of the sensor.

03-31-2010, 07:36 PM   #5
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I also curious about this 2 functions. I on the highlight correction in my KX but did not activate shadow correction function. I am wondering if activating either of these functions will affect the pictures adversely in the sense that it will introduces more noise at higher ISOs?

If thats the case, should I just turn off highlight correction if the benefits that it gives isn't that significant?
03-31-2010, 09:31 PM   #6
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QuoteOriginally posted by LinXitoW Quote
One thing that confused me: The corrections also influence the RAW file, not just the jpeg. This almost scared me, because i always thought no settings whatsoever directly influence the RAW file.
Almost all settings affect the RAW *file*, because the camera always stores a list of the options you used in the EXIF information of the file. The RAW *image data* is not affected, however. But some programs that process RAW files may look at your settings and try to mimic their effect, so it might *appear* you image data was affected. Presumably that's what's happening here. Although since most of the dynmaic-range-extending features work by deliberately shooting underexposed then fudging the result using curves, most programs probably won't be able to mimic the effect of this particular option and will instead simply show you the underexposed image.

QuoteQuote:
Can i get the same results in an RAW processing programme?
Yes, with more control over the results.
04-01-2010, 04:36 AM   #7
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QuoteOriginally posted by aaronius Quote
I also curious about this 2 functions. I on the highlight correction in my KX but did not activate shadow correction function. I am wondering if activating either of these functions will affect the pictures adversely in the sense that it will introduces more noise at higher ISOs?

If thats the case, should I just turn off highlight correction if the benefits that it gives isn't that significant?
I have it off because it can really clip your highlights with a bright background.
04-01-2010, 04:54 AM   #8
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QuoteOriginally posted by bbullins Quote
Disclaimer: Newbie here and I have read the manual, searched the forums, read the suggested forums before starting this thread.

I have a K-x and I am trying to figure out/understand Highlight Correction vs Shadow correction and should they be used, how can the adversely affect the picture. Obviously highlight correction makes the bottom ISO 400 but if I turn on expanded sensitivity it restores that to 200. I guess the question in a nutshell is how do these three interact, what are recommendations on these settings, and what is the downfall to using them? Thanks
Aside from the limiting of ISO, what the highlight and shadow correction do is modify (for JPEG only) the range of exposure similar to contrast adjustment but much more drastic

I did a test on my K7 just to see what would happen.

In a nutshell, normal contrast adjustment works as follows.

Neutral contrast results in an image where between about 25 grey scale and 225 grey scale each stop (Exposure value) increment has a change of about 45 greyscale.

In high contrast this changes to 50 and in low contrast this changes to 40.

In effect, the difference between high and low contrast is about 1 additional stop of dynamic range in the middle of the greyscale range.

Shadow and highlight correction work in a similar way, but each is applied only to the range either above 128 or below 128 greyscale. each adds at least 1 additional stop in the linear portion of the greyscale range either below or above the mid point, therefore if you have both selected, you may get as much as 7 stops between 25 and 225 greyscale.

the cost of this is that each stop in the middle has coarser increments in greyscale since at the end of the day you are still keeping the same 8 bit color in JPEG.

04-01-2010, 06:02 AM   #9
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I haven't played with shadow correction yet, but I have used highlight correction to shoot a sunny landscape, and it was almost as effective as a polarizing filter for preserving the nice blue sky and detail in the clouds. I could not see any downside, so I intend to keep using it for this purpose. I understand it is not a good idea to leave this feature on all the time because it can boost noise at higher ISO's, but used judiciously it's great IME.

I haven't tried shadow correction. I understand it works the same way as highlight correction, except that it laterally compresses the light spectrum on the left side of the histogram, therefore you would use it in conjunction with highlight correction when you have bright skies and dark forest for example. Are there times when you would use shadow but not highlight correction? Maybe a shot of a tree with bright green leaves and very dark bark, where there's no bright sky in the photo?

Last edited by audiobomber; 04-01-2010 at 12:23 PM.
04-01-2010, 12:15 PM   #10
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Thanks, some very helpful answers
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