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09-16-2012, 11:01 PM   #181
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QuoteOriginally posted by rawr Quote
Thanks. It was an interesting exercise.
In this regard I like how PDCU lets me, just with a right-click, copy and paste the correction settings from image to image. So where a sequence of shots share the same lighting, it lets me quickly apply the same WB and other corrections. I need to learn how to do this in LR and the other tools.
you do realize how long it took me to figure all this out?
you managed it in less than 1 day and could process a severely magenta mono-colored photo with three separate processors in probably just a few minutes - and I showed it can even be done on the jpg in less than 5 mins -
and you're still not .......?

09-16-2012, 11:15 PM   #182
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LOL. Thanks. Being a bit familiar with PDCU and C1 Express was useful.

Now I have a pile of shots from Friday night's show under horror LED's to fix up. Ugh...
09-16-2012, 11:19 PM   #183
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QuoteOriginally posted by rawr Quote
Now I have a pile of shots from Friday night's show under horror LED's to fix up. Ugh...
But at least you now know how to deal with them -
and wait til you show everyone your before and after results!

... anyway, if photography were that easy -
everyone would be a master photographer.
09-23-2012, 03:32 PM   #184
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Last night at a larger venue with good stage lighting I took what I thought was an attractive photo in terms of lighting and color:

original resize only (EXIF attached)


that is until I tried to do some brightness and contrast adjustment -
then the magenta lighting on the face blew out losing the details -

it's not just a JPG/sub-sampling issue -
basically the original is close to fully saturated in blue and red -
so any adjustment toward brighter blows them out and flattens the area.

I like the brightness of the edited version - but the color and detail in the original.

Using my standard rescue technique -
I got rid of a lot of the magenta by using the gray-point in PDCU to get this:


Then after the various brightness/contrast adjustments - I re-added back some of the magenta -


10-12-2012, 08:55 AM   #185
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As you know, I shoot shows regularly and by mistake I found a good solution. I shot The Smashing Pumpkins two days ago using "Muted" color space and it worked really well. Once my editor publishes the photos I'll share my results. It worked really great under really difficult lighting conditions.
10-12-2012, 09:02 AM   #186
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QuoteOriginally posted by john5100 Quote
As you know, I shoot shows regularly and by mistake I found a good solution. I shot The Smashing Pumpkins two days ago using "Muted" color space and it worked really well. Once my editor publishes the photos I'll share my results. It worked really great under really difficult lighting conditions.
Sounds really promising.
Really look forward to seeing the results -
do you have any "before" type pics to compare, please?
- ie: shot with regular/normal color setting - like the default bright or natural setting?

Thanks!

PS - just some speculation on why this may work.

A lot of the times the color washes are very to over-saturated - so switching to Muted Color setting would help reduce the saturation.

However, would this be effective in RAW?

EDIT to ADD -
I figured that I may be able to "simulate" this setting -
checked PDCU (Pentax Digital Camera Utility) to see if the camera color settings were available
and found they were under the upper (right) Custom Image tab - there a drop-down menu with the default Camera Setting - and all the color settings are available including Muted:

I've highlighted the Muted in red.

Using the problematical magenta shot:


RAW/DNG using Muted in PDCU -


JPG using Muted in PDCU -

all shots have EXIF attached.

Works for both RAW/DNG and JPG,
and does seem pretty effective!

But please remember this is only a simulation of what the camera may do.
BUT it also shows Post-processing possibilities are open -
not just for RAW, but for JPG as well.

Last edited by UnknownVT; 10-12-2012 at 10:14 AM.
10-12-2012, 09:56 AM   #187
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This thread continues to be a source of very handy information.
Muted certainly seems worth a try.
01-07-2013, 10:01 PM   #188
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I recently got a K-5 - however LED lighting is still very much a problem - especially if a lot of magenta is used -
unfortunately it is very popular - and I tend to agree that it is kind of attractive to the eyes -

However if AWB is used occasionally one gets an extreme balanced shot like this I took yesterday:
Original resized only EXIF attached:


The way I mitigated this shot was to use Pentax DCU
and a single gray-point on the microphone for the accordion player -
to get this:

to me this is a jaw-dropping result from the original rendering

I then did my normal post processing, but added back magenta to convey the impression of what I saw.
after the post processing -


However mostly it wasn't as bad as that shot -
original resized only with EXIF attached:


result after pp:

not so different - merely lessened the magenta cast.

05-08-2013, 01:09 PM   #189
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I posted this in my other thread: K-5 in Use ( 1 2 3 ... Last Page)
but realized it's much more relevant in this old thread -
so for completeness I'll copy and paste the relevant bits here:

I use a compact camera a lot in smaller clubs - but for low available light I much prefer using my dSLR the K-5 (and previously for the past 3 years the K-x).
For backup I usually carry my compact - often I will take shots with the compact as well just to compare.

Over this weekend I took pics of a jazz band in a fairly low light venue - but the difference was mixed lighting - not just different colors but incandescent and LED.

K-5 shot (EXIF attached)


Compare to a similar shot taken on a compact (Canon G15) - EXIF attached -


Note the difference between the details of the pianist in the center of the pictures -
how the magenta (LED) light plays havoc with the K-5 shot.

details 100% crops (EXIF attached)
K-5


Canon G15


Normally for available light (no flash) shots my choice is the K-5 - because I prefer its rendition and HighISO performance.

This one case because of the mixed lighting the results of the more humble compact was a lot more preferable, to me.

I've pondered this "magenta problem" for quite some time (I started this thread over 3 years ago)
I think I may have stumbled on an explanation of sorts.

The hint was a while back in Post #185 in this thread - in using "Muted Color".

This would suggest that Pentax dSLRs (at least K-5 and K-x) tend to over saturate some of the colors to cause some of this LED magenta problem (ie: red and blue)
most of the time this is not a problem under more natural lighting - as this would tend to avoid any sickly greenish tint to flesh tones etc.
in fact, I would go as far to say the K-5 and (previously the K-x) have given me some of the very best renditions at the low light jazz club using just AWB (and subtle setting) -
for lots of samples please see K-5 in Use ( 1 2 3 ... Last Page) and for 3 years' worth in Kx in Use ( 1 2 3 ... Last Page)

How do I illustrate this?

Actually I found a possible example at dpReview's comparison studio test images -
in that shot is a test chart of graduated colored panels without any separators
I selected the bottom right corner where the magenta patches were -
I used ISO3200 as that is better but close to the normal ISO I shoot at
but for the Canon G15 compact I used ISO800 as that has a much faster lens at f/1.8, which allows me to shoot at 2 stops lower sensitivity.
(Just for completeness I chose the closest Canon and Nikon dSLRs to compare at the same ISO3200)



Looking at the 100% crop patches one can see how the lowest right most two patches almost merge on the K-5 sample - and the colors are more saturated -
whereas the Canon G15 patches are quite distinct - despite being a tiny sensor in comparison -
Notice how much more saturated the K-5 patches are -
look at the next row up see how much deeper and more saturated those patches are compared to any of the other cameras.

My take is that Pentax dSLRs (at least the K-5 and K-x) tend to saturate images - and that probably aggravates the LED/magenta problem -
but most of the time this is not a problem as it does give us nice rich colors - and most of my shots are very pleasing to me.
05-09-2013, 08:45 AM   #190
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QuoteOriginally posted by UnknownVT Quote
Looking at the 100% crop patches one can see how the lowest right most two patches almost merge on the K-5 sample - and the colors are more saturated -
whereas the Canon G15 patches are quite distinct - despite being a tiny sensor in comparison -
Notice how much more saturated the K-5 patches are -
look at the next row up see how much deeper and more saturated those patches are compared to any of the other cameras.

My take is that Pentax dSLRs (at least the K-5 and K-x) tend to saturate images - and that probably aggravates the LED/magenta problem -
but most of the time this is not a problem as it does give us nice rich colors - and most of my shots are very pleasing to me.
Your findings seem to be quite right. But comparing JPGs always leaves the issue of the in-camera preferences choosen. We have a fairly wide range for adjusting presets to our liking (and most people will simply leave the factory presets) and this would influence the saturation very much. So, I guess, if adjusting saturation and contrast to lower values, the K5 should cope better with these colour patches.

Ben
05-09-2013, 09:19 AM   #191
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QuoteOriginally posted by Ben_Edict Quote
Your findings seem to be quite right. But comparing JPGs always leaves the issue of the in-camera preferences choosen. We have a fairly wide range for adjusting presets to our liking (and most people will simply leave the factory presets) and this would influence the saturation very much. So, I guess, if adjusting saturation and contrast to lower values, the K5 should cope better with these colour patches.
Thanks for your confirmation Ben.

I agree that our cameras allow a myriad of settings possibilities and the default setting on the K-5 is Bright Color - which does indeed over-saturate colors (Pentax are known for this on Bright Color).
I have my K-5 (and previously K-x) set on Natural Color - but that still has severe LED magenta (as well as red and blue) problems.

The hint came in Post #185 earlier in this thread - in using "Muted Color", which sets lower saturation -
I tried to simulate this using PDCU in Post #186 to show the effect on an overly saturated predominantly magenta shot.

Even though it was not ideal - one can see how effective this was.

To me this was enough evidence to show that problems with LED colors - since they are very pure and "spiky" (ie: devoid of any significant other frequencies) -
Typical "white" spectrum generated by discrete RGB LEDs -

a LED magenta "spectrum" would be like the figure above with the middle green spike removed -
one can see why our cameras would have difficulties with LED magenta.

Problems especially for Magenta (made up of red and blue LEDs) - is due mostly to over-saturation of those color channels (red and blue in this case)
- reducing saturation would most probably help -
using Muted Color - even if it is not ideal - probably gives a better fighting chance for any post processing to get better balance.

RAW of course is more flexible and one might be able to do more/better - but there has been a lot of discussion previously in this thread to show that RAW is not a panacea to this LED magenta problem -
in fact using PDCU my best results from the "challenge" photo was actually from the JPG!

See "challenge" starting at Post #103
the links to the paired DNG and JPG as used in Post #23 (Important: see follow up Post #86)
>>
IMGP4490.DNG
and
IMGP4490.JPG

cheers,

Last edited by UnknownVT; 05-09-2013 at 09:49 AM.
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