Auto ISO 100 on K-3

**nicoprod** · 11-27-2014, 10:31 AM

I can't figure out why my K-3 will not step down to ISO 100 when I have the automatic ISO set to 100-1600, even though it has sufficient light to do so. Thanks for the help.

**boriscleto** · 11-27-2014, 10:42 AM - **1 Like**

Do you have highlight/shadow correction turned on?

**nicoprod** · 11-27-2014, 10:45 AM

Ah that was it.... You know I thought shooting raw would disregard the highlight/shadow correction... So it does not eh? Thank you!!!!

**Madaboutpix** · 11-27-2014, 10:51 AM - **1 Like**

In P mode, the tendency to go to Auto ISO 100 may depend a bit on the Program Line used (e.g. with High-speed priority it should be markedly reduced).

Otherwise, I wouldn't be surprised if you have set the Highlight Correction to "On". In that case ISO 100 is not available. You can change that directly in the control panel or via the <camera symbol>2 menu.

**nicoprod** · 11-27-2014, 10:55 AM

Thanks, but does raw shooting correct for highlights and shadow if corrections are on? I thought raw was not applying any correction whatsoever?

**Madaboutpix** · 11-27-2014, 11:25 AM

The same question was asked by a K-x user in this thread here:

https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/95880-hi...orrection.html

The upshot seems to be, that such corrections, while not affecting the RAW image data directly, are stored in the RAW EXIFs, and may be accessed and used by some RAW processors in developing files.

In the K-3, there is also an Auto option for both corrections, which I have activated. Without having done rigorous testing, I have a hunch it does reduce the need for adjustments in Lightroom. If I want native ISO, I will select ISO 100 manually via the dedicated button.

**nicoprod** · 11-27-2014, 11:30 AM

Originally posted by Madaboutpix

In the K-3, there is also an Auto option for both corrections, which I have activated

Thank you. I just did a quick testing and auto highlight correction allows ISO 100... I will shoot this way for a while.

indykpol · 05-03-2015, 06:06 AM

I just did the testing, and in my case it is the shadow compensation that allows ISO100, not the highlights correction.

ScooterMaxi Jim · 05-03-2015, 07:55 AM - **1 Like**

Here is what's going on regarding HC and SC in Raw.

The On setting in HC does apply to Raw, essentially underexposing by one stop - providing (extremely good) instructions to the raw converter on the proper roll off profile to be applied. Some lower end converters don't apply the instructions, but LR and C1 (among others) recognize the instruction. Without the information, you simply get one stop underexposure. In my K-3 experience, setting HC to Auto will only result in its application when severe blow out is occurring. Earlier implementations of Auto were more aggressive (K30/K50/K01) - hitting the right balance pretty much all the time. On the K-3, think of Auto as disaster prevention - saving some highlights when over-exposure is extreme. Shooting TAv I almost never see the HC trigger - even in high-contrast situations.

SC applies only to JPEGs. There is no impact on Raws - on any of the Pentax models.

stevebrot · 05-03-2015, 10:30 AM

Originally posted by ScooterMaxi Jim

Here is what's going on regarding HC and SC in Raw.

The On setting in HC does apply to Raw, essentially underexposing by one stop - providing (extremely good) instructions to the raw converter on the proper roll off profile to be applied. Some lower end converters don't apply the instructions, but LR and C1 (among others) recognize the instruction. Without the information, you simply get one stop underexposure. In my K-3 experience, setting HC to Auto will only result in its application when severe blow out is occurring. Earlier implementations of Auto were more aggressive (K30/K50/K01) - hitting the right balance pretty much all the time. On the K-3, think of Auto as disaster prevention - saving some highlights when over-exposure is extreme. Shooting TAv I almost never see the HC trigger - even in high-contrast situations.

SC applies only to JPEGs. There is no impact on Raws - on any of the Pentax models.

What he said

Steve

11-27-2014, 10:31 AM	#1
nicoprod Site Supporter Join Date: Nov 2010 Location: New Berlin, WI Photos: Gallery \| Albums Posts: 528	Auto ISO 100 on K-3 I can't figure out why my K-3 will not step down to ISO 100 when I have the automatic ISO set to 100-1600, even though it has sufficient light to do so. Thanks for the help.

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11-27-2014, 10:42 AM - 1 Like	#2
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	Do you have highlight/shadow correction turned on?

11-27-2014, 10:45 AM	#3
nicoprod Site Supporter Join Date: Nov 2010 Location: New Berlin, WI Photos: Gallery \| Albums Posts: 528 Original Poster	Ah that was it.... You know I thought shooting raw would disregard the highlight/shadow correction... So it does not eh? Thank you!!!!

11-27-2014, 10:51 AM - 1 Like	#4
Madaboutpix Site Supporter Join Date: Dec 2011 Location: North Rhine-Westphalia Posts: 1,440	In P mode, the tendency to go to Auto ISO 100 may depend a bit on the Program Line used (e.g. with High-speed priority it should be markedly reduced). Otherwise, I wouldn't be surprised if you have set the Highlight Correction to "On". In that case ISO 100 is not available. You can change that directly in the control panel or via the <camera symbol>2 menu.

11-27-2014, 10:55 AM	#5
nicoprod Site Supporter Join Date: Nov 2010 Location: New Berlin, WI Photos: Gallery \| Albums Posts: 528 Original Poster	Thanks, but does raw shooting correct for highlights and shadow if corrections are on? I thought raw was not applying any correction whatsoever?

11-27-2014, 11:25 AM	#6
Madaboutpix Site Supporter Join Date: Dec 2011 Location: North Rhine-Westphalia Posts: 1,440	The same question was asked by a K-x user in this thread here: https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/95880-hi...orrection.html The upshot seems to be, that such corrections, while not affecting the RAW image data directly, are stored in the RAW EXIFs, and may be accessed and used by some RAW processors in developing files. In the K-3, there is also an Auto option for both corrections, which I have activated. Without having done rigorous testing, I have a hunch it does reduce the need for adjustments in Lightroom. If I want native ISO, I will select ISO 100 manually via the dedicated button.

11-27-2014, 11:30 AM	#7
nicoprod Site Supporter Join Date: Nov 2010 Location: New Berlin, WI Photos: Gallery \| Albums Posts: 528 Original Poster	Originally posted by Madaboutpix In the K-3, there is also an Auto option for both corrections, which I have activated Thank you. I just did a quick testing and auto highlight correction allows ISO 100... I will shoot this way for a while.

05-03-2015, 06:06 AM	#8
indykpol New Member Join Date: Mar 2015 Photos: Gallery Posts: 11	I just did the testing, and in my case it is the shadow compensation that allows ISO100, not the highlights correction.

05-03-2015, 07:55 AM - 1 Like	#9
ScooterMaxi Jim Veteran Member Join Date: Jul 2009 Location: Minnesota Posts: 1,520	Here is what's going on regarding HC and SC in Raw. The On setting in HC does apply to Raw, essentially underexposing by one stop - providing (extremely good) instructions to the raw converter on the proper roll off profile to be applied. Some lower end converters don't apply the instructions, but LR and C1 (among others) recognize the instruction. Without the information, you simply get one stop underexposure. In my K-3 experience, setting HC to Auto will only result in its application when severe blow out is occurring. Earlier implementations of Auto were more aggressive (K30/K50/K01) - hitting the right balance pretty much all the time. On the K-3, think of Auto as disaster prevention - saving some highlights when over-exposure is extreme. Shooting TAv I almost never see the HC trigger - even in high-contrast situations. SC applies only to JPEGs. There is no impact on Raws - on any of the Pentax models.

05-03-2015, 10:30 AM	#10
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by ScooterMaxi Jim Here is what's going on regarding HC and SC in Raw. The On setting in HC does apply to Raw, essentially underexposing by one stop - providing (extremely good) instructions to the raw converter on the proper roll off profile to be applied. Some lower end converters don't apply the instructions, but LR and C1 (among others) recognize the instruction. Without the information, you simply get one stop underexposure. In my K-3 experience, setting HC to Auto will only result in its application when severe blow out is occurring. Earlier implementations of Auto were more aggressive (K30/K50/K01) - hitting the right balance pretty much all the time. On the K-3, think of Auto as disaster prevention - saving some highlights when over-exposure is extreme. Shooting TAv I almost never see the HC trigger - even in high-contrast situations. SC applies only to JPEGs. There is no impact on Raws - on any of the Pentax models. What he said Steve