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07-01-2008, 07:30 AM   #1
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Camera settings for RAW

Having in the past been an advocate of JPEG and getting your shot right in the first place, I have now seen the error of my ways and have become a RAW convert especially for handheld landscape shots where now I can often recover blown sky and still find shadow detail. I cannot myself achieve this satisfactorily with JPEGs.

But I am still learning and I have questions:

The histogram in the camera is a result of the in-camera RAW to JPEG conversion. Changing the camera settings (brightness, WB etc) changes the histogram.

I always find that if there is a brightly lit red object in the shot this will blow before other colours (K10D) and often, even with RAW it cannot be fully recovered to show the true redness of the object.

Thus it is very important not to expose too far to the right so I always use the histogram and try to underexpose just a tad to preserve redness. (Latest red subjects to give me difficulty have been poppies in a field and Ferrari F1 cars testing at Silverstone.)

But the in-camera histogram simply shows overall mid-tone brightness and avoiding things like slightly blown red poppies needs a bit of guesswork.

So – at last my question – What in-camera settings in terms of image tone, saturation, sharpness, contrast and WB (I currently use auto WB) would you recommend to produce an in-camera histogram that most closely resembles the real RAW data? (note that I don’t care about what the in-camera JPEGs look like – I just use these to check composition and focus)

Any advice would be appreciated.

07-01-2008, 11:36 AM   #2
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Here's my two cents. I think the settings that you mentioned have no effect on how the RAW file look when it is imported to any RAW converter other than Pentax Photo Lab. For example, if you open the RAW file with Adobe Camera RAW, ACR would apply it's own default values for these settings. So the in camera setings have no effect whatsoever.

Now if you bring the same RAW file inot Pentax Photo Lab, the in camera settings are automatically applied. The sliders that you see in PPL are automatically set to correspond with the in camera settings. If you don't change anything the image that you see and the image that you get directly from the camera in jpg would be identical.

I blieve the image you see on the camera screen is also effected by the camera's settings.

So if you set a very high contrast setting in the camera, when you view it on the camera screen the histogram would be stretched. When you bring it into PPL it will also be strectched. If you bring it into ACR the histogram would be a little less stretched.

I hope this helps.
07-01-2008, 02:10 PM   #3
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Isn't that why the K10D offers a seperate histogram for each channel, so you can see before any particular one blows out? Or am I wrong here?
07-01-2008, 07:03 PM   #4
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QuoteOriginally posted by ukbluetooth Quote
I always find that if there is a brightly lit red object in the shot this will blow before other colours (K10D) and often, even with RAW it cannot be fully recovered to show the true redness of the object.

I was playing with both ACR and PPL tonight and I notice a real nice red box looked completely different on the two converters. PPL reds looking exactly like the original and the ACR reds looking washed out and faded. I think your problem with the reds is not that much blowing the highlight but more about using the wrong RAW converter.

07-01-2008, 07:33 PM   #5
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QuoteOriginally posted by Stratario Quote
I was playing with both ACR and PPL tonight and I notice a real nice red box looked completely different on the two converters. PPL reds looking exactly like the original and the ACR reds looking washed out and faded. I think your problem with the reds is not that much blowing the highlight but more about using the wrong RAW converter.
Yes RAW converters do matter. But usually just tone is different. If your reds are washed out in ACR it's probably a colorspace issue, sRGB vs aRGB.
Reminds me of the old "Rawshooter essentials" converter. Reds were usually an orangy red while software such as Silkypics produced RED...
nothing to do w/ colorspaces though, justprofiles/default curves.

Last edited by jeffkrol; 07-01-2008 at 07:39 PM.
07-01-2008, 07:51 PM   #6
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QuoteOriginally posted by Jodokast96 Quote
Isn't that why the K10D offers a seperate histogram for each channel, so you can see before any particular one blows out? Or am I wrong here?
No that's what they are there for. Problem is they (as in all DSLR's) are not totally accurate since their based on your jpg settings. No camera that I know of produces a RAW histogram.
One of the tweaks some nikon shooters use called UniWB in order to push the channel multipliers to a 1:1:1 state. That allows the use of the luminous histogram.
A CC40m filter and custom white balance will push a Pentax D to have close to 1:1:1 multipliers and mimic the UniWB state.
When a RAW file is white balanced for daylight the red channel values are multiplied by a coefficient of around 1.5. That easily pushed red objects to blowout.
ETTR, uni-WB, and Nikon's new cameras - Photo.net Nikon Forum
Re: What is UniWB: Nikon D3 - D1 / D700 Forum: Digital Photography Review
it is a special white balance setting that disables white balance

the idea is as following. white balance is essentially 2 multipliers which are used to equalise sensitivity of red and blue channels to the sensitivity of green channel. those multipliers are dependent on the light spectrum (color of light), so they are variable. because they are applied to raw data after conversion to digital, there is no point in using them in camera. application of this coefficients in raw conversion through click-grey method or by copying white balance from a setup shot provides same result.

on the other hand, in camera those coefficients seriously distort histogram display in red and blue channels, preventing good exposure judgement.

Oh and to see what your histograms are up against WB coefficients):
http://www.pochtar.com/NikonWhiteBalanceCoeffs.htm

Last edited by jeffkrol; 07-01-2008 at 08:02 PM.
07-02-2008, 01:01 AM   #7
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QuoteOriginally posted by jeffkrol Quote
No that's what they are there for. Problem is they (as in all DSLR's) are not totally accurate since their based on your jpg settings. No camera that I know of produces a RAW histogram.
One of the tweaks some nikon shooters use called UniWB in order to push the channel multipliers to a 1:1:1 state. That allows the use of the luminous histogram.
A CC40m filter and custom white balance will push a Pentax D to have close to 1:1:1 multipliers and mimic the UniWB state.
When a RAW file is white balanced for daylight the red channel values are multiplied by a coefficient of around 1.5. That easily pushed red objects to blowout.
ETTR, uni-WB, and Nikon's new cameras - Photo.net Nikon Forum
Re: What is UniWB: Nikon D3 - D1 / D700 Forum: Digital Photography Review
it is a special white balance setting that disables white balance

the idea is as following. white balance is essentially 2 multipliers which are used to equalise sensitivity of red and blue channels to the sensitivity of green channel. those multipliers are dependent on the light spectrum (color of light), so they are variable. because they are applied to raw data after conversion to digital, there is no point in using them in camera. application of this coefficients in raw conversion through click-grey method or by copying white balance from a setup shot provides same result.

on the other hand, in camera those coefficients seriously distort histogram display in red and blue channels, preventing good exposure judgement.

Oh and to see what your histograms are up against WB coefficients):
http://www.pochtar.com/NikonWhiteBalanceCoeffs.htm

Thanks JeffKrol this is very enlightening.

So if I set my in camera white balance to a lower temperature the JPEG histogram would better indicate if I am blowing reds in RAW? (by this I mean turning them slightly yellowish)

On second thoughts is this correct - should I set it to a higher temperature to overemphasise the red in the histogram so that I can compensate in the exposure? I think its the latter but now I am getting confused.
07-02-2008, 06:06 AM   #8
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QuoteOriginally posted by ukbluetooth Quote
Thanks JeffKrol this is very enlightening.

So if I set my in camera white balance to a lower temperature the JPEG histogram would better indicate if I am blowing reds in RAW? (by this I mean turning them slightly yellowish)

On second thoughts is this correct - should I set it to a higher temperature to overemphasise the red in the histogram so that I can compensate in the exposure? I think its the latter but now I am getting confused.
Actually setting it to any color temp doesn't really solve the situation (see the Nikon chart) as some channel will get multiplied. Well it shouldn't but some people have found w/ the k10 that setting a certain color temp helped them deal w histograms (5000K seems to be the recommended).
Re: K10D, WB and color histograms: Pentax SLR Talk Forum: Digital Photography Review

Here's the start to the "UniWB" theory
maybe you will like it(huge file): Nikon D3 - D1 / D700 Forum: Digital Photography Review
> Why is one so green?


because white balance is not applied. I set it to "1". that is what the sensor captured. white balance in your shots is applied to underexposed red and blue channels. they are simply multiplied by 1.6 after the capture. so dynamic range is decreased, noise is increased, sensor is not used in an optimal way.

UNFORTUNATELY Pentax will not import WB coefficients and ANY color temp will multiply either or both of the blue/red channels. So second effort is to use a filter and a custom WB. Then you can more safely push the exposure up without blowing channels.
Some other references:
Test: Increased DR and lower noise with filter: Nikon D3 - D1 / D700 Forum: Digital Photography Review
It's a bit counter intuitive. I've tried it briefly but found filters to be a Pain for me.
I like to just advertise it as a technique (and one that is probably used more than is talked about)
As a side note for some reason Nikon seems to be "locking out" the WB coefficient import for some odd reason.

07-02-2008, 07:19 AM   #9
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QuoteOriginally posted by jeffkrol Quote
Actually setting it to any color temp doesn't really solve the situation (see the Nikon chart) as some channel will get multiplied. Well it shouldn't but some people have found w/ the k10 that setting a certain color temp helped them deal w histograms (5000K seems to be the recommended).
Re: K10D, WB and color histograms: Pentax SLR Talk Forum: Digital Photography Review

Here's the start to the "UniWB" theory
maybe you will like it(huge file): Nikon D3 - D1 / D700 Forum: Digital Photography Review
> Why is one so green?


because white balance is not applied. I set it to "1". that is what the sensor captured. white balance in your shots is applied to underexposed red and blue channels. they are simply multiplied by 1.6 after the capture. so dynamic range is decreased, noise is increased, sensor is not used in an optimal way.

UNFORTUNATELY Pentax will not import WB coefficients and ANY color temp will multiply either or both of the blue/red channels. So second effort is to use a filter and a custom WB. Then you can more safely push the exposure up without blowing channels.
Some other references:
Test: Increased DR and lower noise with filter: Nikon D3 - D1 / D700 Forum: Digital Photography Review
It's a bit counter intuitive. I've tried it briefly but found filters to be a Pain for me.
I like to just advertise it as a technique (and one that is probably used more than is talked about)
As a side note for some reason Nikon seems to be "locking out" the WB coefficient import for some odd reason.


Thanks again Jeffkrol - this is precisely what I was looking for.

I have obviously been incorrect using Auto WB. I will now experiment with using WB 5000K and see if I can better use the resulting histogram to increase exposure without blowing reds.

I also agree that using filters would be a pain.

Many thanks.

Last edited by ukbluetooth; 07-02-2008 at 07:46 AM.
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