Luminous Landscape Forum

Raw & Post Processing, Printing => Adobe Camera Raw Q&A => Topic started by: Raw shooter on May 21, 2011, 07:12:08 pm

Title: Creating a Custom Camera Profile - White Balance - before or after
Post by: Raw shooter on May 21, 2011, 07:12:08 pm
Using the ColorChecker Passport software in creating a Camera Profile for use in Adobe Camera Raw.  Raw file is a NEF.
Studio flash, need 6500°K only (product photography)
** The camera uses a Custom White Balance for in-camera jpgs, and of course, Camera Raw sees it in the metadata and is used As Shot.

Question is when/how is the file White Balanced:
    1) WB the NEF in Camera Raw 1st, then save as a DNG - Take DNG to ColorChecker Passport create a Camera Profile
or
    2) NEF straight to a DNG - Camera Profile created in CC Passport, then White balance the NEF in ACR
or
    3) NEF straight to a DNG - Camera Profile created in CC Passport, then White Balance the DNG in ACR

In ACR, the White Balance has to have values when processing Raw files.  Any guidance will be much appreciated.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: digitaldog on May 21, 2011, 07:17:31 pm
All I’ve ever done was convert and build the profile. I think if the WB is way, way off, the app pops an error (it certainly does for exposure).
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Raw shooter on May 22, 2011, 01:12:47 pm
Thanks Digital Dog.  No, the white balance is very close with As Shot in ACR.
I was hoping for more neutrality in the whole grayscale.  The Custom Camera Profile didn't get that, although overall - it's much better than before and quite a bit better than of any of the canned profiles in ACR. 

I guess I may be wanting too much out of a camera profile.  Perhaps using a large sample size (more than the ColorChecker Card) will get us there someday.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Stop Bath on August 28, 2011, 09:31:00 pm
Thanks Digital Dog.  No, the white balance is very close with As Shot in ACR.
I was hoping for more neutrality in the whole grayscale.  The Custom Camera Profile didn't get that, although overall - it's much better than before and quite a bit better than of any of the canned profiles in ACR. 

I guess I may be wanting too much out of a camera profile.  Perhaps using a large sample size (more than the ColorChecker Card) will get us there someday.

Raw shooter, did you ever get a satisfactory answer to your inquiry?  I'd be interested in the answer too.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Nigel Johnson on August 29, 2011, 05:58:41 am
Raw Shooter,

I am not certain about the ColorChecker Passport software but understand, from other posts by Eric Chan, that the Chart Wizard of the DNG Profile Editor ignores any previously set white balance and sets its own. Files used with the resultant camera profile should have an appropriate white balance set.

If the Passport software works the same way, setting WB before creating the profile will have no effect on the profile but you may have to set WB for the NEF or DNG after the profile is assigned to it (As Shot should still be available).

I hope this is of help,
Nigel

edit: typo corrected
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: digitaldog on August 29, 2011, 10:15:02 am
I am not certain about the ColorChecker Passport software but understand, from other posts by Eric Chan, that the Chart Wizard of the DNG Profile Editor ignores any previously set white balance and sets its own.

The folks at X-rite told me Passport is the same. WB isn’t a factor.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Raw shooter on September 01, 2011, 05:33:31 pm
Thanks Nigel and digitaldog,
I have experimented lots with these camera profiles - especially the ones made by the ColorChecker Passport software.  The NEF file arrives in Camera Raw with an accurate White Balance (custom) from my camera, as a suggestion in the metadata.  So the 'As Shot' is Camera Raw is correct.  The White patch on the ColorChecker chart is neutral.  The second patch is almost neutral as well.  So I save out as a DNG.
The ColorChecker Passport creates a Camera Profile.  Pure Gold!  The Grayscale is neutral and the other colors now are virtually perfect.  My color problems are now in the past.  I was late to this Camera Profile party, but am now a convert.

I have read digitaldog's posts through the years on Camera Profiles, but didn't really think is was something I needed.  Thought the Custom White Balance did the job - but wrong I was.
Thanks for the help - everyone has been great.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: stamper on September 02, 2011, 04:41:00 am
The problem is - imo - that anyone looking at your images won't know that the colours are "accurate". Only you. Satisfying yourself is the priority but if you like to show your images to other people then that will mean that "accurate" means nothing to them? Even if you state that the colours are "accurate" as captured I am sure they won't necessarily be impressed. I haven't personally gone down the road of " accurate" colours and "pleasing" colours is my goal as I suspect most photographers. Then again I don't output for business fashion shoots or people who want faithful reproduction. :)
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Peter_DL on September 02, 2011, 12:23:42 pm
I haven't personally gone down the road of " accurate" colours and "pleasing" colours is my goal as I suspect most photographers.

"Accurate" may not be the final goal, however, it is supposed to provide a better starting point, rather than randomly distorted, to come to "pleasing".

--
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: RFPhotography on September 08, 2011, 12:25:09 pm
White balance and colour accuracy are two different things as Andrew points out.  Think of profiling the camera in the same way as profiling a scanner or printer/paper.  The colour produced by the sensor may not be the 'correct' colour of the object being photographed (or scanned) and the printer may output a different colour from what the input colour is.  The profile makes those corrections. 
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Peter_DL on September 08, 2011, 12:42:53 pm
White balance and colour accuracy are two different things as Andrew points out.  Think of profiling the camera in the same way as profiling a scanner or printer/paper.  The colour produced by the sensor may not be the 'correct' colour of the object being photographed (or scanned) and the printer may output a different colour from what the input colour is.  The profile makes those corrections.

??

Accurate white balance is needed for accurate profiling.

When it comes to a pleasing rendition, pleasing white balance more often tends to deviate from accurate - talking about to preserve the mood of a scene, than with accurate colors as defined by the profile vs. "pleasing" hue twists. Although the latter are often enough needed as well (relative to accurate). However, that's just my perception.

Peter


--
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: RFPhotography on September 08, 2011, 01:17:09 pm
Not talking about 'pleasing', Peter.  Talking about 'accurate'. 

White balance is applied after the fact with RAW.  The 'As Shot' in ACR or other RAW converters is just a suggestion based on in camera settings.  It doesn't play into what colours were captured by the sensor.  That's why, as I understand it, the profiling solutions ignore the in camera white balance.  The goal with the camera profilers is to correct for inaccuracies at the sensor/colour mixing level. 
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Raw shooter on September 08, 2011, 02:16:12 pm
All the Camera Profiling Software (Adobe or Xrite) will not use the original camera raw file; ie NEF or CR2.  They must be converted to DNG - which must have a white balance applied.  In the DNG, is the White Balance just metadata or is it cooked into the DNG?

Because if its just metadata, then any white balance could be ignored - but if that applied white balance is 'cooked' into NEF (colors are altered by a custom white balance in ACR) then yes, the lighting source would be neutralized - prior to the Camera Profile being created.

If the custom white balance data is ignored during the Camera Profile creation (Adobe or Xrite) then either software would have to choose a white point.  I would guess 6500K would be the default, but the true answer is unknown.

If 6500K is built-in to the Camera Profile, then the resulting Camera Profile would be useful for photographers seeking color accuracy in neutral flash conditions only.  Those shooting sunsets and mountain tops would find trouble seeing their pictures as shot.  They would now need a new custom white balance in ACR or Lightroom - which may leave the Camera Profile somewhat useless.

This is where the original question lies.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Peter_DL on September 08, 2011, 02:19:20 pm
Not talking about 'pleasing', Peter.  Talking about 'accurate'.

Ok, understood.


White balance is applied after the fact with RAW.  The 'As Shot' in ACR or other RAW converters is just a suggestion based on in camera settings.  It doesn't play into what colours were captured by the sensor.  That's why, as I understand it, the profiling solutions ignore the in camera white balance.  The goal with the camera profilers is to correct for inaccuracies at the sensor/colour mixing level.

The only minor comment I'd have, is that white balance could (have) be(en) done as well by CT conversion filters in front of the lens. Corresponding to the basic theorem of ETTR that any +/-Exposure can be balanced by linear up- or down-scaling of the naked (unclipped) Raw RGB data, and vice versa. Here, to be seen on a per channel basis.


Peter

--
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: digitaldog on September 08, 2011, 02:22:07 pm
Again, in terms of creating DNG profiles, both Adobe and X-Rite’s generators don’t care about the white balance of the DNGs.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Raw shooter on September 08, 2011, 02:29:07 pm
Again, in terms of creating DNG profiles, both Adobe and X-Rite’s generators don’t care about the white balance of the DNGs.

OK, so what lighting conditions are assumed by Adobe or Xrite when creating a Camera Profile?  How is that Camera Profile used in ACR if I need a shoot white balanced?
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: digitaldog on September 08, 2011, 02:41:22 pm
You can build a single or dual illuminant profile depending on the package. None preclude you from using a white balance with the profiles. You shoot the target under an illuminate (say daylight or tungsten). It is what it is and you’d be advised to use them for matching scenes but again, once selected, go right ahead and use the WB tools if you so desire. A dual illuminant profile is more ideal if you are trying to use it in a wide ranging set of lighting conditions. But with respect to a really custom setup (say a studio with strobes), you’d put the target in the shot, build a profile and use that profile for all strobe work. The DNG for building that profile doesn’t need a user to set WB or tell it about WB to build said profile.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Raw shooter on September 08, 2011, 02:56:19 pm
Thanks digitaldog,

Let me see if I get what you are saying.
So if I personally use a studio flash, then a single illuminant Camera Profile is my best option - and this Camera Profile would have the grayscale neutralized.  ACR still needs White Balance temp and tint numbers - and I'm guessing the 'as shot' is still looking at the metadata of the incoming NEF files.  I would guess that may change the colors of the new Camera Profile - unless a new Custom White Balance is recorded by ACR(using a target illuminated by the flash)and saved as the new Camera Raw Default.  After that, all works great.

On the other hand if the photographer shoots in lots of lighting condidtions, then the dual illuminant Camera Profile would be better.  So this is more like the canned Camera Profiles built into Camera Raw - which can be custom white balanced on the fly.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: digitaldog on September 08, 2011, 03:02:09 pm
So if I personally use a studio flash, then a single illuminant Camera Profile is my best option - and this Camera Profile would have the grayscale neutralized. 

Yes and maybe (who knows what colors adjacent to the subject may require you to custom WB). But yes, ideally you build a custom profile for a situation like this. That said, I don’t personally see the need to carry this out for ever shot (a good daylight profile works all over the place in daylight). I know you see tutorials where the shooter is shooting a target for every scene and setup. For critical color work, if you are trying to impress your client, sure, can’t hurt.

Quote
ACR still needs White Balance temp and tint numbers - and I'm guessing the 'as shot' is still looking at the metadata of the incoming NEF files. 


Yes, its just a metadata suggestion. The metadata has no effect on the raw data.

Quote
On the other hand if the photographer shoots in lots of lighting condidtions, then the dual illuminant Camera Profile would be better.  So this is more like the canned Camera Profiles built into Camera Raw - which can be custom white balanced on the fly.

I think mixed lighting would be more appropriate for a dual illuminant profile. I have a single daylight custom profile, a single Tungsten profile and for a lot of images under those illuminants, they work great. If I went into an odd situation (Fluorescent, metal halide) and had a Macbeth, I’d take a shot and build a profile for that.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Raw shooter on September 08, 2011, 03:25:20 pm
Thank you digital dog.  Appreciate your time and detailed answers.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: RFPhotography on September 08, 2011, 03:52:43 pm
That's not WB though, Peter.  If you've got a colour correction filter on the front of the lens (e.g., warming, cooling) then that is going to impact the colour captured at the sensor and it would completely throw off the software.

ETTR really plays no part in the creation of a camera profile using something like the ColorChecker Passport.  It simply needs a good, correct exposure.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: Peter_DL on September 09, 2011, 11:24:02 am
That's not WB though, Peter.  If you've got a colour correction filter on the front of the lens (e.g., warming, cooling) then that is going to impact the colour captured at the sensor and it would completely throw off the software.

It is, Bob,
it is indeed as simple:

+/-EV camera exposure = global linear scaling of the Raw RGB data, >/< 1 (except for possible clipping issues and noise of course).
Colour correction filter on the front of the lens = linear scaling of the Raw RGB data with different weighting per R/G/B channel = White Balance.

Another question might be, if this is really supported by the Raw conversion software.

Peter


--
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: RFPhotography on September 12, 2011, 02:05:17 pm
Right.  And if the weighting of the light captured is altered at the sensor level then reversing it or altering it after the fact wouldn't be possible.  Or at least would be much more difficult.  The choice of in camera white balance doesn't affect the exposure or light captured.  A colour filter on the lens would affect both.  I don't think I have any colour filters tucked away in the deep, dark recesses of my office (I'm actually kind of afraid to look for fear of what else might be in there - who knows, I might find Jimmy Hoffa) so I can't experiment but I think I might have some old shots in my library so let me see what I can find.

OK, here's an example.  One shot has no filter on the lens.  The other, of essentially the same scene, has a Cokin 007 which is a very deep red/quasi-IR filter.  Both have the same White Balance of 4100.  The information captured at the sensor is altered with the filtered image.  There's no way this could be corrected for in a RAW converter.  Using a warming, cooling or other colour filter on the lens would cause the same type of alteration of information captured at the sensor level to a lesser degree.  The filtered images have a 'white balance', really a colour cast that's locked in and can't be altered so it can't be stripped out by the profiling software.  Whereas if the WB is just in the metadata and isn't locked in via a colour cast, it can be stripped out.  This is why you can't create a camera profile from a JPEG file, the WB is locked in and impacts the colours in the image.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: madmanchan on September 14, 2011, 04:52:27 pm
The main thing that color filters (e.g., placed in front of a lens) will "throw off" is the mapping of white balance gains (or, equivalently, "camera neutral values") to temperature/tint values. In other words, the relationship between the adopted white point of the scene and the raw values will be thrown off if using a normal color profile that was built without the filter. So using WB presets like "Daylight" or "Cloudy" in the raw conversion software won't work properly. As Shot WB will almost certainly also not work properly. On the other hand, a click-WB will usually continue to work fine.
Title: Re: Creating a Custom Camera Profile - White Balance - before or after
Post by: ErikKaffehr on December 13, 2011, 01:03:36 am
Hi,

That's extreme filtering, It has nothing to do with spectral balance.

I would suggest to use DNG profiler without filter and use the normal gray balance tool using a grey card (CC, WhiBal etc) to set color balance. If you are using some light balancing filter all the time you may as well build your profile with it.

Best regards
Erik



Right.  And if the weighting of the light captured is altered at the sensor level then reversing it or altering it after the fact wouldn't be possible.  Or at least would be much more difficult.  The choice of in camera white balance doesn't affect the exposure or light captured.  A colour filter on the lens would affect both.  I don't think I have any colour filters tucked away in the deep, dark recesses of my office (I'm actually kind of afraid to look for fear of what else might be in there - who knows, I might find Jimmy Hoffa) so I can't experiment but I think I might have some old shots in my library so let me see what I can find.

OK, here's an example.  One shot has no filter on the lens.  The other, of essentially the same scene, has a Cokin 007 which is a very deep red/quasi-IR filter.  Both have the same White Balance of 4100.  The information captured at the sensor is altered with the filtered image.  There's no way this could be corrected for in a RAW converter.  Using a warming, cooling or other colour filter on the lens would cause the same type of alteration of information captured at the sensor level to a lesser degree.  The filtered images have a 'white balance', really a colour cast that's locked in and can't be altered so it can't be stripped out by the profiling software.  Whereas if the WB is just in the metadata and isn't locked in via a colour cast, it can be stripped out.  This is why you can't create a camera profile from a JPEG file, the WB is locked in and impacts the colours in the image.