White ballance with D30, Got the Blues when I should have pu

[Fishsnagger]

I am a Canon D30 owner, and recently overheard employees at work discussing the
difficulties of obtaining true color from digital cameras when the subject is african violets in particular purple/blue ones. I talked to this person about their white ballance settings but was told they only had auto mode. This person was wanting to upgrade cameras, but only if it would do a better job of capturing the flower's color. I willingly took the flower home to photograph it under different lighting.. tungsten, sun, fluorescent, and flash using the available white ballance modes and the custom mode. I also used the S230 to photo the flower. I had decent result with tungsten light and natural light (cloudy), but poor results under fluorescent and flash. Questions are: (1) Is capturing blues and purples a particular problem with the D30?, and (2) what is the correct technique for using custom white ballance including what setting to use when photo is taken of white card? (3) Does white ballance work in RAW mode? It seems by definition it would not. I had mixed results surfing the web for the answers to (2) and (3) I would appreciate feedback on these topics. The information from below sources seem to be conflicting

Thanks,

Fishsnagger

http://www.luminous-landscape.com/reviews/cameras/canon_eos_digital.shtml

States White Balance does not apply to RAW images.

http://www.luminous-landscape.com/tutorials/dig-exp.shtml

Has technique for setting white ballance in RAW format, but this is with 1D

http://www.fredmiranda.com/D30FAQpage/index.html#5

In the FAQ page here it states that it does not matter which white ballance mode is used
for taking the exposure used for custom white ballance. He mentions an after-the-fact fix for
white ballance probelens at http://www.fredmiranda.com/TipsPage/index.html

[Dans_D60]

Modern digital camera sensors read and store only in black and white. Color filters are used to sort the brightness of each color. All filtered colors combined will accurately reproduce the shot. However, different lighting conditions will drastically effect how each filter will interpret the amount of filtered light. Digital photography is no different than traditional film or transparency. Both technologies depend on color filtering techniques along with color balance based on ambient lighting conditions. Color temperature is a term borrowed from physics. Photographic color temperature is not the same as the color temperature defined in physics. Photographic color temperature measures only the relative intensity of blue to red in degrees Kelvin (K). 2000K = Early Sunrise, 2500K = Tungsten Lights, 3500K = Photo Floods, 5600K = Studio Strobe Lights, 6000K = Bright Sunshine, 8000K = Overcast. As with film, early sunrise or indoor tungsten lighting will result in orange/red cast if we were using “daylight” film or had our digital camera set to “daylight”. Film and the digital sensors need an ambient white light balance “reference point”. White is used as it is supposed to be combination of all colors. Film is a little more “forgiving” than transparency and transparency is a little more forgiving than digital. Setting white balance for digital cameras is more critical than film. However, shooting in RAW will allow you to set the white balance (color temperature for ambient white) after the shot in the post processing phase. Of course, you can set the “default” white balance to anything you want while shooting in RAW. The default value is used when you perform your post processing. Nonetheless, you may change the white balance to anything you want as many times you want in this post processing phase. Most RAW conversion programs will even allow you to pick a single pixel point in your shot as the white balance reference. I prefer Breeze Browser which allows a lot of flexibility with white balance during RAW conversion: http://www.breezesys.com Remember, in RAW mode all pixel data is retained so changing the white balance reference point for the filter algorithms after the shot is no big deal.
Hope this helps!
Dan
http://www.dpcg.com/photo

[Roger_Cavanagh]

Fishsnagger,

I agree with what Dans_60 has said. The big advantage of shooting raw is being able to adjust white balance after the event. One thing he didn't mention was the use of custom white balance using a gray card (the D30 manual says white, but neutral is the key requirement and it's too easy to get blown hightlights with white). In tricky lighting conditions, this can be an extra aid in getting correct colour.

You asked about getting blues and purples right with the D30. I would say that these _are_ difficult colours. One of the reasons I like Pekka's LinearSharpen method is that it does a better job on blues/purples than other profiles I've looked. OTOH, sometimes the reds are a bit too powerful and a tweak is required.

You have to bear in mind that you can never get perfect colour. All digital cameras (and film for that matter) only capture a restricted range of "real world" colours. With the D30 the widest possible colour gamut is achieved by shooting raw and using linear conversion.

Regards,

[Fishsnagger]

Thanks Dan_D60

Thanks for the reply! I will checkout Breeze Browser … maybe, as you said, it has more controls over white balance settings. Although I understand the post-processing controls that are available through RAW Converter, it seems inadequate!

I performed a quick experiment using 125W tungsten bulb directed at a white cloth. The camera setting is 1/60 at F8.0.
(1) Shot one – AWB mode (All in RAW mode)
(2) Shot two – Custom with (1) as reference
(3) Shot three – White balance set to Tungsten
(4) Shot Four – Custom with (3) as reference

Pre-Processing??? (I suppose it is processed when viewing the image using preview mode within RAW converter) Results:

(1) Shot 1 is orange—Bad!!!
(2) Shot 2 is perfect
(3) Shot 3 has a slight orange cast –much better than 1
(4) Shot four is perfect – cannot distinguish from (2)

Now as Dan_D60 mentioned, I can select any of the shots within RAW Converter and change the white balance setting. For example, I changed (2) through (4) to Auto mode, and they had the same orange cast. Likewise, I changed (1), (2), and (4) to Tungsten mode, and again they all appear the same. So it seems as though the white balance setting during the shoot just servers as a note – “Hey buddy, you took this shot in tungsten light”.

Now there is a difference!!! The shots (2) and (4) where “Custom” white balance was used were better (more white—true to life) than (1) and (3). Moreover I could not obtain as good a result using the modes and white picker on (1) and (3) as (2) and (4) in “Shot Settings”. It seems as though (2) and (4) have the contents of (1) and (3) plus additional information (i.e. “Shot settings” is other than the common modes in (2) and (4)).

If anyone differs please advise, as I am painstakingly trying to wade through the incompleteness of my owners manual, and the various information found on the web.

Also PLEASE address the issue of accuracy in the blue to purple color variations. Last night I tried in vain to get a decent flash exposure of this dreaded purple african violet. Still no matter what I use other than Photoshop, they come out blue (maybe a hint of purple). Anyone??????


Thanks,

Fishsnagger

[Fishsnagger]

Thanks Roger

I am glad to know someone else finds these colors difficult to capture. Now I am not a perfectionist: I would settle for close…. the flower is purple, or a variation of purple, and no blue whatsoever is present. My shots with the flash are most definitely blue.

I will have to investigate Pekka's LinearSharpen, I have not expanded much from the native capabilities of Photoshop. But I don’t guess this will help if the colors aren’t close to begin with.

Thanks for the information,

Fishsnagger

[Roger_Cavanagh]

Fishsnagger,

You can do purple:

http://www.pixelpixel.org/bw_mask/images/slide/image06.jpg

This is the purpliest :) picture I've got on-line. Initial processing was LinearSharpen followed by some tarting around.

It's a good match to the orignal flower.

Regards,

[Fishsnagger]

Roger,

I will try the grey card. Perhaps this will prove to be the difference. I like your photo; I suppose this was taken outside. I have good luck outside, just not under fluorescent or flash. Thanks for the information and inspiration. I will keep plugging away.

Fishsnagger

[ootsk]

I've got a newbie question. As I've heard before, it seems that it is better to choose your WB yourself instead of using AWB. How about shooting in a flourescent room, with fill flash? Now you are combining two different types of light. Which WB do you use? And what would the results be?

[Roger_Cavanagh]

fishsnagger wrote:
I like your photo; I suppose this was taken outside. I have good luck outside, just not under fluorescent or flash.

Yes, it was outside. I had a look through my archives, but I haven't got any blue/purples flowers taken with flash. Got red roses, white lilies, red amaryllis, orange gerbera, pink gerbera ... oh, found a blue silk cornflower, but don't think that counts. :)

Regards,

[Fishsnagger]

I tried Fred Miranda’s D30 AutoWB fix in Photoshop (http://www.fredmiranda.com/Action_profilesPage/index.html). It seemed to help a little, thought not enough for the flash shot. I could not find much information about this action. From the name, I assume that it is for auto white balance. If anyone has experience with this and can explain the scope of use, I would appreciate hearing from them.

Fishsnagger

[Fishsnagger]

Roger_Cavanagh wrote:
Fishsnagger,

One thing he didn't mention was the use of custom white balance using a gray card

Roger,

Please provide a part number for the gray card. I want to try this, but am a little confused what to buy. I found a part nubmer KOD-R27 at one website, at Amazon they sell a three piece set (I think it was two 4"x5" cards and one larger card 8"X10"), and at Kodak's web page they have a multi-purpose card -- a large card with gray (18%) and on the edges it has white (95%) and black (5%). I think maybe this is for motion pictures?


Regards,


Fishsnagger

[Roger_Cavanagh]

fishsnagger wrote:
Please provide a part number for the gray card. I want to try this, but am a little confused what to buy. I found a part nubmer KOD-R27 at one website, at Amazon they sell a three piece set (I think it was two 4"x5" cards and one larger card 8"X10"), and at Kodak's web page they have a multi-purpose card -- a large card with gray (18%) and on the edges it has white (95%) and black (5%). I think maybe this is for motion pictures?


Regards,

Fishsnagger

Fishsnagger,

I got my gray card years (and years and years :) ) ago. It's completely gray on one side and white on the other. It has CAT 152 7795 on the instructions, but whether this still current... ???

I also have the Kodak Color Separation Guide and Gray Scale (small) - the Q13 card - CAT 152 7654. This has two small cards: one with colour patches and the other with gray patches in varying degrees of intensity. Not good enough for profiling, but handy for testing.

Regards,

[Roger_Cavanagh]

Fishsnagger,

Following up my last reply. I went to the Calument site and did a search for gray card:

http://www.calumetphoto.com/syrinx/ctl?ac.ui.pn=cat.CatTreeSearch&PAGE=Controller&keywords=gray+card&x=17&y=8

It comes up with both items and the larger version of the Q13.

Regards,

[reittila]

D30, fixed daylight setting. Two Elinchrom Style 600 flashes. Raw files converted with BB 2.3 to linear 16-bit tiff. Pekka's 342 with normal sharpening and some minor final tweaking in PS7.
At least th blue colour is quite close.
www.prfoto.com/blue1.jpg and www.prfoto.com/blue2.jpg

[Fishsnagger]

I would like to thank everyone for their thoughts and suggestions, in particular Roger Cavanagh for providing so much information. In general, I am very pleased with my D30, and have only begun to tap its potential and hopefully my own.

Thanks again,

Fishsnagger