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07-03-2013, 11:27 PM   #1
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Defined White Balance

I want to create a white balance for a filter that gives a green cast during shots. The green cast makes it difficult to see how my exposure looks like after the shot. I want the WB to be applied when I am shooting.
I have been reading the k-30 manual to see if this is possible. I know there are settings in the white balance menu that one can save a defined white balance. But somehow I cant seem to get it to work. Any help?

Culture

07-04-2013, 04:44 AM   #2
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I think you need to set up a custom white balance. Just take a photo, with the filter mounted, of a grey card or colour scale (you can buy this or print it out, find it in a magazine) and then press the WB button and choose "custom WB" and set it up.
But let's explore this topic further. AWB will probably try to remove the green cast automatically. Or if you shoot raw, you can set up the white balance in the raw editor software, where you have more control and can see the actual photo, not just a jpeg thumbnail on a tiny uncalibrated screen.
One more thing, what kind of filter are you using? On digital, the only filters you should be using are polarizers and maybe ND filters. UV filters (and skylight, haze, colour filters, etc.) are mostly pointless on digital cameras, they usually have little to no effect and lower the IQ. They were very useful, even necessary, back in the film days.
07-04-2013, 09:56 PM   #3
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Thank you Na Horuk. I will try that and see how it goes.

The filter is a welding glass that I use as an ND filter. Its a cheap way to try long exposure. The only downside to that is the green cast I mentioned above.
07-05-2013, 03:34 AM   #4
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Ah. The problem in that case could be that the welding glass is removing other colours. And if your camera cannot find any, for example, red colour (even if there is red on the other side of the filter), then even post processing and white balance can't add it. Thats why ND filters are usually "neutral grey" - so that all the colours get through in the same proportions that they would otherwise.
What I would suggest is to try black and white (or other monochrome) as a fix. That way, its mostly the exposure and composition, the shapes and lines that are important; not so much the colours.

Edit: you can test this by taking a photo in raw, with the welding glass filter, and then look at the histogram per colour channel. If some are missing or have unexpected drops, that might indicate that the welding glass doesn't let that wavelength/colour of light pass. Then you can either avoid subjects with that colour or use it as an artistic tool, to emphasize greens.

07-08-2013, 12:30 AM   #5
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This really makes sense. I have wondered why even after processing I get no additional colours. I think the red is being left out.

I will make tests and see. Anyway its a cheap and fun way to try long exposure.

Thanks. Culture
07-09-2013, 07:12 AM   #6
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interesting, i was fiddling with the different WB modes and i got very mixed results with the same WB mode on and different subjects. ( sky and luminosity was the same, or very similar in any case). The difference was always towards the same type of variation, but with different results in the darker colors. the light colors where always behaving in a regular pattern. At the time i was thinking , ok you got this, changing the WB all the time will make the pictures more true to what the eye sees. Except it's tedious and with changing weather you can screw up and forget what settings u're in.

I'm wondering if the auto WB is any good? I've got majorly blue tinged pics of the auto setting, and it sort of bugs me when a rather unpleasant person next to me says that my 300 mm lens is shit compared to her ugly little canon. Although her pics looks strange and forced, color wise.

Does the community recommend changing the WB settings to follow weather and luminosity to the letter? Or do you guys have confidence in the auto settings? ( appart from that i'm in full manual)

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07-09-2013, 07:13 AM   #7
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oh yeah the red comes out alot in auto mode too!!
07-09-2013, 08:13 AM   #8
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QuoteOriginally posted by Katmandude Quote
Does the community recommend changing the WB settings to follow weather and luminosity to the letter? Or do you guys have confidence in the auto settings? ( appart from that i'm in full manual)
I assume you're talking about normal photography, without any kind of filters? In that case auto WB should be okay. The only times you really should change it is for tungsten (light coming from lightbulbs, like indoors or at night). You can also try CTE to bring out dominant colours, like in sunset scenarios. But choosing the wb for your scene gives you the most control over your images. If you shoot raw, you can manipulate white balance very precisely in raw converter software, without losing any quality.
If you shoot jpeg, you can also change the colour settings in the info menu. You can choose bright, vibrant, film reversal.. any of those should bring out colours more than "natural." WB affects the orange/blue and green/pink axis of the colours. The jpeg setting actually affects individual colours and colour saturation, so thats what you want if you want specific colours to be stronger
But red colours can be a bit problematic anyway, a lot of users have expressed that they don't like the way digital sensors render red colour, it often has a pink or purple tint.

07-09-2013, 08:22 AM   #9
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QuoteOriginally posted by Na Horuk Quote
Ah. The problem in that case could be that the welding glass is removing other colours. And if your camera cannot find any, for example, red colour (even if there is red on the other side of the filter), then even post processing and white balance can't add it.
This is also true for underwater photography. It isn't just the light levels that decline as you descend. The available colors start disappearing beginning with the red end and gradually moving toward blue. You can't amplify what isn't there. Generally speaking at 100 feet / 30 meters, even on a bright sunny day it is impossible to distinguish red from black. Pull out your dive light and the color transformation can be startling.
07-09-2013, 09:32 AM   #10
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don't use any filters. and what you said is very true Na Horuk. I'm shooting in jpeg for the moment in bright mode. still getting less color saturation than most of my fellow birdwatchers. My pictures look more natural , theirs more "special" not that i want that sort of color explosion. but it is a bit annoying to have total control of what i'm seeing thru the lens.
i'll experiment more with this ^^
07-09-2013, 09:48 AM   #11
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If you shoot jpeg, the camera "develops" the images for you. You have some control over it, but you get more control over it if you shoot raw and then edit the photos on your computer. But that takes more time and some people think its "cheating" even though all the pros do it, and its been done with film as well, since the beginning of photography. Nobody publishes "undeveloped" photos.
And yes, some other brands tend to oversaturate colours, add extra sharpness and contrast, more than Pentax. If you change the settings on your camera or post process the raw files yourself, you can get all the same stuff out of your photos. Take a look at some bird threads on this forum, some sample photos.
07-09-2013, 10:20 AM   #12
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QuoteOriginally posted by Katmandude Quote
I've got majorly blue tinged pics of the auto setting
AWB is fairly accurate outdoors on the K-30. I might do a tiny tweak when I have mixed lighting (e.g. both sun and shade) depending on where my primary subject is located.

If you are seeing lots of bluish pictures on your monitor, I would guess that you need to calibrate your monitor. Almost without exception, the factory default for every PC monitor uses a color temp of 6500K (and sometimes 7500K) which is equivalent to deep shade and therefore too blue in most home or office settings to properly render colors. Further, colors are over saturated so business graphics using primary colors really jump on the screen.

Software-only based calibration tools are better than nothing - but from my experience, not a whole lot better. Software-only tools use your eyes and brain to make adjustments. Your brain has its own version of AWB and auto-ISO and will continually lie to you. Calibration tools that use a hardware based sensor to evaluate what your monitor IS doing versus what it SHOULD be doing do a MUCH better job.
07-10-2013, 01:37 AM   #13
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the blueish tinge is on all my monitors, both mac and pc. And they all are calibrated. that being said is does get worst on the PC workstation. THAT being said, they are getting old XD.
Anyways, did a field test last evening on plants in py garden, with heavy sunlight right next to intense shade. came out pretty nice,color on the flowers are right on the buzzer with minimal changes to the WB settings. tweaked it with the info button moved to B1, M1 to offset slightly from yellow. for areas with sand stone went further out. For sunlight areas under canopy tried the other way. More tests to come
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