『DSLR の基礎知識――AWBの有効な範囲』のクチコミ掲示板

[Peter@kakaku]

DSLR の基礎知識――AWBの有効な範囲

Under the incandescent lamp (tungsten lamp) or fluorescent lamp, do not use the Auto WB. The correct method is: Using the tungsten WB or manual WB.

Up to now, all DSLR cameras' Auto WB without includes the light source of tungsten lamp. Auto-WB color temperature's range is 4000-800(K) or 3000-7000(K).

If you accuse the DSLR's Auto WB too yellow, under the tungsten lamp, it is your own error.

About the fluorescent lamp, their spectrums were non-continuum and another portion the high peak value, their color index merely was Ra 0.6 - 0.80, and it cannot use for the Auto WB. And fluorescent lamp cannot get satisfying effect at the color photography.

(Ra, color-rendering index)

For the movie photographs the light source's color index usual higher than 0.90, but their service life below 600 hours, that as their color temperature's permissive range.

A high quality flashing light mostly is Ra 0.95 and Its color temperature 5400K, without the color filter.

The incandescent lamp (tungsten lamp) is 2700K or 2900K (less than 100W), but its color index higher than 0.95.

Tungsten Halogen lamp: 2900k or 3200k, colors index Ra 0.95, but after aging or the voltage drops would drop the color temperature. Its color temperature could keep higher 2900K merely 300 hours.

The outdoor sunlight's colors index is Ra 1.0, Its color temperature 3000 - 10000(K).

another similar topic: Do not compare that Auto-WB by the DC and DSLR between, their work principle were completely differed.

If you have recorded the RAW format files then processing it, then all no problem, which you merely need to operation the software with get better WB.

Some DSLR's WB data:

K10D, K100D:
AWB 4000-8000(K)
incandescent lamp 2850(K)
fluorescent lamp D 6500(K)
fluorescent lamp N 5000(K)
fluorescent lamp W 4200(K)
flashing light 5400(K)

Nikon D200:
AWB 3500-8000(K)
incandescent lamp 3000(K)
fluorescent lamp 4200(K)
flashing light 5400(K)

Nikon D80:
without data in manual

Canon 30D, 5D:
AWB 3000-7000(K)
Tungsten lamp 3200(K)
fluorescent lamp 4000(K)
flashing light 6000(K)

Canon 400D:
without data in manual

書込番号：7533059

[tbls_5d]

Are you smart person?
Don't explain how to use AWB.
Please explain AWB Logic.
Can you? (^o^)」よっ！

書込番号：7533663

[Peter@kakaku]

I think that:

you are a wise person, and you
could explain AWB Logic with
your AWB Logic.

書込番号：7533864

[Peter@kakaku]

I merely pondered
about correctly uses the AWB or WB
for DSLR.

書込番号：7533914

[カルロスゴン]

Hi Peter,
Is that your own idea and data?
If no, you should clearly submit us the
original source instead. I don't think
you should waste your important time
for such a long long translation.
The best way you should do is to
explain in Japanese simply, alright?


Take care,
Carlosgon

書込番号：7534496

[ジャヤガノ]

I suppose that a standard of the color
temperature is slightly different
in each makers.

If we require exact color in any light
sources, we had better take photos
with RAW fomat and develop those
by attached software.


AWB of recent DSLRs is becoming　more
available in any situation..
But I usually use RAW format.


The DSLR's WB data is useful for me.
Thank you for your imformation.

* Peter@kakau san,
I am pleased if you teach
the linked homepage.

書込番号：7534498

[Peter@kakaku]

Hello カルロスゴン,

Do you have carefully read
some DSLRs User manual?
K20D, K10D, K100D,
NIKON D200,
CANON EOS30D, EOS5D
all have shown the AWB and WB data
in their User manual. Nevertheless,
more primer user
possibly does not read it.

About each light source,
you can read their data
by the manufacturer offered.
In addition,
some related photographic
the base books
there have some explanation.

If the user had experienced
the film times,
and the positive-film had used,
then would be very easy to understand
these questions.

The film has the Daylight
and Light difference,
although today is digital times,
but DSLR's Auto-WB does not omnipotent,
it is approximate to the Daylight film,
at present still so.


Regards

書込番号：7536341

[Peter@kakaku]

The Light source's color-rendering index has another expression method:

Ra 0-100 CRI.

incandescent lamp (tungsten lamp),
2700K or 2900K (less than 100W),
2500 or 2700 K (less than 40W)
color index higher than Ra 95.

Tungsten Halogen lamp,
2900k or 3200k,
colors index Ra 95,
but after aging or
the voltage drops
would drop the color temperature.
Its color temperature could
keep higher 2900K merely 300 hours.

fluorescent lamp,
their spectrums were
non-continuum and another porti
on the high peak value,
their color index merely Ra 60-80.
it cannot for the Auto WB.
And cannot get satisfying effect
at the color photography.

outdoor sunlight,
colors index Ra 100
color temperature 3000 - 10000(K).

For the movie photographs
the light source's color index
usual higher than Ra 100,
but service life below 600 hours,
that as their color temperature's
permissive range.

書込番号：7536403

[Peter@kakaku]

The tungsten lamp color temperature
does not in the DSLR AWB's scope,
but it has a very good
color-rendering index, Ra 95 or 100.

The ordinary fluorescent lamp is
one of worst
in the color rendering index,
and do not suit for the photography.

that 2 types Light source are
our ordinary illumination source.

The high color-rendering index series
fluorescent lamp did not for the
illumination,
their price is extremely expensive.

What is color rendering index (CRI)?
http://www.goodmart.com/facts/light_bulbs/cri.aspx

color temperature,
http://www.fullspectrumsolutions.com/cri_explained.htm

http://www.sizes.com/units/color_temperature.htm

書込番号：7536570

[Peter@kakaku]

演色評価数

平均演色評価数Ｒａ
http://www.mariot-club.com/word/funhei.htm

いかに基準光源による色彩を忠実に再現しているかを指数で表したもので、原則として100に近いほど演色性が良いと判断されます。
ただし、色温度の高低差により基準光が異なるため、色温度差のあるランプ間でＲａ値のみの比較は間違いのもと！
また、色の好ましさを表していないので単にＲａ値が低いというだけではそのランプの実用的価値が低いとはいえないので注意。
白熱電球・ハロゲン球 Ｒａ１００
蛍光灯（普通形） Ｒａ６０〜７４
蛍光灯（三波長形） Ｒａ８８
メタルハライドランプ Ｒａ７０〜９６
水銀ランプ Ｒａ４０〜５０
高圧ナトリウムランプ Ｒａ２５〜８５
（ランプによってそれぞれちがうのです）

http://www.iwasaki.co.jp/kouza/313/index.html

http://www.iwasaki.co.jp/kouza/313/img/313_1.gif

演色(color rendering)

特殊演色評価数(special color rendering index:Ri):試験色1〜15個々の値。

　平均演色評価数(general color rendering index:Ra):試験色1〜8の平均値。

照明光が物体の色の見え方に及ぼす影響のことです。光源の特性と考えたときは、演色性といいます。演色評価数(color rendering index)は、試料光源の下で試験用物体色の色知覚が規程の基準光の下での同じ物体の色知覚に合っている程度を表します。JISでは、色ずれのない(完全に合っている)状態を100としています。

書込番号：7536741

[Peter@kakaku]

色彩入門：　12．照明その2

演色評価数,

http://www11.tok2.com/home/yoshih/color_abc_12.html

書込番号：7536758

[Peter@kakaku]

光源の種類によって、物の見え方が異なってきます。それは、光源によって、分光分布がちがうからです。光エネルギーが自然光のように一様に含まれているほど自然光と同じようにみえます。これを、演色性といい、Ｒａ（アールエー）で表します。


http://www.icoffice.co.jp/zukan/lighting/l_bunpu.jpg

http://www.icoffice.co.jp/zukan/l_optical.htm

書込番号：7536768

[ジャヤガノ]

Peter@kakakuさん

演色とRAの分かりやすいリンクHPを紹介いただきありがとうございました。

EOS40Dを使用しておりますが、マニュアルには格光源設定の色温度の記載が無かったんですよ。
EOS30と5Dが同じなので、恐らく40Dも同じなのでしょう。
参考にしてみます。

どのみち、RAWで撮影して、添付ソフトなどでイメージした色に追い込んでいますが・・・・

＊先の返信で顔設定を間違え（恕）になってました。すみません。

書込番号：7539091