D7000 question on measuring color temperature: In reading Darrell Young's excellent book "Mastering the Nikon D7000" he states on p377 under "Measuring Actual Ambient Light by Using...

michaelgem

In reading Darrell Young's excellent book "Mastering the Nikon D7000" he states on p377 under "Measuring Actual Ambient Light by Using PRE": "This method allows you to measure ambient light values. ...It's very accurate since it's an actual measurement of the source light's Kelvin temperature."

That is what I want to do, measure the Kelvin temp of various sources to check for compatibility when mixing them.

He then shows how the camera measures and stores the white balance values, but nowhere is there indicated a place to get a readout of the Kelvin temperature.

Can someone tell me how to obtain the measured white balance value in Kelvin temperature, ie. 5200K is neutral daylight, 6500K northern daylight, 3100K cool white fluorescent, etc.?

Michael

snowbear

Is it possible he's referring to setting a custom WB? You photo a plain white (or grey) field and the camera bases WB on that reference photo. That's how it works on the D40, but there is no value given, unless it's in the EXIF somewhere.

There are meters that measure color temperature, but I understand they are expensive. CFL bulbs have the temperature printed on them (I have one that is 3000K)

MT Shooter Loc: Montana

You can set the Custom WB on the D7000 to any Kelvin temp you want to set it at. But you would still need another way to measure that color temp, the D7000 will not do it, I have tried everything I can think of with mine and it does not seem to have that capability anywhere.
Any idea what the "PRE" refers to?

GoofyNewfie Loc: Kansas City

"Any idea what the "PRE" refers to?"
Steve PREfontaine? Sorry, too much green beer and hanging around with the bagpipers.
Used the 7000 today and watching any threads about it.

michaelgem

MT Shooter wrote:

You can set the Custom WB on the D7000 to any Kelvin temp you want to set it at. But you would still need another way to measure that color temp, the D7000 will not do it, I have tried everything I can think of with mine and it does not seem to have that capability anywhere.
Any idea what the "PRE" refers to?

PRE (Preset manual) - Use to measure WB for the actual ambient light.

As you know manual white balance (PRE) measures the ambient light from a white or gray card in order to determine the incident lights color temperature to adjust the camera for it.

"It is very accurate since it's an actual through-the-lens measurement of the source light's Kelvin temperature."

The frustrating thing is that although it measures the source light's color temperature it apparently does not make that Kelvin temperature available. So near yet so far. Extremely annoying.

I got to believe there is a way to wring it out of the D7000. :-)

Michael

MT Shooter Loc: Montana

michaelgem wrote:

quote=MT Shooter You can set the Custom WB on the... (show quote)

I do shoot a grey card to preset WB when I need to, but it never tells me exactly what the Kelvin temp actually is.
I have also found that my Grey Tundra 821 camera case is VERY close to 18% grey and will work in a pinch.

michaelgem

Does anyone know a way to ask this question of someone at Nikon, or is that like trying to get Microsoft to answer anything?
Michael

Iowegan

There's a firmware upgrade for the D7000 to version 1.02 for A.
Ver 1.03 for B, but I don't see anything for this topic.

http://support.nikonusa.com/app/answers/detail/a_id/17542/~/d7000-firmware%3A-a%3A-1.0.2-%2F-b%3A1.03-upgrade

MT Shooter Loc: Montana

michaelgem wrote:

Does anyone know a way to ask this question of someone at Nikon, or is that like trying to get Microsoft to answer anything?
Michael

If its a service issue or question, the Nikon service number is 800-645-6678.
(They will ask you if you have the latest firmware updates installed.)

michaelgem

snowbear wrote:

Is it possible he's referring to setting a custom WB? You photo a plain white (or grey) field and the camera bases WB on that reference photo. That's how it works on the D40, but there is no value given, unless it's in the EXIF somewhere.

There are meters that measure color temperature, but I understand they are expensive. CFL bulbs have the temperature printed on them (I have one that is 3000K)

Considering that meters which measure color temperature are expensive, and the D7000 is an extremely accurate measurer of color temperature, why in heaven's name do they not make it available as a read out?

Michael

Iowegan

I just asked Nikon via tech support questions, if this a feature the currently 7000 has, or, might in the future.

Lilybear

michaelgem wrote:

Does anyone know a way to ask this question of someone at Nikon, or is that like trying to get Microsoft to answer anything?
Michael

I emailed Nikon from their website the other day because I had a question about my D90. They sent me an answer in about 2 days.

sbesaw Loc: Boston

MT Shooter wrote:

You can set the Custom WB on the D7000 to any Kelvin temp you want to set it at. But you would still need another way to measure that color temp, the D7000 will not do it, I have tried everything I can think of with mine and it does not seem to have that capability anywhere.
Any idea what the "PRE" refers to?

Got rid of all my D7000 books when I sold it to Shanna. I use "pre" with an expo disc and it works great. use it a lot for indoor BB games and it get's WB spot on. Just rotate WB until it show's "pre", check that you are in manual and have a decent exposure, put the expo disc over the lens, Hold the WB button down until the word "pre" starts flashing, point camera at subject being lite by light source, press the shutter button.

If the D 7000 reads it, it will show "good" in the top display and you will have that WB setting until you shut off the camera.

BboH Loc: s of 2/21, Ellicott City, MD

Neither my D3 nor my D300 will display the Kelvin it measures. However, both allow me to set a Color Tempreture on a scale from 2500 to 10,000 and then fine tune. I'd be rather surprised if the 7000 doesn't do the same.

MT Shooter Loc: Montana

BboH wrote:

Neither my D3 nor my D300 will display the Kelvin it measures. However, both allow me to set a Color Tempreture on a scale from 2500 to 10,000 and then fine tune. I'd be rather surprised if the 7000 doesn't do the same.

It does.