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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberMon 06-Jun-11 01:31 PM
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"Sekonic L-758"


Powder Springs, US
          

I don't know if this is the right forum, but I don't really see an exposure and metering forum, so here goes.

What is the advantage of the profiling on the L-758? I understand recognizing the clipping points and DR of a particular camera, but how does it have practical application?

The light meter can't expand the clipping points or squeeze the light its measuring into your camera's DR, so what does it do? I suppose it can tell you whether there are elements in the subject that are outside the DR or clipping range, but does it identify those elements without spot metering?

Aren't the flashing highlights in the camera's monitor a better indicator of clipping on the overexposure end?

I'm guessing there is a graph of the points on the display with a graph of the cameras range so that you could dial in an EV where the overexposure clipping points on the meter and camera graphs align?

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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blw Moderator Awarded for his high level of expertise in various areas Nikonian since 18th Jun 2004Mon 06-Jun-11 03:25 PM
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#1. "RE: Sekonic L-758"
In response to Reply # 0


Richmond, US
          

More generally, I've been wondering for years how a flash meter like this helps. (I think I have a good idea of how the spot meter and incident meter are useful.)

_____
Brian... a bicoastal Nikonian and Team Member

My gallery is online. Comments and critique welcomed any time!

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberMon 06-Jun-11 03:55 PM
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#2. "RE: Sekonic L-758"
In response to Reply # 1


Powder Springs, US
          

Well I'm certainly baffled where some think it fits in with CLS. With studio strobes and PWII units and shooting manually, I see it, because I use it. I think you mean something else though.

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberMon 06-Jun-11 05:56 PM
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#3. "RE: Sekonic L-758"
In response to Reply # 0


Phoenix, US
          

Scott and Brian:

I investigated the camera profiling feature when I acquired my L-758 DR several years ago, and concluded that it was not worth the time and effort, given the on-camera histogram and highlight screens. For many of my night law enforcement shoots I was tethered to my notebook computer which gave me a nice large image seconds after the shutter closed.

In addition to the one-degree spot, and reflected/incident readings, the 758 has an averaging function that can be useful when spot metering different areas on distant objects having a high dynamic range.

With the DR version of the 758, I can trigger my Nikon speedlights in SU-4 mode and studio strobes when they are equipped with Pocket Wizard Plus II or Multimax RF units. Once you enter shutter speed, the meter provides aperture and the percentage of illumination from the speedlights. Subtracting this from one hundred gives you the percentage contributed by the ambient illumination. Handy when trying to balance ambient and speedlight contributions.

I use the Sekonic C500R color temperature meter which can also trigger PW equipped speedlights/strobes, giving me the precise color temperature of combined illumination sources. When I first acquired this meter, I carried it with me almost constantly, measuring color temperatures everywhere I went. People thought I was daft, but I learned a great deal about color temperature and the variations that exist, simple by pointing it in a different direction. Example: measuring an overhead light source, then measuring its color temperature after the light has bounced off a wall. Interesting ...

The C500R also provides the light balancing and color correcting filters required. Once you set the color temperature target in degrees Kelvin in the meter, it provides the exact filter pack required to match it under the measured source. I'm just getting into this arithmetic, and am exploring the absorption/transmission curves associated with the various Rosco filters available. Also interesting ...

Hope this helps a bit.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberMon 06-Jun-11 07:14 PM
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#4. "RE: Sekonic L-758"
In response to Reply # 3


Powder Springs, US
          

Thanks Hal,

You have confirmed my gut feelings. I was contemplating getting a 1 deg spot metering attachment for my L-358, or moving up. I think I'll lean more towards the attachment.

I am contemplating the C500R, but would like to know how close you can get in camera just my matching the color temperature. You mention getting an array of filters, so I'm thiinking not close enough.

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberMon 06-Jun-11 08:36 PM
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#5. "RE: Sekonic L-758"
In response to Reply # 4
Tue 07-Jun-11 03:18 AM by HBB

Phoenix, US
          

Scott:

The C500R can provide a more accurate color temperature number than the pre-sets in the camera: Daylight, Cloudy, Tungsten, etc.

Color temperature meters do not do well with discontinuous spectral distribution sources like fluoresecent tubes. The camera preset may work better.

Should you acquire one, I suggest carrying it with you for a while and measuring everything in sight, as I did. It will be a real education.

Run some tests using the camera pre-set WB values, and compare them to the same image captured captured under the same illumination using the C500R Kelvin reading.

In digital mode, the C500R reads in ten degree Kelvin increments, from 2,300K to 20,000K. My D3 offers custom WB values from 2,500K to 10,000K in assorted increments of 60K at the 2,500K end, to 910K at the 10,000K end. I suspect the reason for the different intervals is to maintain a more or less constant mired interval throughout the range.

A color temperature meter is a very useful tool, but it does require some study and practice.


Edited to add: Indeed, the custom WB numbers in my D3 do result in an almost constant difference of 10 mired between values. There are two exceptions:

1) 2,560K is 9 mired below 2,500K and 11 mired above 2,630K.

2) 3,130K is 11 mired below 3,030K and 9 mired above 3,230K.

Mired is the reciprocal of degrees Kelvin, multiplied by ten raised to the sixth power.

Mired = micro reciprocal degree = (1/Degrees Kelvin)*(10^6) = (10^6)/(Degrees Kelvin)

2,500K (tungsten) is 400 mired.

5,000K (daylight) is 200 mired.

10,000K (blue sky daylight) is 100 mired.

Probably more than you wanted Scott ... If you would like, I can provide an example of how mireds are used with a color temperature meter to determine the filter pack required when the subject is illuminated by two different color temperature light sources.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberMon 06-Jun-11 09:10 PM
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#6. "RE: Sekonic L-758"
In response to Reply # 5


Powder Springs, US
          

I'm sure it would be an education. I know that in my house, the tungsten lights don't come close to matching the presets. When I dial in 2500K, things look much better. I'm thinking the tungsten preset is really for studio hot lights, as it should be, if you can only have one tungsten preset.

I always wanted a color meter with film, but aside from its expense there were all the filters and bulk. It might be more practical with digital.

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberMon 06-Jun-11 09:57 PM
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#7. "RE: Sekonic L-758"
In response to Reply # 6


Phoenix, US
          

Scott:

We have a row of six 75 Watt tungsten/halogen track lights above a dining area table that measure 2620K at full brightness. In a utility room are overhead fluorescent tubes measuring 4850K. You should see the difference in a well-balanced print when viewed under those two different sources ... amazing.

In another area are an identical set of track lights, near a medium-sized, south-facing window. On the glass pointing out the window, the C500R reads 4850K. Back six feet from the window, under the track lights and pointing at the window, it reads 3920, slightly above the average of the window daylight and the tungsten-only reading. Back about ten feet, the meter reads 3220K.

Using 3920K in the camera will result in objects closer to the window being slightly blue, and more distant objects illuminated primarily by the track lights will appear slightly red. At the 3920k setting, the camera will add enough blue to bring the image up to the "standard" 5000K to 5500K white balance. This will not be quite enough to overcome the 4850K blue coming in from the window, and it will be adding red to the objects under the 2620K reddish/yellow tungsten bulbs.

What to do in this case, if uniform color temperure illumination throughout the scene is desired?

1) Wait until night, gel the speedlights to match the tungsten bulbs, set the WB to tungsten, and shoot.

2) During daylight, gel the entire window to match the tungsten and set the camera WB to tungsten. In this way, any scene outside the windows can be captured without looking terribly blue. Rosco gels come in 22 x 24 inch or so sheets, for a few dollars each.

Doesn't this sound like fun? Be aware Scott, having one of these meters can become addictive.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberTue 07-Jun-11 03:29 AM
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#11. "RE: Sekonic L-758"
In response to Reply # 5


Powder Springs, US
          

Actually I am nerdy enough to have written a program for my HP48GX that calculates mired values. It now resides in my HP50G. So it's not more than I need to know. Actually, learning the practical application would be worthwhile pursuing.

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberTue 07-Jun-11 04:26 AM
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#12. "RE: Sekonic L-758"
In response to Reply # 11


Phoenix, US
          

Scott:

Both of us must have inherited the nerd gene.

I wrote an Excel spreadsheet that accepts the camera WB and light source figures in degrees Kelvin, calculates their mired values, then does a table lookup and spits out the filter necessary to convert the source's color temperature to the camera's WB. As you already know, the arithmetic is pretty simple.

The current range of my spreadsheet will accept a difference of + 200 (amber filters) to - 200 (blue filters), when the source mired is subtracted from the WB figure. This covers most of the available filters: Kodak, Lee and Fuji.

Yes, my C500R meter does all that at the push of a button, but how much fun is that?

Some of us truly have way much too much spare time on our hands.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberTue 07-Jun-11 12:39 PM
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#13. "RE: Sekonic L-758"
In response to Reply # 12


Powder Springs, US
          

How many filters are there in a practicable set? How close do you need to get to the true light source color?

If the camera resolves to 10 mire, then I wouldn't think you need many.

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberTue 07-Jun-11 07:29 PM
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#14. "RE: Sekonic L-758"
In response to Reply # 13


Phoenix, US
          

Scott:

A complete set of all filters for LB (from +200 to -200 mired) would be three dozen, and for CC (from 1.25 to 50 magenta, and 1.25 to 50 green) another two dozen.

If your lighting is fairly stable, as in a studio, you could likely get by with a handful for fine tuning. If your work takes you to unknown, on-site locations with unknown lighting, it might take a few more. In the film days, you had three basic color temperture emulsions: 3200K, 3400K, and 5500K and that was it. Once you loaded a specific film in the camera, the WB was fixed and you needed a lot of filters to match a variety of differing sources. Hence, the numbers indicated above.

Ten mired spacing over the 2,500K to 10,000K range in the camera covers a lot of ground, assuming once again, that you are using a color temperature meter to capture the Kelvin number to dial in to the camera's WB.

To date, with my herd of SB800s, the only filters I have used are tungsten. Should I do more interior house photography, I could see the need for a few more, but not many unless it is a really unusual situation.

Higher end studio strobes will produce +/- 1/10th stop exposure accuracy over the five to seven stop range, and +/- 20 degrees Kelvin in color temperature. With specs like that, plus the WB range available in digital cameras, the need for huge sets of filters diminishes.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberTue 07-Jun-11 08:59 PM
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#15. "RE: Sekonic L-758"
In response to Reply # 14


Powder Springs, US
          

Hal

> In the film days, you had three
>basic color temperture emulsions: 3200K, 3400K, and 5500K and
>that was it. Once you loaded a specific film in the camera,
>the WB was fixed and you needed a lot of filters to match a
>variety of differing sources. Hence, the numbers indicated
>above.

Exactly so, that's why it was never practical for me, aside from the expense. It would take too much time to get a shot and probably lent itself better to Hollywood cinematographers.

>Ten mired spacing over the 2,500K to 10,000K range in the
>camera covers a lot of ground, assuming once again, that you
>are using a color temperature meter to capture the Kelvin
>number to dial in to the camera's WB.

That's why I'm wondering whether filters are required at all for digital, if we can adjust the temperature to within 10 mires. I guess it would be nice to see photos bracketed within +/- 10 mires in perhaps 2 mire steps.


Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberTue 07-Jun-11 10:15 PM
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#16. "RE: Sekonic L-758"
In response to Reply # 15


Phoenix, US
          

Scott:

Per your suggestion:

For a 100 degree Kelvin color temperature range of 2,551 to 2,451, slightly above tungsten values, the mired numbers run from 392 to 408, in nine increments of two, totaling 18 mired. Without instruments, I doubt we could see much of a difference over the 100K range.

For a 484 degree Kelvin color temperature range of 5,747 to 5,263, bracketing 5,500K daylight value, the mired numbers run from 174 to 190, in nine increments of two, totaling 18 mired. I suspect we could see a difference over this 484K range.

The higher the Kelvin color temperatures, the greater difference a two mired interval makes. Ergo, your choice of Kelvin range has a big influence on whether or not you can see the difference in a ten or twenty mired range.

The mired approach to color temperature makes a lot of sense when applied to color space charts, as it produce more uniform intervals than would be the case using Kelvin numbers. This is why Nikon, and probably others, chose a constant ten mired interval for custom white balance input, as we discussed yesterday.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberTue 07-Jun-11 10:51 PM
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#17. "RE: Sekonic L-758"
In response to Reply # 16


Powder Springs, US
          

Hal,

>For a 484 degree Kelvin color temperature range of 5,747 to
>5,263, bracketing 5,500K daylight value, the mired numbers run
>from 174 to 190, in nine increments of two, totaling 18 mired.
> I suspect we could see a difference over this 484K range.

That's where I am wondering. If the mired values for filter correction are the same, maybe the eyes don't see a big difference?

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberTue 07-Jun-11 11:25 PM
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#18. "RE: Sekonic L-758"
In response to Reply # 17


Phoenix, US
          

Scott:

Remember, mired numbers run in inverse proportion to degrees Kelvin: The larger the mired number, the lower the degrees Kelvin (warmer color). The smaller the mired number, the higher the degrees Kelvin (cooler color).

Examples:

2,000 degrees Kelvin = 500 mired.
10,000 degrees Kelvin = 100 mired.
20,000 degrees Kelvin = 50 mired.

10 mired is the difference between 20,000K and 25,000K: a 5,000K difference.
10 mired is the difference between 2,000K and 2,041K: a 41K difference.

Remember how Mired is calculated: Mired = (1,000,000)/(Degrees Kelvin).

The mired range in my D3 runs from 2,500K (400 mired) to 5,000K (200 mired) for entering custom white balance numbers. Your camera probably has a similar range. Start with a subject under constant tungsten illumination. Then set your custom white balance to 2.500K, or the lowest setting available, and take a picture. Then, without changing the subject or the lighting, set the custom white balance to 2,560, or whatever the next WB step is, and take another picture. Repeat this, one WB step at a time, until you have reached 4,000K or so.

Then, without any post processing, start with the 2,500K image on your monitor and bring the other images up beside it one at a time, and see how many degrees of Kelvin separation are required before you can see any difference in the on-screen images. Should be an interesting exercise.

Remember also, that the color space on your monitor may be smaller/different than the color space on a print from a high-end ink jet printer on quality paper.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberWed 08-Jun-11 02:02 AM
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#19. "RE: Sekonic L-758"
In response to Reply # 18


Powder Springs, US
          

Hal,

I realize that the mired values increase as temperatures drop, inversely times 1000000. But, if you calculate the filter required by taking the difference between the mired value of the film/sensor and the mired value of the light source, then the required filtration can remain constant as the temperature difference increases and visa versa. At least that is mathematically so.

For instance:

Sensor temperature = 2500K = 400 mired
Source temperature = 2564.10k = 390 mired
Filter required = 10 mired

Sensor temperature = 7500k = 133.33 mired
Source temperature = 8108.11 = 123.33 mired
Filter required = 10 mired

If the same filter set corrects for both a 64.10K difference and a 608.11K difference, I would think we would see the differences as being the same, but maybe not.

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberWed 08-Jun-11 05:17 AM
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#20. "RE: Sekonic L-758"
In response to Reply # 19


Phoenix, US
          

Scott:

Agreed, a 10 mired difference will work in both cases, for reasons already discussed.

To clarify a bit: we are talking in both cases of the requirement for a +10 mired filter, which will add a bit of amber to the image, in order to warm it up a bit. If the subtraction produced a negative mired number (e.g., -10), we would be adding a blue filter to cool the image down a bit.

You said: " ... I would think we would see the differences as being the same ..."

I am not sure what you mean by this: the differences between what and what?

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberWed 08-Jun-11 12:55 PM
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#21. "RE: Sekonic L-758"
In response to Reply # 20


Powder Springs, US
          

Hal,

>You said: " ... I would think we would see the
>differences as being the same ..."

>
>I am not sure what you mean by this: the differences between
>what and what?


The human eye's perception of the color shift. The difference in degrees Kelvin, although 10 times as much at higher temperatures might not yield different color shifts to the human eye?

IOW, if we took 4 pictures, two corrected for the sensor's temperature, and two without the correction, we might not find the pair shot at the higher temperatures to be widley different from the pair shot at the lower temperatures?

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberWed 08-Jun-11 05:42 PM
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#22. "RE: Sekonic L-758"
In response to Reply # 21


Phoenix, US
          

Scott:

Since no two people perceive color in exactly the same way, the only answer I have is to run the test I suggested earlier, and see what you observe.

Remember, that the sensors in our cameras and the color space limitations of our monitors and printers may not reveal differences that exist at one end or the other of the Kelvin range.

I will add the test to my Two Dew list ... stay tuned.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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txrpls Registered since 20th Dec 2007Thu 09-Jun-11 10:08 PM
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#23. "RE: Sekonic L-758"
In response to Reply # 3
Thu 09-Jun-11 10:12 PM by txrpls

San Antonio, US
          

>
>The C500R also provides the light balancing and color
>correcting filters required. Once you set the color
>temperature target in degrees Kelvin in the meter, it provides
>the exact filter pack required to match it under the measured
>source. I'm just getting into this arithmetic, and am
>exploring the absorption/transmission curves associated with
>the various Rosco filters available. Also interesting ...
>
>Hope this helps a bit.
>
>Regards,
>
>HBB in Phoenix, Arizona
>Nikonian Team Member
>
> Photography is
>a journey with no conceivable destination.


Very interesting thread and I have held off purchasing a C-500 for the very reason that I don't want the correcting filters I want the correct color shifts to set in the camera body. Maybe I am wishing for too much. As demonstrated in the attached link a color temperature can have considerable color shifts.

http://en.wikipedia.org/wiki/Color_correction

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberThu 09-Jun-11 10:58 PM
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#24. "RE: Sekonic L-758"
In response to Reply # 23


Powder Springs, US
          

I think what's key here is how much of a change in mired units does it take for the human eye to perceive a noticeable change. I have no idea. It does seem that 10 mired units resolves closely enough to negate the need for filters in all but the most demanding situations.

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberFri 10-Jun-11 12:30 AM
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#25. "RE: Sekonic L-758"
In response to Reply # 23


Phoenix, US
          

Mark:

Thanks for joining us in this thread.

On page 144 of my D3 manual is a list of the color temperatures used for the different preset selections: Auto, Incandescent, etc. Also incuded are Kelvin values for sodium vapor lamps, five different fluorescent tubes, and high temperature mercury vapor lamps.

The Auto white balance range of the D3 is from 3500K to 8000K, which should cover a majority of situations.

In my view, while the Auto and other preset WB selections cover a lot of ground, for those interested in greater precision a color temperature meter will still be handy under unusual conditions.

Examples:

1) Under the Fluorescent preset, there are five Kelvin numbers, ranging from 3000K to 6500K, a difference of 179.5 mired. Unless you can get close enough to the tube to read the type (Warm-white, white, cool-white, etc.) how will you know which preset value to select? The Fluorescent preset also includes sodium vapor lamps at 2700K and high pressure mercury lamps at 7200K. Would you have guessed that there was this much difference between them? I probably wouldn't.

2) The Auto WB ranges from 3500k to 8000K. I have several tungsten soources around here that are at 2600K or so, a difference of 51.3 mireds.

3) In early morning under a clear sky, with my back to the sun and holding the C500R in front of me, pointing up, I can acquire readings way above the 8000K limit of the auto WB selection.

If one can acquire a good color temperature meter, it is a marvelous learning tool. I loaned my earlier Minolta Color Meter IIIF to a friend recently, and he was thrilled with what he learned. Absent the meter option, once one learns to accurately estimate the color temperature of various illumination sources encountered, I suspect a reasonable improvement over simply selecting Auto WB will be achieved. This would likely take some practice and eye/brain conditioning, but should be an achievable goal.

The big, remaining, unanswered question is: How large a mired change is required before the average human eye/brain can perceive it. Nikon chose ten mired as the interval between 2500K and 10000K for some reason. I guess I will have to perform a simple test to see if I can detect a ten mired difference between two indentical images, captured under the same illumination source. Stay tuned.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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txrpls Registered since 20th Dec 2007Fri 10-Jun-11 03:20 AM
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#26. "RE: Sekonic L-758"
In response to Reply # 25


San Antonio, US
          

Hal, I understand all of the mired, but it would sure be nice to adjust the green-magenta or the amber-blue axis from information from the color meter.

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberFri 10-Jun-11 06:45 AM
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#27. "RE: Sekonic L-758"
In response to Reply # 26


Phoenix, US
          

Mark:

The C500 and C500R will provide the filter pack for the amber-blue axis and the green-magenta axis, where it is applicable.

The amber LB filters range from +9 to +200 mired, and the blue LB filters range from -10 to -200 mired.

The magenta filters range from CC-1.25M to CC-50M, and the green filters range from CC-1.25G to CC-50G.

When appropriate, the meter responds with the amber-blue filters, and the magenta-green filters. In the absence of a magenta-green requirement, it provides just the amber-blue.

I have been able to find just one example here in the house where a magenta-green CC filter was indicated in addition to the amber-blue LB filter. The target setting on the meter was 2500K, and I metered a set of fluorescents at 4870K. In addition to the A16+A3 amber LB filters to meet the 194 mired difference, it indicated a 4 magenta CC filter.

I am unable to replicate the magenta-green calculations because the meter does not provide the relative strength of the RGB components in the illumination it is measuring. The instruction book provides no light either. Sigh!


As you may have guessed by now Mark, this is primarily an academic exercise to explore the workings of my C500R.

Tomorrow, Friday, I will conduct the simple test to try and determine how small a mired change I can perceive.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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txrpls Registered since 20th Dec 2007Sat 11-Jun-11 10:28 AM
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#28. "RE: Sekonic L-758"
In response to Reply # 27


San Antonio, US
          

Hal

Glad you are taking the time to check this out. If the suggested CC values could be translated to the in camera color balance axis I would jump on a C-500 tomorrow. With all of the smarts built into my D3s I would think this would be possible without having to use light balancing filters.

Have fun,

Mark

Visit my Nikonians gallery.

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberSat 11-Jun-11 06:09 PM
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#29. "RE: Sekonic L-758"
In response to Reply # 28
Sat 11-Jun-11 06:19 PM by HBB

Phoenix, US
          

Mark et al:

The promised color temperature test can be found here, pinned at the top of this forum.

I don't understand everything I know about the results yet, but it is a start, and I am looking forward to comments. That said, I believe that the C500R offers more accurate camera WB settings because the Auto selection range in my D3 and D3X is 3,500K to 8,000K. Their Custom WB range is 2,500K to 10,000K, thus affording more accurate ten mired settings over a much wider range.

I am willing to repeat the test should discussion reveal a flaw in my logic, setup, or assumptions.

Thanks for you participation Mark.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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walkerr Administrator Awarded for his con tributed articles published at the Resources Awarded for his in-depth knowledge in multiple areas Donor Ribbon awarded for his very generous support to the Fundraising Campaign 2014 Nikonian since 05th May 2002Mon 06-Jun-11 10:15 PM
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#8. "RE: Sekonic L-758"
In response to Reply # 0


Colorado Springs, US
          

I've tried it, but found the profiling feature more awkward than beneficial. I think you're generally better off setting your picture control settings to generate as accurate of histogram as you can get. In my case, I set contrast to low, the color profile to neutral, but don't go the final step of using a UniWB or turning off sharpening. That makes the histogram slightly less accurate, but in practice I rarely find it to be a problem.

On the other hand, an incident meter or handheld spot meter can be handy at times, but I usually leave mine at home in lieu of using the histogram these days. It's sometimes easier for judging a contrast range when your camera is on a tripod (especially when using grad filters), but I've gotten pretty good at estimating those.

Rick Walker

My photos:
GeoVista Photography

  

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ScottChapin Moderator Awarded for his high level skills in various areas, including Aviation and Birds Photography Charter MemberTue 07-Jun-11 01:13 AM
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#9. "RE: Sekonic L-758"
In response to Reply # 8


Powder Springs, US
          

Thank you, Rick,

My L-358 stays home most of the time too. I've been reluctant to ask the profiling question for fear of sounding sacrilegious and ignorant. At least I know I'm on track with it. If I didn't already have the L-358, I would go for the L-758 for the built in spot meter.

Scott Chapin
Powder Springs, GA, USA
Nikonians Team Member

  

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HBB Moderator Hal is an expert in several areas, including CLS Awarded for his excellent article contributions to the Resources. Charter MemberTue 07-Jun-11 03:17 AM
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#10. "RE: Sekonic L-758"
In response to Reply # 9


Phoenix, US
          

Scott:

I tacked on some additional mired calculation data in response #5 above. Let me know if you would like to pursue this topic in any more depth.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.

  

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