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Author Topic: Transmissive camera profiling target...  (Read 2097 times)

Czornyj

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Transmissive camera profiling target...
« on: June 29, 2010, 07:02:02 pm »

I like CC Passport, but there's one small problem with this product - it's somehow problematic to use for, let's say, wedding photojournalism.

I imagined myself, that a kind of diffuser with transparent target on it and maybe a close-up lens combination could be simplier to use in such situation, but before I'll start to experiment with sticking staind-glass effect foils and old IT8 targets on WB caps I'd like to ask: do you think there's a chance that something like that would work, or maybe there's some kind of a catch I didn't think of, and it's not feasible to make it work?
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digitaldog

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Transmissive camera profiling target...
« Reply #1 on: June 29, 2010, 07:07:13 pm »

Are you shooting mostly raw? Because unless you shoot JPEG with differing lighting situations, I suspect the biggest  benefit of Passport would be to build maybe two or three DNG profiles (daylight, tungsten, a mix, etc). IOW, not sure there is a need to be attempting to shoot every scene with the Passport or just occasionally when time and an odd illuminant presents itself.

Someday what we need is a small, inexpensive Spectrophotometer built into the camera that captures information about the illuminant, tags that to all the images captured under this lighting and builds an on the fly profile. That day may be a bit far off considering the cost to build such a device that most photographers would buy.
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Steve Weldon

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« Reply #2 on: June 30, 2010, 02:01:01 am »

Quote from: Czornyj
I like CC Passport, but there's one small problem with this product - it's somehow problematic to use for, let's say, wedding photojournalism.

I imagined myself, that a kind of diffuser with transparent target on it and maybe a close-up lens combination could be simplier to use in such situation, but before I'll start to experiment with sticking staind-glass effect foils and old IT8 targets on WB caps I'd like to ask: do you think there's a chance that something like that would work, or maybe there's some kind of a catch I didn't think of, and it's not feasible to make it work?
I've used a host of such products for years.. and most recently have been using my standard CC with their free software to get an idea how the CC passport would work.. and ended up ordering one with my recent NEC puck purchase mostly out of curiosity.

I've noticed two main things with these devices.

1.  You need to train your assistant to get them into the scene every time the light shifts/changes for you.. its far too much hassle to have to think about it yourself for event shooting.

2.  These devices never get things 'perfect', and perfect usually isn't what I want anyway.  What I really want is to get that elusive hue/tint value close enough to easily work with which allows me to adjust the temp to taste.  


Its seem to me.. that most of the time AWB with an experienced eye tweaking the WB in post is the most practical and fast solution and acceptable for most.. but sometimes light is difficult and its nice to have these to lean on and use as 'a tool' but not the ultimate tool.  Its just one more way to get the job done.

Mixed light becomes the most difficult.. and the most difficult to train the assistant to see and then to choose where to put the CC in relation to the light.  We do this enough with slow paced shoots to so the assistant gains experience so the faster paced events like weddings become possible.

I encourage you to try to make something better.. we all want something better.  It might push one of my current devices into the depths of the photo equipment graveyard located in the rough looking cardboard box last seen in the storage room behind the old ironing board and in front of the new NEC monitor shipping boxes..
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shewhorn

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Transmissive camera profiling target...
« Reply #3 on: June 30, 2010, 11:27:27 am »

For white balance only the ColorRight Pro looks intriguing. I've not tried it myself though.

http://colorright.com/colorright-pro-p-30.html

Since it's something you shoot through it's a lot easier to use as you don't have to rely upon placing a target, removing it, and then shooting.

Cheers, Joe
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shewhorn

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« Reply #4 on: June 30, 2010, 11:33:41 am »

Just another thought. I own the Passport CC but I've found that the software that comes with it doesn't render the most accurate profiles. I've had much better results using Adobe's DNG profile editor to build the camera profiles but ultimately as Steve mentioned, I pretty much just adjust WB in post on the fly. The recently updated camera profiles from Adobe for the D700 are an improvement over the previous profiles. I personally have found that using any kind of target based product that must be placed in the scene to be too cumbersome when shooting events (and too difficult to keep track of). In a church alone you often have halogen lighting on the altar, a few feet away where the couple is is often mixed with light reflecting off of the altar as well as some form of tungsten light AND a mix of natural light. Then you have areas that are just natural light being filtered by whatever windows the church has (and often there's stained glass in the mix).

That's just too many different sources of light for me to be able to use a target effectively. It would just take too much time during the shoot, and in post to make sure the right profile is associated with the right shot.

Cheers, Joe
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Czornyj

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« Reply #5 on: June 30, 2010, 12:01:40 pm »

Quote from: Steve Weldon
1.  You need to train your assistant to get them into the scene every time the light shifts/changes for you.. its far too much hassle to have to think about it yourself for event shooting.

Quote from: shewhorn
I personally have found that using any kind of target based product that must be placed in the scene to be too cumbersome when shooting events (and too difficult to keep track of). In a church alone you often have halogen lighting on the altar, a few feet away where the couple is is often mixed with light reflecting off of the altar as well as some form of tungsten light AND a mix of natural light. Then you have areas that are just natural light being filtered by whatever windows the church has (and often there's stained glass in the mix)

That's exactly why I started thinking about such transmissive target. In churches, wedding ballrooms etc. there's usualy a wild spectral coctail, so it would be nice to have some kind of diffuser with transparent target, that will average the spectra of the scene, and correct eventual illuminant oddness, that cause color distortions.

It's not a perfect solution, as it's simplified and D50-centric, so - like Andrew - I'd also rather mount a ColorMunki on the hot shoe, but it still needs a target, or a whole new spectral workflow - like alredy discussed in this topic:
http://luminous-landscape.com/forum/index....149&hl=papa v2.0&st=60
« Last Edit: June 30, 2010, 12:34:58 pm by Czornyj »
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Marcin Kałuża | [URL=http://zarzadzaniebarwa

BobD

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Transmissive camera profiling target...
« Reply #6 on: June 30, 2010, 04:39:09 pm »

I agree with the overall assessment that using the CC passport for every different shooting situation is not practical for fast moving event photography. However, creating a generic "shoot-specific" profile for the "wild spectral coctail" like maybe the reception foyer with a window, fluorescent and tungsten light mixture does seem practical.

But I find the value of the CC Passport is to normalize the inherent color bias of your camera and more importantly of multiple camera bodies.  Creating "dual-illuminant" profiles for each different body will help get the color of those "teal" and "champagne" dresses "more consistent" on multiple camera shoots.  A multiple camera shoot could be a two-photographer formal event or a family with multiple cameras on the same vacation shooting the same terracotta wall.

The Xrite CC Passport plug-in for Lightroom automates the creation of these "digital camera profiles" (DCP).  On IMPORT, Lightroom can recognize the camera and apply the correct DCP to the file. Even if the same card was inserted in multiple cameras bodies - LR would recognize the exposures from the different cameras and apply the correct "dual-illuminant" profile to the appropriate file!

Remember, you still need to keep the WB into your workflow and click on the light gray patch of the CC target (or a light neutral in your photo).  The use of the DCP is only to normalize the bias of the lighting conditions and the bias of the camera.  

If you shoot the CC Passport under controlled conditions (Daylight and Tungsten A), you can then create a standard "dual-illuminant" profile for each camera and take full advantage of ACR's dual illuminant look-up-tables.

Bob DiNatale
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