Doug Kerr
Well-known member
Drew Strickland, proprietor of the ProPhotoHome forums and manufacturer of the Color Parrot white balance tool, has recently introduced a new design of that device, identified "behind the scenes" as version 1.2. He was kind enough to provide us with an early production sample for testing (Carla wants to kill him!).
So we did just that. Here is a link to our report on our findings:
http://Pumpkin.Annex.home.att.net/articles/ColorParrot_1.2.pdf
These were all "laboratory" tests. We may later do some "actual photographic" tests, although there are some real complications in doing so in a meaningful way, and we* are getting a little low on Parrot energy. So we may leave that to others.
*"What this "we", paleface?" -Ka-la Tsu-la Gi-ga-ge (Carla Red Fox)
I will present a summary of our findings here. Please note that the description of the test methods, the definition of the various quantities, and so forth are all covered (in excruciating detail) in the actual report, so please take advantage of that before you ask, "did you measure that with two nails and a potato, or what?".
Here is the bottom line:
Directivity pattern
The Color Parrot 1.2 has a relatively narrow directivity pattern. At the 50% response point (that's "3 dB down", for you antenna guys), the pattern is 1/4 the width of the classical "cosine" pattern (or of the pattern of the ExpoDisc diffuser we tested for comparison). Drew tells us that this is by carefully-crafted intent, and is beneficial to the performance of the device, especially when used in the controversial (at least here) "from the camera position" mode. We don't understand how that works - we just report the data.
The pattern of the 1.2 is somewhat narrower than that of the original version ("1.0"), so whatever you think that might do for you, you've got more of it now. If you're a believer in "cosine" diffusers (as suggested by the theory of "at the subject" incident light chromaticity measurement), this bird ain't for you.
Chromatic neutrality
The Color Parrot 1.2 tested as having a very respectable chromatic neutrality error - about 0.002 du'v' units. That is in the same ballpark as the ExpoDisc (a little better, in fact, give or take some experimental uncertainty), and is noticeably improved over version 1.0.
Equivalent total transmission
This essentially tells us how "hot" the image on the sensor is for any given illuminance of the incident light on the face of the diffuser.
For the Color Parrot 1.2, this is on the order of 3 times that for the ExpoDisc, whose total transmission is carefully "tuned" to 18%, since it (unlike the Color Parrot) it is also intended for "incident light exposure metering".
Drew points out that the "hotter" transmission of the Color Parrot 1.2 averts problems in trying to make white balance measurements with Nikon cameras (in what I call the "on the fly" mode, where no reference frame is captured for later study) in low light environments. (Evidently, in that situation the camera just gives an error message.)
This ratio is up noticeably from version 1.0 (so, if you're a closet Nikon shooter, take heart).
So we did just that. Here is a link to our report on our findings:
http://Pumpkin.Annex.home.att.net/articles/ColorParrot_1.2.pdf
These were all "laboratory" tests. We may later do some "actual photographic" tests, although there are some real complications in doing so in a meaningful way, and we* are getting a little low on Parrot energy. So we may leave that to others.
*"What this "we", paleface?" -Ka-la Tsu-la Gi-ga-ge (Carla Red Fox)
I will present a summary of our findings here. Please note that the description of the test methods, the definition of the various quantities, and so forth are all covered (in excruciating detail) in the actual report, so please take advantage of that before you ask, "did you measure that with two nails and a potato, or what?".
Here is the bottom line:
Directivity pattern
The Color Parrot 1.2 has a relatively narrow directivity pattern. At the 50% response point (that's "3 dB down", for you antenna guys), the pattern is 1/4 the width of the classical "cosine" pattern (or of the pattern of the ExpoDisc diffuser we tested for comparison). Drew tells us that this is by carefully-crafted intent, and is beneficial to the performance of the device, especially when used in the controversial (at least here) "from the camera position" mode. We don't understand how that works - we just report the data.
The pattern of the 1.2 is somewhat narrower than that of the original version ("1.0"), so whatever you think that might do for you, you've got more of it now. If you're a believer in "cosine" diffusers (as suggested by the theory of "at the subject" incident light chromaticity measurement), this bird ain't for you.
Chromatic neutrality
The Color Parrot 1.2 tested as having a very respectable chromatic neutrality error - about 0.002 du'v' units. That is in the same ballpark as the ExpoDisc (a little better, in fact, give or take some experimental uncertainty), and is noticeably improved over version 1.0.
Equivalent total transmission
This essentially tells us how "hot" the image on the sensor is for any given illuminance of the incident light on the face of the diffuser.
For the Color Parrot 1.2, this is on the order of 3 times that for the ExpoDisc, whose total transmission is carefully "tuned" to 18%, since it (unlike the Color Parrot) it is also intended for "incident light exposure metering".
Drew points out that the "hotter" transmission of the Color Parrot 1.2 averts problems in trying to make white balance measurements with Nikon cameras (in what I call the "on the fly" mode, where no reference frame is captured for later study) in low light environments. (Evidently, in that situation the camera just gives an error message.)
This ratio is up noticeably from version 1.0 (so, if you're a closet Nikon shooter, take heart).
