Photovision Digital Calibration Target

bobbyz wrote in post #8851810
I was deciding between this photovision and lasolite ezybalance and finally went with the ezybalance.

I had that one first, ended up swapping it for the photovision.

Yes, the Photovision calibration targets are expensive, but IMO they are superior. If needed, cringe when buying one. But I assure you, once you've used it, you'll be glad you bought one.

Bryan

There's a discount for the PhotoVision targets, B&H has the 14" for $35 free shipping.

Tim3less wrote in post #8855841
There's a discount for the PhotoVision targets, B&H has the 14" for $35 free shipping.

That is a good price!

asysin2leads wrote in post #6361743
Ok, I finally got around to putting together a few sample images to show off the capabilities of the digital calibration target (http://www.photovision​video.com …en=CTGY&Categor​y_Code=DCT). The EXIF should be intact. BTW, I am NOT looking for critiques of the images. These were handheld shots. I just wanted to show off what the calibration target can do.

I took these under some nasty lights at work. As you can tell, they give off an orangish tint.

BEFORE:

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AFTER:

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The bottom shot's colors are way too cold for my taste. Whitebalance cards work, always have, as do caps and such... but your colors are off there.

nureality wrote in post #8863856
The bottom shot's colors are way too cold for my taste. Whitebalance cards work, always have, as do caps and such... but your colors are off there.

Well then you tweak them a bit. Gray card or digital target, you should tweak things. Use it or don't use it. Makes me no never mind. I was simply showing what the calibration target is capable of.

Just picked one of these up and like the results so far.

Teh difference on that ambulance it outstanding, even my wife wasa impressed with the changes, and she hats me buying photo "gadgets" LOL.

EnglishBob wrote in post #9155253
Just picked one of these up and like the results so far.

Teh difference on that ambulance it outstanding, even my wife wasa impressed with the changes, and she hats me buying photo "gadgets" LOL.

My wife and I went to the Captivated by the Light seminar together. When he used the target to show the difference in the WB, my life leaned over and said, "You'll be buying that tonight." I have to listen to my wife, right? I had a wedding last Saturday. The carpet was purple. It's amazing the difference in the colors of purple w/ and w/out the calibration target.

so let me try to understand how this works, WB is very confusing to me.

1. you shot the ambulance without adjust WB.

2. then you put the calibration target in front of your camera and take another picture.

3. then you retake the same ambulance and the camera automatically adjust to it? and if it does, what if you shoot something else and will WB be thrown off again?

sorry im a noob..i know.

polobreaka wrote in post #9247773
so let me try to understand how this works, WB is very confusing to me.

1. you shot the ambulance without adjust WB.

2. then you put the calibration target in front of your camera and take another picture.

3. then you retake the same ambulance and the camera automatically adjust to it? and if it does, what if you shoot something else and will WB be thrown off again?

sorry im a noob..i know.

There's a couple of ways to do it:

Method #1 -

* Shoot in raw
* Camera's white balance set to auto - the color temp will likely vary from shot to shot but it doesn't matter since you're going to fix it later.
* At some point in the shoot, take a picture of an object with out a color cast to it. ie a neutral grey card. This object must be taken under the same lighting color as the rest of your shot
* In the computer, get the picture containing your neutral target and use the eyedropper tool to tell it that's what neutral should be
* Apply that setting to the rest of your pictures

Method #2 -

* Fill the frame with a neutral object under the same lighting conditions as the rest of your shoot and take a picture
* Go into the camera's menus and tell it to use that picture as the custom white balance
* Set your white balance to custom
* Shoot away
* If the light changes, you'll have to redo your custom white balance

In a multiple color temperature environment, such as a wedding reception place etc., one would need to Customize WB using this target at every area where the light color temperature is unique - if a photo was being taken under those lights. This is impractical in a quick moving wedding environment - even with an assistant holding it - since this target needs to be used under those lights - unlike a WB tool, such as the "filter" types like the ExpoDisc, or ColorRight - that sits right on your lens. Any difference between these filter types and PhotoVision target in RESULTS you get? Anyone used both methods and please say whcih way is preferred and why. Also, does using flash at various distances confuse the whole thing?

We use our target at weddings. It's relatively simple to get a quick shot with the target in each area. I find it much more useful than attempting to get a custom WB at each stage.

RDKirk wrote in post #8240582
You're right about white balance, and if you take an exposure meter reading from the entire card, the black and white tones average out to the same gray level as the gray tone. But the claim is that the three spikes the target gives you on a histogram will tell you something about how to be sure the exposure correctly places those tones.

Personally, I consider it a gimmick. It can be made to work, but it doesn't give you the information it claims to give.

To do that, it would have to be a two-dimensional target--a cube with three tones on each face, or at least the faces visible to the camera. Only the face illuminated by the main light would show a true white (the highlighted white) and only the face illuminated by the fill light (the shadows) would show you the true black (the shadowed black).

If you have only one target turned to the main light, the black tone (being a highlighted black) is photographically a dark gray. If you turn the target toward the camera, the white tone (being a shadowed white) is photographically a light gray.

And in fact, none of those tones is the tone of primary interest for digital exposure. The tone of primary interest for digital exposure is "the brightest highlight that must retain detail" (which would be Zone Eight in Zone System parlance).

That tone must be identified in the scene and placed at the top of the histogram to gain the greatest dynamic range and the least noise the sensor is capable of capturing. The three-toned target doesn't even have that tone.

Not sure why your doubt! Here's a series I just shot. Note that I did not use the three spikes in the histogram to make any of these shots per ETTR, but shot them as indicated by the camera meter (or as shot per flash under ETTL control).

First, the PhotoVision target adjusted for WB using the dropper tool in Lightroom, a shot made under cloudy/rainy skies...

You proved my point very nicely. May I use those images the next time I have this discussion in a forum?

First, look again at the histograms--not a single one of them shows the "white" spike over on the far right where it belongs. And, indeed, in the image the "white" is not white...it's merely light gray.

Second, all your test images are 2-dimensional, and as I pointed out we normally photograph 3-dimensional subjects. That's also where that target fails.

What you need is a Zone 8 tone that you can reliably peg to the top of the histogram.

RDKirk wrote in post #9420879
You proved my point very nicely. May I use those images the next time I have this discussion in a forum?

First, look again at the histograms--not a single one of them shows the "white" spike over on the far right where it belongs. And, indeed, in the image the "white" is not white...it's merely light gray.

Second, all your test images are 2-dimensional, and as I pointed out we normally photograph 3-dimensional subjects. That's also where that target fails.

What you need is a Zone 8 tone that you can reliably peg to the top of the histogram.

Wait you are missing the point of 'proper exposure' vs. 'optimal exposure for shadow detail to be best captured' (the Expose to the Right).

A meter, using a 18% gray card or the middle zone of the Photovision target, gives you a 'proper exposure' reading for accurate reproduction of objects in the scene at their inherent brightness. That was achieved with the camera meter causing the middle zone of the target to have values about 40-40-40, and was missed by the ETTL flash exposure. This is the traditional film exposure for optimum recording of brightnesses on film, and also for inherent accuracy of tonal reproduction on both film and on digital. I mentioned that I deliberately did not try to use ETTR! Keep reading...

As discussed in PhotoVision's DVD about its use, one can use EC to move the exposure to the right, so that the white zone's spike is registered just inside the histogram and so that more of the 4096 levels of brightness are used to capture shadow detail. And then you have the correct offset for ETTR practioners. No guessing about metallic reflections and where they appear on the histogram, since it would be normal for such highlights to record without any detail...off the histogram. No guessing how far to the right, because you move the exposure to the right yet keep the white spike inside the histogram.

The middle zone of the PhotoVision target is Zone V, the black zone is Zone III, the white zone is Zone VII. So Zone VIII is not present, as you stated. But regardless of the scene, it does represent fixed levels of tonality, whereas the typical reflected light scene has photographers guessing about which pixels could or could not fall off the right edge of the histogram. Zone VIII might be better than Zone VII, I'll admit.