Photovision Digital Calibration Target

[asysin2leads]

Ok, I finally got around to putting together a few sample images to show off the capabilities of the digital calibration target (http://www.photovisionvideo.com/store/shop.mvc?Screen=CTGY&Category_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:

http://img522.imageshack.us/img522/4686/img7853pl1.jpg

http://img522.imageshack.us/img522/295/img7854ne1.jpg

AFTER:

http://img522.imageshack.us/img522/828/img7857na9.jpg

[pennypue]

Holy crap, Batman!!! I think I should pick one up.

While I'm ordering lotsa other stuff, stimulating the economy, I might as well get one of these too!

[tim]

This thread was just linked from another thread. Can you show us what happens when you use the white balance dropper in camera raw to set the white balance? Sample the side of the ambulance.

[asysin2leads]

This thread was just linked from another thread. Can you show us what happens when you use the white balance dropper in camera raw to set the white balance? Sample the side of the ambulance.

I can. I am not on my computer right now, but I will.

[funhouse69]

I picked up one of these targets at a seminar years ago and used it once in a while and I have to say it really does make white balance pretty easy. At the same time I let my friend use it for a wedding she shot for a friend and I was impressed at how it worked to get the White Dress perfect as well as the Black Tux. I keep mine in my bag but don't personally do a lot of portrait work. At the same time I never really thought of using it in other situations.

[Scottes]

I'm curious about this device. Why Black, grey, and white? A grey card would set white balance and exposure. And the grey cards are a heckuva lot cheaper.

[RDKirk]

I'm curious about this device. Why Black, grey, and white? A grey card would set white balance and exposure. And the grey cards are a heckuva lot cheaper.

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.

[funhouse69]

I'm curious about this device. Why Black, grey, and white? A grey card would set white balance and exposure. And the grey cards are a heckuva lot cheaper.

Basically in an application like Phase One and I believe Photoshop you not only can set the "White" point you can choose all 3 to get the colors "Perfect" I've done it in Phase One and I really did like the results. Again I don't use mine as often as I used to or should but I might revisit it.

[Buspilot]

Ok, I finally got around to putting together a few sample images to show off the capabilities of the digital calibration target (http://www.photovisionvideo.com/store/shop.mvc?Screen=CTGY&Category_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.



What size target did you purchase? I would be interested to know how much need you see in your personal shooting for a large target.

[FlyingPhotog]

I'm curious about this device. Why Black, grey, and white? A grey card would set white balance and exposure. And the grey cards are a heckuva lot cheaper.

So you can set White, Grey and Black points using the eyedroppers in Levels or Curves.

[RDKirk]

So you can set White, Grey and Black points using the eyedroppers in Levels or Curves.

Except that the target does not give you those three tones to set those points, as I explained above. You can get one or two of them, but not all three and usually not more than one.

[asysin2leads]

What size target did you purchase? I would be interested to know how much need you see in your personal shooting for a large target.

I bought the 14" and the 34" targets as a package. I like the 34" because the backside is white and is a pretty decent reflector. I got a pretty good deal on the package or I wouldn't have bought them. I'm pretty tight w/ money.

Some may think of it as a gimmick, but it works, as you can see in the above images. It serves my purpose and am happy with it.

[ben_r_]

I have the 14" one and love it! IMO its the best option out there!

[mufutau55]

I just pick-up the 14" too for $35, with the discount Photovision sent me for their DVD 2009 discount set. I have not used it yet.. Hope to use it soon.

Mufutau

I have the 14" one and love it! IMO its the best option out there!

[bobbyz]

I was deciding between this photovision and lasolite ezybalance and finally went with the ezybalance.

[ben_r_]

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.

[bps]

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

[Tim3less]

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

[ben_r_]

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

[nureality]

Ok, I finally got around to putting together a few sample images to show off the capabilities of the digital calibration target (http://www.photovisionvideo.com/store/shop.mvc?Screen=CTGY&Category_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:

http://img522.imageshack.us/img522/4686/img7853pl1.jpg

http://img522.imageshack.us/img522/295/img7854ne1.jpg

AFTER:

http://img522.imageshack.us/img522/828/img7857na9.jpg

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.

[asysin2leads]

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.

[EnglishBob]

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.

[asysin2leads]

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.

[polobreaka]

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.

[mike_d]

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

[Eoseni]

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?

[Permagrin]

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.

[Wilt]

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...
http://i69.photobucket.com/albums/i63/wiltonw/Cloudy.jpg

...and then using the Sync to use same settings to adjust the MacBeth ColorChecker card under cloudy/rainy skies...
http://i69.photobucket.com/albums/i63/wiltonw/Cloudy_color.jpg


Now the PhotoVision target adjusted for WB using the dropper tool in Lightroom, a shot made under fluorescent light...
http://i69.photobucket.com/albums/i63/wiltonw/Fluourescent.jpg

...and then using the Sync to use same settings to adjust the MacBeth ColorChecker card under fluorescent light...
http://i69.photobucket.com/albums/i63/wiltonw/Fluourescent_Color.jpg

Lastly, the PhotoVision target adjusted for WB using the dropper tool in Lightroom, a shot made under on-board flash under ETTL control...
http://i69.photobucket.com/albums/i63/wiltonw/ETTL.jpg
and note that I had to use LR to add exposure in post processing to make the 18% gray section have a value of about 38-38-38, since Canon ETTL did its usual BS underexposure!

...and then using the Sync to use same settings to adjust the MacBeth ColorChecker card under ETTL flash, (again with LR to add exposure since Canon ETTL did its usual BS underexposure!)...
http://i69.photobucket.com/albums/i63/wiltonw/ETTL_color.jpg

In all shots of the PhotoVision target only, in the Tone Curve histogram of LR you can clearly see the three spikes representing the black, gray, and white tonal areas of the PhotoVision. So you clearly can use PhotoVision target to change your exposure in camera in order to accomplish ETTR. And you clearly can see that use of the eyedropper tool can White Balance different lighting during post processing, just as they claim. And the same could be done with Custom White Balance at the time of exposure, just as they claim.

Here are all six, as shot (daylight WB, different WB light sources...fluorescent; rainy sky; on board flash)
http://i69.photobucket.com/albums/i63/wiltonw/Asshot.jpg

So what do YOU think is the overblown claim, RDKirk?

[RDKirk]

So what do YOU think is the overblown claim, RDKirk?

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.

[Wilt]

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.

[Absolutely Fabulous]

how does this work if you set it up then change lighting conditions?

[RDKirk]

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.

You're using knowledge and experience to make up for the shortcomings of the tool. The target isn't doing the work its claimed to do, you're doing it.

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.

The target gives you a blank, detail-free white section. Blank, detail-free "white" is not supposed to be Zone VII. Zone VII is light gray. You know that and you compensate (using your knowledge and experience) for the fact that the target is not accurately representing what it claims to represent.

The most necessary bit of information for a digital exposure is the intensity (location on the histogram) of the brightest tone that must retain detail. Zone V is actually irrelevant. What you need to know is which part of the scene is Zone VII, and you need to make sure you place that tone at the top of the sensor's range. The tri-toned target does not give you a bright tone with detail (you must have detail to see the point you start to lose it)--it gives you white without detail.

Further, in normal use facing the camera (illuminated by the fill light), that white isn't really white and you have to use your knowledge and experience to determine where on the histogram it needs to fall to render it properly. It doesn't tell you what you really need to know, and to use it all you have to juggle what it does tell you.

[Wilt]

The target gives you a blank, detail-free white section. Blank, detail-free "white" is not supposed to be Zone VII. Zone VII is light gray. You know that and you compensate (using your knowledge and experience) for the fact that the target is not accurately representing what it claims to represent.

The most necessary bit of information for a digital exposure is the intensity (location on the histogram) of the brightest tone that must retain detail. Zone V is actually irrelevant. What you need to know is which part of the scene is Zone VII, and you need to make sure you place that tone at the top of the sensor's range. The tri-toned target does not give you a bright tone with detail (you must have detail to see the point you start to lose it)--it gives you white without detail.

Further, in normal use facing the camera (illuminated by the fill light), that white isn't really white and you have to use your knowledge and experience to determine where on the histogram it needs to fall to render it properly. It doesn't tell you what you really need to know, and to use it all you have to juggle what it does tell you.

But the problem is that digital is like shooting slides and the dynamic range of transparency film is widely acknowledged to be only 5EV...five Zones! Wouldn't it be necessary to have Zone VII and a half brightness area on the target for digital ETTR practioners?

Color neg has about 7EV of dynamic range. And black and white negative film has about 8-9EV of dynamic range, which is what the Zone System was conceived to help with.

The Zone System's Zone VIII really only gets applied at a practical level with color neg and black and white film, but we're talking about digital here. And HDR was invented as a technique to address the limitations of dynamic range, but ETTR itself is inherently not as applicable under that technique.

And having a spike at Zone VII still is useful, you simply don't snug it up against the right edge of the histogram as tightly as a spike in Zone VIII. Why do you need a bright tone with detail (Zone VIII), if fundamentally you know that the target spike is placed in Zone VII?! After all, the Zone System is all about 'placement', and scenes do not always have the same dynamic range to be captured.

[RDKirk]

But the problem is that digital is like shooting slides and the dynamic range of transparency film is widely acknowledged to be only 5EV...five Zones! Wouldn't it be necessary to have Zone VII and a half brightness area on the target for digital ETTR practioners?

[quote]And having a spike at Zone VII still is useful, you simply don't snug it up against the right edge of the histogram as tightly as a spike in Zone VIII. Why do you need a bright tone with detail (Zone VIII), if fundamentally you know that the target spike is placed in Zone VII?! After all, the Zone System is all about 'placement', and scenes do not always have the same dynamic range to be captured.

Remember that the range of the digital sensor is "anchored" at the top end (unlike film, the range endpoints of which flop in the breeze, coming to land at many possible points depending on development).

The very top end of the digital range is Zone X and can be nothing else. But remember that the Zones describe tonality of the scene as it has been reduced to a reproductive medium, so although to the eye a bright white is less bright than a bright light, in the reproductive medium, that might not be so. It's still true with the digital sensor--255 is as high as it goes, whether depicting a white sheet of paper in sunlight or the sun itself.

So we can't safely use a blank white tone as the anchor point because we can't know how white blank white really is--blown is blown is blown.

You can look at a white tone in shadow (the white tone of the tri-toned target facing the fill light) and accurately place its spike where it should be (reproduced as a light gray) because you already know that it should be a light gray instead of white. You're using the knowledge and expertise you already have to make up for the shortcomings of the tool. But for that matter, you could have gone through the same exercise with a gray card because you know what you're doing anyway--you didn't need no steenkeeng tri-toned target.

The immovable object that is the top end of the digital range actually makes exposure rather simple: Correctly place "the brightest tone that must retain detail" at the top of the range and that's the best single exposure you can set on the camera. You can then, if you desire, add more light to the shadows, but that's the best you can get out of the sensor itself in a single exposure.

[Wilt]

[quote]

Remember that the range of the digital sensor is "anchored" at the top end (unlike film, the range endpoints of which flop in the breeze, coming to land at many possible points depending on development).

The very top end of the digital range is Zone X and can be nothing else. But remember that the Zones describe tonality of the scene as it has been reduced to a reproductive medium, so although to the eye a bright white is less bright than a bright light, in the reproductive medium, that might not be so. It's still true with the digital sensor--255 is as high as it goes, whether depicting a white sheet of paper in sunlight or the sun itself.

So we can't safely use a blank white tone as the anchor point because we can't know how white blank white really is--blown is blown is blown.

You can look at a white tone in shadow (the white tone of the tri-toned target facing the fill light) and accurately place its spike where it should be (reproduced as a light gray) because you already know that it should be a light gray instead of white. You're using the knowledge and expertise you already have to make up for the shortcomings of the tool. But for that matter, you could have gone through the same exercise with a gray card because you know what you're doing anyway--you didn't need no steenkeeng tri-toned target.

The immovable object that is the top end of the digital range actually makes exposure rather simple: Correctly place "the brightest tone that must retain detail" at the top of the range and that's the best single exposure you can set on the camera. You can then, if you desire, add more light to the shadows, but that's the best you can get out of the sensor itself in a single exposure.

I might know what I am doing, but the PhotoVision comes with an instruction DVD to educate the uninformed, so the knowledge is not that unique even to a novice.

[thepiecesfit]

It doesnt really look good to me. Clinically perfect white balance when there is a color cast in lighting just looks fake and unnatural.

[Eoseni]

I agree with thepiecesfit. But I'd prefer to get everything WB-wise under control, then in post, add or subtract temperature from shots to taste rather than shoot ending up with multiple temperatures, and having to deal with each one separately. It's a pain.

[M_ark]

hmmmm green roads...
i think sometimes the best thing to do is to shoot b/w and call it art/old fashioned/etc.

Re: shooting at weddings - i don't, but when event shooting i'm be more inclined too shot raw and expose for the environment, and then adjust en masse using the best 'temp' appropriate in post on a 'per-lighting-conditions/location' basis.

re: the OP - there's not much difference between unifing the entire scene in a golden/yellow tones OR shooting in black and white and then appling a gold/yellow colour cast/overlay to the whole scene.IMO