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Author Topic: Expose to the right.  (Read 16250 times)
ChristopherFrick
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« on: May 08, 2008, 09:41:40 PM »
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Hello all,

My name is Chris from Perth Western Australia. Lately I have been shooting autumn scenes in the orchard growing valley near where I live. If anything I'm also using the experience in getting to know my Canon 40D better.

I have read the articles on "expose to the right" (ETTR)  and watched the ACR video but I'm still not 100% happy with my results. If I ETTR so that the brightness histogram on the camera falls short of clipping I'm finding that the highlights on yellow and red leaves are swamped with no chance of detail or recovery in ACR.

However the RED channel (according to the camera's histogram) is clipped. In my ETTR technique I focus on the brightness histogram not clipping and not caring about the R, G or B channels.

Should the rule be to ETTR until the first channel just falls short of clipping ie R, G, B or brightness?

Regards,
Chris.
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Panopeeper
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« Reply #1 on: May 08, 2008, 09:52:42 PM »
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Read http://forums.dpreview.com/forums/read.asp...essage=26534648

Creating the WB template can be done much simpler, but you can download the one mentioned in that post.

Set sharpness, contrast, saturation, tone to 0 (this is the *middle* setting, except for sharpness).

You can achieve ideal ETTR within 1/3 stop and rely on the in-camera clipping indication (blinking). However, the preview and the thumbnail will be greenish and you *always * have to pick WB in the raw processing. Always shoot a white card or whatever if the scenery does not contain anything for WB picking.

I copied the WB template into the folder of the CF card and made it read only; this way it remains there even if you "erase all".

If necessary, you can change the WB from the preset to whatever and change it back afterwards. I have not moved away from this since I have created this template. I almost always shoot with exposure bracketing, check out the histograms and the blinking and if necessary, make another shot. Before processing, I select the best exposed shot with Rawnalyze, though you can rely on the in-camer histogram as well. DO NOT rely on the histogram shown by DPP or ACR et al.
« Last Edit: May 08, 2008, 09:53:34 PM by Panopeeper » Logged

Gabor
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« Reply #2 on: May 09, 2008, 06:40:42 AM »
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Hello all,

My name is Chris from Perth Western Australia. Lately I have been shooting autumn scenes in the orchard growing valley near where I live. If anything I'm also using the experience in getting to know my Canon 40D better.

I have read the articles on "expose to the right" (ETTR)  and watched the ACR video but I'm still not 100% happy with my results. If I ETTR so that the brightness histogram on the camera falls short of clipping I'm finding that the highlights on yellow and red leaves are swamped with no chance of detail or recovery in ACR.

However the RED channel (according to the camera's histogram) is clipped. In my ETTR technique I focus on the brightness histogram not clipping and not caring about the R, G or B channels.

Should the rule be to ETTR until the first channel just falls short of clipping ie R, G, B or brightness?

Regards,
Chris.
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Chris,

In exposing to the right you really don't want any channel to clip, at not least not clip beyond what can be recovered by the raw converter in some high dynamic range cases.

Since the green channel receives the most exposure with daylight illumination, if often clips first with subjects that have all three primary colors more or less balanced. For a good discussion look at this link: [a href=\"http://www.cambridgeincolour.com/tutorials/histograms2.htm]Cambridge in Color[/url]. The luminosity histogram is not that sensitive to blue and and red, since  green represents 59% of the perceived luminosity, while the red and blue channels account for just 30% and 11%, respectively. Hence, the luminosity histogram may not detect clipping in the red and blue channels.

You should look at the RGB histogram to check for clipping in these channels. The camera histogram comes from the JPEG preview of the raw file with the camera settings applied. As Panopeeper suggested, you should use neutral settings in the camera and I would suggest using the widest color space available, usually Adobe RGB. The camera histograms are usually conservative and may indicate clipping when none is present.

To achieve white balance, the red and blue channels are multiplied by a factor greater than one and the green channel is left alone. This applies to daylight illumination. Because the red and blue multipliers are greater than unity, they may be blown in the white balanced rendering but not in the raw file. To get a better idea of the status of the raw file using the camera histograms, you can use a UNIWB as Panopeeper suggested.

Another approach is to use a tool such as Panopeeper's Rawanalyze to look at the raw files and learn how the camera histogram performs under various conditions. With Nikon cameras it is easy to upload a UNIWB into the camera and place it in one shooting bank, calling it up when necessary. I have done this with my D200 and D3, but find it is not usually necessary to use the UNIWB in most situations. With ACR you have to upload NearUniWB where the coefficients are near unity but not 1.0 or else ACR will think you have a double exposure.

Finally, in converting the raw files in ACR you should use ProPhotoRGB if you see saturation clipping in a narrower space (aRGB or sRGB).

Bill
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ChristopherFrick
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« Reply #3 on: May 09, 2008, 09:23:23 PM »
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Thanks Pano and Bill.

I've grabbed Pano's 40D CR2 file and will play with the camera settings in a few days when it stops raining   (but we need it!)

Does the Picture Style have an effect too? It's not mentioned.

Regards,
Chris.
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Panopeeper
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« Reply #4 on: May 09, 2008, 09:33:55 PM »
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Does the Picture Style have an effect too? It's not mentioned.
A picture style is the collection of the settings sharpness, saturation, etc. When you select a picture style, you select all included settings. Thus you can assign the neutral settings to a picture style. There is a style called "neutral", why not to use that? I don't remember if all settings were neutral in the neutral style, for I may have changed it.

I know I have written it, but you *must* remember this: always make a WB shot (but do not use it as WB preset, of course), except if there is some smooth white/grey whatever, for you *always* have to pick WB.
« Last Edit: May 09, 2008, 09:36:53 PM by Panopeeper » Logged

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ChristopherFrick
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« Reply #5 on: May 09, 2008, 09:44:27 PM »
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Only reason I mention picture styles is because I noticed when playing in Canon's DPP and changing styles how the image goes from ok'ish to fugly.

But on a side note how do you do a practical WB shot when your subject/target is >50m   away or a wide panoramic?
« Last Edit: May 09, 2008, 10:02:38 PM by ChristopherFrick » Logged
Panopeeper
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« Reply #6 on: May 09, 2008, 11:18:06 PM »
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how do you do a practical WB shot when your subject/target is >50m   away or a wide panoramic?

I have no experience with, but I think it is a good idea for certain situation: the Expodisk.

Normally one makes a WB shot in the direction of the real target, in order to catch the light reflected from the same direction as the light arrives from your real target.

The Expodisk (I hope I rememebr the name correctly) is semi-transparent, it has to be on the lens, and one shoots in the direction of the *light source*; this way the distance to the target is irrelevant.

The downaside of thie method is, that it does not work with mixed light. As cuh, reflected light from example from large water surface or from a greened mountain side will not be accounted for.
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ChristopherFrick
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« Reply #7 on: May 10, 2008, 09:17:19 PM »
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Well I have tried the WB trick and yes it's a clever little workaround for the 'raw' histogram. The green image is a little off putting though.

I think I'll set the WB trick as a custom setting to get the exposure values through LIVE VIEW then shoot in manual with daylight WB just so I can review the image quicker in ZoomBrowser. Trial and error etc.

Thanks very much.

Regards,
Chris.
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lovell
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« Reply #8 on: July 18, 2008, 07:02:49 PM »
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It is not a sin to clip the highlights.  One has to determine what the primary and secondar elements of their composition are.  And if it benefits the primary element/s to clip the highlights of elements in the composition that don't matter, then so be it.  

I think the biggest mistake that users of ETTR do is to prevent any and all clipping, and at the detriment of the primary element/s in their compositions.

Clipping done judiciously often provide the best image information/details.

There is an unnamed landscape photographer that shows up in this forum now and then and he boasts that his comps never blow highlights, and he is right, however looking at this vast gallery of excellent comps, one very quickly sees a pattern of blocked up shadows, and way too dim mid tones, but who cares?!?  The highlights are never clipped!!!  lol

Continue to practice ETTR, and shoot raw, and never, never, never judge exposure by looking at the image on the camera's LCD display...it lies too much....better to ascertain exposure by looking at the histogram.  However the blinkies on the image displayed can be helpful to show areas of "possible" blown highlights.  And eventhough you may be shooting raw, nuetralize/turn off all in-camera post processing, like contrast, saturation, sharpening, that sort of thing....nuetralize/turn off PictureStyles, which are the stupidest "feature" Canon has given us...keeping these on will only effect the tiny jpg that gets generated in-camera for the sake of displaying the image on the camera's LCD...it does not effect the raw and since it doesn't why allow the camera to "deceive" you?  Also, never try to expose so that the image looks "right on"....often a correctly exposed raw image will look flat, over exposed, lacking contrast, lacking pop, and more often then not, this is a very good thing; a good foundation to build upon during post process mastering later on the PC.

One more thing, when shooting raw try to get the WB as close as possible because it's value will effect exposure, even if WB can be tweeked later for raw images.  Use color space ProRGB as it is the widest.
« Last Edit: July 18, 2008, 07:11:25 PM by lovell » Logged

After composition, everything else is secondary--Alfred Steiglitz, NYC, 1927.

I'm not afraid of death.  I just don't want to be there when it happens--Woody Allen, Annie Hall, '70s
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« Reply #9 on: July 18, 2008, 07:25:54 PM »
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wow.. I am tottally confused ! Whew I could never have ever created photographs in 100% ice & snow using a digital camera.. WITH FILM is was so easy one frame per subject. no bracketing ever !

No light meter, no batteries, I did all the thinking. not some computer in a camera.

I enjoy a very high degree of confidence using FILM .. Out on the ocean ice, I can walk around all day long, year in and year out. no light meter, just a roll of film and every frame is consistently exposed properly. Each of these images I have posted is straight out of the camera. NO POST PROCESSING

I fear this is quickly becoming a lost art. People think that photoshop is a must to use to create a photograph.

Find some very old issues of National Geographic These pros used FILM ISO 25 Now look at what these pro's did using film with no post processing what so ever. !!!

Mastering Color Theory will help you out so much in many different ways when you understand how the six different colors work with each other and the effects they have . Color(s) are very predictable they obey rules. if you learn these rules you will have no problem at all correcting your images !!
[a href=\"index.php?act=findpost&pid=199592\"][{POST_SNAPBACK}][/a]

1. Why do you think one needs a light meter with digital and not film?  With digital we have histograms so the need for a light meter is much, much less, and I've not used mine since I switched to digital many years ago.

2. Until you master digital workflows, I would (1) not trash digital, and (2) not compare it to film yet, and (3) not draw any conclusions between the two yet.

3. You really can't say that you do all the thinking when shooting film UNLESS you master the prints in a wet darkroom.  Digital allows the photographer to do more of the thinking and have more control then just shooting film and NOT performing wet post processing.

Lost art?  One could argue that you "lost the art" with film by not mastering your exposures in a wet darkroom.  Now I don't think you lost the art by not using a wet darkroom, so how can you coclude that post processing digital captures is somehow losing the art of it all?  Ansel Adams post-processed nearly all his captures.  This is no different from post processing digital images on a computer.

Often newbies to digital (not photography) fail to learn how to expose digital captures.  It is not necessarily like film.  With digital it's about capture the most image details/nuances across the dynamic range.  Think of exposing for slide film, as there are similarities in regard to highlights.  The great thing about digital is that with raw, ettr, and proper mastering later on the computer one can "extend" the dynamic range and the awesome tools that many programs provide allow one to easily and quick do what might have been very time consuming and complex in a wet darkroom years ago.

Digital provides more control, more artistic license, cheaper, faster, and often better.  Often way better then film.  Remember the weird color casts of color film?  I do.  Dozens of films rendering color dozens of different ways.  Not saying this is bad, but lets be fair here.

As to the National Geographic photogs of years ago that used film, many of those same guys and nearly all of the new guys shoot digital today.  Do you suppose they would do that if quality went down?  I don't think so.

I suspect that once you master digital camera workflow, and post processing workflow, you too will see that digital is much better then film, cheaper, and easier to apply darkroom techniques.
« Last Edit: July 18, 2008, 07:39:44 PM by lovell » Logged

After composition, everything else is secondary--Alfred Steiglitz, NYC, 1927.

I'm not afraid of death.  I just don't want to be there when it happens--Woody Allen, Annie Hall, '70s
ChristopherFrick
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« Reply #10 on: July 18, 2008, 09:45:40 PM »
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One more thing, when shooting raw try to get the WB as close as possible because it's value will effect exposure, even if WB can be tweeked later for raw images.
[a href=\"index.php?act=findpost&pid=209285\"][{POST_SNAPBACK}][/a]
WB effects exposure?Huh That's not my understanding. The only thing that affects exposure is shutter speed,  aperture and ISO.

Regards,
Chris.
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Panopeeper
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« Reply #11 on: July 18, 2008, 11:24:10 PM »
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ETTR is not for exposing perfectly like the final product will be. It is for maximizing the potential of the raw image data.

If the look of the preview image (i.e. the embedded JPEG) is important (for example if the customer is standing behind the photographer and expecting the half-baked product convey how the final product will look like), then maximizing the potential is very difficult, because the in-camera settings need to reflect the raw processing; thus the histogram and clipping indication do not reflect the unadultered raw data.

However, if the fidel look of the preview is not important, then not only the contrast, saturation, tone (and to a much lesser degree the sharpness) need to be neutralized, but the WB as well. In fact, the WB is the very most important setting affecting the in-camera histogram and clipping indication. In other words, there is no perfect ETTR with a "real" WB, except by chance or bracketing.

Btw, the "stupidest feature Canon has given us" is nothing more but a set of the other settings (sharpness, contrast, saturation, tone). In other words, it is a "shortcut". For example one can define a style with all settings "neutral", which is useful when aiming at ETTR. (IIRC, the factory setting of the "neutral" style is neutral.)
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Gabor
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« Reply #12 on: August 01, 2008, 05:37:40 PM »
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It is not a sin to clip the highlights.  One has to determine what the primary and secondar elements of their composition are.  And if it benefits the primary element/s to clip the highlights of elements in the composition that don't matter, then so be it.   

I think the biggest mistake that users of ETTR do is to prevent any and all clipping, and at the detriment of the primary element/s in their compositions.

Clipping done judiciously often provide the best image information/details.

There is an unnamed landscape photographer that shows up in this forum now and then and he boasts that his comps never blow highlights, and he is right, however looking at this vast gallery of excellent comps, one very quickly sees a pattern of blocked up shadows, and way too dim mid tones, but who cares?!?  The highlights are never clipped!!!  lol


[a href=\"index.php?act=findpost&pid=209285\"][{POST_SNAPBACK}][/a]

What you seem to be describing here is the opposite ETTL, underexposing by typically 2/3 - 1 1/2 stops to protect the highlights and then boost the image with a very strong curve. It was very popular in the early days of the D2x to do this. But it does generate blocky shadows and quiet frankly on the D2x not the best skin tones.

In ETTR you keep overexposing until you think you've just about hit the clipping zone - if you feel brave perhaps a bit more if you think that your sensor RAW convertor can take it!!

I use ETTR on a frequent basis, I also bracket when on a tripod to enable blending. I conducted some tests and found on my D2x that shadow detail was improved.
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image examples are at my website  stevendraperphotography.com   and Polepics is      "Here"
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