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Author Topic: Better than ETTR ?  (Read 38498 times)

Bart_van_der_Wolf

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Re: Better than ETTR ?
« Reply #60 on: August 09, 2011, 10:09:24 am »

However, the fact is that ACR and Photoshop are the programs I use to develop my images. I don't see much advantage in using one program to analyse my RAW images and another program to develop them.

Hi Ray,

It might teach a valuabe lesson (without having to repeat it for every file), e.g. that Highlight Recovery should only be used after an adjustment of the exposure (and perhaps the brightness) slider(s). When Rawnalyse tells you that there are no clipped highlights, then why use the HR tool?

Cheers,
Bart
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fdisilvestro

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Re: Better than ETTR ?
« Reply #61 on: August 09, 2011, 11:57:53 am »

I think it is very useful to know if the original RAW file has clipped channels or not. The behavior of LR / ACR depends on that. If there are clipped values, the highlight recovery is automatically invoked when applying negative exposure values with the exposure slider.

See this old LuLa thread with interesting info about this (from that message and the following ones)

Other things to consider:

-As far as I know, LR / ACR applies R=G=B for highlight recovery, which is rather limited in some cases (i.e. color propagation may be a better strategy in some situations).

-Some cameras have different saturation levels for each channel at base ISO, this happens to most Nikons. For example, the D300 at base ISO, the green channel clips at about 3830 (12 bits) instead of the supposed 4096. If this is not handled properly, clipped highligts will not look neutral. (LR / ACR deals fine with this)

douglasf13

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Re: Better than ETTR ?
« Reply #62 on: August 09, 2011, 12:06:51 pm »

I have no problem with the above...I don't suggest ALWAYS doing ETTR...only when it's appropriate. But, I don't really agree with the warnings regarding color. I've not experienced that with ACR/LR. Course, I'm pretty good at adjusting both tone and color with both. Can't comment on Raw Photo Processor cause I've never used it...maybe it's more of a problem for Raw Photo Processor than ACR/LR?

Look, if you know what you are doing, you'll know when and how to use ETTR...if you don't, go right ahead and flail about like regular people and leave image quality on the table–you're choice.

I don't want to tug on Superman's cape here or anything with you, Jeff, but we're talking about Iliah Borg sharing these color opinions.  If anything, it may because of he has more discerning color expectations than you do, and I only mean that in regards to him probably having higher color expectations than ANYONE, and so it's tough to draw the line between theoretical and practice.  FWIW, RPP is what most of us use when we decide that ACR is lacking in terms of both color and detail, and the output difference between the two is quite remarkable, albeit RPP is much more difficult to use.  I own Lightroom, and use it for cataloguing and quick processing, but I send the raw to RPP for more critical use.  You certainly should give it a try sometime.
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Schewe

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Re: Better than ETTR ?
« Reply #63 on: August 09, 2011, 12:42:15 pm »

If anything, it may because of he has more discerning color expectations than you do, and I only mean that in regards to him probably having higher color expectations than ANYONE, and so it's tough to draw the line between theoretical and practice.

Hum...really? I actually got a chuckle out of that.
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deejjjaaaa

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Re: Better than ETTR ?
« Reply #64 on: August 09, 2011, 01:03:40 pm »

Hum...really? I actually got a chuckle out of that.

how do you know that do not "leave image quality on the table" (c) Schewe if you did not try RPP ?
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Schewe

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Re: Better than ETTR ?
« Reply #65 on: August 09, 2011, 01:29:43 pm »

how do you know that do not "leave image quality on the table" (c) Schewe if you did not try RPP ?

I have no interest in testing/using other 3rd party raw processors...I'm kinda invested in ACR/LR ya know?
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deejjjaaaa

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Re: Better than ETTR ?
« Reply #66 on: August 09, 2011, 01:55:35 pm »

I have no interest in testing/using other 3rd party raw processors...I'm kinda invested in ACR/LR ya know?
nobody doubts the business side of that...
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douglasf13

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Re: Better than ETTR ?
« Reply #67 on: August 09, 2011, 02:17:57 pm »

One would think that trying other 3rd party converters would help in making the one you're involved with better. I'm a paying customer of LR3, but I still export raws to RPP all the time, and it certainly isn't because I want to add more steps to my workflow. Granted, I guess if I'd never tried RPP in the first place, my ignorance would be bliss.

Honestly, it makes me a little nervous if the people working with Adobe haven't thoroughly investigated other converters like RPP, as I've been hoping they'd use it as an example on how to improve their converter in the future. My mistake.
« Last Edit: August 09, 2011, 02:19:46 pm by douglasf13 »
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Schewe

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Re: Better than ETTR ?
« Reply #68 on: August 09, 2011, 02:45:27 pm »

Honestly, it makes me a little nervous if the people working with Adobe haven't thoroughly investigated other converters like RPP, as I've been hoping they'd use it as an example on how to improve their converter in the future. My mistake.

Actually, it's not at all unusual to specifically NOT use other products in the tech industry...makes it a lot easier to testify that another product had no influence in the development of a competing product. Same reason why I've personally never tested anything from NIK software while being involved in the development of PhotoKit Sharpener (still haven't).
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Alan Goldhammer

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Re: Better than ETTR ?
« Reply #69 on: August 09, 2011, 02:45:42 pm »

One would think that trying other 3rd party converters would help in making the one you're involved with better. I'm a paying customer of LR3, but I still export raws to RPP all the time, and it certainly isn't because I want to add more steps to my workflow. Granted, I guess if I'd never tried RPP in the first place, my ignorance would be bliss.

Honestly, it makes me a little nervous if the people working with Adobe haven't thoroughly investigated other converters like RPP, as I've been hoping they'd use it as an example on how to improve their converter in the future. My mistake.
It might be nice if the developers would port RPP to Win7 so the other half of the photo world could give it a try.  Until that happens, I'm an Adobe captive (though there is nothing wrong with that mind you).
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douglasf13

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Re: Better than ETTR ?
« Reply #70 on: August 09, 2011, 03:21:08 pm »

Actually, it's not at all unusual to specifically NOT use other products in the tech industry...makes it a lot easier to testify that another product had no influence in the development of a competing product. Same reason why I've personally never tested anything from NIK software while being involved in the development of PhotoKit Sharpener (still haven't).

Interesting point which I hadn't considered.  Of course, the guys RPP speak a lot to the difference between converters and how one should take the converter being used into account when making an exposure.  In fact, to quote Iliah Borg from a couple of weeks ago,

"...Do you think different raw converters allow for the same dynamic range and the same distribution of dynamic range?

Have you ever attempted to use, say, D7000 exposing at ISO 200 like it is ISO 800 and process it in different raw converters?

If I expose for ACR or LR I can allow some highlights to be blown out, but G-d forbid to underexpose. Contrary to that with, say, RPP. So different raw converters do mean different exposure strategies."


  Jeff, if you're not actively testing other converters, I would think that your opinion on the ETTR matter should be notated as being relevant only in the case of using ACR, no?


« Last Edit: August 09, 2011, 03:34:33 pm by douglasf13 »
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douglasf13

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Re: Better than ETTR ?
« Reply #71 on: August 09, 2011, 03:37:48 pm »

It might be nice if the developers would port RPP to Win7 so the other half of the photo world could give it a try.  Until that happens, I'm an Adobe captive (though there is nothing wrong with that mind you).

Yeah, unfortunately, it's only an OSX program, and it can't be easily converted.  According to the makers, "I do not see Colorsync being implemented for Linux.  RPP relies on several OS X mechanisms, and porting it to any OS that does not support those is a major effort, literally re-writing RPP from the scratch is needed."

You may want to give Raw Therapee a shot.  It is also very good.
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Alan Goldhammer

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Re: Better than ETTR ?
« Reply #72 on: August 09, 2011, 03:45:39 pm »

Yeah, unfortunately, it's only an OSX program, and it can't be easily converted.  According to the makers, "I do not see Colorsync being implemented for Linux.  RPP relies on several OS X mechanisms, and porting it to any OS that does not support those is a major effort, literally re-writing RPP from the scratch is needed."
Too bad.  I was always taught to keep machine dependent code separate from the underlying program code so that porting it would not be so difficult.  I guess I will just have to take a pass at this.
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Schewe

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Re: Better than ETTR ?
« Reply #73 on: August 09, 2011, 04:44:54 pm »

  Jeff, if you're not actively testing other converters, I would think that your opinion on the ETTR matter should be notated as being relevant only in the case of using ACR, no?

Correct...I never said anything to imply that I was referring to ALL raw processors. In fact, the only other raw processors I've looked into is the camera company's offerings and in the case of my P-65+, Capture One (which handles ETTR pretty much the same way as ACR/LR).

The ONLY raw processor I claim to be an expert on is ACR/LR...I kinda have to be an expert to write a book on the subject. (and I DON'T claim to be an expert on C1...just an average user :~)
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fdisilvestro

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Re: Better than ETTR ?
« Reply #74 on: August 09, 2011, 04:45:25 pm »


You may want to give Raw Therapee a shot.  It is also very good.

I'll second that. Raw therapee has a RAW pre-processing tab where you can "normalize" the RAW data before any other processing. This basically multiplies the RAW values by a factor, something like a first step towards a ISO as a Metadata implementation

ErikKaffehr

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Re: Better than ETTR ?
« Reply #75 on: August 09, 2011, 04:46:06 pm »

Hi,

There is also raw therapy...

Too bad.  I was always taught to keep machine dependent code separate from the underlying program code so that porting it would not be so difficult.  I guess I will just have to take a pass at this.
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Ray

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Re: Better than ETTR ?
« Reply #76 on: August 09, 2011, 09:06:57 pm »

Hi Ray,

It might teach a valuabe lesson (without having to repeat it for every file), e.g. that Highlight Recovery should only be used after an adjustment of the exposure (and perhaps the brightness) slider(s). When Rawnalyse tells you that there are no clipped highlights, then why use the HR tool?

Cheers,
Bart

Hi Bart,
Perhaps I already do that intuitively. When an image looks as though it's overexposed, I first reduce the brightness which is set at a default +50, then bring back exposure. If the image still shows clipping, I will then use the HR tool, then reduce highlights with the tone curve.

If I can disguise the fact there are clipped highlights, or to put it another way, kid myself and kid others that there are no clipped highlights, then I don't find it particularly useful to learn that one or more channels are in fact still clipped, although it is of some academic interest. Generally, as long as it doesn't look clipped, that's fine by me.

However, if I were analysing the spectrum of an image from a distant star in order to obtain accurate information relevant to the verification of some scientific theory, I imagine I would be very concerned about the clipping of channels, whether apparent or not.

I've generally found ACR to be either better than other converters at recovering highlights, or at least as good, whenever I've taken the trouble to make a comparison.

Making more extreme adjustments to my previous example, it seems clear that the blue sky is definitely blown out to a degree which ACR cannot rectify. However, I doubt that any other converter could do a more convincing job of reconstructing that lost data.
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Guillermo Luijk

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Re: Better than ETTR ?
« Reply #77 on: August 10, 2011, 03:31:08 am »

I don't see much advantage in using one program to analyse my RAW images and another program to develop them.

If you compare the input to ACR (RAW data) with the output from it (RAW development), you can try to reverse engineer how ACR works in different situations, and use that knowledge in the future. If you only have the output, you can just sit back and stare at your monitor for a long, long time... you'll never know what happened.


Making more extreme adjustments to my previous example, it seems clear that the blue sky is definitely blown out to a degree which ACR cannot rectify. However, I doubt that any other converter could do a more convincing job of reconstructing that lost data.

I think we could be mistifying too much how ACR (or any RAW developer) works in the highlights. As far as I know, when a single (or more) RAW channel gets clipped, most RAW converters just replicate luminance (R=G=B) from the available information in the non-clipped channels. There is no mystery here (-H 2 option in DCRAW does the same), the rest is a matter of contrasting the clipped area so that textures are more visible.

With these last settings, it seems your image still has colour in the sky (not sure if some parts are B&W though), so perhaps you had nothing clipped in the RAW file and it was just your previous processing (your previous ACR settings) that produced the cyan sky. Think for example that setting Exposure 0.0 doesn't mean exposure is not changed. There is the Baseline exposure metadata in your RAW file (generally meaning overexposing), and there is the white balance which is another change in exposure but for individual channels.

If you don't want to analyse that RAW file perhaps you could upload it to some fileserver and I'd do it for you. We could then leave Plato's cave where ACR prisoners live, jump the wall and look into the real world of RAW. Just for academic purposes of course.

« Last Edit: August 10, 2011, 09:00:26 am by Guillermo Luijk »
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HSway

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Re: Better than ETTR ?
« Reply #78 on: August 10, 2011, 04:54:13 am »

... ETTR is about optimal exposure for the data. If you clip and didn’t wish to, that was an exposure error.


Hello all,

this post appears my first post on Luminous Landscape but the site is not that unfamiliar to me. I’d hope to be more active on this platform.

Reading the exchange that has progressed further since, the above post reflects about exactly my approach, definition and practice in relation to maximum exposure possible for given scene and high value of DR. Strictly speaking, exposing below the highlights ceiling (whatever we decide, and whatever our approach to shines and reflections is) is limiting the sensor capacity that records our image. That way I actually don’t understand ETTR as a special measure but a routine. More like optimizing DR span that we usually tune in line with our approach/vision worked relative to a size of the displayed image or the print.
Apart from rather rare occasions such as misty conditions for example, where the spread of light takes different proportions due to diffusions and where we can drive our exposure choices more by our preferences (quality of tonal levels, noise levels possibly) than what I’d call most of photographers and also my needs.

Best regards,

Hynek
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PierreVandevenne

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Re: Better than ETTR ?
« Reply #79 on: August 10, 2011, 09:12:06 am »

It's the weight of tradition and the fact that manufacturers didn't want to shock a non technical audience.

A modern camera, while keeping aperture and speed as they are (well, it could be interesting to vary those continuously or in very small steps) should simply expose the scene as high as it is possible in the zone of linear response of its sensor at its optimal gain level.  All the rest, either in firmware or software, is just post-processing anyway.
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