OUAT - Tall grass prairie

Uuglypher

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Bison and original folk who lived lightly upon this land are gone.
The plough reigns!

(raw capture, ETTR, iPhone11ProMax)

Dave
 

Uuglypher

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Bison and original folk who lived lightly upon this land are gone.
The plough reigns!

(raw capture, ETTR, iPhone11ProMax)

Dave
OK...howzabout the image to which my previous post referred?
(Yeah...envision me in sackcloth and ashes!!!)
Dave
5FDBA6E8-744A-4611-A87A-0CA914A8E4B1.jpeg
 

terse

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What are you using to develop your raw captures? (I usually use Lightroom Mobile. I try Raw Power now and then, but I still get better results from LR.)
 

terse

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This looks like one of the fields near us, here in England.
And like the interior valleys of California, too, except you'd probably see some hazy mountains in the far distance.
 

Uuglypher

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What are you using to develop your raw captures? (I usually use Lightroom Mobile. I try Raw Power now and then, but I still get better results from LR.)
Hi,Terse,
Now I gotta ask you, what raw camera app are you using? I miss the histogram not provided by LightroomMobile, and find the zebra stripes to be less-than-accurate in finding the ETTR exposure.
Dave
 

terse

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Hi,Terse,
Now I gotta ask you, what raw camera app are you using? I miss the histogram not provided by LightroomMobile, and find the zebra stripes to be less-than-accurate in finding the ETTR exposure.
Dave
I rotate through a lot of camera apps, hoping to find one that suits me perfectly, but no...

Most often I use ProCamera or the Lightroom Mobile camera (either Pro or HDR mode). I have the sense that zebras in general are overenthusiastic in all the apps I've tried. The histogram in ProCamera seems more accurate, but it's so damn small (and I mostly shoot outdoors in daylight, so the screen's often hard to read anyway). I haven't found histograms in other camera apps useful at all -- no clipping indicators as in ProCamera. I've tried Halide, ProCam, ProShot, Chromatica, Camera-M, Moment cam, and CameraPixels (which is excellent for other things, like focus stacking). Undoubtedly others I've forgotten.

ProCamera drives me nuts at times. As Nichols said in the Ultimate DNG book, it lets you make the proper white balance settings for uniwb, but you can't save that as a preset. And once you have it set up, if you shift lenses, the settings are wiped out. Then if you shift back to the original lens, those settings are wiped too. Argh.

I have tried his TLC method also, putting the two colored gels over the lens, and it works well, but those gels scratch and buckle if you just look at them sideways.
 

Uuglypher

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I rotate through a lot of camera apps, hoping to find one that suits me perfectly, but no...

Most often I use ProCamera or the Lightroom Mobile camera (either Pro or HDR mode). I have the sense that zebras in general are overenthusiastic in all the apps I've tried. The histogram in ProCamera seems more accurate, but it's so damn small (and I mostly shoot outdoors in daylight, so the screen's often hard to read anyway). I haven't found histograms in other camera apps useful at all -- no clipping indicators as in ProCamera. I've tried Halide, ProCam, ProShot, Chromatica, Camera-M, Moment cam, and CameraPixels (which is excellent for other things, like focus stacking). Undoubtedly others I've forgotten.

ProCamera drives me nuts at times. As Nichols said in the Ultimate DNG book, it lets you make the proper white balance settings for uniwb, but you can't save that as a preset. And once you have it set up, if you shift lenses, the settings are wiped out. Then if you shift back to the original lens, those settings are wiped too. Argh.

I have tried his TLC method also, putting the two colored gels over the lens, and it works well, but those gels scratch and buckle if you just look at them sideways.
Hi,Terse,
Your detailed- and definitely not terse- response is much appreciated. I had hoped that the excellent exploded histogram of 645Pro would end my quest... but no such luck.

The ones I’ve tried so far are Halide, LightroomMobile, ProCam, ProCamera, Moment, 645Pro, Manual, and Raw+.

The search continues.

I got into UniWB several years ago with my Sonys, but, in my hands, tho logical and functional, it felt more tedious than simply and easily determining each camera’s extra raw/accessible DR and then being sure to use it.

Haven’t tried his TLC method yet. Not sure I want to fiddle with the (imagined ?) tediousness of the filters.

I do appreciate your insights, obvious experience, and comments.
Thanks, and best regards,

Dave
 

terse

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Hi,Terse,
Your detailed- and definitely not terse- response is much appreciated. I had hoped that the excellent exploded histogram of 645Pro would end my quest... but no such luck.

The ones I’ve tried so far are Halide, LightroomMobile, ProCam, ProCamera, Moment, 645Pro, Manual, and Raw+.

The search continues.

I got into UniWB several years ago with my Sonys, but, in my hands, tho logical and functional, it felt more tedious than simply and easily determining each camera’s extra raw/accessible DR and then being sure to use it.

Haven’t tried his TLC method yet. Not sure I want to fiddle with the (imagined ?) tediousness of the filters.

I do appreciate your insights, obvious experience, and comments.
Thanks, and best regards,

Dave
So how did you go about determining the extra dynamic range? Have you done that with your phone? I've been thinking the same thing but hadn't figured out how to go about it yet.

The uniwb and TLC do produce good results but are definitely fussy enough that I don't use them that often. Once I got the proper gel filters from eBay for the TLC, I had to figure out a way to attach them so that they stayed flat and could be easily removed. I tried adding them to a 37mm filter adapter from Moment (I have a Moment case) and adding them inside the case, but both ways the problem was keeping the gels flat. I got the best results by taking two thin pieces of cardboard, cutting holes in them to match the lens opening, using them to sandwich the gels, and then sticking them to the phone case with restickable tape. The gels stayed flat that way, though the cardboard definitely gave a funky look to the phone (not in a good way).
 

Uuglypher

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So how did you go about determining the extra dynamic range? Have you done that with your phone? I've been thinking the same thing but hadn't figured out how to go about it yet.

The uniwb and TLC do produce good results but are definitely fussy enough that I don't use them that often. Once I got the proper gel filters from eBay for the TLC, I had to figure out a way to attach them so that they stayed flat and could be easily removed. I tried adding them to a 37mm filter adapter from Moment (I have a Moment case) and adding them inside the case, but both ways the problem was keeping the gels flat. I got the best results by taking two thin pieces of cardboard, cutting holes in them to match the lens opening, using them to sandwich the gels, and then sticking them to the phone case with restickable tape. The gels stayed flat that way, though the cardboard definitely gave a funky look to the phone (not in a good way).
Hi. TRS,


Read this over and. If you would, and. when convenient, point out to me to any areas or points that aren’t clear or require elaboration.





If and when it’s content passes muster I’ll pare it down and condense and post it in continuum of the earlier posted introduction.


In the interim, it should answer your question.


Don’t be surprised when you find that your wide (1x) and tele (2x) cameras have different ERADR at the same ISO. Depending on the camera compared and ISO used, my wife’s and my iPhone cameras may have as much as a one and 1/3 stop difference in ERADR! Accurate testing is the name of the game!











Xxxxxxxxxx





Is raw really for you?





First, if one’s interest is to display their photographic images only via online venues and as small prints, say no larger than 16x20, and one is not interested in creative/artistic post processing, there is really no reason to consider using raw exposure.





Raw exposure comes into its own when used to produce extra-large prints of high quality that are best viewed at normal viewing distance and under proper illumination. Also, any photographer who enjoys creative and artistic post-exposure processing will greatly enjoy the creative versatility provided by raw image files.





I regret not yet having followed up on my earlier promise to continue the saga of utilization of our cameras’ individual complements of extra raw-accessible dynamic range (ERADR).





So here goes!





It started with the concept of ETTR (Expose to the Right) - the idea proposed in 2003 by the late Michael Reichmann of Luminous Landscape who recounted a conversation with Tom Knoll ( author of Photoshop and Adobe Camera Raw - the basis of Lightroom) that one should expose a raw digital image such that the histogram approaches as closely as possible to the Right End of the camera’s Jpeg histogram frame without actual tripping the highlight clipping warning (blinkies or zebra stripes). In 2004 the late Bruce Fraser was next to expound upon proper raw image data exposure,





Proper raw exposure requires production of the brightest possible image without clipping highlight detail, but coming as close as possible to clipping without actually doing so!





Fraser also pointed out the necessity of determining how much DR there was actually available to use.





This premise of proper raw exposure has been repeated, or stated in words to the same


effect by Jeff Schewe, MartinEvening, John Shaw, D.J. Lloyd and other authorities.





The obvious corollary is that to achieve the stated goal that the entire available dynamic range must be utilized in the raw exposure.





Although many photographers had stumbled over the frequent ability to recover accidentally “overexposed” highlights by utilizing some extra DR to the right of the Jpeg histogram frame ( so-called DR “headroom”), it remained, as it does today, a topic about which the camera manufacturers are loath to discuss. It took a while before some photographers of the curious sort began to actually quantitate that “overhead”.





Long story short - turned out that a few sensors have 1/3 to 2/3 stop of ERADR; and about 75% to 85% have at least one to one and 1/3 stops ... and some have as much as two and 2/3 to three full stops of ERADR. Yes; it’s a crap shoot as to how much ERADR your newly purchased camera has. I have personally tested - or evaluated exposure series from - 45 to 50 interchangeable lens cameras. And, of course, my wife’s and my iPhones (11ProMax) each have the wide (1x) and tele (2x) cameras, each of which have had to be tested. I can confidently attest that the claim that there is no variation in DR among cameras of the same brand and model is total hogwash!





One third stop of ERADR, ‘tho minimal, is, indeed, still useful. The commonly found one full stop of ERADR is a wonderful Godsend in terms of increased image data quality ! And any ERADR beyond that is simply icing on an already exceptional cake allowing even bigger and better enlargements and amazingly increased latitude in post processing.





So....How to determine one’s camera’s ERADR?





Chose a scene under reliably constant lighting with a DR without excessive contrast and the histogram of which fits within the Jpeg histogram frame. An overcast sky or a scene in open shade on a sunny day are ideal.





Use a tripod or other sturdy camera support.





Set camera to capture raw ( with most smartphones use one of the several third-party apps that provide a camera able to deliver raw image data files; I use Lightroom mobile.) Which app you finally choose should provide what you feel to be a reasonably intuitive interface and - that is a highly personal decision).





Set to Manual





Set to some particular WB ( NOT Auto WB)





Set to a low ISO of 25 to 100 - (NOT Auto ISO)





The first requirement (challenge) is to find the ETTR (expose to the right) exposure that just barely fails to trip the highlight clipping warning of the Jpeg-adjusted histogram frame.





Then start a sequence of nine exposures to cover the possibility of actually finding if your sensor really has three full stops of ERADR; what the heck, if you are feeling lucky, shoot a series of twelve exposures). These exposures are quite inexpensive! Each sequential exposure should be incrementally 1/3 stop brighter ( with shutter duration1/3 longer) than the previous exposure.





When the series is complete, open each exposure in your raw converter (on my iPhone I use Lightroom mobile for my raw converter and for editing/post processing.) Tonally normalize each exposure by sliding the Exposure slider to the left.


I still find it amazing how such bright, washed-out images turn into tonally perfect images so easily,





Note that the “clipping” spike at the right end of the histogram disappears as tonal normalization moves the bright end of the histogram to the left.


Sooner or later you will encounter a frame in which that clipping spike persists through attempted tonal normalization.





That’s It! You’re done!





Count the frames between the ETTR exposure and the exposure with the persisting clipping spike and divide by three. The result is the number of full stops and parts thereof that constitute your camera’s ERADR at the ISO used.





Notice that I said: “...at the ISO used”. Although it is often claimed that EBTR must always be used at a low ISO, that simply is not true. It is a fact that as the ISO is increased there will be an irregular rate of decrease in Dynamic Range. The relationship of ISO and DR, although theoretically linear, in practice, and possibly related to the persistent phenomenon of “performance variance”, is anything but linear. It thus is useful to test your camera’s ERADR at ISOs you commonly use. The fact remains that regardless how high an ISO is used, the expected increase in captured noise will nonetheless be reduced if exposure is accomplished by full use of available DR by EBTR!





OK! You now know the camera’s complement of ERADR at the used ISO. Now how do I use it?





Pick a scenic view with a DR that fits within the Jpeg histogram frame; find the ETTR exposure, add the ERADR appropriate to the ISO used, and squeeze the shutter remote release!





That’s it! You have now joined the ranks of those practicing EBTR (Exposing beyond the Right)!





And again.... why do we go to the extra effort to use the maximum available DR?





To assure capture of image data of the greatest possible quality ( S:N ratio and tonal spectrum) permitted by the bit-depth of the file delivered by your camera ( a 12 bit-depth file from your iPhone). The difference between the 256 tonal spectrum of an 8 bit Jpeg file and a 1096 tonal spectrum from your 12 bit-depth iPhone file is amazing in terms of captured discernible detail.





To assure capture of an image file permitting you the greatest potential exercise of artistic/ creative initiative( beyond absolutely assuring accomplishment of the pre-visualized image you had in mind when you are the exposure.





More tonal spectrum means more potential cusps of potentially discernible detail.


Y’want to capture more image information? Go for the highest available bit-depth and be sure to use every bit of the available extra raw-accessible dynamic range!





Consider the contribution of the brightest stop used to produce the final image; it is responsible for at least 50% of the levels of brightness captured inthe entire image file! Failure to use just one stop of available DR forfeits at least 50% of that image’s potential image data quality.





Now go forth and be able to be rightly charged with “EBTR Raw Capture with Exposure Aforethought” ! That’s a definitely creditable charge upon which to be proudly judged “GUILTY AS CHARGED”!
 

terse

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Aha. I stumbled upon the testing method yesterday, but I hadn't thought of allowing for differences in lenses, ISO, and white balance. Back to the test lab.

I've been using CameraPixels Pro to shoot the tests because it can do bracketed exposures in increments as small as 0.1 stop. It does shoot over and under brackets in one go, so I end up with a bunch of underexposed shots that I just delete.

And once you've figured out the extra range available, the actual shooting method would be to expose the scene properly according to the on-screen histogram or zebras and then dial in the extra range by adjusting the exposure compensation?

Also, a little explanation of "tonal normalization"?

Speaking of brackets... I'd think that once you have the extra range figured out, you could shoot a bracket that would give you a properly exposed JPG and a properly exposed DNG (along with an underexposed throwaway), although maybe there's no use for the JPG if you're intent on DNG.
 

Uuglypher

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Aha. I stumbled upon the testing method yesterday, but I hadn't thought of allowing for differences in lenses, ISO, and white balance. Back to the test lab.

I've been using CameraPixels Pro to shoot the tests because it can do bracketed exposures in increments as small as 0.1 stop. It does shoot over and under brackets in one go, so I end up with a bunch of underexposed shots that I just delete.

And once you've figured out the extra range available, the actual shooting method would be to expose the scene properly according to the on-screen histogram or zebras and then dial in the extra range by adjusting the exposure compensation?

Also, a little explanation of "tonal normalization"?

Speaking of brackets... I'd think that once you have the extra range figured out, you could shoot a bracket that would give you a properly exposed JPG and a properly exposed DNG (along with an underexposed throwaway), although maybe there's no use for the JPG if you're intent on DNG.
- my point was not the “differences in lenses” but that the wide and tele cameras (the two from which raw files can be captured) have their own, see Ed paratr sensors, each of which must be tested.

- as for Camera Pixels Pro offering 0.1 stop increments I’m impressed! I feel lucky to work within the 1/3 stop accuracy offered by the apps I’ve tried in arriving at the ETTR exposure and in quantitating steps of ERADR...but if 0.1stop increments work for you, more power to ya!

-and yes: to use EBTR determine the ETTR exposure and then add the ERADR you determined with test exposure series . Use of EC, of course, works well.

The one part about which I can’t be dogmatic deals with the method you might find most reliable for determining the ETTR exposure: using zebras vs. using the histogram or, as some do, is to determine some other index: a spot meter reading of detailed highlights, of the palm of your hand, or of a gray card and work out an extrapolation from that exposure. Different strokes??? I find it most helpful to analyze how close the zebras and the histogram are and figure which is the more accurate for each individual camera tested.
For example. With one of my iPhone cameras there is excellent agreement of zebras with the histogram displayed before tonal normalization. With the other camera there is a 2/3 stop difference between the two. I have experimented with a bunch of apps and do like the 645Pro and the excellent agreement of its zebras and its in-camera histogram ( but personally find the UI clumsy to use with my Parkinsonian hand tremors). As in many endeavors...your mileage may vary!

- Tonal normalization? When the test exposures - which appear bright and somewhat to very “washed out” are in LR edit mode and the “Exposure” slider is moved toward the left, the pale, washed out image progressively gains a more normal tonal spectrum as the right end of the histogram also slides leftward and looses the “clipped highlight spike” at the right end.

- re: bracketing? Indeed, some do just as you describe and those interested only in the be benefits of raw stick with only those aspects of the process aimed at full DR utilization.

-There will be some cameras discovered that have only 1/3 stop (or 0.1 stop?) of “overhead”. In such cases the photographers are assured that a raw capture with ETTR will have captured the major proportion of its potential image data quality, and are delighted with the fact that they have little reason to deal with the extra steps of EBTR !

Thanks, TRS, Any other questions or points of clarification are welcomed.

Dave Graham
 
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