Why ETTR May Be More Important Than Ever
AuthorTopic: Why ETTR May Be More Important Than Ever Read 8126 Times
Silver MemberPosts: 1Re: Why ETTR May Be More Important Than EverReply #1 on: March 17, 2022 at 2:45 pm
Always enjoy Harvey’s articles. But, in this case, I have to agree with Brammer’s comments: With mirrorless camera’s live view, there is no reason to look at the histogram, just use the blinkies. You may need to experiment with your setup to know where to set the blinky or zebra threshold, but it gives you all you need to know about maximizing exposure latitude.
ParticipantPosts: 63Re: Why ETTR May Be More Important Than EverReply #2 on: March 17, 2022 at 3:34 pm
By using Aperture Priority with exposure compensation you get in the ballpark quickly in different lighting conditions. Just adjust the exposure compensation until you start seeing the blinkies (with a Sony camera) and then back off if needed. While I just shoot in manual, this way would be slightly faster, especially if you are shooting handheld and have to change the ISO. I am probably going to give Harvey’s method a try to see if it is a little easier.Re: Why ETTR May Be More Important Than EverReply #3 on: March 17, 2022 at 3:57 pm
By using Aperture Priority with exposure compensation you get in the ballpark quickly in different lighting conditions. Just adjust the exposure compensation until you start seeing the blinkies (with a Sony camera) and then back off if needed. While I just shoot in manual, this way would be slightly faster, especially if you are shooting handheld and have to change the ISO. I am probably going to give Harvey’s method a try to see if it is a little easier.
Thanks, that approach makes sense. But this way you don’t dial into a pretty much fixed exposure compensation but rather dial it up till you see blinkies appearing. I can see how using aperture priority will get you to a reasonable baseline exposure instantly, which can indeed be useful if speed matters concerning the subject one is shooting.
When Harvey writes “More than 2.0 EV of overexposure was too contrasty, also as expected.”, too contrasty means clipped significant highlights?
ParticipantPosts: 4Re: Why ETTR May Be More Important Than EverReply #4 on: March 18, 2022 at 12:13 pm
As ever, Harvey nudging us to be a bit more systematic – thank you! I too mostly use the blinkies on my a7r4, but the raw always has a bit of headroom that seems to be variable. In some images I seem to have thrown away a full stop from my potential exposure to the right, which is just what Harvey shows is worth retaining. There must be a fundamental technical problem with deriving blinkies and histograms from the raw data, which would be ideal.
I have assumed that the blinkies and histogram are derived from the live video feed to the viewfinder, which is reduced in resolution and dynamic range compared with the raw image. Erik suggests that it’s JPEG based, which I had not thought of because that is a still image compression. Either way the camera is using some unseen criteria to reduce the dynamic range and I guess that brings in the variable raw headroom compared with the blinkies.
I’m going to continue to base exposure on blinkies, but whenever I have the time it’s got to be worth making an extra exposure a stop above indicated , just to see if it’s not clipped and gives a better image when processed.Re: Why ETTR May Be More Important Than EverReply #5 on: March 18, 2022 at 1:46 pm
Erik’s comment about setting exposure for landscapes by increasing exposure compensation to the point of “overexposing” the highlights (as signified by small blinking highlight warnings) and then backing off a little is exactly the procedure I most often followed these past twenty years.
Eventually, I noticed that while I almost never overexposed anything of significance in my images, the mid-tones were a little less vibrant than I remembered in the scene, and the darker tones lacked contrast and detail. In fact, to me they looked “blah”. That’s when I realized that I needed to re-examine ETTR as a possible regular practice for reasons outlined in my article. I also became very much aware that while the overexposure warning blinked and outlined areas of likely blown highlights, that didn’t occur in practice during post edit. Over time I became convinced that the camera and sensor manufacturers were being very conservative.
Understandably, they take a conservative approach that attaches only small negative value to underexposed shadow areas but considers a blown highlight a fatal flaw. They are right in this assessment. However, their motivation as camera suppliers is different from those of many Nature and art photographers. And it seemed to me that with the prevalence of 15+ dynamic range performances in today’s pro cameras a lot was being left on the table.
Rather than risk losing valuable images I decided to “calibrate” my camera by running tests at different exposure compensation levels above camera exposure readings for commonly encountered scenes with prevailing lighting that ranged from normal daylight contrast to high contrast. I did this to see if there was a consistent positive exposure compensation value that I could reliably use as a starting point for most of my daytime landscape captures. I found that a range from +0.5 EV to +2.0 EV produced good results while a “sweet spot” occurred at +1.0 EV. I wasn’t surprised by this as my experience over the years suggested that.
The reason that I made this test is because of unknown variances between different camera brands, models, and production runs. While it appears that those variances are very small compared to those during the film age (based on re-evaluating older images on a variety of pro level cameras) it is still a good idea for photographers to run their own calibration tests before doing what I now do: set my exposure comp dial at +1.0 EV and leave it there. For really important images I still recommend running an exposure compensation auto-bracket from 0.0 to +1.0 EV as a safety measure.
Using this setting regularly, I have yet to produce any overexposure in any of my landscape exposures for any range of daylight conditions except for when the sun appears through a hole in a dark cloudy sky lights a highly reflective element while everything else is in deep shadow. In those cases, I would set the exposure comp dial at 0.0 EV.
Silver MemberPosts: 1276Re: Why ETTR May Be More Important Than EverReply #6 on: March 18, 2022 at 1:56 pm
This is an excellent article by Harvey. Many of you may remember that my friend Michael Reichmann published an article about ETTR on that other site.
Back in the day when Michael wrote his article we were dealing with sensors that had a lot less dynamic range. Nowadays, not only are the sensors in the cameras better but almost all RAW processors have highlight and shadow recovery which was not possible back then.
ETTR is still an important part of capturing as much data from a sensor as possible. That’s why understanding the histogram is so important. So, no matter what method you use A, S, priority or Manual you want to get what you can to nudge the histogram to the right. For some it will be an adjustment of f-stop and shutter speed, others may use exp. comp. and even others may do a bracket of exposures and decide later what single file works best. Heck, you can even combine multiple files in an HDR and get the most out of a scene. Capture One which is my RAW processor now has HDR built for RAW. It outputs a DNG RAW that you then can adjust like a RAW. I love it!.
The bottom line gets the most out of your exposures. The Histogram is your friend. With mirrorless, you can see a live histogram in the viewfinder or rear screen to help guide you. We are really blessed to have all these tools and great cameras and software to make our images the best they can be.
Thanks, Harvey for a great article.
Owner and Publisher of photoPXLRe: Why ETTR May Be More Important Than EverReply #7 on: March 18, 2022 at 4:17 pm
I want to bring to the reader’s attention an inadvertent mistake I failed to correct when I proofed this article about six or seven times. When referring to maximizing Image Quality by using the best equipment you can afford I meant to refer to highly corrected lenses that largely eliminate Longitudinal Chromatic Aberration (LoCA), but as I was writing fast I put in Lateral Chromatic Aberration (LCA). LCA is relatively minor as flaws go, as lateral dispersion of different colored wavelengths is relatively minor and easily corrected in quality lenses. But, as a matter of geometry the dispersion of wavelengths of different colors associated with different lengths and energy levels is significantly greater as they travel longitudinally through the optical axis of the lens (i.e. the focal length). This results in many waves focusing at different points making sharp focus impossible as seen in color fringing. Correction today involves the use of special partial anomalous dispersion glass elements which slows some wavelengths down and speeds others thereby forcing them to converge at the same point. In particular, APO-chromatic lenses greatly minimize this characteristic. The result is sharper focus which also helps bring out more of the smaller and more subtle transitions in tone and color at fine detail levels. This is a long winded way of explaining micro-contrast which helps make color images of Nature more vibrant and life-like. So, the article was meant to have read LoCA, not LCA.
AZfotoproRe: Why ETTR May Be More Important Than EverReply #8 on: March 19, 2022 at 9:58 am
Yep, it is indeed a very good article, Harvey, that made me think my approach to ETTR over. Trying your approach is certainly worthwhile.
Have a nice weekend!
ErikRe: Why ETTR May Be More Important Than EverReply #9 on: March 19, 2022 at 2:58 pm
Thanks Erik. I appreciate the kind words. Of course everyone has their own way of doing things and are free to choose whatever they feel most comfortable with, or what makes sense for him or her. I did want to share this with the photographer community because – in my opinion – the improvements were so dramatic.
ETTR has been around for a relatively long time. However, it isn’t quite as productive to just pick an arbitrary exposure compensation value and add it in as equipment and individual photographer procedure and preferences can affect the outcome. This is why I advocate making individual field tests varying the amounts of “overexposure” with your equipment for a few different lighting conditions to see where the optimum setting would be. On my Sony A-1 that optimum was one full stop of “over-exposure” above the camera’s default position. But, small variations around that number were still excellent choices. The results with other cameras (and lenses) may vary from that, though after reviewing older images with other cameras not as much as I previously thought. Also, my recommendations are based on landscapes with natural light. Studio work as one example is a whole new ballgame although in principle there should be commensurate benefits there too.
So, do a little experiment to find your best setting for the exp-comp dial and then make a number of varied exposures with it to see if there is one particular setting that consistently produces the best results which should include improved vibrancy and fine detail in all of the tones. By all means bracket when the image is too important to risk losing. But, the point is that what I advocate does not in any way slow the photographer down. Quite the contrary once you have a reliable exp-comp setting and use it as your default camera setup.
I will be very interested to see how this works out for you. So, please share your thoughts and a few JPEG’s with me after you’ve made your trial runs.
AZfotoproRe: Why ETTR May Be More Important Than EverReply #10 on: March 20, 2022 at 2:11 pm
thanks a lot for the encouragement. Today I had a chance to try out ETTR to a higher degree. Whilst I kept my preference for manual exposure, I exposed beyond the kicking in of the blinkies. It was a sunny, slightly hazy day today. I tried out various angles relative to the sun. Typically blinkies would kick in when the exposure scale showed +1.33EV, dialling back to +1.00EV would make the blinkies disappear. I took several shots with the exposure scale +1.00EV, +1.33EV and +1.67EV. Even +1.67EV did not pose any problems for recovering highlights from the raw file. I still need to do more post-processing to figure out how much overexposure allows me to create a pleasing tonality while avoiding shadow noise.
So thanks again for the article and stimulating my interest in doing my own experiments.
ParticipantPosts: 385Re: Why ETTR May Be More Important Than EverReply #11 on: March 25, 2022 at 1:31 pm
Blinkies and histograms not based on the raw data are unnecessary to optimally capture an exposure (on film or digital).
Author “Color Management for Photographers" & "Photoshop CC Color Management" (pluralsight.com)”
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