Digital Exposure – Redefined

If you are a person like me who expose based on in-camera exposure meter reading and in-camera histogram than this article is for you. Time to rethink the way we were interpreting in-camera tools. Thanks to Bob DiNatale for his insightful article in The Luminous Landscape. The Exposure To The Right(ETTR) concept was first brought to us by Michael Reichmann in 2003. Even earlier, the correct exposure was meant to be a bell curve on the Histogram.!

The reason to expose towards right is, the in-camera light meter designed to expose for the mid tones, whereas maximum datas are lying on the rightmost area of the histogram. Have a look at the below diagrams for a better understanding. In general, we might think that camera records the light as it looks in the top portion of the image a. But in reality, the camera records as depicted in the bottom portion of the image a.

ETTRImage – a. The top portion of the image is equally divided stop levels as one may think and bottom portion is how the actual data lies on the histogram.(the image depicts the tonal distribution for a 12 bit RAW image)

Tonal distribution

Image – b. The gray colour highlighted cells are total tonal levels, the respective file can hold. Look at the percentage columns to see the amount of data been hold by the respective stops (the 1st stop is starts from the right most side on the histogram). With relevant to the post, this table is supposed to be the final output from the computer not from the camera. Everything else in the table means the last stops, possibly the 6th & 7th stops together.

Here is the link for the above google spreadsheet with commenting privilege, where one can check the calculations behind the tonal levels and if you wish to share some, do comment there. In few model of Nikon cameras, the user can select whether they want their data to be recorded in 12 bits or 14 bits. Many prosumer and even some professional cameras claim that they record data in 14 bits but they actually deliver 12 bit files only. I wonder if any full frame camera is recording data in 16 bits, but needless to say many medium format cameras do deliver 16 bit images.

Coming back to the objective of the article, Bob meant to say the metering should be done for the brightest area in the scene plus one stop, since the camera meter’s perfect exposure is one stop underexposed than the raw processing softwares.

“An important thing to understand about highlight warnings is that they occur in two places: 1) on the back of your camera – the “Blinkies” and 2) in your software – highlight “Clipping”.

These 2 warnings ARE NOT the same. Although the camera’s High-Alert “blinkies” provide some information, you can only use them as an indication of optimum exposure. The “Blinkies” on the back of your camera occur about 1 stop before the highlight warning in your software – highlight “Clipping”!”

“If the brightest part of your scene has a 90% brightness in your software… Your scene is underexposed by two stops!  Yes, 90% software brightness equals 2-stops under the “Optimum” exposure. If your brightest software value is around 97%, then you have still underexposed your scene by one stop and therefore lost 50% of the available scene data!”

My latest understandings about the digital exposure are below

  1. If you underexpose knowingly or unknowingly even by one stop, you simply lose a staggering amount of 50% of the scene data. You may able to work on it later but you will be bringing in noise and loss of detail as if you have increased ISO while shooting. If you underexpose one stop according to the camera meter than you lose more than 2 stops which is 75% of the scene data.!
  2. Your camera’s light meter is one stop less than your raw processing software. Which means what is perfect exposure for the camera is -1 EV for the raw process software.
  3. If some portion of your photograph is not blinked on the camera’s LCD, you have already lost one stop at least, that is 50% of the data.!
  4. The optimum exposure is not the one which camera delivers, it is your final output from the computer.
  5. As earlier you can use any metering while shooting, but you have to understand how the respective metering gives the output and apply necessary compensations while shooting to get the most data out of the scene.
  6. The blinkie portions shown by the camera has details needs to be recovered by the raw converting softwares.

If you feel there are too much of maths involved here, yes there are, but I thought of learning it. I did had problem with maths when I was studying. It was a nightmare for me when it comes to Maths, I scored as college first in the subject called technical drawing but when it comes to Maths, I was the person who got marks in single digit out of 100!(Laughs…) But here in histogram and exposure, I could easily learn the maths behind it. So you too can learn it easily.

After reading all the refereed articles and if you find something unnatural or doubtful do let me know in comments. Will be happy to dig in further. 🙂

Cheers and Happy Photographing.

Advertisements

Loving Landscapes – A review

Are you new to photography? Do you roam around everywhere with your camera equipment to get that one amazing looking landscape photo? Are you disappointed about the fact that your photos aren’t that compelling enough? Well, to begin with, watch this TED talk video by Angela Lee Duckworth. She clearly states the fact that the key to success is not in the IQ or good looks or talents. It is the grit, the perseverance, the passion for long term goals and the willingness to start over again upon a probable failure. Before going ahead, please watch the video.

 A few weeks ago, while browsing through dPS, I bumped into this e-book which was dedicated to Landscape photography. It was quite intriguing to find a book which focussed only on one particular genre. I went on to read the book with a notion that the photographic idea in the book can be applied according to one’s perception on one’s style of photography. The contents page of the book clearly stated that the book is strictly for landscape photography but with a good understanding, one can apply the concepts to other genres of photography.

The book starts with a clear introduction and it speaks about what is covered in the book and what is not too. The entire book is divided into 12 chapters. The first chapter covers the basics of image capturing and attributes which play an important role in getting the right exposure in a given situation and in attaining an optimum sharpness for a decent landscape photograph. It also touches upon the negatives of a higher ISO, White Balance, Histograms and Focusing. The above attributes have been touched upon in a simple way, in a way not to confuse the readers with extremely technical terminologies.

 The second chapter is “Computers and backups” and this chapter deals with techniques that Sarah and Todd follow in their studios and is pretty straight forward. This topic is by far the most discussed on the internet and one of the most important in this era of digital photography. The next chapter talks about the power of RAW and why it is important to shoot in RAW format, every time! I have covered this topic in an earlier blog and you can check that out here!

 The fourth covers File management and using Lightroom to organize images. This chapter is very useful for those who would like to keep tab on their huge collection of images with ease. The uses of key wording are dealt with in detail along with the advanced search techniques in Lightroom which enables searching of images using the multiple filters. This chapter also explains about the collections and smart collections in Library module and how it works to help you finding the image you are looking for.

Todd

The sixth and seventh chapters explain about the export option in Lightroom which lets you export your image to different social media platforms like flickr or your own website. This chapters emphasize on the develop module’s functions and on how the sliders can be used to enhance your photograph by adjusting the exposure, opening up the shadows, bringing out the colours, enhancing the colours from the raw data your camera has recorded on field.

In the next chapter Sarah explains her work flow in detail. She starts with explaining the crop tool, goes on to the dust removal, applying sharpness, removing Chromatic aberration and also touches upon the basic panel adjustments. The importance of following the mentioned order during post production is explained clearly in the book. All the necessary tools in the develop module are touched upon in this chapter.

Chapter nine talks about the other tools in develop module. The noise corrections panel, HSL panel, Split toning panel, Effects panel and a few other local correction tools in develop module are explained in detail. The uses of these tools and they can be used to enhance the photograph is explained clearly.

Chapter ten touches upon some camera techniques which can be used in creating some effects, namely Photo impressionism, Camera spin and techniques on how to photograph the Milky Way in detail. The next chapter goes on to explain the use of Photoshop for landscape photography. All the important panels and necessary basic tools are explained clearly. Lightroom and photoshop has been explained in such ways that even a first timer (I mean it) can follow and get the results as in the book. The last chapter talks about the Multi exposure workflow in Photoshop, explaining the tools which are required for taking multi exposure photographs, like star trails, light paintings and HDR.

Overall, the book is neatly presented with appropriate screen shots wherever necessary. The photographs used in the books are available along with the book and lets you try what’s being explained while reading, this makes the book a practical guide. Open the e-book along with Lightroom and Photoshop to make this a worthwhile exercise. If you want to enhance your skills in landscape photography you might have to get this book immediately.

Cheers, Happy Photographing. 🙂