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.

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Ebook review – Essential guide to B & W Photography

If you are a person who wants to make wonderful Black and White Photographs and many of your attempts proved to be futile, this book is a must for you. Of course – who does not wish to make great Black and white photographs? This book starts with a clear understanding about Black and White images.

As Scott Kelby once said – “The simplest black and white conversion is to remove saturation and boost contrast”. Yes, he said it is the simplest way. However, not all the conversion is going to be good at its first attempt. You may not aware what is happening to the colours. Possibilities are there you will end up making a dull, normal black and white photograph!

The book’s author David J. Nightingale, an experienced photographer, nailed down all the fundamentals of photography from Tonal ranges to Contrast, RAW files to ETTR, EV to Metering.

After the fundamental sections namely – The Aesthetics of Black & White photography, Equipment and shooting Black & White, David states about the conversion methods, why you should not use the default conversion method given in the software and what it does exactly to your image while converting. The software just takes the brightness level of a given pixel and converts it to a gray scale equivalent. In the next chapter, David explains about few other ways of making black and white photographs in Photoshop Channel mixing, Calculation method and Blending methods. In the end of this section, he talks about different plugins available for Black and white conversion from Silver Efex pro, Topaz and DxO lab in detail from its interface and what one offers. Also the author mentioned his personal favourite methods as well.

In the next section – Adjusting tonal range, Balance and Contrast, he explains about the single most powerful tool in Photoshop “Curves”. Adjusting the tonal range means shifting the original tonal range to what you desire via the curve tool. With the curves tool in place, you can adjust all the tonal ranges to its extreme without losing detail aka clipping. He further explains about the Basic S-curves, the baseline, altering the mid tones and how to do selective adjustments to a particular portion of the image using “Selective adjustments using Curves and Masks”.

Later, he explained about Creative vignettes aka Selective Vignettes – Vignettes been explained in detail here, starting from how it affects the viewer’s perception and the way it leads the eye and ends with how to make specific vignettes according to your photograph.

David made a separate section to cover Black and White Portraiture – Whoa; it is an interesting decision to add one dedicated section for portraiture alone. A section you would most probably love very much, since who does not want to make a striking portrait! David starts with the difference and importance between colour and B & W portraits, what kind of portraits would work with B & W and what won’t?

He clearly classifies the difference between different methods of converting one image into B & W and its drawbacks. For instance, why applying of red filter generically to all images will not work, or with Channel mixer or with Black and White conversion tool for that matter. He also clearly mentioned on how to bring out the details of the face and to brighten the eyes in the portrait. Why eyes are important in a portrait? He mentioned “Not only are the eyes the window to the soul, they can also be key to a successful portrait, but unless they are well lit they can often detract from an otherwise successful image – normally because they appear too dark in relation to the rest of the person’s features.”

The final section – “Monochromatic toning techniques” where David explains about the different methods of adding tone to your B & W images. He starts from the Black and White tool, Hue/Saturation tool, using Photo filters; using Selective colour tool, using Curves tool, and using Gradient Map tool. All of them explained in detail so that you can precisely tone your image as you might have envisaged to either your Whites alone or Blacks alone or to the mid tones alone or to the whole of your image. The important question is why you want to apply a tone to your beautiful striking B & W photograph. It is only to further enhance your image, as the sepia can bring a nostalgic feel about that image, a light blue tone will bring out a warm and industrial feel and so on.

The conclusion part is so striking and interesting that David made all the facts clear, I agree with all of his words. Hope you too will find this e-book helpful, in not only making striking Black and White Photographs, a better photographer as too.

This e-book is filled up all the way with necessary screenshots, interesting tips and tricks in a toned box, which will save you many time and energy. And more importantly this e-book comes with a separate recipe book which explains 10 different type of photographs and how exactly David converted it into a powerful Black and white photograph with all necessary illustrations and screenshots. He added both the original image and the final image after all the processing steps executed.

A word of caution – If you are using Photoshop as your primary editing software, you would love this book, but if you have recently switched to Lightroom as your primary editing software, this book helps you a little. Just thought of reminding you, but nevertheless there are some fundamentals about the filters, plugins, curves which I found very worthy. I hope that you might also feel the same, who knows. Grab one here and don’t forget to comment below how did you feel after reading the book.

Cheers and Happy Photographing.

Inevitable personalities

Sally Mann

Why I like her, because of one photograph she made, the most erotic I have ever seen. None of the nude photographs can come close to this photograph in sense of erotic feeling it creates in a male human’s mind.

Sally mann

The wet cloth, the stickiness of the cloth with the body, a hand with three fingers in the frame which holds the body on the right top of the photograph (obviously male hand), the cleavage, the shrinkage in the cloth due to wetness, the tight crop of the photograph – if you look again there are no space left around the body in the frame, everything made this particular photograph as an outstanding one. Though she made many nude kid photographs and she is controversial too in that regard, this one stands out in her portfolio and one of my favorite.

Steve Mc Curry

One of the well-known personality in photography and without talking about him, compositional topics would never get complete (leave Henri-Cartier at this moment). The below image is one of my most favorite in his gallery.

Steve Mc curry

Two bullock carts parked adjacent to a wall and an another bullock cart about to be parked, the bull shall be untied from the cart in few moments and the bull appears like it is watching the elder woman who is appears to be having a hump as his. The elder woman is walking away from the frame with the help of her walking stick, her left leg stepping forward and her whole weight have been supported by her right leg. All the three legs are visible to the viewer, if you watch again these three legs matches with the three legs of the bull (deliberately avoided the other leg of the bull inside the frame, either while capturing or post capture) is simply sheer brilliance.

Talking about the other features of the photograph would be colour and the overall mood. The green colour door has been complimented by the red colour interior finish inside the right side cart, may be perfect coincidence but it adds value to the photograph. The mood here is slightly esoteric, because of the noise – due to low light ISO boost or deliberate post capture addition, either way it adds value to the photograph. If you look again the photograph,it is underexposed by almost a stop, which again perfect combo with the mood here.

And some interesting things about the master, Steve knows India better than an average Indian knows India, yes he travelled to India 82 times till date and an another interesting thing is he did not locked himself in Black & White images which people tend to give lot of explanations. He took very few photographs in B&W.

 

Michael Freeman.

Couple of months back, I accidentally found his work in internet and are highly impressive. He wrote several books including The Photographer’s eye, The photographer’s mind and I happen to go through those books in a book fair here in Chennai, I have never come across such kind of books, which talks about composition, how a small point/line/spot/anything in any photograph is perceived by human brain with diagrammatic explanations.

Micahel Freeman

The above photograph have been etched in my mind from his work. The first bull from the viewer is looking down and the next one watching straight, but both their horns have placed in such a way that it forms a continuous vertical wavy pattern. If you look at the first bull’s neck where it ends and reaches the hump, from there on the herdsman’s hand takes the curve up and completes itself by keeping his hand on his head. This is the interesting part; the herdsman’s hand and the second bull’s horn bend are somehow parallel to each other and create a balance in the photograph. And the photograph being in Black & White makes all sense together, the first bull’s neck in black colour and herdsman’s shirt being in white colour creates this as a compelling photograph.

After watching different photographs from several masters and reading different books about photography, my conclusion towards a good photograph would be “There cannot be a set of exhaustive compositional rules to make a good photograph, since a unique and good photograph will come with its own rules which may or may not exist before”.

Kindly note all the above three photographs have taken from their websites.

Y Processing.

As a photographer, it is not uncommon to come across these questions quite often; “Is post processing necessary?” “Why do you shoot in RAW and then convert it?” “Should I shoot in RAW or JPEG?” This blog post is trying to answer these questions about processing.

“A photograph is made in the camera, not in the computer”; while this statement remains true, in this digital era, a computer and camera go hand in hand. Processing (Computer) is all about bringing out the best from the RAW data (Picture in RAW format) your camera recorded. This is literally impossible with JPEG.

Before getting into the real subject, a basic knowledge of how your camera captures images in RAW and jpg, will make things easier.  Firstly, RAW is not an Image format; it is the data that is seen by the camera sensor which is recorded into the memory medium. jpg, however, is altogether different. The sensor sends all the RAW data to the processor and the processor converts it into jpg format with the preloaded instructions based on the time the image was captured and exposure value. The important part to be noted here is that the processor discards the rest of the data after converting it to jpg. Remember, the instructions preloaded by the manufacturers are not specific to the images; it is generic and every correction made by the processor on the image like sharpening and contrast, such as, are global and not local. And the reason you get a fairly neat image is because the instructions are based on 10000+ images shot by the various top photographers then across the globe.

This is the very first reason capturing a picture in RAW and post processing is important to bring out the best of the camera.

The second reason is the ability to process the image. Processing here includes White balance correction, exposure adjustment, contrast correction or boosting, correct to the true colors, sharpening, color cast correction etc. The extent to which one has to process the picture is entirely a personal choice. It is your picture, so you should define how it looks, and tweaking around with the above given parameters is acceptable, in all contexts.

It is very important to note that post processing and image manipulation are altogether different. I don’t consider manipulation as a part of photography processing. By manipulation I mean the inclusion or exclusion of some or more parts of the image. The reason one should not manipulate the image is that, I feel that he/she is an expert photoshoper but not a photographer.

Photography is an art form and processing is also part of that very art. Learn it; there are lots of websites out there. I use Light room for my all processing requirements with few plug-ins like Nik collection, Enfuse, Mogrify, The Fader etc. I strongly say that photography and processing is equally important task by its very nature.

I can very strongly vouch that Photography and post processing are equally important tasks, especially in today’s digital era of photography.

Again, all this is a personal choice. Kenrockwell, a very technically sound photographer takes his images in JPEG only. So the choice is entirely yours.

Keep clicking,

Cheers.

Histogram

Why histogram is inevitable?

Before that what is Histogram?

“The horizontal axis of the graph represents the tonal variations, while the vertical axis represents the number of pixels in that particular tone. The left side of the horizontal axis represents the black and dark areas, the middle represents medium grey and the right hand side represents light and pure white areas. The vertical axis represents the size of the area that is captured in each one of these zones. Thus, the histogram for a very dark image will have the majority of its data points on the left side and centre of the graph. Conversely, the histogram for a very bright image with few dark areas and/or shadows will have most of its data points on the right side and centre of the graph.”

Histogram is the one and only tool to show the image’s exposure details, after you do all your composition, lights, metering, shutter speed, aperture, optics etc., you have only histogram to get checked. Even if you lack one stop of light in your image, assuming you going to fix it later in processing you are going to boost noise by pushing the histogram towards the right. Do it on field not via screens (Real good photographers do not want to process their image, they want to fix it in fewer clicks,and that too because of digital, if that cannot be done in few clicks they will throw the image, get out and get a another satisfying shot). And that one stop of light has the most details, more than the details than the rest of the 4 stops (A digital camera’s dynamic range is 5 stops and some more, but for better understanding I have taken 5 stops).

Here you go, divide your histogram in to 5 equal vertical parts (one stop each); the right most one got 50 % of the data in the image, and the next one got 25%, and the further next one got some 13% (middle one), and the next one 6 % and the last one stop at the left most got 3%. Next time when you check your histograms in field, if you are one stop down than you have lost already 50% of the data. When you push your histogram towards right, possibilities are there to clip the highlights, never do it as there are no software can recover those details and there cannot be one. It is not possible to bring back the detail where there is nothing; yes that is what will happen when you push right much.  Next time look at your camera’s LCD to check the histogram not the shot you just took, though looking at the image is helpful to check your composition and composition only.

For aesthetic purpose one might want to bring down the exposure sometimes even up to 2 stops selectively while processing, but no worry you are not going to bring noise by bringing down the exposure slider and that is why you have to push your histogram towards right when you are at field. There is no guarantee that you will be having a stunning photograph or even a moderate one, if you have exposed your image towards the right without clipping. A perfect exposure does mean that the image is well exposed, nothing more and nothing less. Photography is not about technical expertise, it is about your sensibility on the things in this universe.

There are two types of histograms, one is luminosity histogram and the other one is RGB histogram. I have talked about luminosity histogram; I will talk about the RGB histogram at a later point in time.

For further reading about Histograms and pushing towards the right here. Read about photography here.

RAW image capturing in 12 bit mode is assumed here.