All About Histograms

If you’re in the hunt for your first DSLR camera, or you’ve just purchased a DSLR and you’re new to digital photography, chances are you’ve been on the internet and watched one or two videos about things you should know or might want to know in order to get the most out of your camera – these are the “basics” or “fundamentals” type videos, of which there are a ton on YouTube. In some of these videos, they may have talked about something called a Histogram – usually telling you to look on your camera’s LCD screen, after you’ve taken a photo and “see what the Histogram is telling you”, as a way to know whether your photo has come out properly, or is otherwise either too bright or too dark, in which case you will need to make certain adjustments to your camera settings and try taking the photo again.

All well and good, but let’s say you’ve watched one or two of these videos and are still a bit flummoxed as to how to interpret these Histogram things. Well, this is the situation I found myself in for a few months – for a time, no matter how they phrased it, these different photography experts failed to get their know-how through my dense cranium. I hope to share with you how I eventually came to understand what these Histograms meant and how they’re actually very simple to work with, once you understand their meanings.

Right, here goes…

A Histogram is nothing more than a graph that tells you whether your photo has parts that are too bright (overexposed) or too dark (underexposed), to the extent that certain portions of your image data won’t be useable if/when you get your photo back into editing software, such as Adobe Lightroom, to finish processing your photos – trust me, when shooting in the recommended image format referred to as “RAW”, it’s amazing how much detail even the most sophisticated modern camera lenses fail to reproduce, and it’s only when you get your images into a program, such as Lightroom, that you can adjust various settings to bring out the richness and depth of the colors, lights and shadows, which, thankfully, the camera’s digital sensor DOES manage to capture. It just needs software to tease it out – in the pre-digital era, photographers used to do this in the “darkroom”; today, in the digital era, you don’t need to be in near total darkness in order to process your photos, you can do it in a nicely lit room, on your nicely lit computer… which is most probably the reason Adobe didn’t call their software Adobe Darkroom.

So, getting back on track, at very right edge of the Histogram graph, you have data for white; at the other end, over on the very left, you have the data for black. Everything else in between represents all the rest of the colors, or shades/tones of colors that can be present in any given image or scene. Each photograph you take will have its own Histogram assigned to it – this is a graphical record of all the highlights, shadows and colors (of varying shades and tones) in that one image.

Try this simple series of 5 tests – this is what I did and it helped me understand what was going on with the Histograms:

Test 1. Put the lens cap on, take a photo and look at the histogram. There should be a single line on the left of the graph, yes? If there had been all sorts of colors in your scene and you’re getting something too black or too dark, and if the lines of your Histogram are mostly over on the left of the graph, then you’re losing detail and would need to make certain adjustments, such as decreasing the Shutter Speed; choosing a wider Aperture; and/or increasing the ISO. All of these changes help to brighten up your image.

Test 2. Now, take the lens cap off, and point the lens at something white (like a plain sheet of paper) and fill the frame with it (go up close, so that there are no other colors in the scene creeping into your photo). If you don’t have a piece of white paper or anything white to use, turn your ISO up to something like 1600 or higher, then turn the Shutter Speed to a really slow setting – give it a good 30 seconds and point the lens at the lightest color(s) available to you (e.g. walls; ceiling; up at the sky out of a window, etc.) and take a photo. When you look at your Histogram, for this image, there should be a single line, or a very small bunch of lines, over on the extreme right of the graph. The image will appear white and the Histogram data is reflecting this. The camera interprets this as an “overexposed” image. If there had been all sorts of colors in your scene and you’re getting something too white or too washed out, and if the lines of the Histogram are mostly over on the right of the graph, then you’re losing detail, once again. Adjustments you might want to make include increasing the Shutter Speed; choosing a narrower Aperture; and/or reducing the ISO (unless you’re already at the lowest ISO setting, that is). All of these changes help to reduce the brightness of an image.

Test 3. With your camera still trained on that light subject (whether a wall or ceiling or piece of white paper), take a series of photos with ever faster Shutter Speeds. Then, look at the Histogram for each respective image, and you should see the line or group of narrow lines gradually travel from the right side of the graph, over toward the left side (depending on how many shots in this test sequence you can be bothered to take). If you were training your camera on something white, then the images in the sequence should begin to look ever more grey.

Test 4. The fourth test is to go hunting for objects with single colors, filling the frame with each object in turn, and then taking individual photos of these single colors. Photograph something red (filling the frame with this color, so your entire photograph is a mass of red), and there will be a narrow bunch of lines in this photo’s Histogram slightly to the left of the very center of the graph. A photo that’s all yellow will have a bunch of lines further over on the right side of the graph, just over half way from the very center of the graph. Play about with taking photos different single colors, and their corresponding Histograms should give you a better understanding of how the Histogram is helping you to interpret individual colors in any given image.

Test 5. The fifth and final test is to take photos of anything you like. Introduce a variety of colors into your photos and see the wild patterns of their corresponding Histograms. If the majority of the lines are bulked over on the left of the Histogram graph, it’s probably telling you that your image is too dark (too underexposed) and you need to adjust your camera’s settings to brighten it up. Conversely, if the graph is mostly bulked over on the right side of the graph, then your photo is likely to be too bright and washed out (too overexposed) and you need to adjust your camera’s settings to reduce the brightness. If there is black in your image, such as a black car, then there will be a spike on the left of the graph, indicating the black color (this is fine).

After doing these tests, I felt significantly more comfortable “checking my Histogram” and understanding what the graphs were telling me about the individual photos I was taking.

 

All about DSLR Camera Features

Here are 10 features of your DSLR camera that you should know. They will help improve you as a photographer…

1. Shooting Modes #1 (Aperture Priority, Shutter Priority, and Manual modes)

    • Aperture Priority Mode… This lets you control / adjust the aperture, while the camera takes charge of determining the shutter speed, based upon the other settings (including the aperture). Adjusting the aperture causes background elements in your scene to become either crystal clear, or blurred. The wider the aperture, the more the background elements will become blurred, as you focus on your main subject. Conversely, a narrower aperture will enable you to include more things in your scene, without them being lost to the blurring that occurs with the wider apertures. Another thing that aperture adjustment does is to brighten or darken the overall image: with a wider aperture, you’re letting more light in through the lens, and onto the camera’s sensor, so images will become bright. Go the other way, and your images will become darker as you narrow the aperture, as this time you’re letting less light reach the sensor, during the period of the exposure.

 

    • Shutter Priority Mode… This lets you control / adjust the speed of the shutter, while the camera takes charge of determining the aperture. Adjusting the shutter speed will let you freeze motion, if you choose a faster shutter speed; while, a slower shutter speed will increase the amount of motion blur in your images (a good example would be including a subtle blurring of the wings of a kestrel, as it hovers in the sky. You capture this activity with a slower shutter speed). Adjusting the shutter speed also affects the brightness of the image, in a similar way as adjusting the aperture. If you select a faster shutter speed, you’re reducing the time that the shutter is held open, which lets less light into the camera’s sensor, resulting in a darkening of the overall image. Conversely, you will notice images become brighter as you slow down the shutter speed, as you’re causing the camera to hold the shutter open for slightly longer, letting in more light onto the sensor, as a result.

 

  • Manual Mode… This lets you control / adjust both shutter speed and the aperture. Choose this option if you want total control over determining these two settings, rather than letter the camera’s algorithms calculate the most appropriate settings. You may be fine with that; but, then again, taking manual control will allow you absolute control over the artistic process and outcome with your photography.

2. ISO

This feature is pronounced “EYE-so” – unless you want to wind-up nerdy-types who get a bit manic over such mispronunciations, in which case, treat it as an acronym, call it “I.S.O.”, then enjoy their fit of apoplexy. As for what this feature does… it allows you to control the camera’s light sensitivity, based on a numerical system – the lower the ISO numbers (e.g. 100, 125, 200, 400), the less sensitive the camera will be to light, typically resulting in darker images (unless you have a sufficiently bright light source to compensate, such as an external flash unit). The higher the ISO numbers (e.g. 800, 1600, 2000, and beyond), the more sensitive the camera’s sensor, with lighter images being the result. BUT, you need to know that this light-enhancing wizardry comes at a cost, and that cost is a reduction in the overall quality of the image, as a result of bumping up the ISO setting, particularly above the 1600 level.

Camera technology is improving all the time, and every generation of camera gets slightly better at processing images with slightly higher ISO settings. In some cases, it can be better to sacrifice overall image quality, in order to get a “once in a lifetime shot” (I’m not sure that many complained about the relatively low quality of images from the first moon landings, did they?). However, in general, if you’re in pursuit of quality, then it’s often best to go for the lower ISO values – specifically, the lowest “native” ISO setting your camera lets you select. What I mean by this is, some digital cameras will allow you to set the camera into “Extended ISO” mode, which opens up additional ISO settings. For instance, on the Panasonic GH4, the Extended ISO feature lets you drop down to either 80 or 100. Turn off the Extended ISO feature and, whatever the lowest value you see, is the camera’s true lowest “native” ISO setting. On the Panasonic GH4, this happens to be ISO 200. That’s just how this camera is designed and the engineers felt this camera worked at its most optimum levels with a minimum native ISO setting of 200. Some cameras have 100 as their native setting; others, such as the Panasonic FZ1000, begin at 125.

3. Shooting Modes #2 (Single Point vs. Spectrum)

This relates to how the autofocus system works. You may have the experience of turning on a DSLR camera and, when you go to focus the camera, in order to take a test shot, a bunch of different indicators flash upon the LCD or Electronic Viewfinder (EVF). These indicators are the different points of the spectrum that have been activated and the camera calculates that certain areas are the ones that you may want in focus, and these are typically represented by red or green boxes over different parts of the image. What typically works better (and by that, I mean, is more reliable and less annoying), is to go into your camera’s menu system, turn off the spectrum focusing option, and switch your camera so that it focuses just on a single point (typically in the center of the frame – although, you can adjust this, such as placing the single focusing point over the point where a key subject is or will be in your image, so that you get that subject in focus).

4. Back Focus

It seems that a lot of DSLR cameras are set up by their manufacturers so that the shutter button handles both the focusing part AND the exposure part of taking a photo. This can be fine, for a while, and you can get pretty adept at subtly pressing the shutter button half way, to focus on your target subject, before applying a bit more pressure on the same button, to take the photo. However, there may come a time when this system ends up costing you valuable photo opportunities. For instance, when doing light painting photography, you’ll be working in relative darkness, taking time to set up your camera and focusing on just the right point in the image where you want tac-sharp clarity. Then comes the moment when you’ll press the shutter button, to begin the long exposure, so that you can walk out in front of the camera, to wave your torch around, to capture the spectacular movements of light. However, just as you go to press the shutter button, you fail to put the right amount of pressure through the button, and the camera treats it like you’ve requested a change of focus, and the autofocus system kicks in, taking the camera out of the perfectly adjusted focus point. On the more-sophisticated DSLRs, you can save yourself this sort of agro, by decoupling the autofocus feature from the shutter button, and assigning the autofocus to one of the other option buttons. The reason why this method is called “Back Focusing” is because the button that is usually selected for the job of focusing, is typically on the back of the camera, but in close-enough proximity to the shutter button, so that you can easily engage the newly assigned autofocus button with your thumb, while your forefinger remains the trigger finger to engage the shutter button. It does take a little getting used to, but it does enhance your workflow and the way in which you operate your camera.

5. Exposure Compensation

You may not use this feature all of the time, but there are certainly occasions when you’ll want to take advantage of the Exposure Compensation setting, to help improve the overall quality of your image. The Exposure Compensation settings are measured in values, with zero in the middle, then you either go to the PLUS values, to brighten the image, or into the MINUS values, to darken the image. Why would you want to do this, when you’ve already adjusted the brightness with either the aperture, shutter speed, and/or ISO settings? The problem is, with modern DSLR cameras, the algorithms they use tend to result in overcompensation of light quality with the resulting image. If you’re photographing in dark conditions, such as at night or in the evening (when you get those darker blues, for instance), without using Exposure Compensation, the camera will calculate that any source of light, such as street lights, lanterns, etc., will be rendered extremely bright, as the DSLR overcompensates to make sure the light can be seen in the dark environment. Professional photographers will often deal with this by using the Exposure Compensation feature, and dialing down into the MINUS values, typically going to -1 of Exposure Compensation, in order to tone down those light sources in the resulting image. Conversely, when out in a really bright environment, such as in snow, an Exposure Compensation value of +1, or even +2, will help to combat the camera’s tendency to overcompensate in the other way – what you’ll typically find is, without adjusting the Exposure Compensation settings, anything that’s white in your scene will most likely be rendered a really ugly grey color. By adding a value of +1 or +2 of Exposure Compensation, you’re able to bring back that brilliant white.

6. Custom White Balance

I know of some professional photographers who will typically shoot in Auto White Balance mode, most of the time. However, there are times when they won’t do that, such as at an indoor ice rink, where the indoor light can render the white of the ice rink a different color to what you actually see. So, to combat this, they will instead prefer to dictate to the camera what “white” actually looks like. This generally involves you going into the White Balance menu system, selecting a custom preset option, and then you will take a photo of how you want the white to be in all of your photos. For example, you’d point the camera at a bank of snow, or the white of a wedding dress; fill the frame with that color, and take the photo – the camera will then treat that as white, and balance all the other colors in the scene accordingly, until you reshoot with a different custom White Balance, or return it to one of the preset White Balance modes, such as AWB (Auto White Balance), or the Cloudy or Sunny settings.

7. Highlight Control (The Blinkies)

Some DSLRs allow you to turn on a highlighting feature that is often referred to as “The Blinkies” – this is because, when you go to take a photo and have the camera’s settings such that it might result in part or all of the image being washed out or lost in brightness, the LCD screen will “blink” at the areas that will become overexposed – this is something you wouldn’t want if, say, you were photographing a bride on her wedding day… if you overexpose the wedding dress, you are likely to lose any subtle detail, and you most likely won’t be able to recover the detail in post-production (e.g. Lightroom), because the software won’t have any data for those overexposed parts of the image. So, Highlight Control is often a good warning indicator to have turned on.

8. Metering Modes

Your DSLR will probably allow you to change to one of three different Metering Modes, depending on what you intend to photograph. There’s:

    • Evaluative Metering (also known as Multiple metering)… which gets the camera to measure the most suitable exposure by determining the levels of brightness in the entire frame. This is generally the one you will want to use, most of the time.

 

    • Center Weighted Metering… this method is used to focus on the subject in the center of the frame, in order to measure the whole screen evenly.

 

  • Spot Metering… this is going to get the camera to meter in just one area of the frame.

In certain situations, such as music concert settings, if you were to select Evaluative Metering, you will run into problems because the light typically changes every couple of seconds – either different colors, or sometimes the light will shine on the artist, other times the light will shine elsewhere, leaving the artist’s face in more darkness; sometimes the light will shine on one band member and not another… and all of these light variations gives your camera a really hard job of trying to calculate how to measure the light to help create a really nice image. When you go to photograph music concerts, Spot Metering is generally the option you want to go with, because you’re going to be targeting the musician’s face – that’s who you’ve come to see, so you want to make it clear in your photograph who the artist is, and that means capturing them in the best possible light, by using the most appropriate Metering Mode – Spot Metering, in this case.

9. External Flash Control (From Your Camera)

Some of the more modern DSLRs, typically at the higher price range, allow you to operate the functions of a compatible external flash unit, right from the menu system of your camera. This is a really great feature, especially if you’ve got multiple flash units set up all over the place, or you set your single flash unit up in a perfect, but awkward-to-reach spot, where it’s difficult to see the LCD display and buttons on the flash, in order to adjust the settings. Rather than going back to each individual flash unit and having to fiddle about with the settings, which might be troublesome if they’re in a typically high-up, awkward position, you are able to turn your flash unit(s) on or off, raise or lower the power setting, or change how the flash responds, all from the menu system of your DSLR. Both the Panasonic FZ1000 and GH4 cameras have this wireless feature, but you need their compatible wireless external flash units in order to take advantage of this – but, it is definitely worth the investment.

10. The Beep

If you want to make yourself really unpopular, go into any quiet setting, and start taking photos with your camera’s system of beeps fully audible. Don’t do this; it can become a really irritating and off-putting sound. It’s not necessary to have the camera audibly tell you when it has something targeted with its Autofocus system, so it’s best for everyone, if you find out where the sound controls are located in your camera’s menu system, and turn it off (or, at the very least, as low as possible, if there’s such a volume control option on your camera).

 

Avoid This Mistakes During Shoot

Do this simple test below. For each bad habit, give yourself a test score.

01. LEAVE THE CAMERA AT HOME

The best camera is the one you have with you – even if it’s on your smart phone. Not every photo you take is photography competition material, or is of commercial value. Regardless, a huge megapixel count and optimum lens quality on a DSLR is useless if left at home.

02. RELY ON A SINGLE MEMORY CARD

Those little storage cards are hugely expensive, but the temptation to be frugal will bite you on the bum. Murphy’s Law states that your memory card will fill up precisely when you’re shooting that ‘money shot’; when the light is right; or when the entire group is all smiling at you. The remedy? Buy more memory cards.

03. DON’T BACK UP YOUR PHOTOS

I know a friend who fills up a memory card with images, then buys another, fill that up, then buys another – a dangerous habit! He recently confessed he’s lost some of his precious photos. Personally, I have experienced the pain of having a hard drive fail, losing more than a year’s commercial photography work. To be super-secure, you really should store your photographs in three different locations.

04. CHIMP

Constantly checking your images on the LCD display is called chimping. Nothing wrong with it, except if you’re into street photography, or at a wedding or party. You may miss that decisive moment, as you’re too engrossed in the perfectionistic tendency of chimping.

05. SHOOT FROM EYE LEVEL

Amateur shutterbugs tend to hold the camera at head-height. However, this will produce predictable results. When shooting in a location, learn to ‘work the scene’. Drop to your knees, or even lie on the ground, searching for fresh angles. An aerial perspective can be stunning. Remember that the best tool of composition is your feet.

06. FAIL TO CONSIDER THE BACKGROUND

Look for a simple background behind your subject. For example, avoid having a telephone pole (in the distance) that appears to protrude from a person’s head. If you have a long lens, you can employ a narrow depth-of-field to blur the background. This will isolate your subject from the clutter beyond, achieving a degree of separation.

07. CENTRE THE SUBJECT

Ignore the rules of composition at your peril. If you want your photos to stand out, learn and use the Rule of Thirds, rather than place your focal point bang in the middle, like most folks do, (in blissful ignorance). Or, add dynamic by tilting your camera at an angle. Don’t forget to try different types of framing: portrait orientation versus landscape orientation. Or even a really wide panoramic crop.

08. SHOOT ONLY IN BRIGHT DAYLIGHT

Confession time… I am guilty of this. Because I trained back in the bad old days of film, when strong light was necessary to capture good images, I became a fair-weather photographer. Also, I used compact digital cameras for a decade, which were hopeless in low light situations. So I was infatuated with clear, blue skies, as cloudy skies often washed out into a white haze.

However, under a harsh, midday sun, shadows are short and therefore objects do not look three-dimensional, lacking form. Human subjects may squint into the sun, or blink. Worse, they may have an ugly ‘sun-dial’ effect under their noses! Better to pose people in the shade.

Landscapers should learn to work with softer, diffused light – this is mandatory for waterfall scenes. Thunderclouds overhead will introduce a sense of foreboding that blue skies cannot. Golden hour lighting will exude warmer tones and longer shadows.

09. DON’T READ THE CAMERA MANUAL

Same old story: you buy a new camera, put the box away and the camera’s manual stays inside the plastic bag. Perhaps you were too eager to use your new gadget. Well, now it’s time to dig out the manual, and attack it with a highlighter pen.

Be methodical, and diligently work through each function of your camera. You may find features you didn’t know existed!

10. SHOOT ON AUTO

If you haven’t read the camera manual, your photos may suffer from the restrictions of shooting in Automatic mode. Modern cameras are amazing, and can produce great results on Auto, but not consistently. Better to take control yourself. Learn the semi-automatic shooting modes, such as Shutter or Aperture Priority. Then, if you are brave, try shooting on Manual.

11. THINK THAT POST-PROCESSING CAN FIX ANYTHING

This is a lazy habit to fall into. It’s much better to get a shot right in-camera, including the correct exposure, as blown-out highlights cannot be retrieved later. Another consideration is ensuring that the horizon is straight, or you will lose the edges of your image when rotating then cropping it on a computer. Use the 3×3 grid on your LCD display, or a spirit level fitted on the hot shoe.

If you shoot landscapes, buy some ND and ND Grad filters. The most useful filter is the Polariser, the effects of which cannot be replicated using software. Finally, it’s better to do a bit of gardening, removing distractions from a scene, than be forced to clone them out in Photoshop – tedious work!

12. SHOOT ONLY JPEGS

JPEG files are compressed. Unfortunately, this narrows the dynamic range of your photographs, and changes the colour, according to the camera’s presets. This can’t be undone. Shoot using the RAW file format, as this is more forgiving. RAW allows you the latitude to correct exposure and colour, as well as sharpen the image, on computer software. Think of RAW files as digital negatives, that need processing and fine tuning.

13. POST TOO MANY PHOTOS

We all take poor pictures, badly exposed or blurry… but there’s no need to inflict these on the unsuspecting public! Carefully select only your best images, then process these on the computer.

Also, display a variety of images on social media, or online galleries, but limit these to 3-5. Essentially, don’t submit minor variations of the same shot.

So, what’s your score? How many bad habits can you identify with?

Tick these habits and tally up your total.

SCORING

1-3 habits. Wow! You are disciplined, and must have done a few photography courses.

4-6 habits. Not bad. But there is room for improvement.

7-9 habits. Don’t despair; there’s still hope for you.

10-13 habits. You need professional help!