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).

 

Mistake For Beginner Photography

There is an awful lot of things to learn when you get your very first camera, especially if it’s an ultra-modern, sophisticated DSLR, with shed-loads of features. So, it’s not surprising that mistakes will be made by many a newbie photographer. Here’s a short list of ten common mistakes…

Newbie Mistake 1. Flashing From A Distance

Flash can be useful even on a bright sunny day, such as to illuminate subjects when they’re backlit by the sun (to avoid their features disappearing into silhouette). However, while external or pop-up flashes can be exceptionally bright, they’re not going to do anything for subjects that are too far away and beyond the reach of the power of your flash (e.g. mountains).

Newbie Mistake 2. Getting ISO Wrong

In dark environments, you can turn your ISO up to lighten your image; in light environments, you can turn your ISO down to darken your image and improve image quality. If you’re unsure of what ISO to use, just choose Auto ISO and let the camera figure it out for you.

Newbie Mistake 3. Mode Dial Confusion

The Mode Dial is usually the largest dial on the top of the DSLR, often stamped with various letters or symbols. The most common of these are Program mode (noted by the letter P); Aperture Priority mode (A or Av); Shutter Priority mode (S or Tv – Tv = Time value); Manual mode (M). Some cameras will let you set one or more Custom mode settings (so you may see C1, C2, etx.). More sophisticated DSLRs might even let you record video (so expect to see a video camera symbol amongst the other mode letter symbols).

Newbie Mistake 4. Mounting Lens Hood Backwards

For convenient storage, you can usually keep your lens hood mounted the opposite way on your camera. The mistake comes when you begin shooting and you’ve forgotten to take your Lens Hood off to have it fixed on properly. The lens hood for your camera has been designed especially for your camera, to avoid unwanted light affecting your image (e.g. you might get lens flare in a situation where you don’t want it).

Newbie Mistake 5. Forgetting To Change White Balance

White Balance ensures that anything with white in your frame appears white in your photo. Forgetting to change the White Balance can cause unwanted discoloring of your photos (e.g. whites can appear blue, orange, or even a green).

Newbie Mistake 6. The OIS Switch Not Turned Off On A Tripod

This one is a very easy mistake to make. Optical Image Stabilization (OIS) works by calculating the movements you make while hand-holding your camera, and then it attempts to counteract those movements to give a smoother appearance while looking at your LCD or Electronic Viewfinder, as you steady yourself to take a shot. Apparently, the OIS feature on some cameras and/or lenses can introduce movement when stationary on a tripod, so it’s best practice to try and get into the habit of turning off the OIS feature, before you attach your camera to said tripod.

Newbie Mistake 7. The MF-AF Switch

Switching to MF (Manual Focus) enables you to fine-tune your focus manually with the focus ring; AF (Auto Focus) lets the camera do the focusing for you. The mistake might come, for example, when you’re in MF mode to take a close-up or Macro photo of a plant, and then you go to take a “Selfie” and forget to switch the camera to AF mode, so all you’ve got to do is press the shutter button and let the camera focus on you and your mates. The result, without the AF switch on is typically a blurred image.

Newbie Mistake 8. Forgetting To Insert A Memory Card

This can happen if you’ve been transferring images from your SD Memory Card, to your computer, and then for whatever reason, you find yourself caught short for time and having to rush to get the images loaded, either for processing immediately, or for storage for later. When the image transferring process is done, you proceed to shut down the computer but, in a rush, you forget to remove the memory card and return it to your camera (to be formatted, ready for its next use). You rush off to do whatever it is you’ve got to do, and consequently forget that you’ve not returned said memory card to your camera. The next time you go to use your camera, you’re confronted by a warning message on the LCD, telling you that there’s no memory card, so images won’t be recorded. This is fine, if you’re still at or close to home. But, not so good if you’ve travelled far with your camera to shoot an event only to discover you’re minus a memory card as you forgot to re-insert it after transferring that last batch of images.

Newbie Mistake 9. Wrong Choice Of Lens

Imagine setting off to take photos of wild animals out in nature (a safari, or some other awesome trip); you arrive at your destination and discover a once-in-a-lifetime opportunity to shoot a rare animal with her new born; you go to grab your camera and discover you’ve left your ultra-wide angle lens on the camera. By the time you’ve managed to open your camera bag, grab your telephoto lens, take off the wide angle lens, pop on the telephoto, switch on your camera and begin to compose your shot and… oh, darn… you’ve lost that once-in-a-lifetime opportunity. Don’t make this kind of mistake.

Newbie Mistake 10. Forgetting Tripod For Nighttime Photography

When you go to take photos at night, you’re going to be forced to use longer / slower shutter speeds, in order to give your camera’s sensor enough opportunity to capture the light detail that’s out there, but lost in the relative gloom. It’s almost a certainty that the slow shutter speeds you’ll need to use won’t make it possible to hand-hold your camera, without introducing unwanted blur into the resulting shots. If you know you’re going to be shooting in low light, especially at nighttime, ALWAYS make sure you take along a sturdy tripod.