If you do not see pictures in your email below, or do not receive the full lesson, visit the online version at: http://www.betterphoto.com/photocourses/%%photoCatID%%/ All photos and text © Sean Arbabi/ Arbabi Imagery, all rights reserved worldwide. No form of reproduction or usage - including copying, altering, or saving of digital image and text files - is permitted without the express written permission of Sean Arbabi/ Arbabi Imagery and BetterPhoto.com. Lesson #%%lessonNumber%%: The Spectrum of Exposures Dolphins in Ixtapa © Sean Arbabi All rights reserved Now we begin to stretch our exposure knowledge into realms we never could have imagined. It's amazing how your photography can improve so much when you begin to understand exposure better. Now let's take some of the methods we've learned, apply them in a calculating way, and use exposure to our advantage. This week we'll play a bit more, but with the goal of obtaining solid exposures. Although you have the understanding of metering modes, exposure modes, f-stop and shutter speeds, learning about exposure takes practice, play, and more practice- then analyzing your mistakes. Sometimes you find the technically correct exposure is not necessarily the best exposure for creating the mood or feel you were attempting to achieve. Another potential pitfall is obtaining a solid exposure, but discovering your settings didn't give the effect you hoped for. This is where the art of exposure comes into play. I will give you some tools to use exposure to your advantage, through discovering the wonders of "equivalent exposures", learning how ASA or ISO can affect your final shot, and how using certain filters can correct or improve your exposures. The Art of Exposure I'm a big quote guy - love them quotes - and when I think about the art of exposure, a few come to mind. Georgia O'Keefe, the famous Southwest painter, wrote, "Creativity is not a work of art; it is the art of work". Something I definitely believe in, and a good example when it comes to exposing scenes. Creating a beautiful image not only depends on the light in the image, but most often on the exposure you chose; (1) because of proper exposure, and (2) just as much due to the speed and depth-of-field of the image, the settings you chose for the feel you hope to convey. Another quote I recall is from Paul Klee, a successful 20th century painter, "Art does not reproduce what we see; rather, it makes us see". How does this apply to exposures? The same way Georgia's quote does. It's relevant since how you expose a scene is often how you hope to direct the viewer's eye towards the subject or emotion you're trying to convey. Often in photography, our goal is to show people things they would not normally see. American Alligator, Florida © Sean Arbabi All rights reserved By controlling my exposure for this scene, using a wide-open f/stop to create a low depth-of-field, and waiting for the light to fall on the field of focus, the viewer's eyes go to the gator's nose and teeth, giving that feel of "danger" or "predator"- which is what I wanted to communicate. In my opinion, photography has always been a manipulation of reality, and through your vision, and how you chose to expose a particular scene, you may give the viewer your perception of reality, or your artistic impression of the world. Both are unique and different. How so? The first is an accurate representation of how you saw a certain scene- the closest to reality you could achieve in a photograph. The other is how you took the light in a particular scene and manipulated it through your exposure to draw the viewer's eye to your subject, or create a mood that wasn't visible to the naked eye. Fremont Street, Las Vegas © Sean Arbabi All rights reserved To give the feel of old downtown Las Vegas, with it's lights, energy, and crowds, I felt the best way was through a long exposure, not only pulling most things into focus (using a small aperture), but through the movement and motion of visitors and locals in the streets. At this point, in a class on the basics of exposure, you may be thinking, "Wow Sean, you are seriously waxing rhapsotic and gettin' all deep on me". But stick with me - all my rhetoric is leading somewhere, and that place is to equivalent exposures. Equivalent Exposures When I teach live workshops, one of my favorite sections to teach is on equivalent exposures. It's usually a place where people's mouths fall open once they realize what they've been missing. The simple definition of "equivalent exposures" is: once you chose a particular appropriate or correct exposure for a scene, you have the option of choosing many corresponding f/stop-shutter speed combinations on your camera that will allow the same exact amount of light as your initial exposure. What equivalent exposures allows you is the range of creativity you have with a variety of correct exposures in one designated scene. Each combination will produce an identical exposure as the other, but give you different results due to the settings. Equivalent Exposures example chart © Sean Arbabi All rights reserved Here's an example of equivalent exposures. If, let's say, your proper original exposure was f/5.6 at 1/60th of a second (the middle combination), all the other exposure combinations would be equivalent- that is, each would allow the exact same amount of light into the camera, but each with different results due to the varying settings (depth-of-field and speed at which the scene is shot). As mentioned in the diagram above, all of these exposure-combinations are the exact same in amount of light entering the camera, but different in the final result of a scene. The key is the 1 stop change is each setting that gives you the equivalent exposure. For example, when we take f/5.6 @ 1/60th second as the correct exposure, if you increase your depth-of-field 1 stop to f/8, therefore decreasing the amount of light entering the camera by 1 stop, you must lengthen your shutter speed 1 stop longer or brighter to 1/30th second to compensate for that change. You can go the opposite way as well. Open or brighten your exposure from f/5.6, one stop to f/4, and then compensate by darkening or speeding up your shutter speed by one stop to 1/125th second to achieve an equivalent exposure. As you can see, there are many combinations that will provide you with proper exposure for the same scene. And as in the diagram above, f/2 @ 1/500th second will produce a much different scene than f/22 @ 1/4 second - yet both will be properly exposed (if your initial exposure selection was the correct one). Please note: Equivalent exposures can work in one stop increments, but if your camera has 1/2 stop or 1/3 stop increments for f/stops and shutter speeds, it can work the same for those. Just be aware which one your camera offers and adjust accordingly. Equivalent exposures is important for two main reasons. First, it provides you with a choice of varying exposures for any scene, giving you the chance to select what you feel would work best for that scene. Example: I'm photographing a landscape scene along a riverbank. I can either chose a combination of low depth-of-field but faster shutter speed to stop the water in motion (but only give me a few things in focus), or I can chose a wide depth-of-field with a slower shutter speed to pull more things into focus, and maybe blur the water to give it that glassy motion feel. Trinity River detail © Sean Arbabi All rights reserved I could have shot this scene using a variety of f/stop-shutter speed combinations, but by choosing a closed-down aperture (wide depth-of-field), the low light from the small aperture opening allowed me to shoot at a longer shutter speed, giving me the results I wanted- everything in focus, but with a slow shutter speed to give motion and softness to the water. The second reason equivalent exposures is creativity critical, is again it provides you with a number of choices for exposure combinations, but depending on the one you chose greatly changes the way your final scene appears, and the way the viewer sees the image. How so? Let's take the example below: Autumn in Downieville #1 © Sean Arbabi All rights reserved Comparing both images, this first one was shot with a small aperture, around f/32 (@ 4 seconds), bringing everything into focus- the river rocks close to the camera to the mountain and cabins in the distance. Your focus is on the whole scene, and although the viewer's eye may bounce around, this is a landscape shot which acts a whole scene. Autumn in Downieville #2 © Sean Arbabi All rights reserved This second shot, with an equivalent exposure around f/5.6 @ 1/8th second shutter speed, is vastly different although it's exposure matches the first. By using a wide aperture around f/5.6, and adjusting the shutter speed accordingly, the focus is now drawn to what's in focus- which are the cabins at the top of the frame (since most people look to what is first in focus in a photograph). This may be a landscape shot, but the focus is only part of the scene and not the whole necessarily. By knowing this now, you can see the variety of choices each scene you shoot can provide. Do you want to stop that bird in flight, or do you want to pan with in using a slow shutter speed to give it motion and blur? Do you want the focus of your shot to be only the yellow tree along the riverbank with the rushing water frozen in time, or do you want the entire scene to be in focus illustrating the rushing water in motion and the tree along its banks? Do you want the gold miners hands in focus with his gold pan blurred in the background (to draw attention to the gold flakes in his hand), or can you capture his hands and gold pan in focus without too slow of a shutter speed that may blur the scene by accident? Do you want to stop the football players in motion but need to make sure your focus is perfect since using a fast shutter speed only provides you with minimal depth-of-field, or do you want the players to be blurred with a slow shutter speed that also gives you greater depth-of-field and a better chance to have them in focus? Bird and Ocean © Sean Arbabi All rights reserved McDonald Creek detail, Glacier Nat. Park © Sean Arbabi All rights reserved Gold Miner hands © Sean Arbabi All rights reserved Football Players © Sean Arbabi All rights reserved These are all questions to ask yourself while you capture scenes thinking about your equivalent exposures for each. How Film Speed or Digital Speed Setting, ISO or ASA, Change Exposure and Color in a Scene Another important factor to consider, and one that gives you more choices with exposures, is your film speed or ISO setting you chose for your photos. The "correct" exposure for an image is also determined by the sensitivity of the medium used (whether film or digital). For film, sensitivity is referred to as film speed and is measured on a scale published by the International Organization for Standardization (ISO) or ASA (American Standards Association). In the digital world, they refer to it also as ISO (or digital ISO) and the number indicates the digital camera sensor's sensitivity to light. As with all ASA or ISO, film or digital, the "faster" or higher number (i.e. 200, 400, 800), the less exposure is required (a shorter time needed to expose the scene), the lower the number, the more exposure is requires (that is, a longer exposure). But there's a trade off. Kodak ASA/ ISO comparison © Sean Arbabi All rights reserved A Kodak color chart comparing how a lower ASA or digital ISO setting (above) compares with a higher ASA or digital ISO setting (below) regarding color sensitivity, grain, and contrast. Lower or slower speed films or digital ISO settings may need more time to expose the film (or digital sensor), but they also provide a better, more saturated color base than the higher ISO settings. And in addition, lower ISO film or digital settings also provide less grain in an image. Sheep ASA/ ISO comparison © Sean Arbabi All rights reserved Notice the difference between shooting with a lower ASA film (50 or 100 speed on the left), or a higher ASA (400 or above on the right)- this comparison also matches your digital ISO setting on your digital cameras as well) So if you want rich black shadows and smooth saturated color in your scenes, go with a lower ISO. If you need to shoot faster shots (possibly in low light), go with a higher ISO- just be aware of the added grain and loss of rich color the higher you go. The Sunny 16 Rle: If you ever find yourself in a position where your camera's meter is malfunctioning, you can use this oldie-but-goodie rule: On a sunny blue sky day, an approximately correct exposure can be obtained by using your ASA/ISO setting as your shutter speed, while using f/16 as your aperture. For example, if your setting is ASA/ISO 200, if you set your shutter to 1/200th second, and your aperture to f/16, you should obtain a proper exposure on a sunny day. Using Filters: How They Affect or Assist with Exposures In regards to filters, today's photographer can use two types: in camera filters (the tried-and-true method of attaching filters to your camera while you shoot) and the ones you apply after the fact (the Photoshop method of a filter system). I still believe it's best to use filters with your camera and to attempt to get as much as what you want in your original shot, than always adding something later in your computer. For some occasions, if you don't capture certain highlights or details in your original scene, they won't be able to be saved using Photoshop or other software methods (or at least won't look the best or as realistic). With all filters, whenever you add them to your lenses, depending on the color and density of the filter, all will have an effect on your exposures slowing them down- anywhere from 1/3rd of a stop to 3 or 4 stops- but with all cameras these days, the meter usually adjusts the exposure accordingly (with some rare exceptions). It is good to note this though, since for example adding a polarizer filter can slow your exposure by up to 2 stops, which may not help if you are shooting action or wildlife and trying to stop the subject in motion using a fast shutter speed. Using Filters in Camera When in comes to camera filters, there are literally hundreds (if not thousands) you can purchase and use in the field. Personally, and regarding exposures, I stick to just a few to assist me when I'm in need. They are: Graduated neutral density (ND) filter (1 stop to 3 stop) Polarizer Warming filters Neutral density filter (not graduated) Filter chart The four main types of filters I use on a regular basis. © Sean Arbabi All rights reserved Graduated (or Split) ND filters are my personal favorite. Clear on the bottom and darker on top, they come in varying degrees (1 stop, 2 stop, 3 stop, etc.) and the best ones are usually square (giving you the option of sliding them up and down depending on your horizon line). I prefer graduated over split since graduated ND filters provide a softer edge and less noticeable change in most of my shots. Split ND filters have a harder edge, but can work better for certain situations. How do they correspond with exposure? Graduated ND filters can help bring an otherwise too contrasty scene together by darkening the brighter parts of the scene (in the dark half of the filter), while leaving the darker areas alone (in the clear half of the filter). Graduated Neutral Density comparison © Sean Arbabi All rights reserved In two images shot high in the Andes mountains, the top was captured using no filter (and a 24mm lens)- the bottom (using the same lens) was shot with a 2 stop graduated neutral density filter. The bottom image is more how my eye saw the scene, but film, or digital sensor's latitude is not wide enough and over-exaggerates the contrast between the landscape and its reflection. The 2 stop darkening on top pulls the otherwise contrasty exposure back together. Graduated Neutral Density comparison © Sean Arbabi All rights reserved Another landscape example using a 2 stop graduated ND filter to add to the shadows detail while keeping the rich orange hues of sunrise. It's good to note, that these filters work best with wide-angle lenses (20mm-35mm) that can see a wider field of view. Graduated or split ND filters don't have the effectiveness once you start to get above 80mm lenses and up. And although graduated or split ND filters usually are described as dark on top and clear on the bottom, you can rotate them over if need be, or even sideways depending on the bright vs. dark part of your shot. Graduated Neutral Density comparison © Sean Arbabi All rights reserved While captured a summer music festival in Oregon, I decided to flip my graduated 2 stop ND filter and darken the brighter bottom part with the musicians, to allow my film (or digital sensor) to expose the dark audience and log cabin interior above. Polarizing filters also have a special need, as well as an effect on exposure. They generally work to cut haze and reflections (on water, glass, even sunlight off of leaves) at certain angles (usually 30-45 degrees off-axis) resulting in intensified blue skies, greens (with forests and plants), and most primary colors in a scene. For landscapes or skies, they work best, or strongest, pointing north or south (due to a lengthy scientific and atmospheric definition) and begin to lose their strength the closer your point your camera east or west. Rock Formations, Alabama Hills, CA © Sean Arbabi All rights reserved With this scene facing north, and the strong contrast between the yellow-ish tan rock and deep blue sky, a polarizer worked well to add a strong feel to the rich hues. But the drawback with polarizing filters is, as mentioned earlier, the loss of light entering your camera, and hence the slower exposure (or wider aperture) needed. For example, if I'm photographing an athlete running, and want to stop him/her in action, and my exposure is 1/500th second at f/4, if I decide to use a polarizer for any reason, my exposure will mostly be close to 1/125th second at f/4, which might not be fast enough to stop the athlete in motion. I could adjust my aperture by 2 stops and leave my shutter speed at 1/500th, but if my lens only goes as low a f/4, instead of f/2 (which is what I'd need), then it wouldn't be possible. Solution? Remove the polarizer and shoot at the faster speed if stop-action is what you want. Polarizers also add contrast to your scenes, sometimes working okay (as in the example above), but other times causing exposure problems due to the added contrast. Dolphins in Ixtapa © Sean Arbabi All rights reserved Using a polarizer in this case not only help cut glare on the structures behind as well as the sky enriching the colors, but since I was able to shoot in bright mid-morning light, my exposure was still fast enough to stop the dolphins in motion. Warming filters do exactly what they say- the warm the scene up, in varying degrees of warmth depending the filter you're using. They are described in many ways, but the normal set is usually in the 81 series: 81A, 81B, 81C (the further down the alphabet, the stronger the warmth). Warming filters help nicely for overcast days (when your film or digital sensor reads the cool light adding a bluish tone) and when shooting in shadow areas (causing the same blue shift effect to your shots). Yes, one of the nice aspects of shooting digital these days is white balance, which usually adjusts for cool overcast shifts of color in your shots. But I personally leave my white balance off since it can also adjust a nice orange sunset making it more neutral, which is what I wouldn't want. Effect on exposure? Very minimal- from a 1/3 stop to 2/3rd depending on the strength, and again your camera meter adjusts for it. Seals & surf, Pt Reyes, CA © Sean Arbabi All rights reserved On this overcast morning, popping on a 81C filter to my 200mm lens adjusted the cool light (that would have turned the scene slightly blue or cool), bringing the sand and rocky cliffs back to the neutral tones my eyes originally saw. Neutral density filters I don't use that often, but a nice thing to have for specific shots. An ND filter, basically dark all over (again purchased in varying strengths: 1 stop, 2 stop, 3 stop, etc), simply cuts the amount of light entering the camera and allows you to shoot at a slower shutter speed. Why would you need this? An example would be if you wanted to shoot a long exposure, say 4 seconds, of a beach scene, but your aperture at it's max (say f/22), only brought your shutter speed down to 1/8th second. Adding an ND filter, say a 5 stop one, would take that 1/8th second 5 stops (1/4, 1/2 second, 1 second, 2, then 4 seconds) to your desired long exposure speed. Trinity River B&W © Sean Arbabi All rights reserved Shot after sunset, the low light allowed me to take four second exposure of the river. But if I had to leave, say an hour earlier when the light was brighter, by slowest shutter speed option might have been only ½ second, requiring me to use a Neutral Density filter to cut the light and slow the shutter speed to my desired long exposure. Using Filters in Your Computer Filters can also be obtained after the fact using software programs such as Photoshop, Photoshop Elements, iPhoto, and many other image editing programs. As mentioned earlier, I believe it's always best to get as much "in camera" with your original shot than to try and obtain it after the fact. But the beauty of the digital age allows photographers to adjust and manipulate images post-capture in the computer, with great detail, accuracy, and quality. One disadvantage to it is the amount of computer time you can spend on your images and the potential loss of detail in the original shot just not able to return in Photoshop. Imagine if you've taken 500 images in overcast conditions only to wish you had used a warming filter to adjust the cool blue tones of cloudy light- correcting this in the computer results in fixing 500 images one by one (whether done through an automated system you've set up, or manually). That's a lot of manual labor. As an example, I will take the mainstream software of Photoshop (PS) since it is widely used by most photographers. I won't go into great detail regarding PS filters since it isn't that type of class, and in camera exposures are not affected for the most part, but I'll share a few quick tips. PS Self-made graduated neutral-density filters: One nice aspects of an image-editing program, is creating a post-shot graduated neutral density filter-like effect. It's not easy to do though, and can require a lot of time if you want to do it right. Without going into great deal, I basically copy the originally scene (having one overlapping the other in Photoshop), make one darker and the other lighter, then erase the areas that are too light or too dark. Photoshop graduated ND filter effect © Sean Arbabi All rights reserved When I originally captured this scene in Oregon (on the left), I either didn't have my strongest graduated neutral density filter with me as I hiked to the top of the ridge, or used one that just wasn't effective enough. By creating a filter mask in Photoshop and darkening the sunlit areas, while brightening up the shadows, I was able to re-create what I originally saw, as well as create a similar look if I has used a 3 or 4 stop graduated neutral density filter. Again, to go into great deal with mean us turning this class into a Photoshop filter class since there are so many steps, but think of it this way- maybe it can be another BetterPhoto class to consider! PS Warming filters: In this case, although it adds computer time, Photoshop can emulate warming filters very well and actually provides a group of specific ones, matching the numbering system used my camera filter manufacturers (i.e. 81, 85, etc). Just go the menu bar "Image", then "Adjustments", then to "Photo Filter" to see the choices. You can also create your own warming filters through color balance and hue adjustments in the program. PS Polarizer filters: Although, with a lot of Photoshop work, you can probably emulate a polarizer filter on a shot that didn't originally have one but would benefit having the look, I personally don't recommend it, unless you are very advanced with the program, and willing to spend a lot of time on one image. I have done it, through saturation and selective color effects, but again it's something to consider for a Photoshop class and doesn't necessarily pertain to general exposures. Upcoming Attractions Ahh, the end is near, the last week of the course is approaching, and your final exams will be lengthy and painful- just kidding- as we have learned all about exposure, and how to manipulate exposures, we will continue to fine-tune our understanding of how exposures work under various conditions. But first, let us create some new images. Your Assignment: All Exposures are not Created Equal… Find and photograph a scene with three different equivalent exposures (please document each exposure setting). All three scenes should be properly exposed. Capture one landscape scene with no filter and the same scene with (i.e. graduated neutral density, polarizer, split neutral density, etc.) Upload 3 to 5 photos total - Shots 1-3: Create three images of the same scene using different yet equivalent exposures. The three equivalent exposure settings (i.e. f/stop & shutter speed combinations) can be vastly different or close together depending on your subject matter, but make sure you illustrate the difference in each scene. Shots 4-5: Create two images of the same landscape, one using no filter, and the other using a filter that helps create a better image (through exposure). You can use a graduated neutral density, split neutral density, polarizer, or warming filter (but no Photoshop created ones this time out). Note: For this lesson, your exposures should be close to exact. There are two main goals: (1) to see the change in equivalent exposures of the same scene and recognize the wonderful exposure options within a scene, and (2) to illustrate the benefits of using filters for exposures. Specs: Also, please attempt to record as much of the details of your images as possible (such as exposure setting, shutter speed, f-stop setting, lens and camera used, etc). Submit your 3 to 5 images to the Campus Square by %%assignmentDueDate%%. Anytime you need an answer, don't hesitate to ask your questions in our online Q&A forums. Have a great time shooting and enjoy the process! Sean All photos and text © Sean Arbabi/ Arbabi Imagery, all rights reserved worldwide. No form of reproduction or usage - including copying, altering, or saving of digital image and text files - is permitted without the express written permission of Sean Arbabi/ Arbabi Imagery and BetterPhoto.com.