Photo Experiment: Water Droplets

Photography with Water Droplets Photography with Water Droplets Photography with Water Droplets Photography with Water Droplets Photography with Water Droplets Photography with Water Droplets Photography with Water Droplets Photography with Water Droplets Photography with Water Droplets

Another dull weekend. Time to work on another indoor photography idea. As it happened, I just recently came across a video on YouTube showing how to take beautiful abstract images by shooting through a glass pane with water droplets on it. I already had most of the things I needed to do this myself at home – the rest was gathered quickly with a trip to a local hardware store and investing a few Euros.

FOR THE IMPATIENT

Gear Settings
  • Camera
  • 1-2 external flashes
  • Remote trigger for the flashes
  • Tripod with pivoting center column, or boom stand
  • Remote shutter release
  • Glass pane
  • Spray bottle with water
  • Manual focus
  • Manual mode
  • ISO 100
  • 1/125 second
  • Aperture ƒ/22
  • White balance: flash
  • Flashes: manual mode, 1/8 power

THE SETUP

The most important requisite for this setup is of course the glass pane. It should be free of scratches and stains, and wiped clean. It doesn’t need to be large; 12″×16″ is enough. You’ll something to support it; I improvised with water bottles and drinking glasses. Finally, I used some construction paper as the background.

The setup for the camera on the other hand was quite a challenge. I couldn’t use the auto-focus, because in most cases it focused on the objects under the glass pane, rather than on the droplets on top. With manual focus, even at ƒ/22, the depth of field is so shallow that when shooting handheld, the inevitable swaying when standing bent over the table caused most many of the pictures to be out of focus, so I needed a different solution.

Many large (and expensive) tripods have a center columns that pivots for such purposes – my little travel tripod doesn’t. Hence, I tinkered with my light stands. By combining one with a reflector holder and a spare tripod head, I created my own boom stand for the camera. I weighted down the feet of the light stand and made sure all bots and clamps were tightly secured, but still, it was a quite rickety construction. For very careful handling of the camera I needed to use a cable release for the shutter. In the end, this provisional arrangement fully served its purpose.

Setup for the Photo Experiment "Water Droplets"
Setup for the Photo Experiment “Water Droplets”: The glass pane is resting on four water bottles (~12 in. high); later, I put it on lower drinking glasses. In addition, I varied the distance of the camera. When positioning the flashes, you need to ensure that the edge of the glass pane does not cast a shadow into the image.

I placed the flashes on opposing sides of the setup. With a number of a test shots I made sure that the light from the flashes doesn’t create any unwanted reflections on the glass. You also need to avoid that the edge of the glass pane casts shadow lines into the image.

Next, I added the water. I treated the glass with a rain repellant for car windows. This creates a kind of ‘lotus effect’, so that the water doesn’t create just a big puddle, but nice individual drops. Then I sprayed on the water with a simple spray bottle, until there were sufficiently many and large enough droplets.

Finally, I gathered all the items I wanted to place underneath the glass pane to shoot them through the droplets: fruit, a flower, as well as fabric and some utensils from my wife’s treasure chamber ♥.

THE SETTINGS

The final look of the images mostly depends on three parameters:

  • Distance between the glass pane and the object underneath
  • Distance between camera and glass pane
  • Focal length of the lens

Depending on how you vary these, you can fit items of different sizes into the frame, as well as changing the ratio between the sizes of the item and the water droplets it is seen through. The photos in the gallery give an impression on how different-sized drops affect the image using the same background object.

Setup for the Photo Experiment "Water Droplets"
Setup for the Photo Experiment “Water Droplets”: ISO 100, ƒ/22, 1/125s, manual focus adjusted using live view. The flashes are adjusted and triggered via the Godox X1c, and a cable remote is used to trigger the camera.

I tried various focal lengths; most of the images were taken either with the Tamron SP 90 mm ƒ/2.8 Macro, or the Canon EF 50 mm ƒ/1.8, while using identical camera settings. These can be quickly explained:

  • Aperture: ƒ/22. I wanted to have a large depth of field, so that the water droplets as well as the objects underneath would be shown sharp in the final image. I tried different aperture values as well, but I liked the images taken at ƒ/22 the most.
  • ISO: 100. Since the flashes rendered enough light, there was no reason to compromise image quality.
  • Shutter Speed: 1/125 second. The exact value doesn’t matter that much; the important thing is that a photo taken without using the flashes is completely dark. This way, there will be no unwanted distracting reflections of windows or other ambient light sources on the droplets.
  • Flashes: 1/8 power. I set their output in manual mode so that the photos were correctly exposed. When I used very bright or very dark items, I adjusted the power accordingly.

It took a few attempts until everything was how I wanted it to be – but not too long, and then I was ready to start.

THE SHOOTING

After everything was set up, the main challenge was to play around with different items and see how they look like seen through the water drops. In general, colorful items give the best results; however, the patterns should not be too small. Otherwise, the image will be very busy due to the manifold repetition of the pattern in the droplets.

In addition to the objects, I also varied the distance to the glass pane, the focal length and the aperture value. Another possibility for changing the size of the droplets in the image, and thereby alter how the pattern is repeated, is to move the glass pane. Typically, you’ll find larger drops in the center of the sprayed area, and smaller ones further out. This also changes over time. As water evaporates, the smallest drops will disappear entirely, and only the bigger ones remain.

Every time the distance between the camera and the glass pane was changed, or I chose a different focal length, I needed to refocus manually. I used the camera’s live view at 10× magnification. This wasn’t as easy as it sounds, due to the rickety construction of my makeshift boom stand. But with a steady hand, I accomplished the focus adjustments as well as taking the images.

TIPS & TRICKS

As often is the case with such experiments, the devil is hidden in the details, and some problems only show up once you view the images on a large computer screen.

  • The glass pane should really be free of scratches. Even miniature scratches, barely visible with a naked eye, will clearly stand out in the final picture due to the large magnification. This is enhanced by the fact that while the droplets are round, scratches are mostly linear, hence show up as a distracting element. As a result, I deleted all images from my first attempt, and replaced the glass table top by a glass shelf from a display case. The glass from a picture frame might be suitable as well, if it doesn’t have any scratches.
  • A large depth of field requires lots of light, which is why I resorted to using the external flashes. Since the items under glass pane usually don’t move by themselves, it is also possible to take these pictures using only ambient light. You’ll need to watch out for reflections on the glass pane and the water droplets, though (ceiling lamp, windows, TV…). In addition, due to the slow shutter speed, the camera needs to be mounted in a very steady manner.

CONCLUSION

Recommendation: Recommended for imitation – a nice photography variation for a dull weekend. The images created this way make beautiful backgrounds for smartphones, tablets, or slide show presentations.

What I’ve learned: Improvisation. You don’t always need expensive studio gear to take great images, if you know how to help yourself with what’s around the house. And thus, you can turn rather boring items and turn them into interesting pictures.


LINKS

Picture Credits: All pictures – own images.

Photo Experiment: Light Painting with Airplanes

Night Traffic

Long exposures are one of many means to photograph something in a way the naked eye doesn’t see it. Which is one of the reasons why photography fascinates me the way it does. The most popular images of this kind are night-time images of cities, in which driving cars paint long streaks of light through the frame.

This inspired me the other day, when I was looking at one of the many airplanes climbing into the sky nearby during an evening stroll. All airplanes taking off from Frankfurt’s southbound runway 18 fly towards our house, so in the dark evening sky, you can clearly see their bright landing lights and blinking navigations lights. Thus, the idea came up to give it a try and see what this can be turned into.

FOR THE IMPATIENT

Gear Settings
  • Camera
  • Tripod
  • Remote trigger
  • Appropriate clothing
  • Beverages
  • Reading material
  • Flashlight
  • Manual Focus
  • Manual Mode
  • ISO 100
  • 30 seconds
  • Aperture ƒ/11 – ƒ/5.6
  • Continuous shooting
  • White balance: daylight

OVERALL SETUP

A few days ago, the conditions were ideal: the weather was clear and dry. A few clouds were there, but they were high enough so that they wouldn’t be illuminated by the bright airport, and the climbing planes also wouldn’t immediately vanish into them. So I grabbed my gear and walked out into the fields.

There, I looked for a spot from which I had a good view on the planes as they take off, without having the bright streetlights of the next village in the image as well. Most of all, I wanted to avoid any cars passing by that would shine their headlights into the camera.

I had no idea up front what a good field of view would be, so I packed several lenses. I liked the view at a focal length of 35 mm the most, so I mounted the Sigma A 18-35 mm ƒ/1.8. I was able to capture several great night-time photos with this lens before. Since I never opened the aperture any wider than ƒ/5.6, this image could have also been taken with a standard-zoom kit lens.

With long exposures in mind, the camera was of course mounted to a tripod, and I had my remote shutter release with me as well. The main reason for using the cable remote is that I can lock the trigger button, so the camera takes several images in direct succession when set to continuous shooting mode.

CAMERA SETTINGS

This was a matter of trial and error. A few settings were clear from the start: I set the ISO value to 100. This reduces the noise in the image and makes for longer exposure times. As the light changes during dusk, I chose a fixed setting for the white balance, namely daylight. Finally, I focused manually on the horizon and switched the shooting mode to continuous.

Next, I worked out the shutter speed. Looking through the viewfinder and using a stop watch, I tracked an airplane from the moment its lights appeared above the tree line. It took about 80 seconds until it left the frame.

So, what is the best exposure time? Two contradicting factors need to be considered. On the one hand, a faster shutter speed generates more images. This also means there will be more gaps in the light trails, as the camera always makes a short pause between pictures. These gaps have to be closed manually in post-processing. This can be avoided, or at least minimized, by using slower shutter speeds. Unfortunately, this has an adverse effect on the image quality: the longer the exposure time, the weaker the light trails will appear.

I took a few test shots, and viewed the results using maximum magnification on the camera display. The two images below show the difference between a full-minute exposure and a half-minute exposure:

Light Trail (60 sec.)
Detail view of a light trail with 60 seconds exposure time at 200% magnification. The dots painted by the blinking navigation lights are now barely visible.
Light Trail (30 sec.)
Detail view of a light trail with 30 seconds exposure time at 200% magnification. The trail is much brighter compared to the background, and the dots from the navigation lights are now clearly visible.

Finally, I settled for a shutter speed of 30 seconds. The light trails stood clearly out from the background, and a flight time of 80 seconds for each plane to cross the frame meant that I would have to close two gaps in each trail – a reasonable compromise. This also happens to be the longest exposure time the camera supports in manual mode. Even longer exposures require using the ‘bulb’ mode, which makes operating the shutter more complex.

That last value I set was the aperture. I set it so that the overall exposure of the image looked OK to me. The main goal was to make sure the sky didn’t become too bright, to simplify combining the images later. I started at ƒ/11, and then, as it gradually became darker, opened the aperture step by step to ƒ/5.6.

SHOOTING

When everything was set, all I had to do was wait – not for long, though. As soon as I saw the lights of a plan emerging above the trees, I pressed and locked the trigger button on the remote shutter release. Thus, the camera took three pictures in a row. Often, the next airplane was already in sight at the end of taking the third image of the previous one. If not, I let the camera pause for a while.

Over a period of about one and a half hours, from quarter past nine to the last takeoff at 10:45pm, I took 75 pictures in all. Even though it was close to 70°F during the day, it cooled off rather quickly once it became dark. The warm jacket I packed now really came in handy, as did the beverages and reading material.

In retrospect, time passed rather quickly. After the last plane left, I packed everything together, used a flashlight to make sure I didn’t forget anything in the dark, and walked back home.

POST-PROCESSING

The next day, I went about assembling the final image from the individual pictures. The first step was to import everything to Adobe Lightroom CC. I applied a few adjustments to all photos: I activated lens corrections (lens profile and chromatic aberration), and increased the contrast and clarity to make the light trails stand out from the background even more.

Then I picked the image on which I liked the sky the most, and edited it to my liking regarding colors, contrast and details, to make it the background image. The result looked like this:

Night Sky
Night Sky – I liked the sky the most on this image. Thus, I used it as the background and added all other light trails onto it.

In Lightroom, I selected all 75 images, including the background, and chose “Photo” → “Edit in…” → “Open in Photoshop as Layers…”  to transfer them over to Photoshop. This took quite a while, but then all pictures were layered on top of each other in a single project.

The first thing I did was moving the background layer all the way to the bottom, so that all other layers covered it. Then I turned all layers but the background invisible. The next step was selecting three images belonging to the same flight and making them visible again:

Single light trail, part 1
Single light trail, part 1
Single light trail, part 2
Single light trail, part 2
Single light trail, part 3
Single light trail, part 3

The crucial step now was to change the layer blending mode from “normal” to “lighten”. As the result, only those parts of each layer that are brighter than the underlying image are shown – in particular, the light trail drawn by the plane. The outcome of this first step can be seen in the image below:

Adding one trail, before editing
The three parts of the one light trail, with the layer blending mode set to “lighten”, before removing unwanted artefacts and closing the gaps.

This is already quite close to the desired result, but there are a few disturbing artefacts: First, there was another plane flying across in the image in the background, which caused the red and white dotted line near the horizon on the left-hand side of the image. Second, the stars in the top right hand corner are now duplicated, because they moved compared to the background image. And finally, the glow from the airport can be seen behind the trees.

Thus, I collapsed the three layers of the light trail into a single layer, and added a layer mask. Then I masked out all unwanted artefacts in the image – basically, I painted the entire mask black except for the light trail.

The final step was using the clone stamp tool to close the gaps resulting from taking three images. I set the sampling to “current layer”, and opacity and flow to 100%. Here’s the final result:

Adding one trail, after editing
The finished light trail: The gaps have been closed, the trail of the landing plane has been removed, just like the duplicated stars and the glow the behind trees.

After completing one light trail, I hid the respective layer and started on the next trail. I worked on each one individually, because this simplified closing the gaps and removing unwanted artefacts. It also enabled me to adjust the brightness of each trail independently using levels adjustment layers.

The final step was to make all layers visible, collapse everything into a single layer, and export the final image:

Night Traffic
Night Traffic – The final image. Composed from 75 individual pictures, it shows the light trails painted into the evening sky by planes taking of.

TIPS & TRICKS

Some additional information in case you want to try this out yourself:

  • When taking photos of this kind, it is better to take several images with shorter exposure time, and subsequently combine them in post-processing, than to take a single long exposure. This will improve image quality, and even more important, it reduces the risk of losing several minutes of action because, e.g., a car drives by and shines its headlights into your lens.
  • I’ve linked two video tutorials below; one from Canon Australia on photographing light trails, and one from Jimmy McIntyre on post-processing them. They both used cars instead of airplanes, but the procedure is the same as in the image above.
  • With long exposures, there are two factors to consider for the composition of the final image: the static background, and the patterns drawn by the moving lights. It takes some practice to imagine the final picture before actually taking it, so try it out when you find the chance.
  • Taking such photos requires patience – for planning, for shooting, and for post-processing. I spent two hours on the field, plus another three one the computer. Take your time, it will be worth your while!

CONCLUSION

Recommendation: When you have an evening off – go for it! Grab your camera and your tripod, and go to the next street bridge, railway station, airport, local festival – wherever there are moving lights. This way, you can capture amazing and sometimes surprising motion patterns.

What I’ve learned: I’ve gathered some good experiences, for instance how the exposure time affects such long exposures and light painting images. The same goes for working with layers and the clone stamp tool in Photoshop.


LINKS:

Picture Credits: All pictures – own images.

What is…? – Terms, Abbreviations and Lens Designations

Terms, Abbreviations and Lens Designations

Everyone who takes a deeper dive into photography for the first time, gets drowned by a flood of strange terms and abbreviations. Test reviews, tutorials, and online communities are just full of them. What confused me even more in the beginning, was the fact that there is often more than one designation for the same thing – or, vice versa, one and the same shortcut has several different meanings. I am currently replacing some of my gear, so I had to make sure I was adding the correct designations to the respective item descriptions. And since I was at it anyway, I’m writing it down here for future reference – yours, as well as mine.

BASIC TERMS

Photography fills an abundance of books and videos, which describe the basic steps, give instructions, and explain the terminology. I do not intend to compete with that. However, I do want to give an explanation in my own words of the terms I am using regularly in my blog posts.

For most of the terms, I have added links to the respective articles on Wikipedia, in case you want to read more about a certain topic. And if you’re interested in all the details, I highly recommend Mark Levoy’s “Lectures on Digital Photography”.

Aperture

From a technical point of view, the aperture is the opening in the lens through which light hits the sensor. Usually, it can be varied in size (⇒ Wikipedia).

From an artistic point of view, the aperture is the most important tool for creating an image. It controls the depth of field, i.e. the distance range that will be shown sharp in the picture. This makes the difference between a portrait with a soft background, and a landscape photo where the entire frame is in focus. It also influences the amount of light passing through the lens, in particular when using a flash.

  • The aperture setting is always given in relation to the lens. The aperture value is calculated by dividing the focal length of the lens by the diameter of the effective opening. As the size of the opening is the denominator of this fraction, it means that the aperture value is the smaller the larger the opening is.
  • The aperture values are set so that switching from one value to the next always corresponds to either doubling or halving the amount of light let through. This is equal to doubling or halving the size (area) of the aperture opening. The area of a circle with radius r is generally known to be π * r². If I want to double that area, that means: 2 * π * r² = π * 2 * r² = π * (√2)² * r² = π * (√2 * r)². Hence, you need to change the radius by a factor of  √2 ≈ 1.4, if you want to double the area.
  • Thus, the aperture values are always multiples of √2: ƒ/1, ƒ/1.4, ƒ/2, ƒ/2.8, ƒ/4, ƒ/5.6, ƒ/8, ƒ/11, ƒ/16…
Lens with aperture set to different values for comparison (Source: Wikipedia)
  • Since on manual lenses, the aperture ring clicks into place at each of these values, they are also referred to as ‘stops’. Accordingly, the terms ‘stop of light’, ‘stop up’ and ‘stop down’ all relate to doubling or halving the amount of captured light. These phrases are used even if the effect is not achieved by changing the aperture, but by other means, such as changing the exposure time, ISO value, or flash output.
  • Between these ‘full’ values, there are usually values for ±⅓ stop, i.e.: ƒ/2.8, ƒ/3.2, ƒ/3.5, ƒ/4.
  • This notation makes the aperture value, respectively its effect on the exposure of the image, independent from the lens and camera used. Consequently, an image taken of a particular subject and correctly exposed at ‘ISO 100, ƒ/8, 1/200th sec.’ will be correctly exposed with every camera, regardless of size and brand, on which I can dial in these settings. What will be different, though, depending on focal length and sensor size, are the field of view, the angle of view, and the depth of field.
  • When mixing ambient light and flash, the aperture controls the amount of light from the flash in the image, while the ambient light is controlled by the shutter speed.
Bokeh

The term is derived from the Japanese word for “blurred”. In photography, it describes the quality of the out-of-focus areas in a picture taken with a wide-open aperture (⇒ Wikipedia). The bokeh depends on the construction of the respective lens, and the quality of the individual lenses it is comprised of. In particular, portrait lenses usually produce a nice bokeh, to create smooth backgrounds that do not distract in any way from the subject. There are, however, lenses that produce a rather fidgety bokeh, for instance because contours get doubled in out-of-focus areas.

Chromatic Aberration /
Color Fringing

When light passes through drops of water, the individual colors are refracted differently. Sunlight gets split into its individual colors, which we see as a rainbow. The same happens when light passes through pieces of glass in a lens. This means the individual lenses need to be tuned in a very specific way to ensure that on the camera sensor, all the different colors match up again in the intended way. Where this fails, green and purple color fringes appear on contrasting edges in the image, for instance at branches of a tree against a bright sky, or the white frame of an otherwise dark window (⇒ Wikipedia). Chromatic aberration can be corrected in many image-processing software tools, such as Adobe Lightroom.

Crop Factor

To be able to compare different camera types, the main parameters such as the focal length are always converted to the so-called full-frame format. This designation applies to cameras with a sensor the same size as a negative of a 35 mm miniature film (24 x 36 mm). The crop factor equals the ratio of the length of the diagonals (⇒ Wikipedia).

  • Popular formats include APS-C (crop factor 1.5 (Nikon) or 1.6 (Canon)) and Micro-Four-Thirds (crop factor 2 (Olympus, Panasonic)).
  • To compare focal lengths, the values are multiplied by the crop factor: 50 mm on a Canon APS-C camera thus equal – times 1.6 – 80 mm on a full-frame camera. This correspondence applies only to the field of view, however, and not to the angle of view.
  • To compare depth of field, the aperture also gets multiplied by the crop factor. The rear camera on Apple’s iPhone 7, for instance, has an aperture of ƒ/1.8 and a crop factor of 7.2. This roughly equals ƒ/13 on a full-frame camera, which makes it clear why it is almost impossible to get pictures with a blurred-out background using a cell phone camera (large aperture number = large depth of field).
Depth of Field

Depth of field refers to the distance range, within which objects are shown sufficiently sharp in the image (⇒ Wikipedia).

  • In principle, only objects exactly in the focus plane are shown 100% sharp on the image.
  • The further something is away from the focus plane, either in front of it or behind it, the more blurred it becomes. This is a gradual transition, and where an object is still “sharp enough” depends on the resolution of the camera as well as the eye of the beholder.
  • Depth of field is controlled by three factors:
    1. The aperture: low aperture number = shallow depth of field; larger aperture number = large depth of field.
    2. The focal length: the shorter the focal length, the larger the depth of field.
    3. The focus distance: the further away the subject is, the larger the depth of field. Beyond a certain focus distance (depending on focal length and aperture), the depth of field becomes infinite. This distance is called the hyper-focal distance.
  • For this reason, portraits are usually taken with a long focal length and wide-open aperture. Thus, only the face is in focus, while the background becomes as blurred as possible. For landscape pictures, on the other hand, usually a short focal length is used, together with a medium or narrow aperture (such as ƒ/8), to get as much of the picture in focus as possible.
Exposure Triangle

Illustrates the correlation of shutter speed, aperture, and ISO setting for the correct exposure of an image.

  • Each of the three parameters has an exposure component and an artistic component:
    • Each component can make the image darker (fast shutter speed, narrow aperture, low ISO) or brighter (slow shutter speed, wide aperture, high ISO)
    • The shutter speed can either freeze motion (fast) or show motion (slow)
    • A wide-open aperture creates a shallow depth of field, so only the subject is in focus, while a narrow aperture results in a large depth of field, where most of the image is in focus
    • Low ISO values create a clean image, while high ISO values will cause a noisy (grainy) image
    • Depending on the type of photo you want to take, you set one or two of them depending on your priorities, and let the camera figure out the rest.
    • The blog ‘Hamburger Fotospots‘ offers a great cheat card, which illustrates the three parameters listed above, along with their respective effects. The web page is in German, but the ZIP package you can download includes an English version of the cheat card:
Source: Hamburger Fotospots
  • First example: If I cut the exposure time in half, but double the ISO setting, the exposure stays the same (motion blur is reduced, but the picture quality decreases)
  • Second example: If I change the aperture from ƒ/2.8 to ƒ/5.6, I can quadruple the exposure time without changing the exposure (motion becomes more visible, but the depth of field is changed, too).
  • All theory is grey, so here are two YouTube videos that illustrate this very well:
Exposure Time /
Shutter Speed

The time interval during which light hits the sensor. Most cameras allow adjustment between 1/4,000th of a second and 30 seconds (⇒ Wikipedia).

  • Higher-range camera also offer 1/8,000th of a second
  • For long exposure times beyond 30 seconds, there is the so-called ‘bulb’ mode, where the shutter is controlled manually by either pressing and releasing the shutter button, or by pressing it twice.
  • See below for more information about the shutter.
Flash Sync Speed Identifies the shortest exposure time at which a flash without special ‘high speed’ capability will render a fully exposed image. This depends on the build of the shutter (see below), but with most cameras, it is around 1/200th of a second.
Internal Focus On a lens with internal focusing, all moving elements for focusing on your subject are inside the lens. This means that in particular the front element of the lens does neither extend nor rotate when focusing. This is important when using filters that depend on the correct orientation to get the desired effect, such as polarizing filters or graduated filters.
ISO

The name of the International Organization for Standardization in Switzerland. As the shortcut for this organization would be different in every language (in English, it should actually be IOS), ISO is used as a proper name. It is derived from the Greek syllable “iso”, meaning “equal”. In photography, the ISO value describes how sensitive an analog film or digital sensor is to light, as defined in the standard ISO 5800 (⇒ Wikipedia).

  • The default value with most cameras nowadays is ISO 100.
  • The higher the ISO value, the more sensitive to light the film or sensor is. This goes along with an increasing reduction of image quality by increased grain or noise. How strong this effect is on digital cameras depends on the build of the sensor, in particular the size of each individual pixel – the larger, the better. This is why low-light cameras usually have low resolution.
Minimum Focus Distance

The minimum focus distance is the shortest distance on which the camera can still focus with the respective lens. It is important to know that this distance is always measured from the sensor, and not from the front element of the lens. The position of the sensor is marked by a symbol (0) on the camera body. If it is given e.g. as 5 inches, but the distance from the sensor to the front element is already 4 inches, then there is just 1 inch of space left to the targeted object. In general, the minimum focus distance increases with the focal length; for telephoto lenses it can easily be 5 ft. or more. Macro lenses are an exception, because they are built specifically to focus at very short distances, to achieve the large magnification.

Shutter

The shutter is a mechanism inside the camera that allows light to hit the sensor only for the chosen exposure time (⇒ Wikipedia). There are two main types of shutters:

  • An electronic or digital shutter actually isn’t a shutter in the original sense, because light is hitting the sensor all the time. The sensor gets reset (all values set to zero), and after the given time, the values of all pixels are read out. The advantage is that this happens completely silent, as there are no moving parts. Most video, cell phone, and compact cameras work this way, as well as DSLRs in video mode.
  • SLRs usually have a mechanical focal-plane shutter, which allows for very precisely controlled exposure times, as short as 1/8,000th of a second. It is usually built as a pair of two curtains. At the beginning of the exposure time, the first curtain, which until then had completely covered the sensor, slides away. At the end of the exposure time, the second curtain moves out of its resting position, follows the first curtain, and covers the sensor again. At higher shutter speeds (less than 1/200th of a second), the two curtains move so close to each other, that at no point in time the entire sensor is exposed at once. Instead, a slot moves across the sensor so that every region of the sensor gets exposed for the chosen time interval.
    • This slow-motion video on YouTube shows very well what happens inside a camera when taking a picture.
    • Due to the way the shutter works, flashes need a special ‘high-speed synchronization’ mode for working with fast shutter speeds. Otherwise, a black bar would be visible in the image, because only that part of the sensor that was visible between the two shutter curtains when the flash fired, was exposed.
    • Design and way of working of the shutter also explain the terms ‘first / second curtain‘ for firing the flash at the beginning or at the end of the exposure time.
  • Both shutter types do not capture the entire image at once, but the exposure rather moves across the frame. This caused by reading out the pixels row by row with an electronic shutter, or by the movement of the curtains of a focal-plane shutter. The downside is that fast moving objects become distorted in the final image (so-called ‘rolling shutter effect‘). There are also cameras with a so-called ‘global shutter’, which capture the information of the entire image at once. This technology is typically used in rather expensive high-speed cameras.
  • Robert Hall has a video on YouTube where explains the differences as well as the pros and cons of the two shutter types.

ABBREVIATIONS

There are an almost infinite amount of abbreviations in photography. I have selected the ones I often use myself. This section leaves aside all abbreviations that designate lens characteristics; you will find those below in a table of their own.

AF

Auto-focus – The system your camera uses to focus on the targeted subject. There are two distinctly different auto-focus systems: Phase detection is what single-lens reflex cameras employ when using the optical viewfinder. Edge detection is applied when looking through an electronic viewfinder or using the display, for instance on a cell phone. Phase detection is faster, while edge detection is more reliable. In addition, depending on your camera and lens, there are different types of drives moving the lenses accordingly; also see the lens designations below.

APS‑C

Advanced Photo Systems-Classic – This designation embraces digital cameras with a sensor size between 22.5 x 15.0 mm (crop factor 1.6) and 25.1 x 16.7 mm (crop factor 1.5). Basically all interchangeable lens cameras with a retail price under 1,000 € have such a sensor. APS-C is not a standardized label; the actual sensor size varies between manufacturers. Nikon calls their APS-C cameras “DX”.

The designation goes back to the APS system, which was invented back in the 1990s for analog film. The image size is about ⅓ of a 35 mm miniature film. This made it possible to build much smaller cameras, and to store additional information on the film. Due to the quickly emerging digital photography, however, APS never became accepted for analog film, and quickly vanished again.

APS-C as a classification of the sensor size is not related to the camera sensor technology APS (Active Pixel Sensor). This is a type of so-called CMOS sensor, which, due to their compact build and low energy consumption, are used in almost all cell phones and compact cameras.

ILC Interchangeable Lens Camera – A camera where you can quickly change the lens. Often used as a generic term for mirrorless or single-lens reflex cameras, to distinguish them from compact cameras with a built-in lens.
DSLM Digital Single-Lens Mirrorless – Digital cameras without optical viewfinder. They are often also referred to a System Cameras (Example: Sony Alpha a6000). “Single-Lens” means that the image in the viewfinder is captured through the same lens as the actual photo. On older compact cameras, the viewfinder often had its own optics. Nowadays, basically all cameras are digital, the D is often omitted and just SLM is being used. In addition, there are several synonymous acronyms: MILC (Mirrorless Interchangeable Lens Camera), MSC (Mirrorless System Camers) and – my favorite  :mrgreen: – EVIL (Electronic Viewfinder Interchangeable Lens camera).
DSLR Digital Single-Lens Reflex – Digital cameras with an optical viewfinder that uses the same lens as the image sensor (Example: Canon EOS 760D). Again, the D is often omitted and just SLR is used.
MF Manual Focus – Interchangeable lenses usually allow for manually focusing on your subject. This is meaningful in difficult lighting conditions, e.g. for night photography, or for pictures where a moving object shall be captured in a certain position and the auto-focus wouldn’t be fast enough.
MFT

Micro-Four-Thirds – A sensor format with crop factor 2, used primarily by Olympus and Panasonic. “Four Thirds” relates to the 4:3 aspect ratio of the sensor, in contrast to the otherwise usually 3:2.

SOOC

Straight Out Of Camera – This abbreviation is mostly used in online forums and photo communities, and means that the picture it refers to has not been post-processed on a computer in any way.

LENS DESIGNATIONS

Acronyms on lenses tend to be especially confusing, because the manufacturers use different labels for the same functionalities and characteristics.  The table below summarizes the most prevalent shortcuts for the brands I use.

I have left out all terms related to the ‘optical formula’ of a lens, i.e., which specially shaped lenses are built in, and which specific coatings they have. This would go far beyond the scope of this post. In the end, all that matters it their effect on the image quality (distortion, flaring, and chromatic aberration).

Function Canon Samyang Sigma Tamron Tokina
Lens for Full-frame Cameras EF DG Di FX
Lens for Cameras with APS-C Sensor EF-S CS DC Di II DX
Lens for mirrorless Cameras EF-M FE (Sony E-Mount) DN
Image Stabilizer IS (Image Stabilization) OS (Optical Stabilizer) VC (Vibration Compensation)
Auto-focus USM (Ultra-Sonic Motor)

STM (Stepping Motor)

 AF HSM (Hyper-Sonic Motor) USD (Ultrasonic Silent Drive)  AF
Internal Focus IF IF IF IF
Professional Lens L (Luxury) A (Art)

S (Sport)

EX (Excellence)

SP (Super Professional) AT-X Pro
Consumer Lenses C (Contemporary) AT-X
NOTES:
  • Canon: Lenses with internal focus, as well as consumer lenses, do not have a dedicated designation.
  • Samyang: Lenses from Samyang are sold under several different brands, including Rokinon, Bower, Opteka, Pro-Optic, Vivitar und Walimex. They are technically identical, but their prices vary drastically. Full-frame lenses do not have a special label. No lenses with image stabilization are available. Finally, Samyang does not distinguish between different product lines.
  • Tamron: As far as I know, Tamron does not offer any lenses for mirrorless cameras. Consumer lenses do not have a specific label.
  • Tokina: There are no lenses available with image stabilization, or for mirrorless cameras.

CONCLUSION

Recommendation: When you get started, all those terms and abbreviations seem rather confusing. But don’t let yourself be scared by that! To learn the basic terms in the beginning, a book can really help; but in the end, it’s ‘learning by doing’. In particular, the exposure triangle needs closer attention, and you’ll need to memorize the creative possibilities (How do I blur the background? How do I freeze motion?).

What I’ve learned: A lot  😀 And I’m still learning. Even writing this article helped me to better understand a number of things…


LINKS

In addition to the Wikipedia links, additional information can be found here:

Picture credits: Title image: own graphic.

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