Photography under florescent

Florescent lights are everywhere – they come in all shapes and sizes, they are inexpensive and they are energy efficient – they are also one of the worst light sources for photography (the bulbs used in street lamps and some industrial warehouses are much worse – but you rarely find those while photographing while florescent bulbs are everywhere).

There are two problems with florescent lights – flicker and color.

Flicker is the worst of the two, florescent lights flicker, they constantly cycle between different intensities and color, each cycle takes 1/50 or 1/60 of a second, depending on where in the world you are.

When your picture captures just part of a cycle you can get a strange color cast, incorrect exposure and even colored bends in you photo.

To demonstrate I’ve the camera to continues shooting mode and a shutter speed of 1/4000 of a second and pointed it at the round florescent bulb that is right above me, I’ve left the shutter button pressed for about 5 seconds and got a lot of pictures of the same light bulb, I’ve combined them for your viewing pleasure (click image to view larger version):

You can clearly see the color of the light changes between pictures and if you look closely you can also see the amount of light the bulb emits changes drastically between shots.

So what can we do? make sure we capture complete flicker cycles, here the electricity frequency is 50Hz (in the US it’s 60Hz, in most of Europe it’s 50Hz) so I’ve set the shutter speed to 1/50 of a second so I capture one complete cycle and re-run the experiment:

Those 16 identical images are different pictures – it’s just that the total amount and color of light of a complete cycle is completely consistent.

And if a shutter speed of 1/50 or 1/60 does not give you correct exposure you can select a longer shutter speed that covers complete cycles – in the US this will be 1/60 for one cycle, 1/30 for two, 1/15 for four, etc. and in Europe it will be 1/50 for one, 1/25 for two, 1/13 for four and so on.

If you remember in the beginning I’ve said the second problem of fluorescent lights is color – so I took just one more picture of that same light bulb, but this time with I’ve set the white balance to daylight:

If you look at the white ceiling around the light bulb you will see it’s green! you can fix this by setting your white balance to fluorescent – but if you have both fluorescent light and daylight or indecent light in the same picture this will cause a strange color cast that’s hard to fix.

If you mix indecent and daylight you can get the indecent to be white and the daylight to be cold blue or the daylight to be white and the indecent to be worm yellow – both will produce acceptable images but if you throw florescent into the mix you get a green cast – and unless you want people’s skin to look sickly green (or you are photographing zombies) you really don’t want a green color cast.

Also, unlike daylight and indecent light (and light emitted by fire) there are some wavelengths of light that are completely missing from fluorescent lights, this will cause some colors to look completely different under daylight or fluorescent lights – and this can’t be fixed by setting the white balance.

Luckily, the color issue with today’s fluorescent lights is not nearly as bad as it used to be and we can expect (or at least hope) this will continue to get better.

That’s it for today, hope this helps you the next time you take photos in a fluorescent-lit room, see you next week.

Photographing Screens

This week we will talk about photographing computer and TV screens, we will only talk about LCD and LED screens because the older CRT screens that are much more difficult to photograph are mostly not used anymore (thankfully).

Today with LCD and LED screens you can actually get pretty good results by just aiming the camera at the screen and snapping away, but there are still a few things that can go wrong:

Glare and reflections

This is probably the most common problem when photographing any reflective surface (including screens, obviously).

Glare happens when light from any source is reflected on the screen and obscures the actual image that is displayed, in the following image there’s a small desk lamp on camera’s right shining into the screen:

Glare is easy to predict, light that hits a surface is reflected at the same angle in the opposite direction, in the diagram below the red lines represents the leftmost and rightmost rays of light that hit the screen, the yellow area is where the light is reflected into, if the camera is in the yellow area you will see glare, on the other hand if the camera is not in the yellow are you will not see glare – that simple.

In the next picture, I moved the camera to the other side of the screen to get out of the glare area and I got a nice glare free image:

Another option is to move or tilt the screen so to change the glare area without moving the camera or to place something between the screen and light source to block the glare.

Bad exposure (image too dark or too bright)

The camera is designed to think everything you photograph is on average middle gray (at least in brightness if not color), this works out really well because most scenes are in fact, on average, close enough to the brightness of middle gray.

But this fails miserable if what you are photographing is mostly white or mostly black – and since most computer programs today use a white background you are vey likely to hit this problem when photographing computer screens.

In the following picture I loaded a picture that is half pure white and half pure black and used spot metering to expose for the white side – the white is gray-ish and everything is dark:

And then I repeated this for the black side (the picture is blurry because I took it hand held and the shutter speed wasn’t fast enough, please ignore the blur):

To fix the problem I’ve used an image manipulation program to draw a middle gray box on the screen and used this for metering (zoomed in so I see only gray in the viewfinder, switched to Av mode, set my preferred aperture, half pressed the shutter to see the shutter speed the camera selected and then switched to M mode and set those values).

With the exposure set I took another picture of the black and white image and this time both the white and black are correctly exposed.

Tip: if you can’t get both correctly exposed reduce the screen brightness.

Note that for accurate results I should have metered using 18% gray but just choosing somewhere in the middle of the L slider (of the HSL color representation) gets me close enough.

Incorrect white balance (strange color cast)

After we got the exposure right it’s time to also get the colors to display correctly.

To demonstrate the problem I’ve used Google image search to look for “red” and found a nice image of a red rose (image from here), just photographing it gets us an image with muted dark colors:

This is because the camera sees all this red and assumes that some of the color is caused by the light being red – so it makes the picture less red to compensate.

To fix this I’ve used the same gray image I’ve used for exposure to set a custom white balance (check your camera manual to learn how to set a custom white balance) and now I’ve got this:

Tip: you can shoot in raw and set the white balance in post processing, just make sure you have at least one shot where part of the screen is pure white or neutral gray.

Balancing screens with ambient light

Screens are pretty bright, especially with the factory default brightness setting (that is designed to be so bright it catches you attention from across the store), room that have screens in them are usually not so brightly lit – this makes taking a picture with both a well exposed picture on the screen and well exposed background difficult.

To demonstrate this I’ve placed a green toy dragon on top of my screen and turned the brightness all the way up (back to the factory setting):

To bring back the dragon I’ve simply used flash, to avoid causing glare I’ve used what we talked about in the beginning of this post, I’ve moved the flash to the side where it almost doesn’t reflect into the camera and used a black card to “hide” the screen from the flash to remove what’s left of the glare):

This is very much a “flash picture” with all the typical flash shadows, but it was easy to take and we see the dragon – I will write about eliminating flash shadow in a future post.

Flicker (vertical or horizontal stripes)

LCD screens have a florescent tube at the back of the screen and florescent lights flicker (they change both brightness and color), you see this with very fast shutter speeds, video cameras and cameras with electronic shutters (where the camera often reads the sensor line by line and not all at once).

To solve this you have to set the shutter speed so the camera picks up an entire flicker cycle (or several cycles).

In the US the electric frequency is 60Hz (so one cycle is 1/60, two are 1/30, etc.) in most of Europe the frequency is 50Hz (1/50 for one cycle, 1/25 for two …).

LED screens don’t have a fluorescent tube and should not have this problem (but I don’t have a LED screen on my desk to test this)

Moiré patterns (rounded lines)

Moiré patterns usually are rounded stripes that appear when there’s a fine pattern on the subject where the details are two big to register as a solid color but to small to show up correctly (in order for a shape to show up it has to be more than 2 pixels in size).

Here I’ve displayed this vertical lines on the screen (the diagonal and rounded lines are moiré patterns).

This is difficult to fix in post processing and the best option is to minimize the patterns while shooting, you can do this by moving closer of farther, zooming in or out and changing your camera angle (or making sure the subject doesn’t have small repeating patterns).

Noise (random dots)

Any decent camera will only have visible noise in dark areas and screens are pretty bright so noise shouldn’t be a big problem, but it can still appear in dark areas of the image and around the screen.

For the next picture I’ve maximized noise by setting the screen brightness very low, the camera to very high ISO with a narrow aperture and fast shutter speed and I’ve took a 100% crop from a dark area.

To minimize noise just get more light into the camera (increase screen brightness, use a wider aperture, a slower shutter speed or if the noise is around the screen add more light).

 

That’s it, see you next week.

Silhouettes

This week we will talk about creating silhouettes.

Silhouettes are created when the background is considerably brighter than the subject and you expose the image for the background and not the subject.

In this post we will cover 4 different situations where you can easily create silhouette picture.

But before we begin there are 3 important things to consider when shooting silhouettes:

  1. Shape – In a silhouette you only see the shape or outline of an object, not the details – so it’s important the subject have a distinct recognizable shape, sometime, especially with people you will want them to pose in a very exaggerated pose so the shape is recognizable and they don’t become a shapeless blob in the photo.
  2. Background – because there is no detail in the subject the background details become much more important, make absolutely sure to get your background right.
  3. Focus – if you focus on the subject the background may be blurred (and remember all the colorful details are in the background), if you focus on the background the edges of the silhouette can be blurry – you can choose what you prefer or you can use the hyperfocal distance to get them both in focus.

Sunset Silhouettes

Warning: Don’t look directly at the sun, especially trough an optical viewfinder, even at sunset (electronic viewfinders and live view are safe). Don’t point the camera at the sun for more than you absolutely have to, especially in live view mode but also when the shutter is closed.

Using the sunset as a background for your silhouette shoot is easy:

  1. Take a shot of the sunset without your subject
  2. Make sure you like your sunset image, check the image is not over exposed and doesn’t have any blown highlights
  3. Use exposure lock or manual mode to keep your camera on the settings you used for taking the sunset image
  4. Place your subject in the frame, compose and take the shot

Remember to work quickly, during sunset the light can change pretty fast.

Silhouettes against the daytime sky

The sky during the day is pretty bright and you can use it as the background of a silhouette – especially if your subject is in the shade.

This is best done if there are some clouds (because we want details in the background) but not if its completely overcast (because we want the sky to be bright)

For this example I’ve placed our good friend the toy lion on a light stand, set the camera to spot metering mode and took a picture basing the exposure only on the lion and I’ve got this:

You can see the sky is completely blown out (actually this is not a bad white background product shot) this is a good start because the same brightness difference that over exposed the sky will under expose the lion and create the silhouette, here is the same photo but this time metering for the sky:

They sky are no longer bright – because we metered on the sky they became “middle brightness” – the lion is not yet a silhouette because we have too much light (after all, we are outside in the day time and there’s not a could in the sky), to turn this into a silhouette we need to load this into an image editor of some sort (I’ve used the free paint.net) and open the curves window:

The important thing is that even with the sky too dark and the lion too bright the sky is still much brighter than the lion, we drag the point at the lower left corner of the curves graph to the right – this means “make everything that’s darker than this pure black” – drag it along the bottom until the subject is completely black.

Now, to fix the sky we drag the top right edge of the graph to the left, this will make the non-black parts of the image brighter (just stop long before the sky goes pure white).

This added a bit of noise to the image (because I worked on the JPEG, it would have been much better if I used raw) so I’ve used the “reduce noise” option of paint.net (that is pretty bad, but good enough for this image that only had a little bit of noise) and this got me this:

 

Creating silhouettes in a “studio”

I don’t have a studio, but I do have a living room I can use when no one else is home – I’ve used some toys for the background, I’ve place a flash without any diffuser at full power very close to the background and set my camera to correctly expose the background.

I’ve placed a toy giraffe as far from the background as I could, this means that the flash-subject distance is much grater than the flash-background distance and that means the subject get’s very little light (remember the light falloff post?).

Right out of camera I’ve got this image:

There’s still a bit of detail in the giraffe, I could use curves or levels adjustment to make it completely black but I like it the way it is

Silhouettes with a pure white background

And last but not least, silhouettes against a pure black background – this combines the studio silhouettes above with the white background technique I’ve talk about in the past.

I’ve just set the camera so the giraffe came out completely black with an off-white wall behind it (as far away from the wall as possible) and I’ve place my flash near the wall pointed at the area behind the giraffe, I’ve than set the flash power to the minimum required to over expose the wall so it’s completely white (by taking a few test shots) and I’ve got this:

There are some parts of the background that aren’t pure white, but they aren’t touching the giraffe and so are easy to fix (or crop), for the next picture I’ve painted them white and use the level adjustment to make everything that isn’t pure white go black:

Taking a picture of a room interior with the view outside

Today we will talk about making a picture that shows both the inside of a room and the view trough the window – and we’ll do it when the view outside is in direct mid day sun.

Let’s begin with two test shots just to show the problem:

For the first shot I’ve used spot metering to expose for the outside, it is very bright outside and I wanted to add a flash later so I’ve set ISO to 100 (the lowest value on my camera) and the shutter speed to 1/200 – the camera’s max sync speed (the “max sync speed” is the highest shutter speed you can use with a flash), I’ve let the camera select the aperture and the camera selected F/11 and I’ve got this:

The outside is a little bit under exposed because all the white in the picture (but not by much) and the inside is completely dark.

For the next shot I’ve metered for the inside, I’ve let the camera do all the work by spot metering on somewhere in the room that is a little farther than the window and the camera selected f/5 at 1/3 of a second (ISO is still 100) – this got me this picture:

This picture is a little bit over exposed and the colors are washed up (the washed up colors are probably caused by lens flair from the bright light outside).

What those picture show us is that the difference in brightness between the inside and the outside is way to big to capture in a single image.

Now, since the whole post is about capturing both in a single image it’s pretty obvious I’m going to do something to fix the problem – and that something is to increase the brightness of the room to match the outside.

I’ve connected my cheap YN465 external flash to the camera (the built in popup flash doesn’t have the power for this) and pointed it directly up into the ceiling so the reflected light will illuminate the room evenly.

I’ve put the camera in manual mode and set it to expose correctly for the outside, then I’ve taken a few test shots at different flash power settings until I’ve got the inside brightness up to where I want it to be.

For this picture I’ve set the flash on full power and opened up the aperture a bit to f/7.1 to get a bit more light both for the inside and the outside.

Note that the outside is still much brighter – this is because I didn’t want to make the inside and outside the same brightness, I don’t want to hide the fact that it’s eye-hurting bright outside and a little dark inside – I just want to get them to the point I can capture both in the same picture (if I did get the inside and outside to be at the same brightness it wouldn’t look natural).

Now that we got the camera and flash settings dialed in we can bring in our model and start taking pictures:

If we try to take that picture without the flash we will get a silhouette – and that’s the topic for next week.

Soft Light and Hard Light

At first soft and hard light seems like red and purple music – the word just don’t make sense, but soft and hard light are actually very important and simple concepts in photography.

In a nutshell soft light is a light that makes shadows with softs edges and a gentle gradient change from light to shade while hard light makes shadows with hard well defined edges.

To help demonstrate the effect of hard and soft light I’ve taken two pictures of my friendly neighborhood lion (that made its first appearance in the aperture post), for the first picture I’ve put the lion on a tripod near a window and just took a shot on Av mode – we will talk abut why windows give soft light below, you can see the very pleasing change from the brighter right side to the darker left side and that the left is well lit even with just one light source on the right side.

For the second picture, I’ve put the lion on a pillow and used a flash on the far right, we will talk about why a far a away flash is considered hard light in a second, you can see the left side of the head is dark, the fast light transition on the face and the sharp line the shadow makes on the pillow in the bottom right and top left sides of the picture.

If you look at the texture of the lion’s fabric you can see that in the soft light picture it looks, well, softer, everything looks smother and small features (like the seem in the middle of the lion’s body) are visible but look small and insignificant – this is why this is a very good portrait setup, it makes skin look softer and smother and is generally a very flattering light.

The hard light picture on the other hand makes the lion seem rougher, small features are more exaggerated (the seem in the middle of the body is now a very clear dark line) – this is why this light does not generally make people look good, but it does add drama and can work for photographing people if you want that dramatic look and don’t want to make our subject look like a fashion model.

Now, how do we create soft or hard light? simple, the bigger the light is and the closer it is to the subject the softer the light, let me explain:

If we have a light source that is a single point, like the left diagram below, there are areas that are lit and areas that are completely dark – all the light comes from a single source and each ray of light can only hit one thing before it’s reflected back – but if we make the light source bigger, like the right side of the diagram, not all the light comes from a single point, and there are areas where light from one side of the source is blocked but is still lit by the other side – those are the areas of soft shadows.

As we make the light source larger the soft shadow areas grow until, if the light source is very large compared to the subject, the dark area disappears completely, in the diagram below we see a much larger light source at the same distance as the previous diagram.

And finally, in the next and final diagram, we see a light source of the same size closer or farther away and we see that the farther we take the light source the smaller the soft shadow areas become and the light get’s closer to a point light source, that is why the sun, while huge, is a very hard light source.

So, the sun is a hard light source because it’s far away and our flash is a hard light source because it’s small – so where do we find soft light?

We get soft light by reflecting or diffusing light on some surface, for example, light outside on a cloudy day is soft because the light “spreads out” on the clouds and the entire sky becomes one large light source, also, during sunrise and sunset the sun is lower on the horizon and so the light passes trough more of the atmosphere resulting in a softer light.

Window light is also soft because the entire window acts as a light source and so is light reflected from any large surface.

For flashes, aiming the flash at a wall of the ceiling softens the light because the light source is now a big piece of the wall instead of the tiny flash bulb – also, there are a lot “light modifiers” you can put between the flash and subject to soften the light, the most common is without a doubt the umbrella (instead of the flash head the entire umbrella is the light source – making it much bigger).

Hard light is also much more prone to reflections and specular highlights than soft light.

It’s important to mention that when we are talking about small and large lights we mean in relation to the subject, your camera’s flash is tiny when photographing a person from across the room but quite large for a close-up picture of an insect.

So, to summarize, here’s a table of the properties of soft and hard light and two pictures of a red plastic dinosaur, taken with the same camera settings, the right side was lit with a bare flash far away (hard light) and the left side with a small softbox right out of frame (soft light) – click image for larger version:

  Soft light Hard Light
Shadows Soft edges Sharp edges
Texture Smooth Rough
Light transitions Gradual Immediate
Reflections Less reflections More reflections
Light Source Big and close Small or far
Good for Beauty shoots Dramatic pictures

Photographing a dark subject on a dark background

After last week’s post on photographing white subjects on white background it’s only natural to talk about the exact opposite and photograph something black on a black background.

If you remember to photograph a white scene we basically set our exposure to about 2 stops brighter than the camera tells us and everything worked out, so you may expect that for a black scene you just set your exposure to about 2 stops darker and call it a day – but things are not that simple (if they were this would have been a very short post).

The first problem is that black on black will result in a image that is, well, black – we get a picture where it’s actually difficult to see the subject and when we scale the picture down it can become a completely black box with no visible details, in the white on white picture we had shadows that defined the shape of the white objects here the shadow doesn’t help us because it’s also black.

So if we want people to be able to see what we are photographing we really want to keep the subject almost black and make the background gray.

Than we get to the technical problems, when everything the camera sees is black there is very little light getting into the camera – this means this is going to be a long exposure and you need a tripod, it also means auto focus is going to be slow if you can auto focus at all and that you really want a camera with an optical viewfinder (your camera’s screen or an electronic viewfinder are going to be completely black).

Also, if you use a DSLR light coming in trough the view finder can completely mess up the camera’s light meter (because there’s much more light in the room then is reflected into the lens) so make sure to have your eye on the viewfinder or at least cover it with something.

Black surfaces also tend to be reflective, but that’s a different problem we’ll talk about on another post, so I’ve selected non-reflective subject and background for this post – a camera lens on a fabric background.

So, first let’s see how the camera is doing without our help – I’ve put the camera on a tripod with a remote shutter release, switched to Av mode and selected F/11 as the aperture because I want the entire lens to be in focus in focus (I was very close and F/11 gave me just under 9cm, or about 3.5 inches of focus) – this gave me a 13 (!!!) seconds exposure at ISO 400 according to the camera’s light meter and resulted in this image:

You can easily see the picture is both way too bright and way too pink, the brightness we expected but where did all this pink come from? to keep this a low budget production (I expect my readers are not pros with easy access to studio equipment) I’ve use a black T shirt as the background and while that shirt looks completely black it actually reflects much more red light then blue or green – especially with such a long exposure.

Let’s look at the histogram:

You can see the image is very bright with almost the entire image in the right side of the histogram, you can also easily see the picture is not as color neutral as we expect from a mostly black image with a little too much green and way too much red (you can also see by the small bump at the far right we have some over exposure, this is the light reflection on the top of the lens).

So, how do we know what’s the right settings for really nice black? the camera’s LCD screen does not help us here (since. like we said in last week’s post it’s brightness is way too inaccurate) and it’s hard to judge the difference between “nice rich black” and “way too dark” by the histogram – so I took 15 pictures at a third of a stop difference starting at the camera’s exposure and ending when the picture was very obviously under exposed and then checked the results on the computer (this is called “bracketing” taking multiple photos around what you think are the correct settings to make sure you get a good one).

For you enjoyment here is a composite of the center part of all those images:

The best image was the one exactly two stops darker than the camera’s meter (how wonderful – this is what was supposed to happen), and here is that photo:

And it’s histogram:

Now all that’s left to take care of is that horrible pink color, obviously the best solution would have been not to use a fabric with a red color cast to begin with – but I’ve decided to fix it in post processing instead, I’ve loaded the out of camera JPEG in the free paint.net and adjusted the color channels in the “Levels” window, I’ve then done another quick levels adjustment on the reflection in the top of the lens and got:

And the histogram:

Obviously I could get a better result if I used the raw file and loaded it into Adobe Photoshop or Lightroom – but I wanted to show you what can be done with two minutes and free software.

 

That’s all for today, next week we’ll take a break from black and white subjects and look at something else.

Photographing a white subject on a white background

The light metering in modern cameras is great and in most cases the camera’s automatic (or semi automatic) modes do a good job at setting exposure – but the camera sets exposure based on the assumption that whatever you are photographing is of average brightness (about 18%, if you care about the technical details), this works great for average scenes but fails miserable for scenes that are mostly bright or dark.

The stereotypical examples for photographs that are white are snow and brides but since I don’t have either of those here I’m going to photograph milk – a bowl of white milk on a white plate on a white tablecloth.

I’ve put my camera on a tripod, attached my 50mm lens, switched the camera to Av mode (A on some brands), set the aperture to f/3.2 for a shallow depth of field and let the camera work it’s magic:

This image actually looked pretty good on the camera’s screen and I could only see how dark it is on my computer screen – that’s why you can’t trust your camera’s screen to judge exposure and you have to look at the histogram, the histogram is a graph that shows you the brightness of the image, there’s almost t always a way to view the histogram in the camera when you preview the photo, here is the histogram for this picture:

See that bump in the middle? that means that most of the image brightness is almost in the middle, that would be fine for most images but with all that white we want this picture to be much brighter.

So what do we do? we actually have two solutions to this problem:

The Good – Exposure Compensation

Your camera has something called “exposure compensation” – it’s a way to tell the camera “do what you meant to do just do it X stops brighter/darker”.

If you want something to look white but not be over exposed it should be about 2 stops brighter than average, for the following photo I’ve set exposure compensation to +1 and two thirds:

This image actually looks too bright in the camera preview – just to remind us we can’t use the camera preview to judge exposure, and the histogram for this image:

See the big bump on the right? that means most of the pixels in the image are very bright and the fact the bump doesn’t touch the right edge means we haven’t over exposed the image – perfect.

The Better – Manual Mode

Using exposure compensation is good but there’s an even better way – use manual mode, yes the big scary manual mode, it’s actually easy in this case.

To set your exposure in manual mode just zoom in (or get close) so your camera only sees white, set you camera to one of the semi-automatic modes and set your expose compensation, now take a test shoot and check the histogram, if you are happy with the results just switch to manual mode and set the same values the camera used.

So why use manual mode if you use the same settings as in the auto mode? because now the settings won’t change if the white animal you are photographing jumps in front of a dark rock or if the bride dressed all in white is joined by a groom in a black suite.

Let’s take our milk image in manual mode:

And now add something big and black just to fool the camera’s light meter:

See how the white milk keeps the exact same color between images?

You can see the black hat is actually seriously underexposed but I don’t care because the white milk is my subject – and in manual mode the camera doesn’t try to second guess me and compensate – keeping details in both the whites and the blacks is a topic for another day.

 

Hope you enjoyed this tutorial, now it’s time to use our setup to eat breakfast.

Making the Background Black

Last week I’ve posted about how to make the background white, this week we’ll go the other way and make the background black, the doll in the picture to the right was shoot in exactly the same location as the white background shoot from last week, the wall behind the doll is off-white in reality.

As with white background the trick is that the camera is limited in the range of brightness it can capture, go above that range and you get pure white, go below and you get pure black. Also, again like width the white background, the distance between the subject and background is critical – the longer that distance is the easier it is to get the background to turn black.

The trick is very simple. you set your flash to low power and get it as close as possible to the subject – and than because the distance from flash to background is relatively much more than the distance from flash to subject the background gets very little light compared to the subject and since we used a weak flash to begin with that light is not enough for the background to even appear in the picture.

Now, since my “studio” is a tiny room I couldn’t  get the required distance to get the background to turn black in-camera – so I’ll show you how the get an almost black background in-camera and then finish the effect with less than a minute of post processing.

I shot this in exactly the same place as last week’s white background pictures, our model for today is an hello kitty doll (because it is brightly colored and will look good against the black background), I’ve also covered the glass we used in the white background picture with something black (the back of the same picture frame I took the glass from).

First set you camera to manual (M) mode, your shutter speed to your camera’s sync speed, your ISO to the lowest value and your aperture to something small, F/11 is a good starting point – you want a setting that will produce completely black image if used without a flash.

Now for the flash, you want to flash as close to the subject as possible without it showing in the picture, you also want to control the light, in this case I’ve used a DIY softbox (take a cardboard box, cut and glue to make a funnel shape where the small side is the size of your flash head, cover inside with aluminum foil, cover large opening with something white that is not completely opaque, I used a diaper) and I’ve also placed some black packing material on the far side of the softbox to block the light from hitting the background (something that blocks the light from going where it shouldn’t is usually called a flag).

Here’s how it looked from above:

You can clearly see the cardboard softbox, the flash is below the cardboard flap at the back of the softbox, you can also see the flag and on the other side you can see a folder silver car windshield cover (I’m not sure what those things are called), in this picture it is used as a reflector, bouncing light back to our “model” so that the right side of the doll won’t be in complete darkness.

Now I’ve played with the aperture and flash power to get a good exposure of the doll without getting any light on the far wall – and, as I said before I couldn’t do it – so I’ve taken a picture where the background is almost black and the doll is a little too dark (but don’t worry, we will solve this problem in a minute) the somewhat disappointing photo is (click to see larger version):

You can’t really see it but the background in this picture is actually not completely black, if we increase the brightness of the picture the background will appear – but this can easily be solved by the levels or curves tool of your favorite graphics package, because we are doing a low budget photo shoot I’m going to show you how to fix the problem in two ways using two free software programs:

In paint.net I’ve used the levels tool, I’ve pulled the lower handle on the input slider just a bit to make the background really turn black and than pulled the middle handle on the output slider a lot to brighten the doll.

In GIMP I couldn’t get the result I wanted using the levels tool so I’ve used curves instead, I’ve kept the far left of the curve at zero to turn the background black and raised the rest of the curve to brighten the doll, I had to fine tone the curve a bit so I don’t lose details in the white parts.

Here are the results from the two programs with the settings I’ve used:

Adjust

You can see there are some visible reflections in the black paper thing the doll is sitting on (it’s most visible in the middle paint.net version), but those are easy to edit out – just paint over them with black.

And the final result is (click for larger version):

And that’s how to get the background to turn black for product photographs, hope you enjoyed this tutorial.

Making the Background White

In this post we will see how we can get completely white background for product photography with just one flash.

The mouse picture was shot is JPEG, it has been cropped, resized and sharpened but I didn’t do anything in post to make the background white – so how do we get that white background?

The trick is extremely simple, the camera can only capture a very limited range of light intensity, we can move that range up to capture pictures of bright subjects or down to capture pictures of dark subjects but at the end we are limited by that range – anything brighter than the top of the range will become pure white (known as “blown highlights”) and anything darker than the bottom of the range will become pure black (“blocked shadows”).

Having blown highlights or blocked shadows unintentionally in the picture is considered a bad thing – but if we know about them and control them we can use them for our advantage.

In this post we will see how we can get white background, next week we will look at getting black background.

The first thing we need is space, light power falls off very quickly when we get farther from the light source – so if we can get some distance between our subject and the background we can more easily control the brightness of each of them individually.

Our model for today is s small green dinosaur, the dinosaur is standing on a piece of clear glass (actually some kind of plastic) I took out of a cheap picture frame, the glass is wedged into the space between two drawers so it’s suspended in the air.

Now we are ready to shoot the dinosaur (without flash – because we will use the flash later to light the background), for this we don’t even need to use manual mode, I’ve set the camera to Av mode (because that’s how I like to shoot) put the camera on a tripod (because I want to use lower ISO and longer shutter speed) and aim it at the dinosaur.

This is the photo I get:

Now it’s time to add flash, the flash is set to manual mode, connected to a cheap radio trigger and aimed at the wall behind the dinosaur, we want to set the flash to the lowest power level that will give us the white background – we want it bright enough to completely turn the background white but we don’t want light from the flash bouncing around and lighting our subject.

For this particular flash at this particular situation it was 1/64 of full power – I’ve got there by setting the flash to the lowest power and taking test shoots every time trying a slightly higher power level until I got to the level that burned the background (hint: the camera LCD screen is very bad for checking brightness but most cameras have a feature you can turn on that will make blown highlights blink).

Here is what the setup looked like, note the flash on the floor (because I didn’t have anything to put it on) pointed at the wall – sorry about the image quality, this picture was taken with my phone:

And this gets us this photo:

You can see that the near edge of the glass and the drawer holding our set are visible – but we don’t care because a simple crop will give us:

 

And that’s it, hope you found this useful, next week we’ll talk about making the background black.

The Exposure Triangle

There are 3 factors that control the amount of light that enters your camera: Aperture, Shutter Speed and ISO. Those factors are called the exposure triangle.

My favorite metaphor for the exposure triangle is that taking a picture is like filling a bucket with water, to get the correct exposure you need to get the right amount of light into the camera (or water into the bucket), to control the amount of water you can keep the water flowing for shorter or longer amount of time (shutter speed), use a ticker or thinner water pipe (aperture) or replace the bucket with a smaller or larger bucket (ISO speed).

It’s worth noting that the exposure triangle has nothing to do with the triangle shape we all know and love, but “exposure triangle” is a catchy name (better than the more geometrily correct exposure cuboid).

Changing the amount of light with any one of the 3 factors will give the same brightness as changing the same amount with any other factor – but not the same image because aperture also affects depth of field (among other things), shutter speed controls how you capture motion and ISO changed the amount of digital noise in the image.

To demonstrate this I’ve set the camera on a tripod in front of a toy microphone, set it to manual exposure and manual focus, and I’ve also set the white balance (because auto white balance can change white balance between pictures)  – and took 13 photos , 1 correctly exposed according to the camera light meter and then for each of the 3 factors I took 4 pictures at +2, +1, –1 and –2 stops from the correct exposure.

I took the JPEG images right out of camera and combined them into the table below to show that the brightness really does change by the same amount.

Combined

The darker band on the right side of the pictures is actually the corner of the room.

You can’t see the changes in depth of field or noise in those small images but that’s ok because you also can’t see them in the full size, the maximum aperture is small enough to get the entire microphone in focus and the background is a solid color – so no visible change in depth of field, also, there is plenty of light and my camera has good high-ISO performance so there’s no visible noise in the high ISO images.

Also, the “correct exposure” picture is too dark and the over-exposed pictures are better – this is because the light background fooled the camera, exactly why this happened and how to deal with this will be the topic of a future post.