How to achieve black background with lighting?

<p><img src="http://lh3.ggpht.com/_acf0NenIE2I/S7wzG3XHwvI/AAAAAAAABus/pqCflyFctn0/DSC_0257_cropped_300.jpg" alt="" width="300" height="287" /> I tried some studio photography at home with things I got from home. I used a white cotton cloth for backdrop. I used a very small portable torch like white light source to focus light on the lemon. Then I photoshopped the image to separate the subject. I am pretty happy with the result(this is my first experiment with light) except for the flare/over exposed region where i focused the light on. Any suggestion to avoid the flare is really appreciated. Also, is there a way i can make it less prominent using post processing? Thanks in advance.</p>

<p>Post-processing in software is not a bad way to get pure black (or any other) backgrounds. It's sometimes easier to not have to go to post-processing/compositing, and I think you will eventually find a way to get pure blacks in the exposure.</p>

<p>The blown highlight comes from two problems: light source too concentrated; light source too close. Perhaps have the torch further away. You'll still probably get a blown highlight, but it will be a smaller patch. You can either diffuse the light source a little bit or try using a polarizer to minimize its reflection.</p>

<p>Hi Naveen the black background comes from the light fall off. Let me try and explain. If you set you camera in manual and ISO 100 1/125th second and F16 put the fruit on a surface with an open ended background say 2 or 3 meters and camera in normal low light evening interior situaton and shoot the friut. You will probably get a black picture. That being the case you need to get you light on the fruit and move it as close as possible and set the power so the exsposure is perfect for the camera settings and not the other way around. Now shoot the picture. All should be black appart from the area lighted by your blitz. (best off camera). Now the question is how far the light goes. The rule is here the closer the light the quicker the fall off. The futher the light is from the friut the longer after the light is effective. That should be a good place for you to start. Look maybe you see with these to shots what I mean. shot one I have backed off to shoot the whole scene. <a href="http://www.photo.net/photo/10227929">http://www.photo.net/photo/10227929</a> and now shot two is the framed shot of the flower alone. <a href="http://www.photo.net/photo/10227950">http://www.photo.net/photo/10227950</a> in my example I have a hidden light throwing a touch of light on the background or it would be totaly black.</p>

<p>The overexposure of the one area is probably because you are using a focused source of light. You would probably be happier with the results from a more diffused light source. That's why people use softboxes and diffusers. However, can get pretty nice, diffused light from a simple incandescent or halogen household light. I'll post two below, the first illuminated by a 50W hanging halogen lamp, and the second illuminated by a 75W incandescent bulb. For a black background with less fuss, try black cloth (I use an old fleece jacket), and keep it back from the subject. you may need some postprocessing to darken it, but less.<br>

<img src="http://dkoretz.smugmug.com/Nature/Flowers-and-mushrooms/IMG1837b/447549092_Y5AXG-L.jpg" alt="" /><br>

<img src="http://dkoretz.smugmug.com/Nature/Flowers-and-mushrooms/2010-04-02-204301-ZS-DMap-2/826087120_ci2Bu-L.jpg" alt="" /></p>

<p>Naveen,</p>

 

<p>“It’s all about the light.” Specifically, it’s about the ratio of light on your

subject to the light on your background.</p>

 

<p>You can achieve that effect outdoors, on a bright sunny day, with no additional artificial light. Just

position your subject in the sun and make sure your background is in deep shade. An open cardboard

box, laying on its side with the open end facing you, can do the trick (so long as it’s big enough and close enough

to fill the frame).</p>

 

<p>There’s an excellent exercise you should do with a $15 cardboard gray card. (If you

can’t easily get your hands on one, go to Lowe’s and get a quart of Laura Ashley LA

1616 “Chimney Sweep” paint and roller it on a piece of cardboard.)</p>

 

<p>Set the camera on a tripod and fill the frame with the gray card. Shoot in manual mode. Set the

aperture to f/8 and leave it there. Adjust the shutter speed so the bug in your camera’s meter is

on the middle stop and take a picture. Increase the shutter speed by three clicks (one full stop) and

take another picture. Continue that process until you’ve taken a picture at least three stops

<em>below</em> the bottom of your camera’s meter (you’ll have to keep track of how

many times you’ve clicked the wheel). Also do the same thing but slow the shutter speed to get

brighter pictures.</p>

 

<p>When you’re done, examine all the pictures on your computer. You should be able to gain an

excellent understanding of how the position of the bug in the meter relates to the tone of the final

image.</p>

 

<p>Pick an exposure that’s dark enough for you to be happy with it as your background,

keeping in mind that it’s pretty easy to make a near-black background completely black in post-processing. Examine the subject you wish to photograph — your lemon, for example. Decide

what exposure corresponds to the average tone you want in your lemon in the final print (two full stops

above middle would be my rough guess). Count how many stops separate the two.</p>

 

<p>Now, put your lemon on your stage. Use your camera’s spot meter on the lemon to set the

exposure to whatever you picked (two stops above middle if you agree with my guess). Point the meter

to the background and count how many stops separate the two. If it’s not enough, add light to

the lemon or make the background darker.</p>

 

<p>Press the shutter, and you should have exactly the effect you want, right out of the camera, with

only minimal post-processing necessary.</p>

 

<p>Of course, you’ll have to experiment a bit to get the hang of it, but it’s really quite

straightforward and is the same basic technique you’ll want to use for all manual exposure.</p>

 

<p>Cheers,</p>

 

<p>b&</p>

<p>As to whether you can restore the blown highlight in post-processing: if you didn't shoot RAW, probably not.<br>

Yet another way of thinking about your close-up picture and the blown highlight at top: it's about the lighting ratio, which is the ratio between your main light (the torchlike source you used) and your fill light (which you didn't have).<br>

Suppose you had a block of styrofoam next to your camera lens, or on either side, or directly in front of your camera with a hole cut out for the lens. The styrofoam would reflect the main light back onto your subject. The shadows would be brighter in proportion to your main light, but less exposure would bring them back down to where they are in your current picture--and also bring down the area lit by your main light, so it is no longer blown out.<br>

In other words, it's not just a matter of exposure, but of contrast, and less subject contrast will bring down the range of tones to something your camera's sensor can reproduce: that is, something within its dynamic range.<br>

Actually, you've got some fill light from the white cotton cloth which your lemon was apparently resting on. Although you eliminated the cloth in post-processing, its reflection is still apparent on the bottom of your lemon--a glaring artifact which your now-skillful eyes will doubtless regard with great concern. <br>

When life gives you lemons, make yet another still life. ;-)</p>

<p>Really appreciate ur ideas. I will try all of them. Thanks again.</p>

<p>In a lot of situations, photographing with black backgound paper yields backgrounds that are more dark gray than they are black. I shoot exclusively in RAW and use the CS4 "Camera RAW" to do the first processing. There is a slider labelled "blacks". By moving it to the right, it deepens the blacks beautifully without really affecting the image itself all that much.</p>

<p>Naveen, one of the best multitaskers in my rolling lightstand case-hardshell golf case in previous life- is a piece of real black velvet about 6x4. Expensive, maybe 40 bucks. gaffer Tape it to the wall behind subject, it absorbs about 90% of all light and is pure black bg for up to torso shots. Got an ugly chair, have model sit on it. Want a floating head shot, wrap the body with it. Posing a baby on the ground, it is a ground cloth. folded up, it cushions the more fragile stuff at the top of the case. Want to do subtractive lighting, place it on shadow side of subject, I clamp it to a boom arm and pull it in til its just appears in frame than back out slightly. </p>