 Posted 6/11/2007 9:21:27 AM
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Everytime I see a photo with a black background for the subject, I wonder how it's done. Please explain in detail.
Go when you can, go where you can, shoot what you can
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Posted 6/11/2007 10:34:14 AM
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| I'm not sure about other people but I achieve it two different ways or a combination of the two: The simplest is a black background. I use velvet. The other is a bit technical to describe but If you are using an artifical light source it explains how the black background is achieved without a black background. The "Inverse square law of illumination" states that the illumination is inversely proportional to the square of the distance from the point source of light and the subject. In short, If you double the distance between the light source and the subject you quadruple the amount of light required to maintain the same exposure. The more distance that you put between the subject and the background the darker the background will appear if they are both lit by the same point light source. I use this quite often when using studio lights. In a dimly lit room it is possible to achieve a black background even with a white one as long a the distance between the subject and the background is sufficent for the light from the flash to fall off enough. Add a couple of barndoors to keep the flash from directly hitting the background and it's fairly easy to achieve the black background. It is a concept that is important to understand if you are doing studio work because you use it often when placing reflectors for fill light. If you want a 2:1 light ratio then all you need to do is place a mirror at a distance that makes the light travel 1/4 farther than the main light. You can do the same thing with 2 strobes but there will be a difference in the quality of the light (the one farther from the subject will be a bit more harsh.)
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Posted 6/11/2007 1:14:16 PM
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Thank you, Chris. I believe I now understand how the background for so many of the flower shots was achieved, but this morning I saw a photo of a lion with a black background. I can't imagine how you do that with an animate (and dangerous) subject.
Go when you can, go where you can, shoot what you can
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Posted 6/11/2007 1:47:55 PM
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Can I chirp in here?  With flowers this can be achieved with early morning or evening light outdoors. As long as there are not other bright buds in the background bud (lol edited to say "but" heh heh)these can be edited if needed. ( do also achieve this in other light situations as well , just depends on the bkrnd at hand) It works with or without editing. if the bk is just a little too light but lets say with just all green foliage in the bk,,,I can use darken shadows in picasa to make the bk completely black.. DOF is very important too as it helps lessen the editing needed , if not cancelling it out altogether. I am not sure what other great photogs do with their flower/blck bk pics or if mine are as appealing but that is how I accomplish it as I do not have any means to do indoor/studio shots.. I do know that you can very well carry black fabric and drape it for a bkrnd outdoors as someone else once suggested..(sorry I cant remember who that was  ) So just thought it might help ..
I may not always be wRIGHTbut I am never wrong Profile -  Top 24 - 
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Posted 6/11/2007 3:03:25 PM
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There is always the of careful editing.
Were the lion in front of a dark cave or ledge then I could see it. If you could find the image once more I'll try to figure it out.
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Posted 6/11/2007 5:39:20 PM
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This calls for the color range command.
I have been working on a video tutorial for this the last couple days as I have had a request for one.
If you don't feel like waiting, you can read help in Photoshop on how to use color range to select an object. Here's the key, once you have selected your object, go to the Channels pallet (tab is on the layers pallet) and click on the NEW CHANNEL icon at the bottom, which looks like a little post it note (only not yellow) with a corner folded up. Now your selection is saved as part of the document itself. Now you can reselect that area anytime by holding down Cntrl (command on Mac) and clicking your left mouse on the alpha channel.
There is a lot more to it from there in order to get smooth transitions between foreground and background but that's why I need to do a video...
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Posted 6/11/2007 7:00:50 PM
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Thanks, everyone. I'm limited by knowledge and PS Elements. Tonka, I might take a look at Picasa. I wonder how you could link that to PSE? Chris, I don't know how to locate that Lion shot, so I guess I'm out of luck.
Go when you can, go where you can, shoot what you can
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Posted 6/11/2007 7:40:38 PM
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| I am not sure about "linking" picasa but I use both programs separately. You should be able to navigate picasa rather easily.. If I need to use both programs, I edit the pic ,save as and then open it back up in PSelem.5 then finish and save for web.. There is also an export/resize in picasa.. If you use elements first and then want to use picasa.. IT is a bit of a pain but sometimes well worth it .. .. Have fun..oh and make sure you get the latest version of picasa....
I may not always be wRIGHTbut I am never wrong Profile - Top 24 -
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Posted 6/12/2007 6:54:06 AM
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Thanks, Tonka. I'll grab Picasa and see what I can do.
Go when you can, go where you can, shoot what you can
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