…the computers are being hooked up again soon, and I expect by tomorrow this time my usual teaching posts will be able to continue. Until then, enjoy going out and shooting!
I am moving today from Mono to Oakville, ON. That means for once perhaps no post. Not that I would not love to write, but it looks likely that Internet connectivity may take a day to set up.
In the mean time, why don’t you, if I may make a suggestion, take the lens cap off and go shoot some pictures. Right now. With a 50mm lens (or if you have a crop camera, a 35mm lens, or a zoom lens set to the “35mm” focal length zoom position. With particular emphasis o:
- Rule of thirds
- Blurred backgrounds
I shall try to post later, but if not, you will know why.
I am often asked “should I use sRGB or AdobeRGB or some other colour space when I shoot a picture, or when I export a file?”
Yes. To sRGB, that is. Choose sRGB in your camera, and choose sRGB when exporting a file from Photoshop or Lightroom.
There is a lot of ‘religion’ and a lot of misinformation here.
- Colour spaces are conventions for how a file describes colours. There are many colour spaces.
- sRGB is designed to be usable for cheap screens, cheap printers, etc, and has somewhat fewer reproducible colours in its colour space.
- Strictly speaking, AdobeRGB and others are “better”, therefore.
- But… they are not supported by all devices and by all software.
- So if you use these, your viewer may not be able to see them properly!
- sRGB is therefore the safe option and it should always be chosen unless you know the viewer can definitely see other colour spaces.
- When you shoot RAW, the camera saves all colour info, so the setting is not important. It is only when you expert from Lightroom or Photoshop into a JPG file that you need to choose.
The following two images are ProRGB and sRGB outputs, respectively:
Now the sRGB file:
Now on my Mac, the second image looks great but the first image looks very flat and desaturated.
You may see the same files – if so, lucky you. But would you really want to put up, or send, a file when a large part of your audience will see flat colours? I did not think so. So – choose sRGB.
Why do we use a “green screen” background to shoot subjects sometimes?
Here’s why. The simple colour (usually a specific green, though it could be blue or some other colour) can be replaced easily by a new background.
Say I want to shoot a wakeboarder in Egypt. Makes sense, the desert, wakeboarding, right? So to do this, I can fly her and a bunch of lights to Egypt.
Or, I can do the following instead.
First, shoot her against a green screen background:
Then go to Photoshop (not that I like Photoshop – I do not, but for serious manipulation work like this it is the standard) and do the following:
- Open the photo in Photoshop.
- Select ‘Color Range…’ from the ‘Select’ menu.
- After the Color Range dialog box comes up, click on the eyedropper tool, drag the ‘Fuzziness’ slider to around 30, check the ‘Invert’ checkbox, choose ‘Grayscale’ from the ‘Selection Preview’ popup and make sure the ‘Selection’ radio button is pressed.
- With the eyedropper tool, click in the green area of the image. You should see much of the green area as white, and the rest of the image (which gets selected) as black. If there are still areas of the green screen which are not white (e.g. wrinkles in the backdrop), hold down the Shift key and click on them with the eyedropper until all of the green area is selected.
- If there are still pixels here and there that are white, you can lower the Fuzziness until it is easier to click on the areas. You can use the ‘Refine Edge’ dialog from the ‘Select’ menu.
- Once you’re satisfied with your selection, click ‘OK’.
- You should see the object you are trying to select selected. If there are any problem areas (i.e. you see scrolling ants in areas inside or outside your selection that shouldn’t be selected), use the lasso tool (hold down Shift or Option (Mac)/Control (Windows) to add to or subtract from the selection) to make your selection perfect.
- Now you are ready to remove the green screen. Make sure you’re working with the proper layer, and, if you are on the ‘Background’ layer, double-click it and click ‘OK’ to make it into a normal layer, then select ‘Inverse’ from the ‘Select’ menu to reverse the selection.
- Now press the ‘delete’ button or select ‘Clear’ from the ‘Edit’ menu to remove the selection.
- The edges of your object/person may have a slight ‘halo’ around them. Clean them up by selecting ‘Layer>Matting>Remove White Matte’ or ‘Layer>Matting>Defringe…’; usually 1-3 pixels will do the trick.
- Now you can put any background you would like behind your cut-out object. I select ALL in the first image, then COPY, then I open the second image, and select PASTE. Now I scale, rotate, etc.
Now you get this:
(Go to full screen to see the detail.)
Much cheaper than flying to Egypt. No? And it took only a minute or two. If you have never tired “green screen”, you might find it occasionally fun or necessary.