1. Tips for Photography Assignment FYS100 Creative Discovery in Digital Art Forms Spring 2007 Burg

2. What should the resolution of your initial pictures* be? Weigh high resolution against the inconvenience of large file size. Compare the resolution of picture 1 (background) to picture 2 (from which you’ll cut out something). How big will the cut-out element be, in pixels? Then how much space will it take up in picture 2? Note: I use the terms “picture” and “image” interchangeably.

3. What final size do you want for your pictures? I asked for a printable one that will print out at a size of 10 x 8 inches (or 8 x 10 if you want it taller than it is wide). I chose that size simply because it fits on the 8 ½ x 11 inch paper in my printer, and it’s a standard size for matting and framing. We talked about using 1024 x 768 or 800 x 600 for the web-based picture, noting that this is a standard 4 x 3 aspect ratio. But it’s not the same aspect ratio and the printable version. So you’d end up having two versions of the picture with different “compositions” (layout of elements in the picture). You can make your web-based picture the same aspect ratio as the printable one if you don’t want two different compositions (in fact, it’s probably a good idea). (For example, you could use 1000 x 800, 750 x 600, or 500 x 400 for your web-based picture.)

4. How and when do you change the resolution of the picture? It’s best to keep it at high resolution while you work on it, so that you always preserve the maximum amount of data – and thus the maximum amount of detail. Just work on one version of the picture. Then, when you’re done you save it in two different versions – printable and web-based. There are two ways to change the resolution and printable size when you’re done: –File\Image size –Crop tool

5. How and when do you change the resolution of the picture? If you’re going to change the composition – which part of the picture you include – use the crop tool. If you’re not going to change the composition, use the File/Image size menu selection –Constrain the width and height to change in proportion to each other, so that you don’t warp the picture –If you click “resample image” the number of pixels can get larger or smaller. Otherwise, it can’t.

6. So, what’s the bottom line?… A good first step is to crop your background picture to the aspect ratio you want, at maximum resolution. When you’re completely finished editing the picture, save two versions – the printable one at the maximum resolution, 150 ppi; the web-based one at your chosen resolution (and the ppi don’t matter)

7. Resampling Resampling is a matter of changing the number of pixels in an image. Upsampling increases the number of pixels. Downsampling decreases the number of pixels. Resampling always results in an image that is less “true” to the original scene than an unresampled image. –Upsampling entails taking 1 pixel and making n pixels out of it. How does the system (e.g., Photoshop) know what color those pixels ought to be? It interpolates. –Downsampling entails taking n pixels and making 1 pixel out of them. How does the system know which of the n colors it should use for that 1 pixel? It uses some kind of averaging. Upsampling increases the number of pixels. Why would you want to upsample? Possibly to have more pixels to divide up per inch, to get a better printable picture. Why would you want to downsample? Possibly to have fewer pixels in the picture, so it wouldn’t be as big on the computer screen.

8. So what’s the bottom line on resampling? When you change the image size, you have the option of clicking “resample.” If you need to change the number of pixels in the image, then this box has to be checked. Otherwise, you can’t change the number of pixels in the image.

9. The size of an image displayed on a computer screen The size of an image displayed on a computer screen depends on how many pixels there are in the image relative to how many pixels there are on the computer screen. If the computer screen has 1400 x 1050 pixels and the image is 800 x 600, the image will fill 800/1400 of the width of the screen and 600/1050 of its height. If the image is 2043 x 1536, it won’t fit on a computer screen that is 1400 x 1050.

10. How big will an image be when you print it? That depends on how many pixels there are in the image relative to how many pixels you say you want printed per inch. If the image is 2048 x 1536 and you say you want 200 pixels per inch, it will be 2048/200 inches wide and 1536/200 inches tall. You can set the ppi in Photoshop from File\Image size.

11. What file types should you use as you work? Take the two pictures as TIFF files. Transfer the pictures to your computer. (It would be a good idea to make a folder for this project). Open the image files in Photoshop. Save the background image (picture 1) as a PSD file, which is Photoshop’s proprietary file type. (Keep the.tif file on your computer, too.) PSD files retain layers. The element you cut out of picture 2 will be inserted into a new layer in picture 1. Work with picture 1 as a PSD file as you edit. You may want to save incremental versions in case you want to go back to an earlier version at some point.

12. What file types should you use as you work? Crop picture 1 to the number of pixels you want in the horizontal and vertical directions. Remember that you want to print it out at 10 x 8, so this determines the aspect ratio. Insert some element of picture 2 into picture 1. Adjust color, contrast, saturation, etc. Apply special filters and effects as desired. Save your “last” version of the PSD file and use this file to produce two others. –Then the composed image for printing as an uncompressed.tif file. (Flatten the layers first.) –Go back to the final PSD file. Change the resolution to what you want for the web-based version. Then, save it as a compressed.jpeg file. Choose your compression quality.

13. Our classroom pictures, Friday, January 26 Nikon CoolPix 995 –Set at HI image quality (TIFF file with no compression) –Set at Full image size (2048 x 1536) –You have to be in M mode to have these settings –At these settings, you can get 6 pictures on a 64 MB card –If we move to A mode, it drops down to Fine quality (JPEG compression), and you can get 40 pictures on a 64 MB card –Set the camera for closeups (the flower icon)

14. Our classroom pictures, Friday, January 26 Nikon D100 –Resolution set at Medium, 2240 x 1488 –Quality set at TIFF RGB –At these settings, you can get 6 pictures on a 64 MB card –If we drop the resolution down to Small, 1504 x 1000, we can get 15 pictures on a 64 MB card

15. Good references for working with Photoshop Photoshop CS Classroom in a Book, Adobe Press Photoshop CS Bible by Deke McClelland, Wiley Publisher.