// you’re reading...

4 Digital Imaging Thursdays

Digital Imaging Thursdays: March 12

Rating 3.00 out of 5
[?]


Photo Editing Using Photosphop

Almost all “point and shoot” cameras save the captured image in the jpeg format. This is a common format that all photo and imaging software can easily load and edit. Most people that use Photoshop or any photo editing software do not realize that a large portion of the original image quality is lost when the original image is edited under default settings. You can check this by loading an unedited image into photoshop. Once the image has loaded, go to Image/Image Size and look at the default image resolution. The default is 72 ppi (pixels per inch) for most images captured by a “point and shoot” camera. This is the typical resolution used by many camera manufacturers to minimize the file storage requirements for the captured image.

If all you are doing is creating images for use on websites then 72 ppi works well but most of you probably are saving the images for printing purposes. This means printing images in the size of 4 X 6 or 8 X 10. Magazines use 300 ppi to maintain a high level of image quality. You should also use 300 ppi when printing your images at home. This does not mean that the image you currently have should be converted to 300 ppi before printing only. The actual image should be converted the very first time you load the image into photoshop. If the original image captured by your camera is in 300 ppi already then you have nothing to adjust. By allowing Photoshop to apply any image changes like contrast, brightness and color adjustments in higher resolution, you minimize image distortion and unnatural colors around any area modified. Certainly any physical changes to the image like removing objects and adding objects or text will have more detail present when created in 300 ppi resolution.

Below is a chart that suggests the maximum print size that you should use based on the original megapixel of the camera and the resolution of the image saved at 300 ppi.  

Original Image in Megapixels VS Maximum Print Size

Megapixels Pixel Resolution Print Size @ 300 ppi Print size @ 200 ppi Print size @ 150 ppi

3

2048 X 1536 6.82″ X 5.12″ 10.24″ X 7.68″ 13.65″ X 10.24″

4

2464 X 1632 8.21″ X 5.44″ 12.32″ X 8.16″ 16.42″ X 10.88″

6

3008 X 2000 10.02″ X 6.67″ 15.04″ X 10.00″ 20.05″ X 13.34″

8

3264 X 2448 10.88″ X 8.16″ 16.32″ X 12.24″ 21.76″ X 16.32″

10

3872 X 2592 12.91″ X 8.64″ 19.36″ X 12.96″ 25.81″ X 17.28″

12

4290 X 2800 14.30″ X 9.34″ 21.45″ X 14.00″ 28.60″ X 18.67″

16

4920 X 3264 16.40″ X 10.88″ 24.60″ X 16.32″ 32.80″ X 21.76″

As you can see in the chart, an 8 megapixel image minimum is required to print an image in 8 X 10 size while maintaining the 300 ppi resolution. To determine print size, the megapixel value was divided by 300.

To ensure that you maintain the original image quality as much as possible while you edit your images in Photoshop, I would suggest you go to Image/Image Size and adjust the resolution to 300 ppi. Keep in mind though, this will dramatically increase the file size of the image being saved. Especially the PSD file since no compression is used when saving in the native Photoshop format.  When you select File/Save/as jpeg, the second dialog box indicates the jpg option. Make sure the file size/quality is set to maximum. You can either enter 12 in the box as the maximumvalue, select maximum in the pull down menu or move the slider over to the right for a maximum file size.

One last trick you can use is when you are dealing with megapixels of 10 or higher. Since the largest print size @ 300 ppi is larger than 8 X 10, in the jpg dialog box, you can select 10 or medium as the save value. This will allow the saved file to be slightly smaller while still maintaining excellent print quality @ 8 X 10 or smaller.

Black and White Photography

You have probably seen some interesting pictures in black and white on www.flickr.com and other photo sharing sites. Ever wondered how these photos are taken? In most cases these are color photos converted to black and white in Photoshop or other popular photo editing programs. In reality, you can take an actual black and white image by adjusting the camera to black and white if the setting exists. Most perofessionals will refrain from setting their camera to black and white for one simple reason. The quality of the image is not as good as converting a color image to black and white afterwards. Much of the images warmth is lost when taking the picture in black and white. This is due to only a portion of the actual light detected on the imaging sensor is recorded when set to black and white.

When a color image is converted to black and white, you have access to the full lights characteristics captured in the color image for conversion to black and white. This allows the black and white image to retain much of the warmth in the image. You can go to Image/Mode/Greyscale to see how some of your images look in black and white.

Here is a sample of an image converted to black and white: 

The image on the right was converted to greyscale and auto level adjusted (brightness, contrast, color balance).

flowers-colorflowers-bw

Post to Twitter

Discussion

No comments for “Digital Imaging Thursdays: March 12”

Post a comment

Our mobile site

QR Code - scan to visit our mobile site

This is a 2D-barcode containing the address of our mobile site.If your mobile has a barcode reader, simply snap this bar code with the camera and launch the site.

Many companies provide barcode readers that you can install on your mobile, and all of the following are compatible with this format:

Link to Technobrains

Just copy and use the image below as your link image to Technobrains.com Thanks
AWSOM Powered