49526Re: [Z_Scale] Re: sending photos
- Dec 7, 2006FYI, the native resolution of a Windows monitor is 96 dpi, and a Mac is 72 dpi.
Ell, you are correct that when you reduce the file size, you throw away data. SInce you have Photoshop, the best thing to do is to look at your original picture as actual pixels (Apple/Option/0 on a Mac; Alt/Ctrl/0 on a PC). Select the marquee tool, and under the tool options, you have three choices: Normal, Fixed Ratio, or Fixed Size. Set the Fixed Ratio to 4:3 (if you want to select all or most of the original), or Fixed Size to 800 px X 600 px. Fixed Ratio will give you the proper aspect for the 800 x 600 maximum file size (so you could set your crop frame to show the areas of best detail), whereas Fixed Size will give you what's called a 100% crop - a single 800 x 600 rectangle at the resolution of your original).
You could do a couple different 100% crops of the same photo, featuring different areas of your original. Then go in to Image Size and change your resolution to either 72 or 96, then reset the pixels to 800 x 600 (make sure the "constrain proportions" box is checked. Also, the Bilinear algorithm is actually better than the default Bicubic algorithm when reducing file size, and vice versa when enlarging. You'll notice that the file size remains the same as your original crop when you reset the dpi AND change the pixel dimensions, but now you've got an enlargement at the same resolution as the original. If there are smaller areas that look good at full size (i.e. actual pixels), but lose definition at smaller sizes, your better off creating a couple 100% crops of the smaller areas and use a reduced full frame version as a way to show the overall scene.
One last thing - the save for web tool is ok, but it's really no better than doing what I've described. Also, the jpeg format is strictly for photos, but over time has become bastardized by people who don't know better and has become a catch all for any kind of picture file. GIF (Graphic Interchange Format) format is only for GRAPHICS that use less than 256 colors.
Hope that makes sense - it's been a long day and I'm a bit road weary, so hopefully what I've said makes sense.
On Wednesday, December 06, 2006, at 09:48PM, "Ell Geib" <geib@...> wrote:
>I upgraded to Photoshop 7 not too long before the CS versions came
>out. I didn't see the point of upgrading again so soon. I understand
>and do most of the rest of the things you talk about. BUT, I hadn't
>thought of using the Save for Web option. I'll try that and see what
>differences I get. Thanks for that reminder.
>The whole point of my questions: I know how to change the size and
>resolution of my photo files. But for a given photo, and after any
>cropping, when you do things that reduces the file size, that means
>you are throwing away data. At some point that is going to be
>noticeable. For example, in one of the photos I took of my small
>layout at the Rockville show a sign describing the layout is visible.
>In the original photo, or in a reduced sized photo that keeps the
>same resolution (and large file size), most words on the sign can be
>read. After changing to 800 x 600 there is sufficient loss of
>resolution that it is difficult or impossible to read those words.
>Z-scale: minimum siZe, MAXIMUM enjoyment!
>Yahoo! Groups Links
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