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Re: jpeg sizes

Posted: Wed Oct 04, 2006 8:06 am
by Andy
Hi Abby: What kind of computer software do you use to download the photos on to your computer? Do you do any processing of them afterward?

Part of the issue with size may be the resolution. On a computer monitor 72ppi (pixels per inch) is about the max that you can "see" (you can still see them at higher resolution, but there is no improvement in how they look). Said another way, 72ppi is the max most monitors can display (this may have crept upward slightly with the advent of the newer, hi-resolulion monitors -- but this is the conventional wisdom).

In your sofware, there should be an image size option. In that dialog, you should have choices for ppi (often expressed as dpi, which is techically not right for on screen viewing, but for our purposes, doesn't really matter). That should be set to 72. You should also have options for width and height. If you set the the long dimension between 600 and 640 pixels (depending on whether your shot is a horizontal or vertical -- or landscape or portrait, if you prefer), and watch the box which gives you the file size, it should change to around 250k or less. The other dimension will normally change automatically to keep the proportions. Do that with each photo. That should size them to upload (4x6 is about 450 x 600 pixels and should be less than the 250k limit.

Hope that helps.

BTW, pbpub might correct me here. I believe this is his area of expertise.

Re: jpeg sizes

Posted: Wed Oct 04, 2006 8:39 am
by Heather Forcier
Actually, resolution / dpi / ppi is only relevant when it comes to printing. This setting should not need to be changed for web.

What is important is "image size" - especially in pixels. Reasonable web images run 400-600 pixels on the longest side. When you save a JPEG, you can alter the quality level which will increase or decrease image compression and change the resulting file size in kilobytes. In a program like Photoshop, you will get an indication of the final size in kb at the different quality settings, so you should be able to find something that ends up at about 250kb.

There is a helpful article on processing images for the web here:

http://www.naturescapes.net/042005/gd0405.htm

Re: jpeg sizes

Posted: Wed Oct 04, 2006 1:52 pm
by Andy
Heather: Thanks for the clarification on this. My explanation might be why the "blind" should not lead the "blind." :D I remember now reading and learning this.

Abby: Heather's method--and explanation--is much simpler to do and easy to understand than mine. In addition to being partly wrong on the ppi/dpi issue, you don't even need to worry about that to upload. I hope you will upload them so we can see them. Let us know if we can help.

Re: jpeg sizes

Posted: Wed Oct 04, 2006 3:15 pm
by Andy
Abby: When you are doing the "tweaking" (color, contrast, crop, etc.), you must be in a software photo editing program. There will be an image size dialog there somewhere. You should be able to change the H x W pixel dimension. Just follow Heather's comments and it shouldn't be a problem. That's really all you need to know about pixels for this purpose.