After the message on this list about music and graphics intensive websites,
I asked for tips from the NEGenWeb group in reducing load times. I thought
this one was especially useful and that some of you might be interested in
it. There's an additional note that she sent at the end.
Connie
-------- Original Message --------
Subject: Re: [NEGenWeb-L] Roll Call Oct 1
Date: Fri, 01 Oct 1999 16:29:02 -0600
From: Nancy Shaw <shawnan(a)ricochet.net>
Reply-To: nancy(a)pc-arts.com
Organization: PC Arts
http://www.PC-Arts.com
To: Connie Snyder <cjsnyder(a)midusa.net>
CC: NEGenWeb-L(a)rootsweb.com
References: <37F4BF1C.8233EA03(a)midusa.net>
Connie,
It is interesting you should mention load time for pages. I have been some
work in this area and will tell you a short (hopefully) story about file
size. I scanned a photo at 150dpi 100% size. I then resized the image in
Paint Shop Pro and saved it as a jpg with no compression. The file was then
300x430 pixels (a nice size for viewing on a monitor) and the file size was
85k. I then just resaved the file with a different file name as a jpg with
50% compression - and the end result was another image that was 300x430
pixels with a file size of 7k. yes that's right 7k. How images are scanned
and how they are saved can make a big difference.
As a general rule of thumb an HTML file with a total size of 100-125k (add
all the graphics files, sound files, and HTML file together to get the
total) will load in about a minute with a 28.8 modem. Being aware of the
total will make a big difference on how you do your layout. If your total is
over the above amount it might be time to re-think the layout -- less
graphics or compression of some jpg files etc. Graphics are nice but quickly
increase the load time of a page. Don't forget to look at the size of the
background image if you use one.
Additionally, how the image is scanned to begin with will also help. For a
photo that will be used strictly on a web page, scanning at 150dpi is
sufficient. The higher resolutions only make a difference when printing.
If you want to have sound - use midi files instead of wav's. much smaller
usually. Oh and if any one wants - I have the midi for "Beautiful Nebraska"
our state song. 11k is the file size - just let me know and I can send it.
One last quick statement - the use of width and height attributes in the img
tag also help load time. If you code your HTML manually it seems like a lot
of extra work, but the page will load faster if the browser can determine
how much space to reserve for the graphics file -- instead of having to load
the file to see what fits, it reserves the space and continues to load other
items (the text) around that space.
Oops I thought I was done - but here is one last thought - animated gifs can
be very large files. Consider using dynamic HTML to achieve some interesing
effects.
Hopefully in the next day or two my new web site will be uploaded and many
of
these tips will be there.
Nancy
WARNING - there were snowflakes blowing around in the air today here. *S*
----
I forgot to say that 3 people looked at those jpg files on two different
monitors - set at different resolutions - and couldn't detect a
noticible difference in quality.
Nancy