A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Frank Reed
Date: 2010 May 12, 20:17 -0700
In the past few days, we've seen attachment issues on NavList. One member has sent four identical copies of a large PDF file containing nothing but a very small amount of text. That text, if copied as text and posted as text, would have amounted to only a few hundred bytes. The PDF attachments total over two megabytes. That's an inefficiency factor of several thousand!
Another member posted a simple map as a JPG file which was over one megabyte in size. The content of the image, if reduced in dimensions and saved in an appropriate format could have been reduced to around 100 kilobytes. That's an inefficiency factor of about 10. Not so bad, but easy to do better.
Also, there was a case where one member posted a rather large "DOC" attachment, and then another member re-posted it, which is pointless. We don't need two copies of the same file.
So why should we care?
First, there's smart, efficient use of the Internet. NavList is a group of people generally quite intelligent, so we should make an effort. That's probably the most important reason. Second, there's the inconvenience for those members who have slow connections. That's a rapidly fading concern since most NavList members now have fast connections, and more than half don't follow messages by individual email anyway (they read them on the web message boards, or they receive daily digests, which do not include the attachments). But the REAL concern here is the problem of spam filters. If just one member decides that they are angry about a large attachment and hits the "spam" button in their email software, that can have consequences for weeks or months and it can shut down email delivery of NavList messages. And YES, this HAS HAPPENED, more than once. Just recently, one frequent poster to NavList sent me a message indicating that NavList messages to his yahoo account were not arriving. This was news to me. I looked into the matter, checked with the people who run the servers that do email delivery for individual NavList messages, and discovered that one of our former members (this was Clive Cooper --I'm sure some of you remember the genuinely "clueless" comments about online activities in his posts) was notifying yahoo.com that all NavList messages were "spam". Yahoo.com then turned off delivery of all messages to all yahoo.com members --not just for NavList, but for EVERY group hosted by these same folks. I am not suggesting that this person was motivated by some antipathy towards attachments. He was just utterly confused about everything. But the same scenario can unfold if we are not careful with attachments, and furthermore some email services will count attachments sent in multiples to large numbers of people as direct evidence of spam EVEN IF no recipient complains. These spam scores are calculated by obscure and carefully protected algorithms (so that the spammers cannot work around them) but very large attachments sent in multiples are frequently counted in such scores.
There is, by the way, a technical limit to the maximum message size on NavList. It is set to three megabytes. There's no reason you should ever send anything larger than that to the whole group. And also, please remember that binary files in email are encoded as text using a coding system called "Base64" which many of you long-term netizens will recognize as a variant on the old UUencode system. This increases the size of your attachments by about one-third. So if you attach three megabytes of files, they are delivered as four megabytes of content.
So what to do about attachments?
Attachments are popular and useful. With very few exceptions, NavList members seem to like occasional, relevant attachments. But there should be very few circumstances where messages larger than a megabyte are required. Here are some simple rules to follow:
1) Is your file fundamentally "text"? For example, do you have a photo of a sign or a screen capture of output from a program? If so, then consider simply transcribing the text. In other words, don't post a photo of text. Type the text into your message. Don't post a 500k file that shows a few hundred bytes of plain text.
2) Is your file an image of some sort, like a photograph or a drawing? Please reduce the file in overall pixel size to something less than 1000x1000. With almost no exceptions, images sent to NavList are meant for viewing on the computer screen. If you take images from your digital camera and upload them without re-sizing, you are sending images files intended for PRINTING so they tend to be quite large in pixel terms. You SHOULD find yourself some photo-editing software for these purposes. I will not recommend a specific product but I DO recommend reading these reviews of free photo editing products on about.com:
You should be able to find something suited to your needs and skills there.
3) Is your file a diagram, map, or low-color graphic? For example, do you have a plain black and white map or maybe a drawing of a spherical triangle? In these cases, you should save your file as a GIF image. This format is excellent for diagrams and compresses them without loss.
4) Is your file a photo or a representation of a natural scene with many colors? If so, save the file as a JPG image and make sure that the quality setting is set to a reasonable level to minimize the file size without significantly degrading the image. Experiment a little if you're unsure what that means.
5) Is your image a single photo contained in a PDF or DOC? DO NOT POST files in PDF or DOC "wrappers"! If it's just a single image, post it as a JPG or GIF (as above).
6) Is your file something besides a single image, like a complex PDF or DOC file with multiple images, diagrams, and accompanying text? Or is it a spreadsheet? For any of these cases, please try to reduce the size of the file if you can. After you're done, if it's still larger than one megabyte, it's ok to post it as an attachment but you should really consider "linking" the file instead of attaching (see next item).
7) For ALL files larger than two megabytes and MOST files larger than one megabyte, you should link the file instead of attaching it. This facility has been available for over a year on the NavList message boards, and I recently bought us a large amount of extra space. You can upload very large files, and they will be available to all NavList users. They will not distribute to all NavList email followers whether they want them or not. Instead, everybody sees a download link for the file. Those who are interested can download as needed. And I should note that those who follow NavList by digest see ALL attachments as links anyway. To upload and link a file, please visit the NavList message boards at http://fer3.com/arc. To post a message, you will need your NavList POSTING CODE which you can get by clicking on any highlighted "posting code" link (yes, there are some NavList users who are such net newbies that they have to be told to click on a link in order to use it). Then compose your message, select "Add Images and Files". After you are done uploading files, you will have the option to select "Link" or "Attach" or "Skip" (which ignores the uploaded file). Choose "Link" if the TOTAL size of the files you have selected is larger than one megabyte (this is usually pre-selected but you can choose otherwise).
George, you asked whether you should have received some notification about your over-limit file. Yes, you would have. Over-limit messages are sent to me for review, but I have to compose a separate email to describe the problem and invite you to fix it. If I don't check my email for a few hours and if I am busy with the real world (what a concept!), it may take a while for me to send that message. And please bear in mind that email, ALL email, is a low-priority activity on the Internet. It is not at all unusual for email to be delayed a few hours though the vast majority of email arrives in less than a minute. You should not worry about a missing message unless at least six hours have elapsed and probably twelve.
Finally, for George specifically, you should remember, as I am sure you always do, that I am a capricious and arbitrary master, and I delete NavList messages whenever I feel like it, bellowing out a maniacal "Mwahahahaha!" as I commit such messages to the bitbin of history. Just kidding.
For everyone, no messages are moderated/reviewed on NavList except those from new members, and even in that case, only for spam issues and very rarely for inappropriate content. I do, however, REQUEST changes in message tone from some new members in order to try to help prevent things from becoming unpleasant.
Thank you for reading this far. Now back to navigation. :)
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