Want to leave your computer for a while without seeming to have disappeared?

Circling ArrowsIf you are a “one-man band” and you want to give yourself the luxury of going on holiday without having to keep up with your emails, then setting an “out of office reply” is the best way of not worrying that your clients and customers think that you’ve disappeared. Home users can do this as well, of course!

What this amounts to is setting something in your email system that triggers an automatic reply when a new email is received. You will still receive the incoming email and you will still be able to check your emails just as you would on any normal day (on your iPad, for instance, while you are sunning yourself). The only difference is that you’ve now warned the recipient not to expect an immediate answer. There’s nothing stopping you from checking your emails just as obsessively as you normally do (!) and there’s nothing stopping you from replying to any of them that you choose to.

The way of setting up “auto replies”, and the flexibility that you have, varies between systems and set-ups. Some possible scenarios are as follows:

  • You have a company email account that runs under Microsoft Exchange Server. In this case, check with the company IT Department to see how to set auto-replies. You can also try the “Out of Office Assistant” in your Outlook Exchange software.
  • You have your own domain name (eg davidleonard.net) and use its email servers. You probably have access to a web-based control panel that allows you to administer the domain. This control panel will probably have options for setting up an auto-reply.
  • You use Gmail, Yahoo, Outlook.com or some other webmail system. There will be options under the “settings” for setting an auto-reply (see below for Gmail as an example).
  • You use Mail on Mac OSX. You can set an auto-reply by setting a “rule” – see below.
  • You use Microsoft Outlook without Exchange Server. You can build your own auto-reply by combining an email template with a “rule” that you create for incoming messages.
  • You use Microsoft Live Mail. Create your auto-reply message in a text editor (such as Notepad) and build it into a rule created under “Folders” and then “Message Rules”.

Gmail AutoReply Settings

Gmail AutoReply Settings

Depending on your email setup, you may have several ways of setting up an auto-reply. You only need one method, of course, for each incoming email. Note that if you use a method that involves setting up your own email software (eg using “rules”), then your computer must be switched on while you are away as the auto-reply would not, otherwise, be triggered. This doesn’t apply if you are setting an auto-reply either by webmail or by your domain’s control panel.

Mac Mail Rules Box

This is what you want your “Rules” box to look like in Mac Mail

There have been times when I have suggested setting up auto-replies to my computer support clients and they have responded by saying “isn’t it just a good way of telling burglars that you are away?” Realistically, I suppose it might be. If you are worried about this then you must take a view on whether the benefits outweigh the risks and act accordingly. Likewise with the problem of sending auto-replies to spammers. It could be that sending an auto-reply to a spam message that gets into your inbox just confirms to the spammer that your email address is genuine and “live” (thereby increasing the value of your email address to them). Note, though, that some methods of setting up auto-replies allow you to choose whether you reply to everyone or just those email addresses that are in your contact list. This will stop your autoreply from replying to spam messages but it would also mean that any potential new client would think they are being ignored until you manually respond. On balance, I prefer my auto-replies to be sent to too many people rather than too few.

It would be a huge, tedious, blog posting if I went through all of the possibilities in detail, but here’s a couple of examples of setting up auto-replies for two of the most popular methods of using email:

Mac Mail (in Mac OSX)

  • Open Mail
  • Click on the “Mail” command at the top of the screen
  • Click on the “Preferences” option
  • Click on the “Rules” tab
  • Click on “Add Rule”
  • Give the rule a name (such as “AutoReply”)
  • Click on the box that is currently selecting “Any Recipient”
  • Scroll down the list of options and click on “Every Message”
  • Under the section headed “Perform the following actions”, click on the current choice of “Move Message” and scroll down to select the option called “Reply to Message”
  • Click on “Reply message text” and enter the text that you would like the AutoReply to contain.
  • Click on “OK”.
  • The next bit is VERY VERY important! When a box pops up and asks whether you want to apply the rule to selected messages, then click on “Don’t Apply”. If you click on “Apply” you will send unwanted “out of office” messages to emails you have already received!
  • Make sure there is a tick in the box for your new rule that makes it active
  • Close the “Rules” box.

Note that you can not schedule the AutoReply in Mac Mail. You have to turn it on and off manually.

Mac Mail Don't Apply

When you have finished setting up your rule, make sure to click on the “Don’t Apply” button!


  • Log onto your Gmail account (via the web interface)
  • Click on the “Settings” cogwheel at top right
  • Click on the “Settings” option on the menu that has just popped open
  • Scroll down the screen until you find the section headed “Out of Office AutoReply”
  • Complete the form, remembering to click on the “Save” button at the bottom of the page when you have finished.

Note that you can select an option that only sends auto-replies if the sender is in your Gmail contacts list.

The next time that an IT horror story breaks through into mainstream consciousness, it could well be caused by CryptoLocker

What is CryptoLocker?

It’s a horrible piece of malware that encrypts the most common types of data files on your computer (especially Microsoft data files such as Word documents and Excel spreadsheets). Once attacked, you can not get access to those files unless you pay the perpetrators to decrypt them. Strangely, it appears that paying the ransom does actually get you the “key” to unlock your files again. Maybe the “perps” are very clever and have realised that if they get a reputation for “honouring their promise” (huh?), then sufferers will be more likely to take a risk and pay.

At this point, Mac users are permitted a smirk – CryptoLocker only attackes Windows computers.

How do you get it?

It’s usually downloaded as an email attachment when the user is duped into accepting something that looks like a pdf file, but isn’t. I received a similar thing just a few days ago (although it displayed as a zip file in this instance). Take a look at Figure 1. It appears to be from Amazon and it would be very easy indeed to apply 20% of my attention to it and just open the attachment. I don’t know if this one contains CryptoLocker, but I do know that this message is fake. Look at the “sent” address. Since when did Amazon send emails out in the name of “crescenzireider@yahoo”?

Fake email message, purportedly from Amazon

Figure 1. Fake email message that may contain CryptoLocker or other malware

Also, this just isn’t how Amazon send despatch notices etc. and, anyway, I have a system (of sorts!) for tracking Amazon orders and know I’ve got nothing outstanding. So, I haven’t opened the attachment and this has kept me safe from any “payload” it may have (and don’t worry – you can’t catch anything from Figure 1: it’s just a harmless image file by the time you see it).

Other common ways of getting you to open an infected file include faking the attachment as a FedEx or UPS delivery note, or faking a document from your bank.

Once you’ve been infected, you will be presented with a demand for money (typically $100 or $300) and a short time (4 days) to pay up. If you don’t pay in that time then your files go to data heaven. The bad guys “forget” the key that will unlock them and that’s that. Moreover, if your regular backups are made on other hard drives on your own computer then those backups are also at risk. Apparently, the malware isn’t yet configured to look in networked drives, but that’s got to be just a matter of time.

CryptoLocker Window

Figure 2. If you see this window, you’ve got problems

How do you stop it?

If you are working in a large or medium organisation (with IT staff) then Windows can be configured to stop you opening all kinds of attachments that are “executables”. This is probably neither possible nor practical for the average home user. To begin with, you need to have Windows 7 Professional, Ultimate, or Enterprise (ie not Windows 7 Home). If you have Windows 8, it needs to be either the Pro or Enterprise version. If you are using Vista you are unlucky, and if you are still using Windows XP then here’s yet another reason to move on – Microsoft support for Windows XP is ending. There is, anyway, a danger of throwing the baby out with the bathwater. Putting restrictions in place to stop you opening a fake file would probably also stop you opening genuine ones – very annoying.

Another thing you can do is to change the view of your files in Windows Explorer so that file extensions are always displayed. This may alert you to the fact that a file that appears to be called “readme.pdf” is actually “readme.pdf.exe”

Why doesn’t antivirus software stop it?

I don’t know. I’ve been to a number of websites to help me prepare this blog and none of them are specific on this point. They just say things like “(antivirus programs) have a particularly difficult time stopping this infection” and “Security software might not detect CryptoLocker, or detect it only after encryption is underway or complete“.


I understand that removal of the software is just a case of uninstalling it in the usual Windows way – ie go to “Programs and Features” in the Control Panel. That doesn’t decrypt your data, of course.

So, where does that leave us?

  1. We have to be even more vigilant than ever in opening email attachments. Don’t open any email attachment until you’ve looked at the email and made a definite decision that you trust the sender. For goodness sake, don’t think, “I’ll open it and just delete it if it’s crap” (which is how, I suspect, a lot of people filter their email). If it’s got CryptoLocker in it then it will be too late by the time you realise what’s happening.
  2. We have to review our data backup situation. Are you one of the millions who “haven’t got round to” creating backups? If so, do you really want to find out the hard way why they are so important? And if you do take backups, but these are just file copies on your hard drive or permanently attached drives, then my advice is to take an “offline” backup asap (eg to a USB drive or DVDs).

Cartoon robber stealing away from laptopSorry for delivering yet another warning of the dangers of the internet. I really don’t want to put anyone off using it, but we need to pay close attention to what we are doing. Think in terms of being “streetwise” about the internet (“cyberwise”?) You wouldn’t park your bicycle, unlocked, on Oxford Street and expect it to be there when you got back, would you? If you apply the same common sense online then I think the chances of being caught out will be greatly reduced.

Setting up an autoresponder in Gmail is quite easy when you know how

What is an autoresponder? Also, known as an “out of office” reply, it is an automatic reply sent by your email provider to someone who sends you an email. It is typically used to let people know that you are probably not immediately available to respond to the message they have just sent you (eg because you are on holiday).

Setting up an autoresponder does not affect your ability to receive, read, or even respond to incoming email. It just sends an automatic message (of your own creation) to let the person know you are probably “not there” at the moment. You can still check your email when you are poolside in Florida (or Skegness) and you can still answer it in the normal way if you wish.

Different email providers offer slightly different options. Some, for instance, allow you to specify the exact times (as well as the days) during which the autoresponder will do its job. Others, like Gmail, switch it on and off for whole days at a time.

So, let’s go through how you set up an autoresponder in Gmail (see, also, the figures at the bottom of this blog):

  1. Log in to your Gmail account in the usual way (eg, by clicking on the “gmail” link on the page at www.google.co.uk and entering your credentials).
  2. Click on the “settings” gearwheel icon towards the top righthand corner of the screen.
  3. Click on the “settings” option about two thirds of the way down the menu.
  4. There is a list of “tabs” that pop up from left to right (from “General” to “Themes”). Make sure that the “General” tab is selected (by clicking on it).
  5. Scroll down the screen until you see a section headed “Out of Office AutoReply” and then complete the section as follows:
    1. Click the “radio button” next to “Out of Office AutoReply On”. This will put a black dot in the circle.
    2. Click the white space next to “First day” and click on the calendar on the starting day for the autoreply. Note that you can move forward to different months by clicking the right-pointing chevrons (double arrows) next to the month’s name at the top of the calendar.
    3. You can either enter an ending date for the autoresponder, or leave it blank (maybe you’ll choose to stay in Skegness indefinitely).
    4. Enter a subject. This will be the “subject line” of the email your correspondent will receive – eg “Thanks for your message. I’m away for a few days”.
    5. Enter the “body” of the message in the large white box – eg “I’m going to be away from October 4th until October 18th. I’ll respond to the email message I’ve just received from you as soon as I can.”
    6. If you would prefer that only people in your contacts list should receive this autoresponse, then click on the radio button next to that option. The reason for having this option is that sending these autoresponses does two things that you might find undesirable:
      • You are confirming that your email address is valid and that you are using it. This is valuable information for spammers.
      • You are saying that you are not where you usually are! if you are the sort of person who wouldn’t put an address label on a suitcase because it tells anyone seeing it that your house is probably empty (and, therefore, eminently burgle-worthy), then you might think there are security implications in using autoresponses.
  6. Click on the “Save Changes” button slightly further down the screen.

The advantages of using autoresponders are that they are a considerate, and even professional, way of dealing with the problem of leaving correspondents wondering why you aren’t replying to their email. After all, most of us expect that an email will probably be answered within two or three days at most. Autoresponders solve this problem.

Gmail - Sign In link

Fifure 1. Gmail – Sign In link

Gmail - Settings Gear

Figure 2. The Gmail Settings Gear

Gmail - Settings Option

Figure 3. The Settings option

Gmail - the General tab

Figure 4. The General tab

Gmail - Out of Office Options

Figure 5. The Out Of Office options

I don’t think I’ll ever get used to the iPhone keyboard

…and I know from discussing this with friends and computer clients that there are plenty of other people who share this slight frustration. If it’s only a case of prodding a few characters then that’s OK. Just take it slowly and pay attention. Better still, use a stylus.

If it’s a long and complicated email that needs to be sent from the iPhone then I’ve concluded that the best way to do this is – don’t. If I haven’t got access to a keyboard better than the iPhone’s then the email can just wait. If it’s that urgent then a phone call is probably the best option.

Steve Jobs with iPhone

I wonder how Steve Jobs got on with typing on the iPhone

But what if it’s a text message that is needed? An iPad’s no obvious benefit as there’s no texting available and neither, in the ordinary course of things, is a proper computer any use, either. I have several times investigated the possibility of texting from a proper computer but have never found a straightforward solution that is worth the effort (or the cost). A while ago I blogged about a piece of software for preparing a text message on a computer and then sending it to an iPhone for onward transmission as a text message. I did use this for a while, but it proved flakey and I gave it up.

That was when I decided it was time to get to grips with an aspect of the iPhone that I had always found too tricky and tedious to bother mastering – “copy and paste”. After a bit of practice, I now routinely use this method to send long text messages. It involves sending an email first from something with a better keyboard than the iPhone (ie a computer or a tablet).

So, here are step by step instructions. You may find, like me, that this makes sending long text messages quicker and more accurate than using your iPhone’s keyboard.

  1. Prepare the message as an email and send it to yourself. I include in the body of the email exactly what is going into the text message. No more and no less. It doesn’t really matter if the email program is set up to add a signature to each message as it’s easy enough to delete this from the final text message just before sending it. The only important – if blindingly obvious – point is that the iPhone must be set up to receive the email that you are going to send to yourself.
  2. Open the email message on your iPhone.
  3. Do a “long press” anywhere in the body of the email message. When the magnifying glass pops up then let go of the long press.
  4. It doesn’t matter what part of the message has been initially “selected” by the long press as a short menu now pops up that includes the option to “select all”. Tap on this option.
  5. All of the text will now be selected and a menu pops up with the single option to “Copy”. Tap on this option.
  6. Press the Home button and open your text messaging program. If the text message that you have just prepared is a reply to an incoming message then open that message. Otherwise, press the option to start a new message and fill in the recipient’s name or mobile number in the usual way.
  7. Tap on the message area.
  8. Do a “long press” on the message area until a menu pops up with the single option to “Paste”.
  9. Tap on the “Paste” option.
  10. Tap “Send” in the usual way.

iPhone in landscape mode

Of course, it’s always easier typing on a smartphone with it held in landscape mode

Et voila… your long, complicated, and accurate text message is on its way without any typing tantrums (or is it just me that has those?).

This method is much, much easier to carry out than it is to explain – especially after a bit of practice. It also means I can go back to being as pedantic as I like in my use of English and my refusal to succumb to using “textspeak” just because it’s easier to type.

I have been trying very hard – and largely succeeding – to put aside my “PC Man’s” prejudice against Macs

This is being made much easier by my continuing very high opinion both of the iPad Mini and my secondhand iPhone 3GS (that never misbehaves apart from the keyboard being tricky).

Surprisingly often, clients ask me why I had the prejudice against Macs in the first place. I think there are probably quite a few reasons and they are not all unreasonable! For instance, I’m sure a lot of “PC people” will recognise my opinion that Macs have a certain way of seeming to be simplistic (and I do mean that word, rather than just “simple”) and patronising to their users. They set up specific – and often irritatingly wrong – ways of doing things and then don’t offer any option to change them. I appreciate that Apple do this on purpose. They want to make their computers accessible and easy to use. Choice brings complexity. Telling us how we must do things keeps it simpler.

One example of this is the listing of names by putting the forename first and surname last, and then sorting on the forename. OK, so this is just the way that they do it in the USA. My point would be that they could try to be a little more conscious of the way other countries and cultures work by providing options. Maybe this sounds like sour grapes, coming from a Brit long after the sun finally did set on the British Empire. Nevertheless, it still seems logical to me to give us a bit of choice.

Relative Dates in Mac Finder

Relative Dates in Mac Finder

Another example is the “relative date”. This is when dates are not displayed as fixed, real, absolutes – eg “20/04/2013”, but as slippery, shapeshifting things such as “yesterday” or “3 days ago”. If I’m looking for a file date or an email dated “20/04/13”, then I don’t want to have to work out what the date is today, subtract the date I’m looking for and then start looking for something that happened “3 days ago”. It’s just bonkers. I challenge you to work out what the day and date were “3 days ago” without using your fingers. And then they’ll all be different again tomorrow, of course.

So, I’ve been trying to find a way of changing how these are displayed in email listings on the iPhone, iPad, and Macs and there doesn’t seem to be one. If anyone knows better, please let me know.

The "relative dates" switch in Mac Finder options

The “relative dates” switch in Mac Finder options

The irritation can, however, be magicked away on a Mac when it comes to file dates being shown “relatively” in “Finder”:

  • When in Finder, click on the “View” option.
  • Then click on “Show View Options”.
  • Then it’s simply a matter of unchecking the box next to “Use relative dates” by clicking on it.

Absolute Dates in Mac Finder

Absolute Dates in Mac Finder

And while I’m on the subject of Americanisms, I would like to see a UN resolution banning the use of the phrase “British English”. This is often listed as a choice of language when setting up software (and I’m not just having a go at Macs here). Apart from the obvious tautology, it suggests, somehow, that we have a variation of the language that is less than the “original and best”. Isn’t it patently obvious that the USA should, instead, be referring to its own version as “American English” and leaves ours as it is – “English”?

Here I go again – Victor Meldrew meets Angry of Tunbridge Wells, but at least I’ve got proper dates back in Mac’s Finder.

I’ve had a couple of new computer trainees recently who have asked about the “right” way of corresponding by email

Victorians being politeI’ve blogged about this before, but never offered a list of all the things I try to include when I’m training on the subject. Apologies to everyone who’s been using email for years, but there may just be something of interest in this list.

  • Don’t shout. Writing everything in capital letters feels to the recipient as if they are being shouted at (unless, of course, you intend to give that impression).
  • Don’t reveal recipients’ email addresses to each other, unless they already know each other. Click here for a detailed article on using CCC and BCC fields in email.
  • Be very careful of using light-coloured fonts. Not all screens display colours the same. What may be legible on your own screen may be difficult to read on another. Someone sent me an email in bright yellow recently and I had to forward it to myself (with the font colour changed, of course) before I could read it.
  • An email "@" signBe very careful of using weird fonts. What may strike you as an expression of your lovable, wacky individuality might just come across as an un-necessary irritant to your correspondent.
  • Avoid text message-style abbreviations and emoticons unless you know they will be well received and well understood. “LOL, BTW, IMTOU, b4, etc” can be very tiresome to people who don’t use them and don’t know what they mean.
  • Spelling, grammar and punctuation are important. It’s easy to mis-understand the precise meaning of emails and it can be embarrassing and time-consuming replying to an email by asking for clarification.
  • An email "@" signRemember that you can “copy and paste” standard paragraphs that you often need and can even create entire template emails. If you find, for instance, that you are often emailing people with travelling directions of how to find you, then it’s probably worth creating one good set of instructions and then filing it somewhere where you can easily find it to re-use it.
  • Be patient. A lot of people are more-or-less constantly connected to their email and will respond within an hour or so. There are other people who only check their email every day or two, and there’s no law that says your email has got to be answered quickly. I find that if I want a quick response from an “occasional” email user then it helps to send a quick text message saying I’ve just emailed them.
  • Do be mindful of legal consequences. It’s a good idea to think of emails as analogous to postcards rather than sealed letters.
  • An email "@" signDon’t send large attachments unless they are necessary. Some email systems can’t handle attachments larger than 5mb. Click here for more on the subject of large email attachments.
  • Don’t tick the box that requests a “read receipt” unless you really need one.
  • Don’t mark your message as “high priority” unless it really is. I used to have a correspondent who marked every single email as “high priority” and requesting a “read receipt”. Words like “boy”, “cry”, and “wolf” come to mind.
  • An email "@" signDon’t reply to an email by starting a new email. Always, always, “reply” to the email. This ensures that the history of the conversation (known as the “thread”) is available to both parties without hunting through other emails. I have had trainees who thought that it is somehow “wasteful” to include the previous message(s) as it has already been sent at least once. In principle, I suppose that it is, but the inefficiency is almost unmeasurable (and completely incomparable with the waste of time (and temper) caused by having to hunt through other emails to see the history and context of the current message).
  • Victorian danceDon’t use the “reply to all” option unless you really do want all of the people in the “conversation” to receive a copy of your message. One of the things that people dislike most about email is the number of messages they receive just because they have been “copied in”. They don’t know how much attention to give to the message and often feel that they must waste their time reading something just on the off-chance there’s something relevant to them.
  • Do include a subject line. I have always thought that it is a matter of courtesy, as well as administrative efficiency, to give an email a meaningful subject – and I don’t think that “Hi there” cuts the mustard!

You may also be interested in this previous article that referred to email netiquette.

Is your Contacts List at the mercy of your webmail service?

Email "@" signs falling from the Cloud into a laptop

It’s well worth saving your Contacts information locally if it only exists in The Cloud.

“Webmail” is the method of accessing email that works via a browser (eg Internet Explorer, Firefox, Chrome, Safari, Opera). There is no “program” on your computer that is dedicated to dealing with your email. All of the necessary programming is provided via the web browser.

If you use webmail to send and receive emails then it’s possible that the only “contacts list” you have is intimately bound up with that email account. This contacts list (also known as an “address book”) may be just the email addresses of your correspondents, but it may also include postal addresses and many other items of contact information.

When you use webmail, the information that you are looking at (email content, contact information etc) is normally only stored on the servers of whoever is providing your service. Now, I know that there is an argument that says “So what? Microsoft/Gmail/AOL/Yahoo all know what they are doing and they will take better care of my data than I ever would. I never take backups“. Call me a control freak, but I would not be at all happy to think that 200-1000 email addresses might be at the mercy of an organisation over which I have absolutely no influence. And although you might be right that these large companies have better data backup procedures than you do, that does not mean that they are entirely reliable.

Here are two ways in which computer clients of mine have lost their contact information:

  • Last summer a client of mine lost control of his Gmail account when it was hacked by someone correctly guessing his password – see this blog on Gmail Passwords for the full story.
  • Very recently a (different) client had problems with his Hotmail account. Microsoft told him that there appeared to have been attempts to hack into his account and they made him jump through all kinds of hoops to get it back. He was luckier than the Gmail client in that he did get back into his account, but all his contact information has disappeared.

Despite these occasional problems, there are definitely arguments in favour of using webmail, so can you do something to reduce this vulnerability? Yes, you can. If you use any of the main webmail services (eg AOL, Gmail, Hotmail, Yahoo) then you have the ability to “export” your contacts list. It would be too tedious to describe the process for each webmail client (ie each webmail service), but the general advice is to click wherever necessary to get your contacts list in front of you and then look for an option that includes the magic word “export”. This may be a sub-option of an option called “manage contacts” or something like that. See the illustration for an example from a Yahoo webmail account.

Webmail Data Export Options

These are the options for exporting Contacts information from Yahoo webmail. The circled option is the one to go for.

You will probably be offered a selection of different formats in which the exported data can be saved, but we needn’t get too distracted by that. If it’s offered, take the “csv” option (which means “comma separated values”). If there’s no “csv” option apparent then take another option such as “Outlook” or “Thunderbird”. The main thing here is that we are saving a copy of your data onto your own computer so that it could be made available in the case of an emergency. Even if it’s in the wrong format a bit of “data massage” will probably put it to rights and you’ll certainly be better off than if you had no local copy at all.

When you’ve completed the process you will have a file on your computer that might be called something like “contacts.csv”. This is a local backup of your contacts data. It can be useful in several ways:

  • To restore contact data back into an existing account.
  • To transfer the data into a new account from the same webmail service.
  • To transfer the data to a completely different account with a different webmail service.

If you do use webmail and decide to spend a little time doing something “techie” and well worthwhile, then have a go at this.

What do we mean by the size of a digital image?

Dandelion pictures superimposed and reducedIn the last week one computer client asked me why I don’t blog more on digital photography and someone else asked me to clarify how you change the size of image files. This kind of technical advice is probably better imparted in a 1:1 computer training session, but let’s see if I can help at least two clients in one go.

On this subject, it’s easy to conflate two different things and get thoroughly confused. These two things are:

  • The amount of information there is in the digital image and, therefore, the amount of space it takes to store it.
  • The physical, measurable size of the image if we print it or view it onscreen.

1) Information in an Image

As explained in a previous blog on digital images – a bitmap digital image (the more common type of digital image) can be thought of as a grid of tiny squares in which each tiny square is a single colour. A single square (known as a “pixel”, meaning “picture element”) can only be a single colour. So, if you have an image that is broken down into a grid of 1000 squares across and 1500 squares down then you have a picture comprised of 1,500,000 pixels. That figure is one way of describing the size of the image. Another way of saying this would be “One and a half million pixels” or, as you will see written on the point of sale literature for cameras, “1.5 mega pixels”.

The next aspect is to consider how much information there is in a single pixel. If the image is a “greyscale” image, containing only black, white and varying shades of grey in between, then each pixel is likely to be assigned one of 256 different shades of grey (including the black and white at either end of the scale). If we wish to record/describe the colour of any pixel then we can assign a number from 1-256 (representing each colour from white to black) to each pixel.

So, the total size of the image in terms of the amount of space it takes up on your computer or camera is the number of pixels (1,500,000) multiplied by the amount of space required to define the colour of each pixel. As it happens, it takes 1byte to define any of 256 colours so our image is going to be about 1.5mb in size. If this is a colour image in which each pixel can be a combination of any of 256 shades of red, green, and blue (known as an 8-bit RGB image) then we will need 3 bytes to define the colour of each pixel so the total size of the image will be 4.5mb.

This is a slight simplification of the actual size of the file, but the reasoning is sound. The file is likely to be slightly larger in practice because it will also contain other information known as “meta data” that doesn’t form part of the image itself (eg information about when the image was taken, the settings of the camera etc). Going in the other direction, though, if the image is a digital photograph then it’s highly likely that it will be in a “jpg” format – in which case the file will be “compressed”, thereby making it smaller (but we needn’t go into that here).

So, if you wish to email an image or upload it to a website and know that there is an upper limit to the size of the image, then it is the factors above that you need to consider – see this blog on emailing large attachments. If you’ve prepared your image in an editing program such as Photoshop and the resulting file size is too big then you need to do one or more of the following:

  • Crop the image (chop bits off it)
  • Reduce the “colour depth” (number of different colours available for each pixel)
  • Increase the compression at the expense of quality (if it’s a jpg, for instance)
  • Change the number of pixels into which the image is divided.

Photoshop Dialog Box for Image SizeIt is the last of these options that we are going to consider here. Look at the dialog box in Photoshop for changing the number of pixels in an image. Note that we haven’t yet mentioned “dpi” and we don’t need to! DPI has nothing to do with the size of the image as it sits on your computer or flies through cyberspace. Just change the number of pixels in the dialog box (under “Pixel Dimensions”) and the size of the image is immediately changed. And note that since we are working in two dimensions, halving the size of each dimension (height and width) would quarter the size of the resulting file. The easiest way of reducing the size of the file is to reduce the number of pixels it contains.

2) Displaying an Image

When displaying an image on a computer screen, or printing on a deskjet or laser printer, the image is made up of “dots” or “pixels” as created by the computer or printer. The density of these dots is what defines the size of the physical result.

So, if we have an image of 1000 X 1500 pixels and print it at a density of 200 dots per inch (dpi) then the printed image will measure 5 inches by 7.5 inches.

If we increase the number of dots per inch we will be packing the pixels closer together. This means that the image will (a) appear sharper (within limits) and (b) be smaller when it is printed.

So, if we print the same image at 300dpi then it will measure 3.3 X 5 inches when printed.

The crucial thing to appreciate is that we haven’t changed the size of the image itself. It’s still 1000 X 1500 pixels and it will still take up the same space on the computer. The decision to print it at 200dpi or 150dpi or 300dpi is separate from the size of the image itself. In practice, whatever your printer tells you it is capable of producing, you are unlikely to see any difference in printed quality if you raise the density (or “resolution”) higher than 300dpi but if you drop it to less than 150dpi you are likely to see the quality drop.

I’m not suggesting that there is no connection between image size and printing resolution. Clearly, whatever the resolution, the printed image will be larger if there are more pixels to print and if there aren’t enough pixels available then printing in lower resolution to get a larger print will reduce the quality of the printed result to unacceptable levels.

The important point I’m trying to make here, though, is that “dpi” has nothing to do with file size. Changing the “dpi” will not change the size of your file.

See this Wikipedia page on dpi for more detail on this topic.

You may also like to refer to these previous blog posts:

File Sizes
File Sizes – 2
Checking File Sizes

Are you concerned about the privacy of your internet activities?

Magnifying glass over computer keyboardA lot of people just shrug their shoulders at this question. They just don’t care what information is being collected about them or their online habits and activities.

Others – including me – think that the “default position” ought to be that only the minimum information should be collected to permit an online function to happen and that no data should be kept unless it is required to protect one or both parties in a contract situation (such as a purchaser giving a full invoicing address).

Someone recently told me that she thought it was “freaky” that Google ads are appearing in her email for products she had recently been looking at on seemingly unrelated websites. Along similar lines, I was recently training a silver surfer client in the use of Gmail and noticed a lot of ads for militaria. I asked him if he had recently had any contact with the army and he said that he had been involved in a veterans’ dinner.

Now, to some people this spying on our activity and fine-tuning on-line ads to capitalise on what they have learned about us is nothing more than a logical extension of how traditional advertising has always worked. After all, if you were selling a boat and wanted to advertise it, you would put the ad in a boating magazine because you’d know that the reader was interested in boats. Is there any difference between that and Google targetting ads about militaria to a Gmail user who has been discussing an army veterans’ dinner in his email correspondence?

If I ask people under 30 this kind of question, their eyes glaze over and a look comes over them that suggests that they’ve just realised they’re talking to a nutter and now they’re wondering if I’m dangerous as well. Ask the same thing to someone who’s old enough to remember the days before CCTV cameras (silver surfers in particular) and I’ll usually get a different response.

For what it’s worth, my own opinion is that it is an outrageous invasion of privacy for Google to read people’s email and use the knowledge gained to target ads to that person. OK, I do realise that it’s a machine that’s doing the reading and not humans. That doesn’t change the principle. Apart from anything else, it’s widely thought that Google never ever throw data away, so anything they’ve recorded about you could, in principle, be checked over by humans or machines at any time in the future. I also acknowledge that Gmail is “free” to use and that people are quite capable of choosing different methods of handling their email. However, that should only give them the right to read a Gmail user’s outgoing – and not incoming – email. If I send an email to someone who uses Gmail what right do Google have to read that email? I haven’t given them permission to do so: I don’t use Gmail.

I’ve been reading a book called “The Filter Bubble” by Eli Pariser. Click here for an interview with The Independent.

"The Filter Bubble" book coverPariser discusses the fact that Google and other huge websites such as Amazon, Facebook et al, not only bombard you with ads that they have tailored to what they know about you, but that they are also tailoring content to show you what they think you will like. So, if you perform a Google search and I perform the same search we may be presented with different results depending on what Google knows about each of us. And I’m talking about the Google organic results, here, not the Google advertising presented in sponsored links. Facebook are likewise filtering which of your friends’ updates are displayed to you depending on how much interest you have shown in that friend in the past. Pariser argues that these online organisations are creating a “filtered” view of the universe such that what you see on the internet is biased in favour of what you already know and like (ie you are in a “filter bubble”). Pariser maintains that, at the very least, this is presenting a distorted view of the world and most people are just not aware that such filtering is going on. I’m not sure about some of the implications that Pariser considers because I suspect that he over-estimates the importance of the internet in influencing our worldview. Nevertheless, I found this book informative, thought-provoking and worth reading (and thanks to Elaine for telling me about it).

If you belong to the part of the population that doesn’t care about privacy and doesn’t care where all this data gathering and filtering may be taking us then you won’t read my blog next week as I’m going to list some of the steps you can take to try to protect your privacy. l feel like a cross between the boy with his finger in the dyke and King Canute, but I do feel happier taking at least a few steps in the right direction and maybe you will, too, if you find things like targeted advertising “freaky” and disturbing.

I am aware that I am open to charges of hypocrisy. I advertise my computer services using Google AdWords and www.google.co.uk is still my home page. I do also buy stuff on Amazon (but not books). That doesn’t mean, though, that I have to approve of their definitions of acceptable boundaries when it comes to information gathering, retention, and use. My stance is that taking small steps to protect my privacy is better than taking none at all.

Dropbox Re-visited

Dropbox logoA while ago I wrote favourably about Dropbox and the way that it copies files of your choosing to one or more other computers automatically. I am still using it all the time to ensure that I have the latest versions of important files with me on my netbook when I am visiting clients. There are two things that I would like to add:

  • There have been concerns that Dropbox is not as private as we might like. Their previous privacy policy suggested that employees of Dropbox were not able to view files stored using Dropbox (the files are stored on Dropbox’s servers as well as distributed among your own computers). It now appears that that is not the case and that they would reveal our data to relevant authorities (in the USA) if subpoenaed to do so. Moreover, since Dropbox do have the ability to view files it means that customers’ files are vulnerable to mistakes or malpractices of its own employees. See here for a good exposition of the situation. Like the writer of that blog, I am considering leaving Dropbox, but am reluctant to do so as I have come to rely on its usefulness.
  • I recently password-protected an (existing) Excel 2010 spreadsheet and then promptly forgot what password I had used. Although I definitely had unprotected backups, they were not current. Then I remembered that Dropbox keeps previous versions of files. By logging on to my Dropbox account I was very easily able to restore an unprotected version of the spreadsheet from just before the time I locked myself out of it. Magic! That’s another reason I won’t drop Dropbox easily.

Email Netiquette Re-visited

Some aspects of what is considered polite and proper in emailing are important – such as not revealing email addresses in the “CC field” when the recipients do not know each other (see Shouty Emails and Email Address Fields for my previous posts on this). Others are less so. I was recently amused by an article on the BBC website about how we greet each other and sign off our emails. Reading through the mountain of comments that the article attracted, I concluded that there is no universal way of either starting or ending emails that will not offend or upset someone. It seems that every single variation has its supporters and detractors.

For instance, some people say it is only common politeness to start an email with “Dear Fred” (assuming, of course, that it is Fred you are emailing). Others say that that is an archaic and irrelevant hangover from letter-writing, and someone else even thought that that form suggested an intimacy that may be inappropriate. Likewise with ending emails: some people like to sign off with “Cheers”, whereas others (including me) loathe that word in that context.

I have concluded that there is no generally accepted manner of either opening or closing emails, so I will carry on as I have always done – which is to adjust my wording slightly depending on the situation and to stick with forms that do not make me squirm with embarrassment if I see them again two weeks later.

……. and, finally

If you would like to re-visit any of my newsletters/blog posts (they are the same thing, the newsletter being the emailed version of new blog posts), the easiest way to find what you are looking for is to look at the sitemap on my website. Just scroll down the page to the “Posts” section, where the links are listed with the title and publication date (in chronological order).

© 2011-2019 David Leonard
Computer Support in London
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