The myth of the retina display

Oct25

As more and more Android phones are coming out with high resolution displays, along the same line as Apple's iPhone's Retina Display, many tech journalists are comparing their screens to the iPhone. They're saying thingts like "it's lower than the iPhone, but still above the 'magic' 300 pixels per inch mark".

It's important to note, though, that the 'magic' 300 really isn't that magic at all. In Apple's announcement, although it wasn't on the slide, Steve mentioned that 300 ppi is the human eye's limit to resolve an image at a distance of around ____ inches.
Many people seem to have forgotten this last part, and are taking the number to just be 300 ppi. If we take the definition of a retina display to be a display that the human eye is incapable of resolving at its intended use distance, then for a larger display, such as a tablet or a computer, the required pixels per inch will be lower. In the case of these larger Android tablets, such as the Galaxy Nexus, which is 4.65 inches, compared to the iPhones 3.5 inches, it's probably safe to say that you'll be holding it a little bit further from your face, and thus the required pixel density will be a little lower.  Thus, the difference of 14 pixels per inch makes even less of a difference than it would if they were held at the same distance.

Device	Resolution	Size	PPI
Retina iPhone	960 x 640	3.5”	329.65
iPad	1024 x 768	9.7”	131.96
Double resolution iPad	2048 x 1536	9.7”	263.92
Galaxy Nexus	1280 x 720	4.65”	315.83

Information courtesy of AnandTech and this DPI calculator

Now, let me consider the rumours of a retina display iPad. If the same pixel density were used for the iPad as the iPhone, 330 ppi, at the same size, the iPad's screen would be a massive 2558 x 1919 However, because the iPad would be held further away, it's probably safe to simply double the iPad's resolution to 2048 x 1536, and call that a retina display. That gives a pixel density of 264, according to this DPI calculator. This not only makes it much easier to achieve (a significantly lower resolution display, which is likely cheaper to manufacture, and would draw less power), but also makes it easier for developers. A simple doubling in size would provide them with the same assistance as they got when the iPhone 4 was released with its retina display.

Idea: Multi-carded cameras

Oct21

This is the first in an ongoing series of ideas. They are just random or interesting ideas for products or software that I have thought of at some time. It may or may not be feasible for any number of reasons. I just thought it was an interesting idea, which I decided to write down.

There are a number of different reasons that a person may want to use multiple memory cards in a single digital camera, but first, let me explain exactly what I mean:

The camera would have two or more slots for memory cards
Each slot would have a small lit button next to it
There would be the option to have custom settings (e.g. quality settings, whether or not to show lines for the rule of thirds, etc.) which change depending on which card is selected
An option to have both cards treated as one large card

It seems to me as though it’s not that difficult to implement, but it could be useful for a number of reasons.

Multiple Users

Sometimes multiple people share the same camera. This isn’t likely to happen so much for the higher end users, but other situations might mean multiple people use the same camera. If they have different ways that they like to use the camera, this could come in handy.

For example, maybe the father of the family is a good photographer, so he likes to have the lines in the viewfinder for the rule of thirds; and he wants the quality and resolution of his photos to be as high as possible, but maybe other people in the family prefer to juts take snapshots, maybe at a lower resolution, but they definitely don’t need to see the rule of third lines.

Multiple cards and settings would make this situation much simpler, not only as they are taking the photos, but afterwards as well. The father might want to take his photos and edit them in Photoshop before uploading them to his Flickr for the world to see, but others in the family just want to upload them straight to Facebook for friends to see. Each person could just take their card to their computer, and do with it what they want.

Different Types of photos

This is very similar to multiple users, but it could just be a single person who likes to take different types of photos. Maybe they like to keep their landscapes in a separate folder to their other photos, or they take photos to be later created into a panorama and want those to be easily accessible.

Backup

Maybe you’re taking photos that are so important to you you can’t take the risk of losing them. Maybe you want to give a spare copy of the raw photos straight to someone else. Whatever the reason, you want the same photos, with the same settings, on two different cards. Very simple.

Extra Storage

This one’s very simple, some people just want the extra storage space. No need for any changes in settings, no need for them to choose when to switch to the other card. Just do it.

Just my idea for a feature that would be useful to have in cameras.

All comments and suggestions are very much appreciated. Suggestions, problems, ideas, general comments, or anything you want to say.

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Follow up: Mac start-up problem

Aug22

As I wrote about in a previous post, I was having trouble getting my new Mac to start up. This is just a quick follow up to say that it’s now working. In fact, shortly after I posted my last one, I tried again to shut it down, and it finally turned off!

I turned it back on again, and held option, but it didn’t work, but this time at least it shut down. Then I tried C, and then D, but they didn’t work. Hoping that I could at least get the disk out, I tried holding down the trackpad, to remove the disk on start-up. The disk was removed, and the computer started up correctly. I have yet to shut down the computer again, but will update this post once I have, to see whether or not I have the same problem again, but I expect not to.

Macs never have the problems Windows PCs have? BS!

Aug21

A little while ago I got my first Mac: a second tier, 13-inch MacBook Pro. I’ve really been enjoying using it, and, due to the faster speed in booting up and the portability, among other things, I have been using it more than my Windows desktop.

Yesterday, I decided I was going to go ahead with my plans to dual-boot Ubuntu Linux onto it. So I went onto my desktop, and did a little bit of research, and came up with this site. Armed with the comment by “cyberdork33”, I went to my MacBook Pro and opened Boot Camp. I

started following his instructions, until it came time to install Ubuntu. I chose to install it, rather than run it off of the disk, and it started doing something that looked like it must be installing, but then it came to a black screen with white text. It had some code, and said to type “help” for a list of commands I could give. I did this, but none of the commands seemed useful.

I gave up, and decided to forget about Ubuntu — I’m happy with Mac OS anyway, all I was going to do was mess around with Ubuntu, I had no plans to use it as my primary OS. So I held the power button, and it didn’t shut down. After a few times of doing this, it finally did loose

power, and I booted up again under Mac OS X. Using boot camp, I restored the disk to a single partition under Mac OS X. I continued using the computer until I went to bed, shut it down, and left it on to charge over night.

The next morning, after I get up, I go over to it and turn it on. I notice it stays on a blank white screen for longer than it should, but I’m doing other things, so I ignore it and let it boot up as normal. When I get to the computer, I notice it has a black screen with white text, saying

No bootable device — insert boot disk and press any key

Typically, given this screen, pressing any key would get it to do something, and even if there is no disk inserted, it will tell you as much. However, when I press any key (in fact, I pressed every single key on the keyboard, from the function keys, to letters, to modifiers), it simply ignores my press. I notice that pressing “caps lock” does not cause the light over the caps lock key to turn on.

Because there is a disk in the drive — and I can’t eject it — I try to power down the device by holding on the power button. But no matter how many times I do this, or how long I hold the button down for — short, long, or just tapping it — it won’t power off.

If I could get it to power off, there are many things I could try. From holding down option to make sure it’s booting off of the correct partition, to holding down “d” to run the Apple hardware test, to make sure there isn’t a problem with the hard drive. However, all of this is irrelevant, since I can’t get the computer to turn off in the first place. I can’t even follow the instructions and insert the restore disk, since there’s a disk in the computer I can’t get out.

I’m trying to power down the computer by killing its battery, but if that doesn’t work, I’ll try taking it into an Apple authorised repair service, and hope that all those people who talk about how great Apple Care is are right.

Don’t read on if you’re concerned about inappropriate language.