7-Zip

The best compression tool around. Has support for nearly all formats you’ll ever use in your life. Make sure you tru the 7zip format, it has really good compression rates.

Download: http://www.7zip.com
Portable: http://portableapps.com/apps/utilities/7-zip_portable

AVG Free 9.0

If you don’t you should care about viruses and malware. It’s all over the internet. But forget about expensive antivirus and security software packs like Norton antivirus that make your computer crawl like a slug. AVG has a free version of their antivirus software that has everything you need plus some stuff you probably don’t – like the link scanner thing which is the first thing I disable after installing.

Download: http://free.avg.com/us-en/download-avg-anti-virus-free-edition

ImgBurn

I used to be a Nero user, but after finding out about this free piece of DVD burning software I switched. It’s faster and simpler, and that’s all that there is to it! You can burn everything with this, files, images, music, you name it.

Download: http://www.imgburn.com

Tip: if you’re looking for a portable solution you can try InfraRecorder portable.

VLC Media Player

This is simply the best media player around, and it’s open source which means free. It plays nearly every format you can imagine (MPEG-2, MPEG-4, H.264, DivX, MPEG-1, mp3, ogg, aac…). You can also convert stuff with it or even use it as a server.

Download: http://www.videolan.org/vlc
Portable: http://portableapps.com/apps/music_video/vlc_portable

PrtScr

I featured this one on my previous post so it’s obviously worthy of being featured in this list also. It’s a real pleasure to take screenshots like this. I love it when such simple tasks become so easy and so cool!

Download: http://www.fiastarta.com/PrtScr

If you’re looking for something similar but portable make sure you try Lightscreen.

RocketDock

In case you’re like me and have always stared at MACs and their gorgeous launcher bar with all the bells and whistles and wondered why the hell doesn’t Windows have something like this – well, now it has, and it’s free. This is particularly useful for me with a dual monitor setup. Now I can free up the quicklaunch icons from Windows task bar and put all my shortcuts on the RocketDock on the 2nd monitor. It’s completely customizable so you can play around a bit and get some new icons.

Download: http://rocketdock.com

Fences

This is not really an essential tool… unless you have that nasty habit of throwing everything you find in your desktop which eventually becomes a really big mess which mimics your real life desk. Fences is like Ikea for your desktop. You keep the same shit around you, but you put in boxes so that it looks nicer!

Download: http://www.stardock.com/products/fences

TeraCopy

This is a very compact tool designed to make copying and moving files easier and faster than usual. Like they say: TeraCopy uses dynamically adjusted buffers to reduce seek times. Asynchronous copy speeds up file transfer between two physical hard drives. It integrates seamlessly in the shell and has some additional features also. Very handy.

Download: http://www.codesector.com/teracopy.php

Notepad++

Here’s Notepad on steroids! Of course, only useful for geeks like myself. You should have at least a small degree of that disease to find this useful. It’s a really fast tool for code editing. It supports all the languages that you know, all that you’ll never know and even those you never heard of. If you still miss any, Notepad++ is totally extensible, you can add whatever you like in there!

Download: http://notepad-plus.sourceforge.net
Portable: http://portableapps.com/apps/development/notepadpp_portable

Spybot

An absolute must for your own security. Spybot scans your computer and removes all the spyware you may have accumulated after watching all those weird sites you like so much!

Download: http://www.safer-networking.org/en/download/index.html

CCleaner

Probably the best cleaning tool around. CCleaner cleans up your computer fast, removing unused files from your system, temporary files, cache, history, old registry entries and some more. If you want to keep your system running fast, go for it.

Download: http://www.ccleaner.com

I hope you find this list useful.
Leave your comments and tell me what other free tools you use!

What’s the aperture?

I assume you have a slight clue on this, but anyway, simply put, the aperture is the actual hole that sits in your lens and lets light go through it until it reaches the sensor (or film plane).  The size of the hole can be controlled by the photographer if the lens (on older systems) or the camera allows it. The f-stop scale that we see in most lenses has this kind of progression:

f/1.4 – f2 – f2.8 – f4 – f.5.6 – f8 – f11 – f16 – f22 – f32

Most lenses nowadays have a slightly longer scale because they offer some steps in between.

How does it really work?

This is the question I have asked myself for a long time. Obviously there is a logical reason behind it, but it’s not that easy to get there just by looking. You probably heard that each f-stop represents exactly half the light that you’d get in relation the previous f-stop (considering that every other variable remains the same – speed and ISO). So, f/2.8 is half the light of f/2. Why didn’t they make it f/4 then? It would be easier to have a linear scale… But let’s go a little deeper. First of all, it’s important to know what the f-stop really means. Every f-stop number represents a ratio of the focal distance of the lens (take 50mm for example) to the actual diameter of the diaphragm opening.

The diaphragm is the device that controls effective diameter of the lens opening. It’s usually formed by a series of blades that form an almost circular shape.

So, f/2 is equal to the Focal Distance / 2. Taking our 50mm lens as an example, that’s 50 / 2 = 25mm (diameter of the aperture). Still following? Ok, so for a 50mm lens at f/2 the diaphragm has an opening with a diameter of 25mm. If you take a 100mm and do the same math, you can easily see that the same f/2 aperture results in a 50mm diameter (twice the focal length, twice the aperture diameter). You must asking “well if the aperture’s bigger, how come the f-stop is the same (f/2)?”. It’s a great question that haunted me for a long time! And if you go and shoot a photo with both lenses at f/2 you will conclude that the amount of light that makes up your picture is the same. More on that later. At this point we know how to calculate the aperture size (diameter) and we know that it’s directly related to the focal distance. What you may not know is that to determine the actual amount of light reaching the sensor (or the film plane) we need to consider the area of the aperture (and not the diameter). Remember how to calculate the area of a circle? Ok, I’ll give you a little help: π * radius² (that’s pi * square radius). Back to our two lenses, the 50mm (25mm diameter, 12,5mm radius) and the 100mm (50mm diameter, 25mm radius):

• The area of our 50mm lens @ f/2 is = 3,14 * 12,5² = 490,6 mm²

• The area of our 100mm lens @ f/2 is = 3,14 * 25² = 1962,5 mm²

Notice that an f/2 aperture in the 100mm lens is actually 4 times bigger than the same aperture in the 50mm lens (1962,5 / 490,6 = 4).

Why did we double the focal length and the aperture area is 4 times bigger?

It’s math! There’s a rule that says that the area varies as the square of the radius. So, if you double the radius that’s the same as saying 2² which is 4. By setting both lenses @ f/2 the 100mm gets double the aperture radius to that of the 50mm. 

If the opening is 4 times bigger how can it be the same amount of light (f/2) on both situations?

The answer has to do with the focal distance, once more. And also some physics: the inverse square law. Wikipedia says:

In physics, an inverse-square law is any physical law stating that some physical quantity or strength is inversely proportional to the square of the distance from the source of that physical quantity.

Read the rest of the article here.

Why the odd progression of the f-stop scale?

• The amount of light is related to the area of lens opening not the diameter
• The f-numbers represent the diameter of the opening (focal length / f-number)
• If you double the area of the aperture, you double the amount of light
• The area varies as the square of the diameter and consequently:
• The diameter varies as the squared root of the area

So if each f-stop (moving backwards from right to left in the scale) represents double the light as the previous number that means its opening has double the area as well (for the same subject  in the same light conditions, if you double the area you double the light).  What happens to the diameter? It varies as the squared root of the area. Because we doubled the area, the diameter will be 1,414 times as great (which is √2 – square root of 2 – double). And that’s how the scale is built, by using this multiplication factor:

• f/2 * 1,414 = f/2.8
• f2.8 * 1,414 = f/4
• f/4 * 1,414 = f/5.6 and so on…

Well if you are still reading this then you reached the end! Thank you for the patience and I really hope I have made it easier for you to understand what you’re doing next time you pick up the camera Feel free to comment and leave me your feedback or your doubts if you still have them (comment here or send me a tweet).