The Author – Bart Busschots
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Mar
21
Tips for Shooting the Moon
Filed Under Science & Astronomy, Photography on March 21, 2008 | 1 Comment
It can be very nice to include the Moon in your shots of buildings or landscapes but it’s not easy. The reality is that the Moon is very small in the sky and that it’s hard to pick up detail on the Moon while also properly exposing your subject. That’s why so many people cheat and get the Moon into their shots using PhotoShop. They stick on a massive zoom lens, shoot the Moon, then stick on a normal lens to shoot their subject and finally combine the two shots into one. If that’s the way you want to do things that’s your call, personally I look at it as cheating and would prefer to do it the hard way and actually capture the Moon and my subject in a single shot.
[tags]photography, DSLR, the Moon[/tags]
Mar
18
HDR with a Nikon D40, Bracketeer & iPhoto
Filed Under Computers & Tech, Photography on March 18, 2008 | 23 Comments
I’m no expert on HDR but since I spent most of my weekend playing with it now seems like a good time to write about it, while it’s all nice and fresh in my mind and all that. One of the first things I noticed when I started shooting DSLR is that the dynamic range of the camera was a lot narrower than the dynamic range of my eyes. I didn’t know it was called dynamic range back then but that’s not really the point. When a scene has a big range in brightness between the brightest parts and the darkest parts then it’s said to have a high dynamic range. Our eyes are quite good in those situations, DSLRs on the other hand are terrible at capturing them. On a sunny evening when the sun is low in the sky casting shadows all over the place you can still see just fine but a DSLR gets into all sorts of trouble.
[tags]HDR, Nikon, Bracketeer, iPhoto[/tags]
Feb
18
Aperture Priority – Get More Out of Your DSLR
Filed Under Photography on February 18, 2008 | 3 Comments
When I first got my Nikon D40 I left it on full automatic mode and basically let the camera choose everything except the zoom. I got some fantastic shots that way but I soon started to crave more control. DSLRs like the D40 give you a number of manual modes to choose from so it’s not an all-or-nothing choice where the camera either looks after everything or nothing. Instead you can choose for a half-way-house where you control the element that’s most important for you and leave some or all of the rest up to the camera. The two most common semi-automatic modes are S (shutter priority) and A (aperture priority). Since almost everything I shoot is animate and stationary I don’t have any great need for control over the shutter speed. However, for the kind of shots I do like to take I like to have control over the aperture. This is why my camera spends almost all it’s time in aperture priority (A) mode and almost all of the rest of the time in full manual mode when I do mad things like take pictures of stars.
Nov
25
Bart’s TimeMachine Tips
Filed Under System Administration, Computers & Tech, Security on November 25, 2007 | Leave a Comment
Time Machine is the fantastic new backup feature built into OS X 10.5 Leopard. It’s pretty simple to set up and it will work if you leave all the defaults as they are. The defaults are fairly intelligent. For example, your Library/Caches is automatically excluded from the backup. However, if you wish to use space on your Time Machine disk efficiently you may wish to configure Time Machine to exclude a few more folders.
[tags]Apple, OS X, Leopard, Time Machine[/tags]
Oct
1
Two Nice Photo Editing Tips for the GIMP
Filed Under Photography on October 1, 2007 | 1 Comment
Those of you who actually poke around my Photo Gallery may have noticed that I’ve had a section for desktop wallpapers there for a while now. You may have wondered why I’d never blogged about it before. Well, the reason is that I wasn’t happy with my wallpapers. They all looked a bit flat to me. I spent a few hours this evening tweaking them and now I’m finally happy enough to announce them. They are still far from perfect. I still consider them amateur creations, but I’m not ashamed to announce them any more. So, here’s the link.
While trying to get these wallpapers into a descent state I came across two very cool GIMP tutorials, one which really lets you boost the colour intensity of your images, and another that lets you create really cool partly colourised black and white images.
[tags]GIMP, Image Processing, Photo Editing, Wallpapers[/tags]
Sep
23
CVS over SSH on a Non-Standard Port
Filed Under System Administration, Computers & Tech on September 23, 2007 | 5 Comments
If you access CVS over SSH you will know that you have to do two things to get it working. Firstly, you have to set the CVS_RSH environment variable to the location of your SSH binary. Secondly you have to use the :ext: scheme for the CVSROOT environment variable (or -d flag). The thing is, there is no place in the :ext: scheme to set a port number! This means that CVS will try to open the SSH connection to the specified server on the standard SSH port. I don’t like running SSHD on the standard port, I much prefer to stick it on a non-standard port, but does that mean I can’t use CVS over SSH? Well, if you leave things to CVS then yes, but luckily OpenSSH is not as retarded as CVS and provides you with a simple mechanism for over-ridding the default port on a per-host basis. The key is to add an entry for the host in question to your ~/.ssh/config file. The sample below tells SSH to use port 123 as the default port when connecting to the server my.machine.ie:
Host my.machine.ie Port 123
This will work on Unix, Linux and OS X as well as through Cygwin on Windows.
[tags]SSH, CVS, OpenSSH[/tags]
Sep
16
Writing Presentations With Keynote ’08
Filed Under Computers & Tech on September 16, 2007 | 12 Comments
I have been an iLife user for years but hadn’t previously bought iWork because it was lacking a spreadsheet program. When iWork ’08 came out with Numbers I decided the time was right to give it a go. Just to put things into perspective, at work I use Microsoft Office (the Mac version), and at home I’ve been using OpenOffice and NeoOffice. OpenOffice and NeoOffice always strike me a striving to emulate MS Office, iWork doesn’t do this. It sets out to do Presentations, Documents and Spreadsheets in a simple and accessible way. It’s refreshing to use an office package with a simple interface instead of the usual glut of buttons everywhere. I’ll be writing about Pages and Numbers in the future but today I want to talk about the oldest of the iWork applications, the presentation app Keynote. This review is based on my experiences creating and then presenting a talk about science to students at my old secondary school the week before last. You can read about how I got on here see a PDF of my slides here.
[tags]Apple, iWork, KeyNote[/tags]
Aug
22
SSH Agent – Simple Yet Secure SSH Keys On OS X
Filed Under Computers & Tech, Security, System Administration on August 22, 2007 | 6 Comments
If, like me, you spend a lot of time using SSH you’ll probably like the idea of being able to log in to servers without a password. If you really want this you can do it by setting up a SSH key pair with an unencrypted private key. This works, it lets you log in to your servers without a password. HOWEVER, it’s a simply disastrous idea from a security point of view. The only reason I don’t do this is because the idea of an unencrypted private key scares the bejeesus out of me. Hence, I still dutifully type my SSH password each time I connect to a server, and each time I check something in to source control. I’ve been keeping an eye out for a simple solution for a while but hadn’t been actively thinking about it for months. That is until I came across Dave Dribin’s blog post Putting the “S” Back Into SSH this morning. Dave rightly points out that there is a solution, ssh-agent, the problem is it’s a command-line tool and by all account not the simplest one to use. So, what’s obviously needed is a nice GUI for ssh-agent. Dave initially thought he’d found the solution in the program SSHKeychain. SSHKeychain is more of a proxy for ssh-agent than a GUI for it though, and Dave soon discovered that it has it’s fair share of problems. So, in the end, I didn’t decide to use SSHKeychain. However, the post inspired me to have another go at finding a solution. Also, the reference to ssh-agent sparked a vague memory in the back of my head of an OS X GUI for something to do with SSH that had the word ‘agent’ in its name.
[tags]SSH, SSH Keys, ssh-agent, OS X, Apple[/tags]
Jan
1
Running NMAP on Intel Macs
Filed Under System Administration, Computers & Tech, Security on January 1, 2007 | 4 Comments
Before I switched to an Intel based Mac I had always used NMapFE as my nmap front end. Since I only need to run nmap on my G4 MacMini at home and my G5 PowerMac at work I didn’t notice until today that NMapFE doesn’t work in Intel Macs. I had recommended NMapFE to Allison of the NosillaCast and she replied to tell me it didn’t work for her. I tried it on my own MacBookPro and sure enough, it doesn’t work. So, I went hunting for a good nmap GUI for Intel Macs and eventually came up with a good solution. The bad news is that this solution involves installing three things separately. But, don’t worry, all three are small and painlessly simple to install.
[tags]nmap, security, Mac, OS X[/tags]
Dec
22
Rogue DHCP Detection Plugin for Nagios on RedHat
Filed Under Software Development, Security, My Projects, Computers & Tech on December 22, 2006 | 9 Comments
I’m pretty sure this is useless on most versions of Linux because the default DHCP plugin that comes with the Nagios Plugins distribution has this functionality and seems to work just fine everywhere except on RedHat-based distros like RHEL, Centos and Fedora Core. On these systems the default plugin does not seem to work and fails to detect any DHCP servers. This plugin is different to the one I gave instructions for before which tests whether a particular DHCP server is answering requests, this plugin finds rogue servers, it will not alert you if any of your actual DHCP servers are down. Hence, you should probably install both. This plugin is not very polished, it is rough and ready but I know it works on RHEL4. If you’re running a different system you may have to do some minor tweaks but this should serve as an excellent starting point none-the-less.
[tags]Nagios, DHCP, RedHat, RHEL, CentOS, Fedora, Linux[/tags]