.: Stigandr.com :.

I have had quite a few people of late asking me about HDR. The usual question is a straight forward “What is HDR?”. So, in an effort to explain this a little for those of you who visit this site, I though I should give a bit of an explanation.

HDR or High Dynamic Range Photography, in basic terms, is a technique where bracketing is used in a digital camera to take several (usually 3, though it can be more or less) images of varying exposure values. These images are then merged in software to produce a single final photo that has a high, often exaggerated dynamic range of colour and light.

In my case I have been experimenting with three images. One is at a normal or near normal exposure, one is over exposed and one is under exposed. The over exposed and under exposed shots are obtained by using the auto bracketing setting on the digital camera set to +2/-2 EV.

(more…)

The guys at IT Security posted an article on the 13th of February titled “The Twenty Minute Guide to PC Security: 20 Tips to Secure your Box“. It is a great read with some very useful tips that all of us should be following if we want to keep our computers, and more importantly, the files on them safe. If you don’t feel like reading the whole article, then Tim Fehlman¹has recently written a really nice summary of the article which he titled “Secure Your Computer in 20 Minutes“.

If you do nothing else, check out at least one of these articles…..today.

1. Tim resides over at Daily Cup of Tech. [<<]

Digital cameras are everywhere, and every other person is taking pictures and getting them printed at their local photo lab. There is nothing new about any of this. It has been happening for a few years now. But, more and more, people are now doing some editing of their photos on their home computers before they take them to the lab for printing. This is where the fun begins. Have you edited some photos on the computer, taken them to the local lab for printing and upon receiving the prints back, found that they do not look the way that you expected? (eg. Too much contrast, over exposed, etc.) Then this article is for you…

Images taken by digital cameras, whether they are saved in JPEG, TIFF or RAW format, include data embedded within the file itself. This data is known as Exif data.¹  The metadata defined in the Exif standard includes things like;

• Date and time information.
• Camera settings (including static information such as the camera model and make, and information that varies with each image such as orientation, aperture, shutter speed, focal length, metering mode, and film speed).
• A thumbnail for previewing the picture on the camera’s LCD screen, in file managers or photo manipulation software.
• Location information. (This may include coordinates from a GPS receiver connected to the camera).
• Descriptions and copyright information.

In most circumstances Exif data can be very useful, especially for semi-pro and pro photographers with high volume workflows, as it makes cataloging of images much easier.²  BUT, the issue with this data arises when the images have been edited on a computer and the resulting pics are printed at a Photo Lab. The reason for this is simple. When images are loaded into a Photo Lab, the Lab scans the images to see if they contain Exif data. If Exif data is present, the following occurs;

1. The Photo Lab sees the Exif data and recognises the image as coming from a digital camera.
2. The Photo Lab makes the assumption that images “viewed or printed straight from the camera have a flat and low contrast look about them“.
3. The Photo Lab employs a set of image enhancement algorithms known as AUTO CORRECT, which can adjust colour and density of contrast based on what it finds in the Exif data.

This process occurs even if the colour and contrast have been corrected in a computer prior to printing³. Consequently, colour and contrast can be feasibly adjusted twice; once in the computer and then again in the Photo Lab, which of course results in a printed image that may have exaggerated colour and contrast.

How do we overcome this problem?

If you, like me, wish to edit and correct your image on your home computer so that you can simply walk into a Photo Lab and print your images without the hassle of editing each individual image, then the answer is simple. You MUST remove the Exif data from the image post editing and prior to printing. But, how do I do this, I hear you ask? If you use Photoshop, then you simply go to “FILE → Save for Web” to do your final save before printing. The “Save for Web” option strips the Exif data from the image before saving it, which means that it is simply not there for the Photo Lab to find when you go to print the image.

Alternately, if you do not have Photoshop, then you have two options. The first is to find a software application that will allow for the removal of Exif data. The second is to leave your editing till you get to the Photo Lab.

Happy snapping and printing.

1. Exif is short for Exchangeable image file format - official abbreviation Exif, not EXIF.[<<]
2. Keywords can be added to the Exif data of an image and used for searching and sorting.[<<]
3. Computer editing of colour and contrast do not affect the Exif data.[<<]

• Do you use many different computers in many different locations in an average week?
• Are you always trying to remember where you saved that file?
• Do you wish you could carry some software applications with you, especially as the PC you are at never has the one you want?
• Do you worry that the files on your USB drive are not backed up?

If you do, then you are like me. In an average week I may use 3, 4, or even 8 different computers. Nearly everyone of those computers is configured differently and has a different set of applications on it. Being able to carry large amounts of data with me on my USB thumbdrives has been a large help for me, but it is still not easy adapting to each different machine.

Well, what if you could carry many of your favourite applications with you? Now you can. There are now a wide variety of software applications that are being modified/adapted to be portable. These are generally being termed as Portable Apps. They are completely stand alone. All of the needed profile settings and such are contained on the USB drive in the applications install folders, and thus, they are completely portable. There are also some very handy autostart menu applications available, so all you do is plug your drive in, wait for the menu to pop up, and then choose the app you want.

Currently portable apps include programs like;

• Firefox
• Thunderbird
• Open Office
• Audacity
• Sodoku
• Nethack
• puTTY
• Clam Antivirus
• And many more….

So, if you need a mobile office on your USB drive, go check out the Resources below and start exploring the world of portable apps.
Resources:

• PortableApps.com
• MyPendrive
• Daily Cup of Tech
• Rob Loach .NET: Portable Applications