2010-02-09 (Tuesday W06)
Exposure value details revealed
http://en.wikipedia.org/wiki/Exposure_value
Note that this is a VERY technical article on Wikipedia.
What we normally need to know is just the fact that EV differences – also known as “exposure compensation” – can be used to have a camera expose differently than it does by default.
-1 EV means ”use half the light”, give me a darker photo, equal to one of:
- Faster shutter speed, half the time.
- Smaller aperture, a greater aperture-value by a factor 1.4 (square root 2)
- Lower ISO, half the value
+1 EV is the opposite direction, giving a brighter photo.
In manual mode (On Nikon cameras at least) this simply adjusts the exposure metering by adding the exposure compensation.
In other modes, the choice of aperture and shutter speed is affected – also the ISO-value, if the camera has an auto-mode for that.
2010-02-07 (Sunday W05)
2010-02-06 (Saturday W05)
2010-02-05 (Friday W05)
Rexx, simple means scripting
The Regina REXX Interpreter is free, available for Windows, Mac and Linux
It is a simple means of creating your own automated tasks.
Given that you observe some cautiousness as you create your scripts, they will run on all of the above OS’es.
As your knowledge grows, more complex tasks can be undertaken.
I’ll show you an example of a task that is “impossible” (pre XP at least) in the CMD.EXE shell on a windows machine:
Say that you have a bunch of images from a digital camera in a folder and that the files has names like this:
IMG1734.JPG, IMG1735.JPG, IMG1736.JPG, … IMG1798.JPG (that would be 1798-1734+1 = 65 images I believe).
Just launch any editor that creates true *.TXT files, then type in the following:
(Only text OUTSIDE /* and */ is really necessary, these are comments).
/* get arguments; prefix, first-number, last-number postfix*/
parse arg pre startnum stopnum post .
/* loop through the numbers from first to last */
do for i=startnum to stopnum
/* use the "ren" command to rename the files with pre and post plus current date instead of 'IMG' */
address command 'ren "' || 'IMG' || right(i,4,'0') || '.JPG' || '"',
' "' || pre || date('I') || '_' || right(i,4,'0') || post || '.jpg"'
end
Note that ‘ren ‘ (just after “address command”) is usage of the rename-command in CMD – to rename files.
On Linux you need to change “ren” to “mv”, as MacOS X has similarities to Linux it may be apropriate there too.
For simple handling: Save the file as ren.rx in the same folder as the images.
Now launch the command prompt (shell) of your choice, that would be Windows+R, type “CMD” and hit ENTER (or click OK) on a windows machine.
As the command prompt appears, type “cd” a space and the name of your images-folder within double quotes, then hit ENTER again. That could be:
cd “path and name to image-folder”
as the prompt appears again, a dir command (“ls -l” on linux) should display the names of the images, and the “ren.rx” file. If that is the case, you should now type:
ren.rx Image_ 1734 1798 _ByMe
to rename the files, with the first as in ”IMG1734.JPG” to “Image_2010-02-05_1734_ByMe.jpg” .
… To have this work on your machine, you need to download and install “Regina” for your OS. It should be here:
http://sourceforge.net/projects/regina-rexx/files/ … you will find a PDF file with the Regina manual there too.
One final note: I HAVE NOT tested the script above as I post this, in my opinion it SHOULD work.
Good luck!
2010-02-04 (Thursday W05)
Camera Lucida
Early writings on the emotional effect of photographs on the viewer
Who: http://en.wikipedia.org/wiki/Roland_Barthes
What: http://en.wikipedia.org/wiki/Camera_Lucida_(book)
Who: http://en.wikipedia.org/wiki/Susan_Sontag
What: http://en.wikipedia.org/wiki/On_Photography
Follower, who refers to these: http://www.multijournalist.se/






