Can a person with a digital camera and only linux on their computer be happy? So far I am doing just fine (and thank you very much!). People who I believe know what they are talking about say that I am really missing out not using Photoshop. Maybe they are right, and if Adobe ever makes photoshop available for linux, I very well might take the plunge, but for now, here is my state of the art.
My little Canon S200 point and shoot would only save .jpg files, and I was perfectly happy just to be able to find a way to get them off of the compact flash card using a USB to compact flash adapter that set me back maybe $20.00 or so. Linux support for this has come along nicely, but I am still using my own set of scripts to copy off the images.
In the dark ages, I used nautilus to browse directories full of images. This is quite frankly pretty awful if you want to see something more than the thumbnail, but a somewhat better than nothing. As shipped, nautilus launches the "eye of gnome" to view images, and if the image is larger than your screen, you will be plenty unhappy.
The gthumb program was worlds better, and what I used every day until they totally screwed it up trying to make it something fancy. A new thing, f-spot promised to be something better yet, but I was not impressed on my first trial run. In particular, gthumb nicely displays the EXIF data saved as part of each image. It also manages to display gigantic images on screens smaller than the image size.
(I have long since abandoned gthumb as a hopeless mess. It was once nice and simple. As of 2022 I am using "feh" which is simple and clean.)
Image Magic provides a handy set of utilities (display, convert, identify) that allow simple command line manipulation of whole images. The nice part about these is that they can be manipulated from scripts to process whole flocks of images all at once.
And now we come to the GIMP, which I have only just begun to tame. This is the linux worlds answer to photoshop (but I have known people running windows to have the gimp alongside of photoshop for some reason not fully made known to me). The gimp infuriates me for the most part at this stage of my learning, but I have managed to use it to crop, resize, and adjust color levels and curves. It can do a lot more, and its power is the usual excuse for its complexity.
The above pretty much summarizes my set of tools at the time I transitioned from my point and shoot to my 20D digital SLR. With this camera I am confronted for the first time with the option to handle raw files, as well as to simply connect a usb cable to the camera itself (both the unload images, but potentially also to control the camera remotely).
I have yet to actually connect a USB cable directly to my camera for any reason, but I am told that Gphoto2 and/or gphoto will allow me to do that. (I pull the flash card and put it into a reader. What could be simpler?
Gphoto2 is a command line thing that looks handy. Gtkam is a graphical front end for gphoto2.
Once all this is set up, it may be as simple as:
gphoto --set-config "Capture size class"="Full Image" --capture-preview
As of gphoto2 2.1.6 (June 2005) there is proper support for the 20D and 350D.
The claim is that if I put the camera in PTP mode via a menu setting,
everthing "just works".
I will let you know when I get a chance to try it.
I am just beginning to fiddle with raw files using the DCraw program, and initial trials are promising and intriguing. There is a lot to learn about and understand here. The next stage is to use the DCraw plugin for the gimp and then pull raw files right into the gimp for processing.
The following links are just a start:
S10sh is a command line thing that manipulates Canon PowerShot Cameras (and who knows what else). Newer versions are available, and I have some of these Here as well.
Tom's Digital Photography Info / tom@mmto.org