1. Is there a picture viewer that automatically detects a digital camera through USB for Linux?

2. Are the following cameras supported to the point that I can view them as normal drives?

Fujifilm Finepix S5200
Fujifilm Finepix S5100
Fujifilm Finepix Z1
Canon Powershot SD550
Canon Powershot A620
Canon Powershot SD30

3. How can I use a USB card reader in Linux with an XD card?

[I need to buy a digital camera and will make my buying decision based on the compatibility of these cameras.]

digikam is widely used, which allows you simply plug your camera in and transfer across the photos required into different albums. Also allows basic editing, emailing, printing of photos, etc. Pretty much any USB camera will be recognised as USB mass-storage device without any problems under Linux. Digikam is able to work with some cameras directly, if not you can simply tell it to look for the mass storage device. Check out the HCL on these forums for a overview of the cameras tired + tested by members here, along with any extra info such as additional drivers.

Hi,

Addressing each of your questions in turn -

1. There are a number of picture viewer type applications for Linux. digiKam, as already suggested, is one such (and a very good app, too). Others to consider include FLPhoto, gThumb, F-Spot, amongst others. When you say 'auto detect', are you meaning that an application runs when you plug your camera in? If so, it's a slightly different question and will depend on your distro and which Desktop Environemtn you're using.

2. as fouldsy says, most cameras these days (certainly those with removeable memory cards) will appear to Linux as USB mass-storage devices, or can be configured as such.

Some cameras use what is known as the 'Picture Transfer Protocol', which should be catered for by the gPhoto library, which add support for a whole host of cameras which don't use mass-storage. You can check you cameras' compatibility by having a look at -

http://www.gphoto.org/

3. A USB card reader will appear as a USB mass-storage device to Linux - so you would just treat it as an extra hard disk drive from which you can copy files. Again, the manner in which such a device is configured / used will depend on your distro and Desktop Environment, so we could do with knowing those to help further.

Well, my distribution is Gentoo and I use KDE. I thought this would be more difficult, but it really isn't. Please explain how I can configure the camera as a mass storage device and same with the card reader.

basically the card reader when you plug it in gets detected
you make a mount point
like
mkdir /mnt/camera
then mount the drive
mount /dev/sda1 /mnt/camera
i put an alias in ~.bashrc and make it one easy to remember command
when you are done unmount it
umount /dev/sda1
and unplug it

check kernel logs if yours is not /dev/sda1 like mine