Re: Digital cameras and Linux
Neil Booth <NeilB@earthling.net> wrote:
> Hi,
>
> I'm considering buying a digital camera or videocam, but am concerned
> about being able to download the JPEG images to Linux. Of course, the
> cameras come with a serial cable and software for downloading the
> images to Windows.
>
> Does anyone know if these cameras simply pass the JPEG data down the
> serial line, or is there some special camera-specific protocol they
> use (rendering it useless without special software)? In the former
> case, how would I capture the data coming down the serial line?
>
> Thanks for any information or advice,
>
> Neil.
>
Hi Neil,
I do competitive analysis of digital cameras for my company. I will
not tell you which camera to buy :-) *but* I will emphatically insist
that you *not* get a Sony Mavica. I will try to explain a few things
that will help you.
First, connectivity. I would recommend going to the gphoto site to see
what their software supports. Their software is intended to allow
image downloads from a tethered camera (serial, USB). This method usually
uses a protocol called Twain. There is a www.twain.org site, I haven't
visited it yet. The driver for the digital camera most likely uses
Twain, as does Photoshop and some other apps that can get images
directly from the camera. I haven't been able to bring cameras home
to test which ones use a proper implementation of Twain or which ones
gphoto works with -- yet. Experimentation and asking around, as you are,
is your best bet for specific information about any particular model.
Second, storage. This is related to the first point. Unless you are using
a camera that allows scripting on the host to control it ( via Digita OS
from FlashPoint technologies ), then you are simply transferring images.
This is all that 99 percent of the people want anyway. So you just
need a reader for the storage media, then the camera driver isn't really
an issue. This is what the person was getting at when he suggested the
Sony Mavica with floppy disks. Unfortunately, the images the Mavica
produces lose a great deal of information when being stored to the disk.
There just isn't enough room an a puny little floppy for all the data,
so the camera compresses the hell out of the image. This isn't just a
problem for Sony, but I don't know of any other cameras that come with
less than a 4MB card for storage. Most now come with min. 8MB.
There are PCMCIA card adapters for both SmartMedia and CompactFlash.
This may be the way to go. I'm not sure what you'd have to do to mount
the card, haven't experimented that far.
Good starter cameras ($300 range) check out the Olympus D-340R, HP C-200,
Fuji MX-1200. All of the cameras in this range are a little slow between pics.
They are 1MegaPixel cameras, so the image quality is just OK for web and 4X6
prints. The Olympus can save an uncompressed TIFF, but that means a 4-5MB
file gets generated. Adds to the image quality, but you'll want
more storage.
Beyond this, remember that digital zoom is just for advertizing. I mean
to say that digital zoom is worthless. If you use the digital zoom,
it drastically reduces the resolution of the image. You can do
this stuff with Photoshop or the Gimp anyway, so you won't miss not
using it in the camera. Optical zoom is valuable for taking good
pics. You will pay for it, as well as a high resolution CCD.
I mention the starter cameras because they were already brought up
by way of the Mavicas and the D-340R. If you want to know about
the other offerings (like Nikon 950 or Olympus C-2000 which are highly
respected), I suggest you look at the following sites:
www.steves-digicams.com
photo.askey.net
www.megapixel.com
www.dcresource.com
Also, prices are much lower on the Net than in the retail stores.
Check out www.computers.com for price lists. If you buy it retail,
you're nuts.
Wade Curry
I am not speaking for Hewlett Packard.
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