This is a very common fault with TX-1 cameras, and it is due to dust on the inner lenses (inside the lens assembly), which happens because the seals and lens movement are designed poorly. Here is my summary of the issue:
1. What can be done to mitigate the risk?
* The most important thing is to avoid dust, especially fine particulate dust. Avoid using it in dusty locations, use a camera case when not in use, avoid dusty pockets. The camera does get dusty inside, and that dust then travels to the inner lens.
* Avoid having the lens open and close (Leave lens retract setting at 1 minute).
* Wipe the outside of the cylinder of the retractible lens before having the lens retract. This will prevent dust from building up on the seal.
* Do not blow near the lens, to prevent blowing dust past the seal (use a lens cloth to remove any dust specks).
* Keeping the camera vertical at all times might help (so any dust settles at bottom rather than on surface of inner lenses).
* If you have had a camera for a while and are worried about this issue (and you are outside of your warrantee/guarantee period), and you are very handy with small complex mechanisms, you could take off the outer body and brush dust away from the seal. It is not easy to get to the seal, you basically need to take off all the same parts that Wolfgang did - see
these photos with the seal removed and
these instructions take you part of the way.
2. How can I tell if my camera has this problem?
* When taking video with a high contrast background (e.g. grass in sunlight), a blurred spot remains static on the image as the camera pans.
* The spot was most obvious on static photos for me taking a shot of sunny blue sky with ISO 1600, f/8, and 10x zoom.
* Dirt or marks on the outside of the main lens might look like a similar problem, but you can tell if the dirt/marks are on the main lens: use super macro, and get camera to focus on something 1mm away from lens (any dirt on the outside of the lens will also be in focus and very noticable - you can trick the camera to focus on the outside of the lens).
3. What is the cause of the problem?
* The cause is a fine peice of dust that has got inside the lens assembly and is on one of the inner lenses (focusing, macro, anti-shake lenses).
* The most probable route of entry for the dust is from the outer surface of the cylinder of the retractible lens, past the seal when the lens retracts or extends, and then moved around inside the lens assemby until it has settled on an inner lens. It is possible dirt can get in from other routes, so keeping the camera dust free using a camera case would help too.
4. What can I do to fix it?
* exNewt
suggested trying ultrasound cleaning.
* You can take apart the lens assembly yourself, or get someone to do it. This is *not* simple, and you have a high chance of killing the camera.
Other information:
Discussions of the issue:
http://forums.powershot-tx1.com/index.php?topic=122.0http://chdk.setepontos.com/index.php/topic,2891.htmlRelevant photos of the seals (the seal is the :
http://s358.photobucket.com/albums/oo26/Wolfgang054/TX1/http://s358.photobucket.com/albums/oo26/Wolfgang054/TX1/?action=view¤t=TX1-Gears.jpg
