Hello,

After using camcorder on high elevations (>14,000 ft) followed by driving my Jeep on very bumpy roads I noticed a pea size air bubble visible when camcorder is moved in the upright position. Normally it stays in the upper part of the lens and is not affecting output. Is this someting I should worry about and contact Canon servise or since warranty expired, learn to live with it.

Andre

I had the same problem. I just went on vacation to Zacatecas, Mexico which is the highest elevated city in Mexico. I filmed for a few days then noticed a pretty large sized water bubble in the lens. It wouldnt affect my shots at all when filming . But if i tilted the camera upside down, the bubble would move. I was so sad. I though water had gotten inside of it as it was raining alot there. But it didnt look like water could even get in there. After getting home I put the camera away saddened that the camera was now useless. I brought it out to capture my footage to my computer yesterday and noticed that the water bubble was gone. It was no longer there. I was so happy. But I was still curious what this was. I guess maybe the cam does have problems with high elevations. So what is this liquid? Where does it come from and where does it go?

Here's my guess: Some optical stabilizer designs use a fluid between layers of glass as the active stabilizing element. If there was any air in the fluid, it could expand at higher altitudes and possibly become large enough to see. There's probably not supposed to be any air in there, but some may leak in over time. When you return to a lower altitude, the air bubble is compressed back to a tiny size. If you examine the lens closely, you'll probably find that it's still there, but much smaller than before.

Well i checked the camera again and its completely gone. When it was there it was fairly huge. Probably finger nail size. And yes it was in between 2 peicesof glass in the lens.

From the Q&A on page 146 of the GL2 manual:

? There are air bubbles inside the lens.
• This is unlikely, but may happen if you use the
camcorder in places where the air pressure is
low, in an airplane for example. The bubbles will
disappear a week or so after you return the
camcorder to normal atmospheric pressure.

Dan's correct - the GL2 uses the vari-angle prism method of optical image stabilisation, where the front sheet of glass is held stationery and the next sheet is allowed to vibrate. That lump on the side of your lens houses this VAP's operating pistons. A fluid is used between the two sheets of plain glass and this forms a prism that bends the light to counteract your camera wobble, and very effective it is too.

But you've found one of it's weak points, and that is that both Canon and Sony admit that air bubbles can indeed form at high altitudes. Normally even quite a big bubble won't affect your footage if you film with the camera anything but vertical - because the air bubble is above the top of the 4:3 recatangle cut out of the lens' image.

So fret not. You can have a big bubble but not have it appear on your footage at all. Take your UV filter and mask it down with black sticky tape - you'll be surprised how only a small rectangle of filter is actually used when shooting.

tom.

Happened to me also, went from 7000 feet back to 900 feet, and wha-la !! !