Sony HC7 odd artifact at manual shutter setting

I recently purchased a Gates housing for my little Sony HC7 and the other day I shot a test tape in a shallow pool. After viewing the video in post I noticed a very annoying and strange thing....

Just about smack middle of my image, is a very small, DARK, diamond shaped spot.

Its not a bubble on the port, as those look differently. The pool was shallow, it was a very bright and sunny day. I was shooting against a bright background. The "dark diamond" appears in all shots, is stable, does not move, and the only time it appears to disapper is when I had the flip up CC filter in place. I did not notice it as much. The dark diamond is much less apparant on darker subject vs. lighter ones.

After careful review of the tape, I determined that the artifact is something internal to the camera and not on the port.

Coincidentally, this also was the first time that I shot at a manual shutter speed of 60th. (In the past, I normally shot in Auto shutter).

Yesterday I performed a simple land test of the camera, shooting a white slate in bright sunlight, on both AUTO shutter speed and also at manual at 60th.. RESULT: The "dark diamond" only appears when the camera is set to manual shutter at 60th, in the bright environment. It is not there in Auto shutter. I suspect its some "feature" in the camera design and how this model camera behaves at a slow shutter very bright light environment.

Below is a simple, crude, out of focus, improperly exposed frame grab of this dark diamond artifact.

Has anyone else observed this behavior of the HC7 or HC9? I'm curious if someone else can duplicate it as well using their camera.

I think you have a spec inside the camera.

On 60 shutter you have a higher depth of field when there is allot of light coming in but on auto the little cameras tend to spin the shutter up instead of closing the iris down so giving you less depth of field and so it does not focus on it. Put it on 120 shutter speed and do the test again.

I get the same if I have a spec on the inside of my port when shooting up into the surface-sun and the iris is maxed out at F11.

Thanks Wags.. I wonder if its dust on the sensor. I'm not sure if its worth sending to Sony for them to try to clean, I fear they might make things worse.

Thanks Wags.. I wonder if its dust on the sensor. I'm not sure if its worth sending to Sony for them to try to clean, I fear they might make things worse.

I had a similar problem with two blobs showing up. At first I didn't see anything on the inside of the port but looked again in very bright light against a white surface and saw two specs. I couldn't believe how tiny they were. Look again at the inside of your port REAL closely and see if there is anything there.

I agree with Mr. Wags.. I think that I have a dust spec inside my camera, either in the optics, or on the sensor itself.

I get this spot when the camera is NOT in the housing as well (so.. its not the port).

Oh well.. Sony claims, claims, that I can return if for cleaning for $225 (still in warranty for parts).

However, I'm not sure if its worth cleaning, as only shows up on really high lighting scenes... (and my fear is that the Sony techs will introduce more dust during their cleaning attempt than they will remove).

I did some more tests and the spot appears at other shuttter speeds, 90th, 125th, but it just depends on how small the aperature is and how bright the scene being shot. It only appears on very small aperatures.