AAArrrrgggghhhh 100-400L speckles everywhere. No dust...?

[Adam Hicks]

This is driving me nuts (said the pirate with the steering wheel on his crotch)

This lens is brand spankin' new. A few weeks old at best. I put a filter on it the second it came out of the box.

If I shoot blue sky I have spots on the screen. It's not the sensor. The same spots were in the same places on my DRebel and now on my 20D, so I know it's the lens (the only common component here.)

Problem is the same with and without the Canon UV filter, and the lens and backlens are dust free. I can hold it to the light and look through the lens, etc and I really can't see anything wrong or any real dust on the lens.

Even if it were a little dust, would it show like this? I can make fences at the zoo disappear but not this crap. Very frustrating!

http://www.golilm.com/photography/100400Lspecks.jpg

Here I hit the Auto Levels in CS to bring it up and exagerate it. But whoa!

http://www.golilm.com/photography/100400Lspecks_withPhotoshopCDAutoLevel.jpg

Mind you when there's not a lot of light blue sky in the image, you can't see these things, and with any amount of dark color the lens takes simply awe inspiring images. What should I do next? The lens was purchased from B&H.

Any advice is appreciated!
Adam

[iwatkins]

Have you cleaned the front lens element at all ? Might be worth a try. What the images shows looks more like water spots than dust (i.e. very uniform size). I would simply give the front element a good clean with fluid.

Chers

Ian

[Adam Hicks]

Well crap. I hate it when I lie. I just tried the exact shots outdoors with my Tamron on the camera and got the same results. Here's what's strange -

Never had the problem until the 100-400 arrived and then these spots showed on the DRebel. Got the 20D and the same problem. Could it be that the 100-400 had dust or some particles IN it that were forced into the camera body / sensor? My 20D is way too new to have these kinds of spots, and they're really identical to the problem I had when it was on the rebel. I need to go back and look at some of the rebel spotty shots. I hate to try and clean the sensor on this 20D being this new, but it looks like I have no choice. The rebel went 10 months without this problem until I put the 100-400 on.

Adam

[Adam Hicks]

Follow up - sure enough it was the sensor. I cleaned it with a cleaning cloth and a very small amount of fluid and it looks 90% better now. Not 100% perfect but darned close.

I did notice that at longer shutter times the problem is more pronounced... when I shot an F22 shot, it looked TERRIBLE! F2.8-F10 wasn't noticable. I never shoot over F10 anyways, but it's amazing how smaller apertures show every speck of dusk and dirt on the sensor / lens /
filter!

At least I can live with this for now. We'll see how long before it happens again. It almost looked like the lens had lightly sprayed oil or something onto the sensor. Weird.

Adam

[Belmondo]

Adam:
I'm glad you we able to improve the problem with your sensor dust. There have been volumes written about the proper way to clean a sensor, and the way you chose is very risky. For future reference, use the search engine to find some of those articles. You can easily damage the sensor, and it's an expensive repair that's best avoided.

Good luck

Tom

[Adam Hicks]

I've seen the card with the cleaning paper / cloth method, which I sort of emulated. I didn't apply any pressure at all to the sensor, just sort of brushed across to remove anything that was sitting freely on the sensor or held by static. I used a soft lens brush blower as well and it seems to have fared fine. I was very carefull as I certainly do NOT want to be mailing off my 20D anytime soon!

Thanks,
Adam