Another Dust Question

These are the first two test images I took with a recently purchased Canon 100-400 lens. Could someone confirm that I am seeing dust on the sensor and not some problem with the lens. There is one big piece near the center of each image and a bunch in the upper left corner. In the plane image, it might be hard to see but its right next to the left tail fin. Anxiously await a response I have 3 days to return the lens. Thanks.
http://i86.photobucket​.com …oxmannn_2006/mo​ondust.gif
http://i86.photobucket​.com …xmannn_2006/pla​nedust.jpg

Does it show up when you use your other lenses?

I was starting to lose light when I tried my other lens so I didn't get a real good shot, but I didn't see any. I don't know what else it could be.

Take a picture at f/22 while focused as close as possible of the bright blue sky. You want it to be as out of focus as possible. Then the dust on the sensor will be the only in focus stuff. You can also move the camera to further the blur effect. My guess is that it is dust on the sensor but it might also be a big hair on the back element as well but I doubt it.

One more thing, after you take that pic, in you editor, crank up the contrast, way up. It will make the dust bunnies pop right out.

looks like sensor dust/gunk to me.

Another question, if there is dust on the sensor would you be able to see it when you lock up the mirror and look into the camera?

Its definitely dust, but firstly check if its on your lens by taking the lens off and checking, then blowing off as much as you can and then reshooting. If its still there then its on the sensor.

Boxmannn wrote in post #2952851
Another question, if there is dust on the sensor would you be able to see it when you lock up the mirror and look into the camera?

Sometimes yes, sometimes no. Snap a out of focus pic of a bright surface at f/22. It will be very very clear.

Boxmannn wrote in post #2952851
Another question, if there is dust on the sensor would you be able to see it when you lock up the mirror and look into the camera?

Only if your eyes are really good, and the lighting is just right, and . . . .

It's a lot easier to just do what gjl711 says.

Thanks everyone. I did as you all suggested and tried all my lens at f/22 and each lens showed the same dust/junk. I didn't even need to use the image editor, I could see it when viewing the LCD image zoomed in. I'm relieved to know it was not my new lens.

You shot the plane pic at f25...It is sensor dust. But change lenses and take another blue sky shot at f22 or above and apply auto levels in photoshop just to be sure. You wont see dust on your lens normally.

Boxmannn wrote in post #2953043
Thanks everyone. I did as you all suggested and tried all my lens at f/22 and each lens showed the same dust/junk. I didn't even need to use the image editor, I could see it when viewing the LCD image zoomed in. I'm relieved to know it was not my new lens.

It's sensor dust for sure. Check out this link. "link to sensor cleaning". Also, if your looking for a kit, Micro-tools has complete kits to get you started organized by camera. Check out this link. "Link to Micro-tools"

Some personal views on Sensor cleaning.