Spots showing up with new 70-200 f/4l

Hi all,
I just received my new, first and probably only L lens today and noticed that when shooting at the sky there are some dark spots showing up. Is this something that I should expect or is there something wrong...Any input would be appreciated. Thanks!

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They are dust spots on your sensor; do a search on here for sensor cleaning and you'll find a ton of info about what they are and how to get rid of them.

You'll notice that they go away the wider your aperture; they're most noticeable as you stop down towards f/16-22.

Perfectly normal - though often annoying - part of owning a DSLR.

Dust and it's got nothing to do with your lens

Though it's surprising to see a blotch like that at F/6.3

phreeky wrote in post #10334922
Though it's surprising to see a blotch like that at F/6.3

Not really - just that 6.3 makes it appear bigger than it really is
Take the same shot (or just blue sky without the plane) at F22 and it will appear as more of a black speck

Hey all,
Thanks for the help. It's the sensor. I thought I had cleaned it really well last time but I guess not. How often should a sensor be cleaned? I don't usually shoot at the sky but was playing with my new lens and my heart dropped when I saw the spots. I have the battery charging right now so I can clean the sensor later today.
-Mary

First, try putting the camera into "manual clean" mode and use a bulb-blower to try to blow off the dust. If this doesn't work, you need to have it wet cleaned.

To have it wet cleaned, you have to send to Canon or another service center or buy a kit to do it yourself. Many use the Copperhill kit to do this.

I worked on cleaning the sensor and got most of the large stuff off. Still a few spots on the edges but much better than it was. I'm going to Calumet tomorrow for a Canon lens seminar they're having and may take the body with me and have them clean it again, prolly a better job than I'm doing. I'm just really glad it wasn't the lens.
-Mary

Here is your problem,,you changed your lens..



Never ever change lenses

Too funny yogestee! Although, I did change my 18-55 kit lens for the 70-200 f/4L. LOL!

Anyway, there is some truth in this lens change matter.

Like small apertures, longer focal lenghts also tend to make dust spots sharper. Before the 70-200, your longest focal lenght was 55mm. No surprise that you suspected the new lens.

I just cleaned a four year old Nikon D80 with the Copperhill kit I bought a while back. You should have seen the dust on the sensor... WOW!

After several cleanings with the wet kit, most of the dust was gone. Then she pulled out a Pentax O-ICK1 Image Sensor Cleaning Kit that her husband had purchased a while back. We tried it out on the stubborn spots that the Copperhill wet method was not getting.

After only one attempt with the Pentax kit, the sensor was spotless. I may have to go buy one of these things.

I got the sensor all clean and now the pics are great! I love my new lens-LOL