Dust on my sensor????

[Spinning]

I have a cannon 50D. I use it a lot.....love it. But I noticed last summer some small greyish colored spots on my photos especially when I was shooting summer diving and many of the shots were of the sky. In Jan it got really bad. So I took it and had it cleaned.
the marks are back. Is this something that should happen so soon? Or do you think the place that cleaned my camera didn't do a great job and I just didn't notice because I wasn't shooting out door diving?

 

[photo_chick]

If it really was dust on the sensor to start with then it shouldn't come back in the same place after cleaning if they did it right. If it's in a different place either they didn't clean it well and left dust in the body, there is dust in your lens and it's redepositing gunk in your body, or you should examine your method for changing lenses.

Post an image. Much easier to tell what's going on if we can see what it looks like.

 

[HPS3]

Spinning, I change lenses frequently and have had dust on my sensors on both my D5100 and Nex 7. There were no local camera shops around me that clean sensors so I learned to do it myself. It's fairly easy. You can search it on YouTube. I've gotten in the habit of using a rocket blower really often. I hold my camera face down with the sensor exposed and blow it out with the blower. Its funny that my D5100 had more problems with the dust than my Nex 7 because the Nex's sensor is exposed without a mirror.

To check for sensor dust, take a photo of something white(door,wall,paper) using a narrow aperture(16-22). You'll more than likely see gray spots.

 

[Spinning]

The marks are not in the same places as before or as many. I am just amazed it took 2 years or so before I had to have the camera cleaned and now it was just a few months. I hardly have changed lenses. I only own 2 at this point.
I will lool for a video. I use to clean my old 35MM all the time but I am a little more timid about cleaning this one myself.

 

[mom2rtk]

Someone here had trouble with the latest Nikon throwing oil onto their sensor. I know you have a Canon, but I wonder if there's any chance you have a similar thing going on? I too am perplexed by how many spots and how quickly they returned.

 

[Shutterbug]

My Canon 40D gets does get dust on the sensor as well and sometimes gunked.
If you want to see how much dust/gunk is on your sensor set your camera to the highest f-stop and shoot at a blue sky. That will def show you all the specks on your sensor.

When that happens to me first thing I do is put camera into manual sensor cleaning. This moves the mirror out of the way so you can see the sensor. I take my rocket blower and blow air at it and try to remove it all that way.
I use a diff brand of this:
http://www.bhphotovideo.com/bnh/controller/home?O=&sku=541904&Q=&is=REG&A=details

I then have a very bright led flash light I shine at angle to see if the sensor is now clear. If I still see "specks" on the sensor, I will use the blower again on it. If that doesnt do it, its more than likely oil blob or fused dust. At that point I use a sensor cleaning swab and clean it.
One swipe usually does it.

 

[HPS3]

That definitely looks like sensor dust. Try the blower method first and if that doesn't work, you can get a sensor cleaning kit. Just make sure you get the right size sensor swab.

 

[YesDear]

The dots you show on your image look like dust to me. Dust is everywhere and your sensor is not sealed. Very easy to get. You need to learn to clean it yourself. Save lots of time and money!

 

[photo_chick]

Looks like dust to me. I agree it seems really fast to get more dust if you just had it cleaned. Have you cleaned your lenses well?

I have a 50D, have had it for 3 years now, and have not had any dust issues or had to clean the sensor. And I'm not really careful when I change lenses if you know what I mean. For whatever that's worth.