Dust inside lens

dsterrito

I apologize if this has been asked and answered.

I have a 28-70L 2.8. Picts are sharp, almost. It seems the right side of the team shots goes soft. Still passable with a little work but probably going to get worse.

There is dust inside and on the elements. I need to get it taken apart and cleaned up and checked out.

Any suggestions would be greatly appreciated.

Dave

photogmomma

dsterrito wrote:

I apologize if this has been asked and answered.

I have a 28-70L 2.8. Picts are sharp, almost. It seems the right side of the team shots goes soft. Still passable with a little work but probably going to get worse.

There is dust inside and on the elements. I need to get it taken apart and cleaned up and checked out.

Any suggestions would be greatly appreciated.

Dave

I'm no help. I have a 28-105mm and I have a spec of dust on the lens - inside. No way to get to it or get rid of it and it's in ALL my shots. I did a tiny bit of research, but found that I needed to send it back to Canon and it would probably cost about half the price of the lens. Since this isn't an L lens, it's just not worth it for me.

But for you, it just might be...

One thing I do to clean the contacts between the camera and lens is just use a pencil eraser. Works wonders. Just be careful not to get the "shavings" into the camera or on the lens. Yuck.

I'll be watching to see if anyone else has ideas!

ziggy53

photogmomma wrote:

... I have a 28-105mm and I have a spec of dust on the lens - inside. No way to get to it or get rid of it and it's in ALL my shots. ...

A "spec" of dust inside a lens can cause a bit of light dispursion, but it cannot form a visible shape. If you have a visible spot, consistantly showing on multiple images, it's on the filter in front of the imager, and should be easily removed.

http://www.dgrin.com/showthread.php?t=8350

ziggy53

ziggy53

dsterrito wrote:

I apologize if this has been asked and answered.

I have a 28-70L 2.8. Picts are sharp, almost. It seems the right side of the team shots goes soft. Still passable with a little work but probably going to get worse.

There is dust inside and on the elements. I need to get it taken apart and cleaned up and checked out.

Any suggestions would be greatly appreciated.

Dave

I take a small single LED flashlight and shine it through the ends of a lens. A point source of light makes it easy to see internal problems with the lens elements, and get a rough idea of their imact on image quality.

Do the test on a few lenses to get a feel for what a clean lens vs a dirty lens looks like.

If it appears that there is a considerable problem internally, then I do recommend that you send the lens to Canon for cleaning.

This may not explain one side of the images being soft. You may also need to check to see if the lens needs alignment as well.

ziggy53

mr peas

From what I've heard, a minute amount of dust in the lens, for ex. just a few specs, shouldnt affect your image quality. It might cause a slight loss in contrast, but a spec shouldnt affect it much at all.

However, a spec or two or more on the CMOS/CCD sensor will definitely make a large difference on your images. Try looking at your sensor, I'm going to bet that there's dust on one of the sides.

If its not on the sensor and it is the lens, it has to have a lot of dust to make it very apparent.

Can you provide photos of the lens and sample photos with the blurr?

pathfinder

A few specs of dust inside a lens on the surface of the internal elements has almost no effect on an image, and certainly will NOT cause a visible spot in the image or the print of the image.

Keep the front and back of the lens relatively clean with a lens brush and ignore a few dust specs inside the lens. If you have so much dust that it is almost continuous inside the lens ( you've been shooting motocross in a dust storm for weeks ), then yes, it needs professional attention.

Dust spots in the image are from dust on the sensor surface ( the anti- aliasing filter in front of the sensor really ) as Ziggy said, and may need cleaning.

If there is only one small spot in the image, I tend to just clone it out and otherwise ignore it, as it is easier than messing with cleaning the sensor.

I do not hesitate to clean my sensors if they are grungy, but my first plan is to minimize the amount of time I spend swabbing and mopping that very expensive silicon.

dsterrito

Thanks everyone for the advice.

I am going to send it to Canon repair NJ on Monday.

I will ask them to take it apart to clean, check element alignment, and re-calibrate the lens. I guess about $200.

There is some slack in the barrels. I will ask them to check that also.

Dave