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My Canon 28-135 is dirty.

rivan

rivan

Diamond Member
I've somehow gotten dust inside the front element on my 28-135. What are my options? Send to Canon? Trust a local shop?
 
Try zooming in and out several times as fast as you can a.k.a the 'pumping method.'
If that doesn't work, just use it as it is? The dust inisde of front element wouldn't do any harm on IQ.
Sending it to a repair shop to remove dust seems.....too much. For a zoom lens, having dust inside is something you just have to live with.

Anyway, how big is that dust or how much of dust do you have in there?
 
Originally posted by: Deadtrees
Try zooming in and out several times as fast as you can a.k.a the 'pumping method.'
If that doesn't work, just use it as it is? The dust inisde of front element wouldn't do any harm on IQ.
Sending it to a repair shop to remove dust seems.....too much. For a zoom lens, having dust inside is something you just have to live with.

Anyway, how big is that dust or how much of dust do you have in there?
Click to expand...

Large image: It's bad.
 
Dust is on the sensor not the lens.
Try sensor cleaning using a blower (Do NOT use canned air spray thing.) If that doesn't work, take it to an any service center nearby you.


BTW, don't use such high aperture value. Doing so degrades image quality due to lens diffaction ( http://www.luminous-landscape....es/u-diffraction.shtml )
I guess you wanted to have deep FOV but f/16 was way too much: not only you lose IQ but also the dust on the sensor becomes a lot more visiable.
 
It's not the sensor - images taken with either of my other lenses attached have no such spots.

As for the image, it's one my wife took - it just happened to be one that showed off the dust well.
 
Originally posted by: rivan
It's not the sensor - images taken with either of my other lenses attached have no such spots.

As for the image, it's one my wife took - it just happened to be one that showed off the dust well.
Click to expand...

Check the lens on the back of the lens assembly. Dust on this lens should have the largest effect on IQ. Can you see major dust in the front element corresponding to the dust seen in the picture?
 
Rear glass is spotless. I can see a big speck of crap that rides on what appears (hard to tell really) the highly curved front element. Hard telling if that's my culprit, but it'd be in roughly the right spot, I think.
 
Originally posted by: rivan
It's not the sensor - images taken with either of my other lenses attached have no such spots.

As for the image, it's one my wife took - it just happened to be one that showed off the dust well.
Click to expand...

because it was a small aperture. an aperture of f/5.6 or greater won't show the dust very much, unless the dust is large.

try with your other lenses, taking photos a clear blue sky, also at f/11 or f/16.

and I would like to echo Deadtrees: DO NOT USE CANNED AIR to clean the sensor. if you mess up, it will leave a residue on your sensor, which is very very bad for image quality.
 
Originally posted by: rivan
It's not the sensor - images taken with either of my other lenses attached have no such spots.

As for the image, it's one my wife took - it just happened to be one that showed off the dust well.
Click to expand...

Trust me, it's the sensor. No matter what kind of dust you have in the lens, it just wouldn't appear like that. Even if you put a huge black dot on a lens, it just doesn't appear like that. Even if you crack the front element, all you'd see is a bit soft image. I mean, if it's the lens, you would see it on your viewfinder in the first place.
If you didn't see those spots using other lenses, it's probably because less apertuer value was used. Regarding that matter, try using f/16 on all the other lenses you have.


 
Originally posted by: Deadtrees
Originally posted by: rivan
It's not the sensor - images taken with either of my other lenses attached have no such spots.

As for the image, it's one my wife took - it just happened to be one that showed off the dust well.
Click to expand...

Trust me, it's the sensor. No matter what kind of dust you have in the lens, it just wouldn't appear like that. Even if you put a huge black dot on a lens, it just doesn't appear like that. Even if you crack the front element, all you'd see is a bit soft image. I mean, if it's the lens, you would see it on your viewfinder in the first place.
If you didn't see those spots using other lenses, it's probably because less apertuer value was used. Regarding that matter, try using f/16 on all the other lenses you have.
Click to expand...

Will do, thanks for the guidance.

Originally posted by: soydios
Originally posted by: rivan
It's not the sensor - images taken with either of my other lenses attached have no such spots.

As for the image, it's one my wife took - it just happened to be one that showed off the dust well.
Click to expand...

because it was a small aperture. an aperture of f/5.6 or greater won't show the dust very much, unless the dust is large.

try with your other lenses, taking photos a clear blue sky, also at f/11 or f/16.

and I would like to echo Deadtrees: DO NOT USE CANNED AIR to clean the sensor. if you mess up, it will leave a residue on your sensor, which is very very bad for image quality.
Click to expand...

Thanks for the help, I'll clear 'er out tonight.
 
Some guy tried to offer me $200 less for a lens I was selling because it had some dust on the inside of the front element. I tried explaining to him that it had no effect on image quality, but he wouldn't listen, so I told him to take a hike. He then put on some boots and began walking towards a mountain.
 
So last night I sat down, flipped up the mirror and looked at the sensor. I didn't see a damned thing. I blew it out anyway, took a couple shots and nothing's changed.

Is there maybe crap on the inside of the back element/back end of my lens? The coating on it makes it pretty difficult to see inside. I also tried the pumping method mentioned above to no effect.
 
Originally posted by: rivan
So last night I sat down, flipped up the mirror and looked at the sensor. I didn't see a damned thing. I blew it out anyway, took a couple shots and nothing's changed.

Is there maybe crap on the inside of the back element/back end of my lens? The coating on it makes it pretty difficult to see inside. I also tried the pumping method mentioned above to no effect.
Click to expand...

The next step would be either using a sensor cleaning kit or having it professionally cleaned. Using a rocket blower won't always get the dust off.
 
Originally posted by: rivan
So last night I sat down, flipped up the mirror and looked at the sensor. I didn't see a damned thing. I blew it out anyway, took a couple shots and nothing's changed.

Is there maybe crap on the inside of the back element/back end of my lens? The coating on it makes it pretty difficult to see inside. I also tried the pumping method mentioned above to no effect.
Click to expand...

Did you try shooting at a high aperture with a different lens?
 
Originally posted by: PurdueRy
Originally posted by: rivan
So last night I sat down, flipped up the mirror and looked at the sensor. I didn't see a damned thing. I blew it out anyway, took a couple shots and nothing's changed.

Is there maybe crap on the inside of the back element/back end of my lens? The coating on it makes it pretty difficult to see inside. I also tried the pumping method mentioned above to no effect.
Click to expand...

Did you try shooting at a high aperture with a different lens?
Click to expand...

Ah, no. Will tonight.
 
Originally posted by: rivan
So last night I sat down, flipped up the mirror and looked at the sensor. I didn't see a damned thing. I blew it out anyway, took a couple shots and nothing's changed.

Is there maybe crap on the inside of the back element/back end of my lens? The coating on it makes it pretty difficult to see inside. I also tried the pumping method mentioned above to no effect.
Click to expand...

Some dust are sticky and might be impossible to get out with a blower. In that case, you need one of those dust removable kits or professional cleaning service as mentioned by shocksyde.
One thing I can assure is that it's not your lens. Dust in the lens causing such spots is just not optically possible at all.
 
Originally posted by: rivan
So last night I sat down, flipped up the mirror and looked at the sensor. I didn't see a damned thing. I blew it out anyway, took a couple shots and nothing's changed.
Click to expand...

Also remember that you take a picture upside down, then the cameras software corrects it for you. So them dust bunnies you see at the top of your frame are actually on the bottom of the sensor.

If I where you I wouldn't worry about it unless you use higher F-stops a lot. Try shooting a well lit white piece of paper at F5.6, F8, F11, F16 and see when the spots start showing.
 
Did you clean out the dust inside your computer? Sometimes that shows up in Photoshop.
 
Originally posted by: jpeyton
Did you clean out the dust inside your computer? Sometimes that shows up in Photoshop.
Click to expand...

Maybe it's a virus? Wait, that's unpossible, I'm on a Mac.
 
Without a doubt - that's sensor dust. You won't (can't often) see it, a rocket blower sometimes doesn't get it at all. The sensor will grab onto dust sometimes as it has a static charge. Next step is to take her to a good photo shop (not ritz) and have them use cleaning fluid to clean it. That'll get rid of the dust. Or send it off to Canon.

 
Originally posted by: shocksyde
Some guy tried to offer me $200 less for a lens I was selling because it had some dust on the inside of the front element. I tried explaining to him that it had no effect on image quality, but he wouldn't listen, so I told him to take a hike. He then put on some boots and began walking towards a mountain.
Click to expand...

I got a Nikkor AF 80-200mm f/2.8 (non-D) for $341 on eBay a year and a half ago because it has a quarter-inch scratch on the front element. 🙂
 
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