Removing dirt from inside a lens?

[jagdpanther]

I was recently given a modified Canon 18-55mm lens and Ive recently noticed that theres a fair amount of crap which has accumulated onto the inside surface of the rear lens

Is there a way to get rid of this or is it a case of remove during PP/buy a new lens?

Ta

~S~

[Rednut05]

Screw driver et Hammer.

[_dobbo_]

Are you saying dust on the lens is visible in the final image? I'd be pretty surprised if this was the case.

[jagdpanther]

_dobbo_ said:

Are you saying dust on the lens is visible in the final image? I'd be pretty surprised if this was the case.

Yes, indeed I am

It doesnt appear to be dust, but rather large particles of something

[dc53]

Are lens's impossible (pretty much) to take apart and put back together by a Canon dealer?
Would cost a bob or two!

Failing that there's always the Dyson!

[_dobbo_]

I'm surprised by that - unless the dust appears as very large smudges on the image?

In my experience even very bad smudges or marks on the front element don't show in an image, but the back is a different story I guess.

[jagdpanther]

_dobbo_ said:

I'm surprised by that - unless the dust appears as very large smudges on the image?

In my experience even very bad smudges or marks on the front element don't show in an image, but the back is a different story I guess.

Its very large pieces of what look to be plastic debris

Ive just purchased two lenses on Ebay for £100 for the pair with UV filters

Sigma 18-50mm DC F3.5-5.6 and a 55-200mm F4-5.6 both new so it'll do the job of the EF-S lens and add some extra range in there too



until I can get myself a F1.8 50mm Prime, a 10-20mm and a 80-200mm F4 L

[heelantoe]

jagdpanther said:

_dobbo_ said:

I'm surprised by that - unless the dust appears as very large smudges on the image?

In my experience even very bad smudges or marks on the front element don't show in an image, but the back is a different story I guess.

Its very large pieces of what look to be plastic debris

How sharp are the marks in the final image? It would be very supprissing if anything in a lens showed up on the final pics.
By the time the light is recorded by the sensor anything in the lens is so difracted it would have to be pretty big to be recorded.
It's more likely to be dust on the sensor. This becomes more noticable when the lens is stopped down. It's the same reason why dust on the sensor is visible at f/13, f/22 etc but not at f2.8, f/5.6 etc.

All that is only relevant of course if you are shooting on a digi camera ;-)

[jagdpanther]

heelantoe said:

jagdpanther said:

_dobbo_ said:

I'm surprised by that - unless the dust appears as very large smudges on the image?

In my experience even very bad smudges or marks on the front element don't show in an image, but the back is a different story I guess.

Its very large pieces of what look to be plastic debris

How sharp are the marks in the final image? It would be very supprissing if anything in a lens showed up on the final pics.
By the time the light is recorded by the sensor anything in the lens is so difracted it would have to be pretty big to be recorded.
It's more likely to be dust on the sensor. This becomes more noticable when the lens is stopped down. It's the same reason why dust on the sensor is visible at f/13, f/22 etc but not at f2.8, f/5.6 etc.

All that is only relevant of course if you are shooting on a digi camera ;-)

aye:

turns out it was crap on the censor as today I made a makeshift cleaning kit including a cotton bud with a lens wipe wrapped around it....pretty damn effective it was too and it got rid of the problem...................so far

[heelantoe]

jagdpanther said:

aye:

turns out it was crap on the censor as today I made a makeshift cleaning kit including a cotton bud with a lens wipe wrapped around it....pretty damn effective it was too and it got rid of the problem...................so far

Careful with those, if there are any big bits of crap they just pull them across the sensor leaving a nice long scratch mark, trust me i've seen it happen
Thing i use is an Arctiv Butterfly. Ignoring the stupid name its a really good tool for getting rid of dust and doesn't use any liquids.
It's a staticly charged brush that wipe across the surface of the sensor a couple of times. gets rid of 99% of dust, is really easy to use and you don't need to buy swabs, fluid etc etc....

[jagdpanther]

heelantoe said:

jagdpanther said:

aye:

turns out it was crap on the censor as today I made a makeshift cleaning kit including a cotton bud with a lens wipe wrapped around it....pretty damn effective it was too and it got rid of the problem...................so far

Careful with those, if there are any big bits of crap they just pull them across the sensor leaving a nice long scratch mark, trust me i've seen it happen
Thing i use is an Arctiv Butterfly. Ignoring the stupid name its a really good tool for getting rid of dust and doesn't use any liquids.
It's a staticly charged brush that wipe across the surface of the sensor a couple of times. gets rid of 99% of dust, is really easy to use and you don't need to buy swabs, fluid etc etc....

sounds like another future investment is on the horizon