cleaning crud inside a lens?

cabbey

So my EF-S 10-22 seems to currently be a casualty of the dgrin shootout. While we were doing a lens change on the side of dirt/gravel road, two cars went screaming past. Try as I did to protect my gear from the dust, I thought I had crud on the rear glass of this lens. Now I've gotten home and tried to clean it, and inspected it with light in a dark room... I removed some dust, but there are a bunch of pieces still visible, and I don't think they're on the outside of the lens.

Does anyone have advice on getting this solved? Any guess at what Canon would charge to do it?


(p.s. as anyone that was at the shootout could guess, the two cars in question were driven by Shizam and Andy. :boid I blame Shizam for the damage though, Andy was actually slightly slower / more controlled :huh , and also the second one, by the time he went by I had everything put away better. )

Andy

glad I'm 'controlled'

Is it under warranty still?

cabbey

Andy wrote:

glad I'm 'controlled'

Is it under warranty still?

I very highly doubt it, I bought it in June 2006. They only have a 1 year warranty if I recall correctly, so it is long out of coverage. I expect I'm going to have to pay to get it fixed. :cry

kdog

I doubt the car episode had anything to do with getting dirt in your lens. It was probably there all along, but you probably never looked at it that closely before. Zoom lenses suck dust, some more than others. If you examine other zooms you might have, I'll bet you see dust in them as well if you look closely. It won't show up in your shots unless there's a ton of it, so don't worry about it. Some day if the lens needs to get repaired, you can get it cleaned out then.

cabbey

kdog wrote:

I doubt the car episode had anything to do with getting dirt in your lens. It was probably there all along, but you probably never looked at it that closely before. Zoom lenses suck dust, some more than others. If you examine other zooms you might have, I'll bet you see dust in them as well if you look closely. It won't show up in your shots unless there's a ton of it, so don't worry about it. Some day if the lens needs to get repaired, you can get it cleaned out then.

This is showing up in the shots, otherwise I wouldn't have noticed.

Specifically, shots taken with that lens BEFORE they drove by are clear. Shots taken with that lens 20 minutes later when we were at the next location and I put it back on, are filthy. Every shot with that lens from there forward has the dirt in it.

Tango

well i gotta say... now you will look for cars coming down the road prior to lens changing??? right???

a cleaning will run you about $150 - $200

good luck though, ive had teenagers cook my cheeseburger and fries with more care than Canon service technicians repair on one of my lenses...

i would believe they will clean you up ok, just dont expect perfection...
and take close pics of your elements prior to sending.
some rave for Canon repair services, but i simply can not...

Tango

oh...and btw hows your sensor? i would have imagined that got most of the dust of the drive by....

pathfinder

Dust inside lenses generally causes a decrease in contrast and haze, but not specific dust mote images seen in the image. And it takes a fair amount to cause ANY visible change in the image.

Are you sure you are not seeing crud on your sensor? I would suspect that sharp defined spots in your images are from dust on your sensor ( anti-aliasing filter really).

An open camera body in a dusty environment will definitely pick up dust on its sensor. I would examine this very carefully before shipping off a lens for service. Shoot a frame of the sky at f16, and then examine the image in Photoshop after an Auto Levels, with a different lens, and see if you don't still see the dust motes.

One way of repairing lenses for scratches on the front element years ago, was just to paint them black - no light passed through the damaged area, and the effect on the image was negligible. Debris inside lenses is usually even less noticeable in an image than dust on the surface of the front element.

Biffbradford

How about a stream of forced air? (other than just blowing into it )

One of those little hand pumpers or a small air compressor (turn down the PSI). Even make a small hose attatchment that will fit inside the lens.

Just thinking out loud here . If it found a way in, it can find a way out!

cabbey

Thanks for the thoughts folks.... good news/bad news update.....

I was about to say the sensor was fine, and that the new lens was already in place when Sam came by... confirmed by the simple fact that images taken with my other lens have been just fine. BUT it turns out they're not "just fine" they just aren't impacted the same way. (more on that later)

We did actually look for cars, and even waited for one to go by before starting the change. It was the rate of speed that Sam passed at that caught us by surprise. It's a rough washboarded road... no one in their right mind would have been hauling ass at that rate. (I've confirmed it was a white knuckle ride, it turns out my wife was IN the van.)

I've used canned air to clean the lens, that's what I was waiting to get back home for. when it didn't get everything I went wet and even that didn't get all of it. (though both helped.)

So here's the sequence of the cleaning:

hand blower (in UT) helped some, but not much.
canned air (back home) followed by blue sky shot... also helped some, but not much.
viewed the optics with a light... ick.
wet cleaning, followed by canned air....
viewed the optics by light... much better, but still some obvious gunk

Now the astute reader would point out at this point much of what pathfinder said in his first sentence. (Nice meeting you in UT btw!) and remind me to go do another blue sky shot. I didn't think that quick, and posted here instead (before the wet cleaning actually). A local friend suggested the blue sky shot. That revealed that the worst issues are GONE. The wet clean on the lens got the last couple bits of junk off. For comparison purposes, I took a second blue sky shot with a known clean lens. (it wasn't even on the trip.) The two shots, plus a third from my other lens, show the same pattern of junk.

I think at this point I've got the lens about as good as it's going to get. And even though there are 5 very obvious bits of gunk on the inside of the rear element (or at least that's where they look to be) I'm going to call cleaning that lens 'done'.

But that leaves me with a handful of darkish spots. (which blend into most images, which is why I didn't notice it on the shots with my other lens while on the road, got them home and brought them up on my good screens and much of the last day and a half of shooting are negatively impacted. :cry )


Click for full size - Uploaded with plasq's Skitch

I've put the camera in sensor cleaning mode and looked at the sensor... I don't see anything on the glass covering it. I did do a force air cleaning.... didn't make any difference. Thoughts?

aktse

Sorry, but that just looks like sensor dust to me.


This is my 40D at one point earlier this year.


It cleaned up with the copper hill method.

edit: -- shouldn't post and work at the same time since gibberish comes out. Oops.

I was told never to use compressed air to clean a sensor since they can contain liquid propellants that can gunk-up the sensor.

aktse

And they're some really good post on dgrin.

Scott's before/after copperhil

This is a very, very long thread, but also lots of useful info.

I came to Moab with a dust blower and an arctic butterfly for this reason, but never used it during the trip. Copperhill works better for me than the blower/butteryfly combo, but I can't easily travel with it. Copperhill even removed grease from Skippy's sensor!

You mentioned that you used a wet cleaning method. Which one did you use? And how many times? It usually takes me about four to five cleanings before most of my gunk is gone.

Now, I'm trying to get sand off outside of the lens and focus/zoom rings.

Good luck.

Cuong

cabbey wrote:

...For comparison purposes, I took a second blue sky shot with a known clean lens. (it wasn't even on the trip.) The two shots, plus a third from my other lens, show the same pattern of junk.
...I've put the camera in sensor cleaning mode and looked at the sensor... I don't see anything on the glass covering it. I did do a force air cleaning.... didn't make any difference. Thoughts?

Its sound to me like you have dust bunnies on the sensor. Unless you looked at the sensor with one of those magnifying sensor scopes, I doubt that you would be able to spot any dust on it with naked eyes. I'd recommend the Copperhill sensor wet cleaning method for this situation.

Cuong

ziggy53

Cabbey,

The sensor needs cleaning. Clean the sensor.

The lens may need cleaning but the marks in the image are all from the dust and stuff on the sensor.

jogle

Sensor boogers may show up more on this lens if you use it often at smaller apertures.

because the rays come in more parallel with small apertures, sensor boogers show up darker and more defined.

cabbey

aktse wrote:

And they're some really good post on dgrin.

Yeah, I was just starting to dig into the search results from sensor cleaning. I suspect I'll be going the copperhill route.

You mentioned that you used a wet cleaning method. Which one did you use? And how many times? It usually takes me about four to five cleanings before most of my gunk is gone.

I'm not sure what the "name" of this process would be... it's just what works for me. It is based on a cleaning process we used for theatrical lighting lenses when I worked in the theatre.

zeiss lens cleaning wipes, wiped center to edge. If there are any stubborn spots, they get a small drop of isopropyl alchohol directly on the glass (yes, I know, it's bad... wah. it works.) which is then worked with the cloth in a spiral (i.e. put a finger on it and turn the finger 1/4 turn). I usually repeat this 3 times with a breath of compressed air between to dry any remaining solution.

This process has worked well for me to remove stubborn things that just a brush/blower/compressed air haven't been able to.

The only exception to this was one instance when I got a giant glob of sticky mud thrown on my lens, in that case the UV filter I had on came off and was rinsed off with a garden hose and warm water with a dash of dish soap.

[qoute=]I was told never to use compressed air to clean a sensor since they can contain liquid propellants that can gunk-up the sensor.[/quote]

Yeah, I've heard the same, and they're right, the "compression" in canned air is from liquids, not "air". But there are three things that you can do to minimize the risks...

1. don't shake the can, or even tip it at an angle. Keep it upright.

2. don't treat the trigger as an on/off switch... be gentle. I don't think I've ever done more than 1/2 open when cleaning my camera. Anywhere on the camera, lens included. Feel it against your cheek or palm... even just a 1/2 blast is far more powerfull than a blower brush.

3. use a bent tube to blow "up" into things. I forgot where mine came from, but I've moved it from can to can for years. It has a 135 degree angle about 1/3 of the way down that makes it IDEAL for blowing up into things to allow dust and what not to settle out.

KD5NRH

cabbey wrote:

zeiss lens cleaning wipes, wiped center to edge. If there are any stubborn spots, they get a small drop of isopropyl alchohol directly on the glass (yes, I know, it's bad... wah. it works.) which is then worked with the cloth in a spiral (i.e. put a finger on it and turn the finger 1/4 turn). I usually repeat this 3 times with a breath of compressed air between to dry any remaining solution.

This process has worked well for me to remove stubborn things that just a brush/blower/compressed air haven't been able to.

Yep, this method will even take care of the problem when you have a sudden sneeze while checking your front element. Don't ask how I know this. It will also work on the innards, but unless you've had a lot of practice getting into cheap and/or useless optics before, I wouldn't recommend trying to get into expensive stuff.

jdryan3

aktse wrote:

Copperhill even removed grease from Skippy's sensor!

And we all know how bad the grease from Oz can be!

aktse wrote:

Now, I'm trying to get sand off outside of the lens and focus/zoom rings.

I definitely noticed a difference as the shootout progressed. You could feel the dirt as you focused.