Specks inside lens? Advice needed

Hello, I'm relatively new to this forum and I'm just an amateur in terms of photography, but I enjoy it more and more.

I recently purchased a 300 2.8L lens off ebay. The seller has excellent feedback and the lens looks to be in excellent shape and appeared to take good pictures (of the couple of sample pictures I took).

After having it for about a week and getting ready to use it seriously, I decided to clean the lens and under an overhead light, when I look down through the lens (the big end ), there are specks on what looks like the next piece of glass inside the lens.

I would love for someone to tell me this is normal, but if not, what could this be? What could have caused it and can it be fixed?

I'm sorry if this is naive question, but I tried doing a search and didn't have any luck. Hopefully someone here has seen this issue or maybe it's even a non-issue.

--Mike

It is normal. particles and dust get inside the glass. It won't have any affect on your pictures so no need to "fix" it.

^^^True. I have a speck in my 70-200 2.8 and it doesn't have any affect on my images(from what I can tell); but on the other hand, I have 3 specks in my 60mm 2.8 macro, and they showed up in every picture. I just sent it out to Canon to have it cleaned.

Thanks for the replies guys. That makes me feel a little better, but the thing that worries me is that it's not a few specks, but hundreds (although they are very tiny and I can only see them if the overhead light is shining directly down into the lens).

Hangbot, if you don't mind, I'm curious as to about how much it cost for Canon to clean?

I wouldn't worry about them, but I took the lens to Laguna Seca for the MotoGP race and I was totally unhappy with my overall results. However, I was using teleconverters for the first time (on a 20D body), so they probably contributed to my bad results (that and my bad technique).

Stupid me didn't take many action shots without the teleconverters since Laguna is really amateur photographer unfriendly, so I don't have anything to compare to.

Using the teleconverters, the lens did not want to focus easily. As soon as I hit the button to focus, it would completely unfocus before trying to focus, rather than simply snapping to focus. Probably more to do with using a 20D body and teleconverters than with the lens itself, but I started thinking about the specks too.

Any input/advise is definitely welcome!

Going to an AMA race in a couple weeks and I'll do some more experimenting.

Thanks again!

--Mike

i got a bunch of dust in my front element part of my 50-500 and I never seen them in any of my shots.

since the 60mm is under a year old, Canon service was free. FedEx on the otherhand, wanted $12 to ship it

Are you kidding? I've shot though chain-link fence with a 300 2.8 and it hasn't shown in the pictures! A couple of dust particles are normal and generally won't affect your image quality on such an impressive piece of glass.

mike1515 wrote in post #3691349
Using the teleconverters, the lens did not want to focus easily. As soon as I hit the button to focus, it would completely unfocus before trying to focus, rather than simply snapping to focus. Probably more to do with using a 20D body and teleconverters than with the lens itself, but I started thinking about the specks too.


--Mike

Did you have the focus set to 6.4m-infinity?

If not it'll go through the 2.5m-infinity range slowing it down a bit. I've used mine with the 1.4TC on a completely overcast rainy day under tree cover and it still focused pretty dang fast.

Yep, just realized my 24-105 has one speck in between the lenses and yes, I sure see it with some pictures, not all!!! Off it goes to Canon.
$12 to ship? Man, that's cheap!

mike1515 wrote in post #3691349
Thanks for the replies guys. That makes me feel a little better, but the thing that worries me is that it's not a few specks, but hundreds (although they are very tiny and I can only see them if the overhead light is shining directly down into the lens).

Hangbot, if you don't mind, I'm curious as to about how much it cost for Canon to clean?

I wouldn't worry about them, but I took the lens to Laguna Seca for the MotoGP race and I was totally unhappy with my overall results. However, I was using teleconverters for the first time (on a 20D body), so they probably contributed to my bad results (that and my bad technique).

Stupid me didn't take many action shots without the teleconverters since Laguna is really amateur photographer unfriendly, so I don't have anything to compare to.

Using the teleconverters, the lens did not want to focus easily. As soon as I hit the button to focus, it would completely unfocus before trying to focus, rather than simply snapping to focus. Probably more to do with using a 20D body and teleconverters than with the lens itself, but I started thinking about the specks too.

Any input/advise is definitely welcome!

Going to an AMA race in a couple weeks and I'll do some more experimenting.

Thanks again!

--Mike

It's normal to have a bit of dust floating around inside, especially if it's a used lens that has been sent you via post... vibrations will loosen up any settled dust in there. Might be an idea to have it cleaned though just in case it is the beginnings of a fungal growth... better to be safe than sorry and it shouldn't cost much anyway.

As far as your dissapointing results at Leguna Seca, I'd put that down to "inexperience". I recently bought a Sigma 100-300 f/4 and with a Canon 1.4x TC strapped on (effectively 420mm) it is very difficult to get sharp shots below 1/500 shutter without a monopod or tripod. Which teleconverters were you using?

20DNewbie wrote in post #3695050
Did you have the focus set to 6.4m-infinity?

If not it'll go through the 2.5m-infinity range slowing it down a bit. I've used mine with the 1.4TC on a completely overcast rainy day under tree cover and it still focused pretty dang fast.

20DNewbie, yes, I had it set for 6.4-Infinity, so that wasn't it. I was using a monopod and I had IS on and set to Stabilizer Mode 2, so I could pan if I wanted, but maybe I should have had IS off... I'm not sure.

--Mike

photobitz wrote in post #3695363
As far as your dissapointing results at Laguna Seca, I'd put that down to "inexperience". I recently bought a Sigma 100-300 f/4 and with a Canon 1.4x TC strapped on (effectively 420mm) it is very difficult to get sharp shots below 1/500 shutter without a monopod or tripod. Which teleconverters were you using?

Photobitz, I have no doubt inexperience was a large contributer. I guess I just thought with the number of shots that I took that I would luck up a little more than I did.

I was using the Canon 1.4x and 2x teleconverters and more of the latter than the former, which I am sure made matters worse.

I'm also sure, as you suggest, that my shutter speed was too low in a lot of shots.

I hope to be going to the AMA race at Virginia International Raceway next weekend, so maybe I can do some more experiementing and can improve.

Thanks for everyone's input.

--Mike

I had similar results at VIR. Almost all the pictures are out of focus (moving objects). I was using monopod. I upped my shutter speed. I used w/o teleconverters, but still very few tack sharp pictures.

I'm beginning to think it is 'my' 20D and its lack of ability in AF AI Servo mode with fast moving objects. I also have a thread under the digital camera section trying to figure this out.

I have a 1D Mark IIN on the way to me, so that should help determine whether it is the camera, the lens... or me, and what gets sent off to Canon for repair. Do they accept people?

Here's a picture of the specks on the inside of the lens. A lot of people say this is normal, but I wonder if this much is normal? Just curious.

--Mike1515

Oh... that don't look so good. I had an old Sigma 400mm that looked similar. I believe it is a fungal/bacterial attack. Rather than big spidery growths that you usually see with mould it's just little pinhead-sized dots. Not sure how much it affects IQ or focus ability though - probably depend on which element is affected. Recommend getting it serviced/cleaned since it will likely only get worse and may eat away the coatings of the elements.