JackB

I have had this ongoing problem with a new Canon Lens. I purchased a new Canon 70-300 F/4 - 5.7 IS USM ii lens in December from Adorama. The first lens had small white specs which were on the inner glass. When I extended the lens they would disappear which indicates they are on the inner glass. Thinking they should not exist on a new lens, I sent it back to Adorama for a replacement lens. I have now returned and received 3 replacements lens and I received the the 4th replacement lens today. All, have had the same problem though the current one is the least visible and none have been visible in photos taken at various apertures. I called Canon technical support and they told me I should send the lens to them for inspection and repair if necessary but they could not tell me anything regarding this or if they had the problem reported previously. Since I cannot see the spots on the photo, I am tempted to keep the current lens and/or send it to Canon for inspection and repair. I really hate to send a new lens to Canon for repair but may be necessary and the best course of action. I purchased this lens at a good price and is now $100 higher so I hate to return to Adorama for refund. The same lense from other dealers may have the same problem. I also could visit a dealer in person to see if they had experienced this or if the ones they have on hand have the same problem

My question: Has anyone else experienced this type of problem and if I keep the lens, will it cause future problems? Should I return the lens and give up on this purchase or send to Canon for inspection and repair? Adorama has been very good with returns and replacements and they have sent the replacements with free overnight shipping and provided labels for the returns . Thanks in advance for any help or opinions you might have.

rjaywallace Loc: Wisconsin

Call Canon and discuss with them, but you will probably be asked to send in the lens. Manufacturers do care.

JackB

Yes, that is what tech support told me when I called them.

Joe Blow

My gut reaction is that it is on the rear element. If it was on an inner element you wouldn't be able to see it. I suspect what you're seeing is the protective film they apply to the glass. Also, the elements inside the lens are are usually coated with anti-reflective coatings that often look like they're wearing off or unequally applied.

These "imperfections" are normal and do not cause a problem. The specific ones you see could be from when two elements are close together / touching or you could just be seeing reflections of the rails inside the barrel. Test your camera by shooting a monotone scene, such as a wall, at various apertures and focal lengths on manual. If you don't see any spots or shadows in your finished product then you can rest assured it is normal. If you do see something then mention it to Canon.

JackB

Thank you. Good information.

Joe Blow

To add, back in the old days, around 1988, I was taking a part time camera course at a local community college. One day our instructor was ill and someone from the college's camera department sat in. His specialty was repairing lenses. The one thing that sticks with me from that day was his observation about things on the lens elements (glass) and how they effect the picure.

Any dust, dirt, scratches, etc on the front or rear elements are simply too close to factor into the photo. He related how he repaired one lens that the owner complained how the aperture wouldn't open all the way. The gentleman opened the lens and found a fly inside. Being inside the focusing elements, all it did was block the light.

Bill_de Loc: US

I would take the advice from the Canon tech. Joe may be 100% correct, but he hasn't actually seen your lens. He is basing his information on your description which might not be exactly what he has seen in other lenses.

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Peterff Loc: O'er The Hills and Far Away, in Themyscira.

I have an old Canon FD 500mm reflex lens that I use. It showed a spot on some images, I found out that it was just a little dirt on the drop in filter. Easy to clean / fix. A more modern lens somehow got a flaw in an internal lens element. It still works, but occasionally shows up as an artifact in an image. It would cost more to fix than buying a new lens which I did.

TonyBot

Years ago, the store where I worked was a big Leica dealer, and on occasion we would see some defects in Leitz lenses that the techie for the distributor told us would not *make a difference* - even one time a "bubble" that was almost two centimeters in diameter. Even though, we would end up selling the lens for a discount (!!!), and soon afterwards the buyer would come in and tell us (meaning, not the Boss) that it was a great bargain and did *not* make a difference. Test the lens, and if you are not satisfied, send it back. If the lens is from one of the Big Three in makers, it probably doesn't make one whit of difference, but again, it's your money and if you're not happy, send it back!

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

Yep

TonyBot

Whoops! Meant two *millimeters* in diameter. Still, highly visible.