Problems with the lens coating(films) on the surface of canon lenses.

[iris]

I have read numerous reviews here of how to clean your lense surfaces....I am wondering if the various canon films that they promote as doing wonderful things for focus are not so great for cleaning?...I bought an expensive lens not to long ago and cleaned it with one of the lens clothes that my opthomologist hands out after my eye appointment for my glasses..I collect these little soft squares whenever I have an eye appointment because they are made for the purpose of cleaning lenses....Houston is a very humid climate and after doing some night photography the lense seemed sticky and so I buffed with the soft cloth...I did not add any sort of cleaning fluid...but I noticed when I had finished that there was the faintest blue smear across the lens surface....Really? I used no more pressure than the sort of pressure you might use to clean your glasses.  Can this bluish smear be eliminated or is this permanent damage to an expensive surfface....? Now I must say I haven't noticed that this smear has affectd my pictures...I have found one in post processing that has a peculiar lighting issue that might be related to the lens surface...Have other people had issues with the "coatings" that are added to the lens surface? I would love to add at least two more lense...but I am afraid to invest again if I rish damage to the lens surface by even buffing with a soft rag?!

[ebiggs1]

WOW, I rarely clean the front element of a lens and never dry.  The Rocket Blower is best for dust on a lens.  Thoes clothes usually have a cleaner of some sort embedded in them.  The coating on the lens is very fragile.  Most small imperfections on the front element will never impact the photo.  

Do you have a local 'real' camera shop (not Best Buy) or a camera reapir shop?  If you do take it to them and ask if they can clean it for you.

It may just be the junk the eyeglass rag left on it.  Don't do that anymore!

[iris]

I don't know that the little soft fiber cloths have anythng at all in them..they are simply soft clothes of the typical kind ...I don't go for the idea that there is any thing added to those wipes...Every optician gives these away with your new glasses...According to numerous posts on all sorts of photography websites...they recommend variously Eclipse (?) solution with soft cloths, and there was a recommended paper to use also with a fluid designed to clean lenses...

Based on what you are telling me, one should do little more than use a bulb type blower or quick dust with a soft cloth or brush.....but as I say, many photography sites are recommending things that I now fear to do!!

[ebiggs1]

The more web sites you read, the more opinions you will get.  Some of them may even be good!  However, mine and John Hoffman's do not include the eye doctor's little cloth handouts.

You are free to take whichever opinion you please and do as you please.  IMHO, I would never use them.  I would never clean a lens dry either.  I have some very expensice white lenses that I have never cleaned the front element. Excepth by using a Rocket Blower, that is.  The front element is OOF and spots or dust, in minor amoutns, will not show up in yours photos.

Most of my lenses have high quality (B+W) protector filters on them.  The front element has never and will never be touched on them.  Of course it doesn't make sense to put a $50 dollar filter on a $100 dollar lens but it is good insurance for a $1000 or $2000 dollar lens.  And the folks that say a hood is protection enough doesn't photograph little kids.

[iris · Accepted solution]

Well, I think because I have become so addicted to photography...I can't stand that a week shoud go by that I'm not shooting and post processing ...so the largest investment I have made in a lens so far is 800 dollars...so as you say the $50 dollar investment for the protective lens cover is my best insurance...

[ebiggs1]

I have been doing this for 50 years.  I have made a living at it. I know what works for me.  Most people that post on web sites do not.  Most, and even ones on this web site, have never put groceries on the table with their camera.  A lot of folks buy an expensive camera and automatically become pros.  They seem to have all the answers.  What I mean is be careful whose advice you take.  Just my 2 cents and woth every penny and who knows I may be crazy too!

[jrhoffman75]

Filters are one of the "hot button" photo topics. It makes a great sound bite to say "Why put a $50 piece of glass on a $800, $1200, $2000 lens", implying that a $50 piece of glass is junk. But, since a filter is simply a flat piece of glass (no fancy grinding curves or exotic glass) it doesn't cost a lot to make a quality flat filter with effective coating. Canon can make a darn good 50mm lens with several elements, autofocus and autodiaphragm mechanisms for a selling price of $125. Depending on diameter some quality filters cost more than that.

Some of Canon's big dollar "L" lens require a filter for complete weather-resistance. 

ebiggs1 is right on. I have never noticed a quality degradation from using a filter and more than once it has kept the front elemnt of my lens from getting bumped.

[TTMartin]

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@jrhoffman75 wrote:

Filters are one of the "hot button" photo topics. It makes a great sound bite to say "Why put a $50 piece of glass on a $800, $1200, $2000 lens", implying that a $50 piece of glass is junk. But, since a filter is simply a flat piece of glass (no fancy grinding curves or exotic glass) it doesn't cost a lot to make a quality flat filter with effective coating. Canon can make a darn good 50mm lens with several elements, autofocus and autodiaphragm mechanisms for a selling price of $125. Depending on diameter some quality filters cost more than that.

Some of Canon's big dollar "L" lens require a filter for complete weather-resistance. 

ebiggs1 is right on. I have never noticed a quality degradation from using a filter and more than once it has kept the front elemnt of my lens from getting bumped.

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I think the argument is usually against the $5-$10 filters which really are junk. A $50-$100 filter from a reputable company and dealer is not going to be junk.

[iris]

ebiggs, I am interested in your comment: " I rarely clean the front element of a lens and 'never dry'."   What do you mean you never dry?   Are you saying that if you are shooting in a mist/fog you leave your lenses alone after shooting and let them dry out naturally?    And I wonder if those magnesium/ salt films might be more sensitive and problematic in some geographic areas than others?      And if the lenses are that sensitive to surface cleaning then  Canon needs to get that information OUT THERE... I can't tell you the number of photography websites that promote the soft cloths, soft brushes and Eclipse cleaning solutions for the lenses,  isopropol alcohol for the contacts, the little squeeze bulb blower to get the dust off...and while the instuctions for the cleaning process are delicate they certainly don't sound like you should hold your breath while performing the operation.  I am beginning to think a friend of mine has the right idea: he just buys a clear protective circular lens to cover  his main camera lens...

[ebiggs1]

"Are you saying that if you are shooting in a mist/fog you leave your lenses alone after shooting and let them dry out naturally?"

For the most part yes.  But again, as I stated in my reply, I do use protector filters on all my lenses that it makes good sense to. If the filter gets damged, I just get another one.

"And I wonder if those magnesium/ salt films might be more sensitive and problematic in some geographic areas than others?

If you are shooting under extreme poor conditions you need to take precautions.  A filter may not be a good choice but a mandatory choice.  Even a shooting bag or rain coat, etc.

"...  isopropol alcohol for the contacts, ..."

This is something that is also rarely required.  The contacts are gold plated and as long as you remove or change the lens from time to time, the contacts will 'clean' themsleves.

" I am beginning to think a friend of mine has the right idea: he just buys a clear protective circular lens to cover  his main camera lens..."

Bingo!