Protection Filters

Filter discussion;

Like many photographers , more so those of us "with more mileage", like me, I religiously fit skylight, UV or clear optical filters to my lenses in the belief that it offers a degree of protection.

They are only ever removed when a "correction or effects" filter is needed.

Understanding that any additional layer of glass fixed in front of a lens does bring a degree of image degradation I have only once found a filter to really create a problem .

What that means in my parlance, is the image was degraded more than negligibly, i.e. noticeably.

The filter was not a budget type but an expensive SMC UV mounted on a DA* 50-150 which is generally accepted as one of the best optics around, hence the difference was more conspicuous.

I recently started to use the HD 1.4 converter more frequently on my DA*300 and whilst I am very happy with it I decided I should try this set up without the filter to see if to what degree the converter affected the 300mm which again as we all know is a stunningly sharp lens.

Having ascertained that the image is slightly different but not in anyway unacceptable, I refitted the filter and very soon realised there was now a more noticeable effect from the filter.

Backtracking I then assessed the filter effect without the converter deployed and the difference was not detectable until the image was enlarged (cropped) significantly and then it was still not not obtrusive or unacceptable

Having just acquired the HD150-450 I fitted an expensive UV filter for protection (not the most expensive but still approaching £70) And It has now become more or less clear that there is a varying effect on IQ as the lens is zoomed until fully extended (450) .

I guess this is not a surprise but now being confronted with purchasing an even more expensive "protection filter" or working without one.

I wroye this post because I would like to learn from other people's wisdom and experiences regarding the the subject of protection filters;

1. Is it generally accepted they are needed ?

2. Has anyone else concluded from practical experience that filter quality is far more critical with large telephotos / large tele zooms / super zooms ?.

3. What is the general opinion regarding the multi coating ?

I was recently told that there are three basic generic versions when it comes to filters

(i) Not coated,
(ii) One-Side coated
(iii) Both sides coated

Is this correct ; if so, for protection only, a filter as in (iii) above would likely not be necessary ?

5. Also as regards the difference in a £110+ filter and a £50 filter there is also the coating specification and quality to consider ? ( experience based Comments welcomed)

6. What is the general opinion on the deployment of a clear optical glass protector (no filterIng) as it often commemted that modern cameras and software can take care of the subtle corrections provided by skylight 1a and UVs

The relevance to this discussion for me is justifying the cost of the best protection filter for the big zoom which will be around £110 - £ 150 depending on what it is and where it is bought.


I would welcome any wisdom from other PU contributors here

Regards

daronl

DaronL,

If you search through the PU archives you will find many threads on this. The consensus usually is its a personal thing!!!

As far as I understand modern lenses are not affected by UV as the optics can handle it. The reason many people use a filter is to 'protect the lens'. However there have been cases of filters damaging the lens when they get broken. The hood is often thought to protect the lens better.

Dave

Thanks Dave,

Interestingly in more than several decades of Photography, I spent many years living and snapping away in very hostile environlments and I have never damaged, scratched or abraded a protection filter which is more food for thought as to wether I need worry about a lens being exposed.

For sure the hood offers good protection from the elements and also can provide somewhat of a buffer to any impact on a front lens element too.

I have incresing suspicion though that with long telephotos an big zooms, in conjunction with teleconverters a filter also chips away away against IQ, more apparent when large crops are made but with the advent of some of these 600mm zooms (Tamron and Sigma) the filter might become more than negligible in adversely affecting image quality.


Regards

Daronl

Daron

I acquired a (tiny) scratch on the front element of my 300mm DA Star F4 when in Wales this last holiday. Always has its big filter hood on. It hasn't affected the use of the lens but is of course annoying. it'll be a bargain on here for someone if I ever sell it.

Despite this mishap I have no intention of putting glass in front of my lenses unless for a filter effect when i hand hold Cokin or similar. I've seen pro's cameras and lenses over the yeas, very beaten up but they still take great photos.

Thanks for your input here Bill; For clarity, my concern is specifically about Sharpness being degraded by the filter in front of the lens element so I would like to get rid of the filter .

Your comment regarding scratches is absolutely correct with protection filters too; one of my fellow photographers uses a very expensive Schneider Filter on his 300mm which has a fairly pronounced score mark at the eight o’clock position and it seemingly doesn't create a problem.

But I think sharpness is a more subtle and important issue for me and the resolution of the latest sensors coupled with the magnification of the big lenses definitely show up inferior optical qualities in all but the most highly specified filters.

My own tests have lead my conclusions in that direction so I would like to do away with the need and the cost of big pro-grade protection filters which is becoming horrendous; if the general experience expressed by PU members concurs it is not a problem then I will not buy Schneider for my 150-450 which is at least £110 delivered .

Regards

I used religiously to stick an UV filter on my lenses -- but came to appreciate that cheap filters were worse than none and expensive filters were ... expensive, and could potentially cause problems in certain circumstances. Why run any chance, however slim, of degrading a shot, having spent a considerable amount of money on a decent lens? None of my lenses carry 'protective' filters. Camera retailers are, though, pretty wise to purchasers' understandable wish to do what they can to protect their investment and are very happy to provide these high-margin items to those of a nervous disposition!

It's called an "add-on" and adds profit to an unprofitable transaction. So you buy a camera and add on a filter, bag, care kit.......

Personally I ditched filters a long time ago. They aren't needed the same as they were for film for effect, with the exception of grads and polarisers. I don't use them for protection, but I do always use a lenshood.

+1

I never use them.
Not much more to say really.
Only use a filter when I want it, such as an ND or polarising filter.

Thanks everyone for your very helpful contributions; I think there's enough of a consensus from the comments submitted to support the view that;

"Purely for protection , filters are really an expensive and unnecessary evil;"

Best Regards

Daronl

I've bought no end of lenses that have come with a skylight filter attached. First thing I do is remove it and put it in the box with the dozens of skylight filters. I screw the 49mm filters together. I'm hoping to get a foot long filter tube one day

Complete waste of time apart from ND filters I don't use them and I wrk in some harsh conditions. I dropped my 100-300mm sigma hard on concrete facedown and the front element didn't get scratched the second and third element however a totally different kettle of fish. If you ever get the chance to strip down a lens see how thick the front element is, they are really thick and very difficult to break.

I always use a hood and like you say unless you buy an expensive one he only thing you are going to do is degrade image quality

Lol I do this too, only pulling them back out again if I sell the lens, so I have something to list as an add on / upsell.

"includes free uv filter" ...

I buy the cheapest UV filters off E-bay and fit them to all my lenses simply because it's so easy to wipe clean a filter when out and about and the front element stays untouched throughout its life.

Last year I dropped my K100 on a concrete floor. The camera (tough as old boots) suffered no ill-effects but the filter was smashed. I've no way of knowing if the lens would have been damaged had it been unprotected, possibly not.

Of course, every picture I take is in some way degraded by adding another layer of cheap glass, but none of my high paying clients have ever complained about the loss of sharpness... oh, wait a minute, no one every pays me for my pictures: I've only myself to please.

(I wouldn't pay £100 for a filter, though.)

Another one for never using them these days. Why would Pentax have developed a Super Protect coat for the front element if they expected people to keep a protective filter on the front of the lens at all times?