using filter in front of expensive glass !!!

this question has been torturing me for some time now.
i attended a photografy lecture many moons ago.
the speaker said that when you put a filter in front of your expensive lens . the lens becomes as expensive as the filter in front of it . unless the filter is used for creative porpuses.
this was in the early 90's. so im stuck with that idea
can you tell the difference when a "uv " filter is used , does it loose IQ?


im listening .

I personally do not use filters. The ones that I have used have all been hoya pro 1 and B&W filters and have never really noticed a difference with or without them.
With the exception of one older filter I used. It had some flare issues.

I would say as long as you are using one that has a good digital multi coating in it you should be fine. weather you use one or not is a matter of personal choice though. I do not, however I am also never really in bad shooting situations.

i would think that . like in electricity , the system is strong as the weakest poin. being here the filter
or is it?

I don't see difference in quality/resolution with or without filter. I use B+W filters that are expensive but worth it I'd say. I think it's a matter of personal preference and also type of use of your lenses. I feel that my lenses are well protected - the glass is in new condition always. When you'll have to wipe your front element, you may damage your coating, scratch the element etc. Filter is easy to wipe, and if damaged, easily replaced. Try replacing your damaged front element...

if you do a search you can find quite a few instances where the filter didn't allow the lens to perform to it's full potential...most of the time these where cheap filters...i think if you get a high quality, expensive filter you'd probably be fine...personally i don't use them...

dave92270 wrote in post #10414850
Try replacing your damaged front element...

try damaging your front element......there's been quite a few videos lately where people have just been straight up ruthless to the front element of lenses...and all seem to come away without a scratch...i don't think wiping the lens can possibly remove the front element coatings either...but if putting a filter on the front of your lens gives you peace of mind...that's all that matters

illrooster132 wrote in post #10414721
i would think that . like in electricity , the system is strong as the weakest poin. being here the filter
or is it?

That is a funny comparison considering how electricity always seems to come down to a 50 cent bulb, 60 cent device or a dollar fuse

a part of me wants to buy filters and try. but dont want to waste money when i can get a better lens.

If you buy good filters, the IQ loss is non-existant.

themadman wrote in post #10415034
If you buy good filters, the IQ loss is non-existant.

If you buy NO filters, you always get the full IQ and it doesn't cost anything.

I don't think the issue is so much a matter of IQ loss, so long as you use a high quality filter and be aware that it might be an issue in some circumstances (if you have light sources in the picture for example, causing flare).

Most of the people who say they are necessary talk about damaging the front element, even wiping off the coatings (see one of the posts above). Believe me, the front elements are a lot tougher than these people think and the coatings are designed to withstand the lens being cleaned, believe me.

I have lenses that have seen many years abuse, they are dented and scuffed, they have had the front element wiped and cleaned hundreds (possibly thousands) of times, with an assortment of soft cloths and even towels and shirt sleeves, if that was all I had available at the time. Yet, the front elements are fine, they have no scratches, no loss of contrast or any other issues. They have rarely seen a filter and only when I have needed one for it's effect (CPL etc).

Somebody mentioned it is easier to change a filter than a front element, this is true. You will probably have to send the lens in for repair to change an element. However, they are also much, much harder to damage in the first place. One thing that IS quite good at damaging them is the flimsy thin piece of glass that people stick on there to 'protect' it. Filters break easily and can break in a manner which forces sharp shards of glass into your precious element, which can scratch it. I have known two people scratch elements by breaking a filter but have never known someone where a filter actually saved a lens from damage.

In the end though, it comes down to personal preference and how much you believe the guy in the store that tells you that you 'need' a filter (in reality, he just wants another sale). The reality is that anything coming in hard and fast enough to damage the element, will go clean through the filter and take out the element anyway.

Do the math and see what works for you. Filters are just too crazily expensive to be justifiable for me. I have quite a number of lenses and, if I was to put a decent filter on each one, it would cost me more than buying a complete new L lens (and some other stuff). In addition, the way my gear gets thrown around, I would likely have regular broken filter replacements to buy which cost even more money. I would rather buy another lens and have that to use instead.

The best protection for your lens is a good quality lens hood, they take the brunt of most impacts and keep the majority of foreign objects away from your element. In addition, they have the benefit of actually improving the image quality.

If the worst should happen and you break the front element, it doesn't cost a huge amount more than a good filter to replace anyway (although there is the inconvenience of sending the lens in to get it done).

You will get people advocating both sides passionately though, it is a common argument in the forums as to whether you need a filter or not. I simply offer up that in my experience (and I have been using SLRs for over 30 years, usually carrying two or three at a time banging into each other and everything else) I have so far not managed to damage an element in any way (not counting the lens that got trashed when it came loose from a fast moving car and bounced along a hundred yards of road - I don't believe a filter would have saved it though) despite never having used a 'protective' filter.

You need to make your own mind up though.

I have a couple of expensive-ish lenses that I often keep a filter on, but then I will take them off for times of critical IQ. In reality though I know most of my shots are not critical and I'm just stuffing around, so I leave them on. They also come off where flaring and so on is a problem, especially for night time shots where even with expensive filters you can end up with mirrored copies of light sources in your pics.

I'm about to just take the front element off completely. However, I tend not to want to clean the glass. But, even with the filter...I still do...hmm...

I will sell you a $5000 filter and so you can turn your 50/1.8 into a $5000 lens.

If filters make you feel better or serve some other purpose use them otherwise don't (unless you want to buy that filter from me in which case they are absolutely necessary). If a cheap filter makes your lens into a cheap POS you should see it in the images, there should be no question in your mind.

Every filter effects the light to some degree. That is how they got the name "filter" after all. The negative effects vary greatly with the quality of the glass used in the filter, and in how you use them. The best filter is only as good as you let it be. Not every bad thing can be obvious. Filter flare is only one problem. Simply a degredation of overall contrast can be caused by a filter. And as you play in Levels to bring up the black point, claim there is no effect from the filter.....

In short yes they can be a problem. However experiences vary to the extreems.

* No UV/'protective' filter can improve image quality on a dSLR.
* All UV/'protective' filters will cause some degradation in image quality.
* The seriousness of this degradation tends to decrease as filter cost increases.
* Good filters will cause degradation that is not noticeable under most conditions.
* All filters, even the best, will cause noticeable degradation in some conditions.

That's my summary of filters and image quality. I don't think there's anything there that is not factual.