using UV filter

[Wavy C]

How many people use a UV filter over the front of their lens to protect it from rain, dust etc?

I've read that using a filter can degrade the quality of the images. Do you find this is true?

[SkipD]

I have never used a filter for "protection". I always, however, use a good quality lens hood to provide both physical protection and prevent flare from strong light sources outside my subject area.

In over 40 years of using cameras, I have never had a lens damaged - even by dropping a camera on the lens. The hood took all the impact force and the lens is still fine 37 years later.

[tim]

If you ask 6 people about this you'll get 7 different answers. For more opinions that you really want have a look at thread like this one (http://photography-on-the.net/forum/showthread.php?t=59596).

Personally I use a filter on my 70-200 F2.8L IS L, but not on any other lens, even though I have a filter for my Tamron too - the Hoya's are too hard to clean. B+W seem easier.

[MrChad]

it has to stop some light but outdoors I always use one to keep crud off the lens elements. Usually it's sunny enough it won't matter. Indoors I usually remove them.

[ttmatsu]

Image quality might be impacted if you use a cheap filter. I've always used quality filters and have never seen any difference in quality. Yes, I've tested with and without the filter in different situations. I mainly use Hoya S-HMC (lets 99.7% of the light through) - there is no difference in shutter speed with or without the filter. The Hoyas are easy to clean - just use a microfober cloth like the optometrist or opticians give out with every prescription. If you use lens tissue, it will smear smudges or oily marks.

The big difference between Hoya and B+W or heliopan is that Hoya uses Aluminum and the other two use brass. Check out the prices on 2filter.com and compare it to where ever you normally shop. Most camera stores have outrageously high filter prices.

You're probably like me, I just feel more comfortable with the filter on. I've had to replace filters that were scratched up - I shoot outdoors in all conditions other than wet. When the wind is blowing, I've had to take my hood off because it was catching too much air.

[wayne53]

My 70-200 2.8L IS has only tasted less than a minute of fresh air. The UV filter has been on there ever since I got it.

[I Simonius]

How many people use a UV filter over the front of their lens to protect it from rain, dust etc?

I've read that using a filter can degrade the quality of the images. Do you find this is true?

I do because if you see the crap from rain etc on the UV filter you'd rather have that on a filter than on your lens

BUT......

see here

http://photography-on-the.net/forum/showthread.php?p=629712#post629712

[cmM]

All my lenses have filters on. There were instances where they saved my front element from scratches/cracks.
I haven't noticed any sort of image degradation due to the use of these filters.

[uumode]

I ordered some dirt cheap S & W filters off ebay in the hope that it might improve the picture quality. In this person's tripod and L lens tests the cheap filter is better than no filter and arguably better than a Hoya S-HMC, don't know why though!

http://www.pbase.com/fstopjojo/image/44870387

[I Simonius]

I ordered some dirt cheap S & W filters off ebay in the hope that it might improve the picture quality. In this person's tripod and L lens tests the cheap filter is better than no filter and arguably better than a Hoya S-HMC, don't know why though!

http://www.pbase.com/fstopjojo/image/44870387

I cannot see how that test is supposed to show anything of any merit whatsoever. :evil:

UV filters will only demonstrate effect on the image i.e. usefulness, when there is a significant amount of UV light to be filtered. There is not likely to be any in this shot. ergo - completely useless test (in fact probably designed to confound the uninformed)

You won't improve picture quality with a filter, unless there is something degrading picture quality which needs to be filtered out.

[uumode]

I cannot see how that test is supposed to show anything of any merit whatsoever. :evil:

UV filters will only demonstrate effect on the image i.e. usefulness, when there is a significant amount of UV light to be filtered. There is not likely to be any in this shot. ergo - completely useless test (in fact probably designed to confound the uninformed)

You won't improve picture quality with a filter, unless there is something degrading picture quality which needs to be filtered out.

I didn't take into account what UV filters are supposed to do, I just viewed the results, and to my eyes the cheap filter produced the best results. (the tester was only testing to see if there was any difference not to transmit any preconceived idea, and took the time and effort to see if it actually made any difference).

[I Simonius]

I didn't take into account what UV filters are supposed to do, I just viewed the results, and to my eyes the cheap filter produced the best results. (the tester was only testing to see if there was any difference not to transmit any preconceived idea, and took the time and effort to see if it actually made any difference).

So if the results showed they all produced a bright red pic but the cheap one showed the reddest you'd go with that?? ;-)

Seriously the results are completely meaningless :rolleyes:

[uumode]

So if the results showed they all produced a bright red pic but the cheap one showed the reddest you'd go with that?? ;-)


Yeah, if I wanted the reddest :)
but in this case I wanted the sharpest image with the most contrast, and I preferred the slightly warmer tone to the S & W filter. I currently use Hoya Pro 1/S-HMC and they kinda give a slightly bluish look, but maybe the Hoya Digital Pro 1's are better with digital cameras.

You can't always rely on technical and product spec to determine what 'should' be the best result. What happened to gut feeling? ;-)
In my case I thought and bought Pro 1/S-HMC filters, when it transpires that the cheap filter might work better for me. (I need to do a few tests of my own when I receive the cheap filters)

[LightRules]

So if the results showed they all produced a bright red pic but the cheap one showed the reddest you'd go with that?? ;-)

Seriously the results are completely meaningless :rolleyes:


>:( :twisted: :evil: .............:D

[ddelallata]

Three of my lenses have filters on them, but not the 70-200 . My 17-40 has the most expensive filter though.....a HOYA PRO1 HMC UV filter. I wanted one of the best possible filters on this baby.

[I Simonius]

Yeah, if I wanted the reddest :)
but in this case I wanted the sharpest image with the most contrast, and I preferred the slightly warmer tone to the S & W filter. I currently use Hoya Pro 1/S-HMC and they kinda give a slightly bluish look, but maybe the Hoya Digital Pro 1's are better with digital cameras.

You can't always rely on technical and product spec to determine what 'should' be the best result. What happened to gut feeling? ;-)
In my case I thought and bought Pro 1/S-HMC filters, when it transpires that the cheap filter might work better for me. (I need to do a few tests of my own when I receive the cheap filters)

Hi uumode, I'm not saying that the cheaper filetr isn't as good as the more expensive one. I have no Idea which is best.

What I am saying is that you don't get a better picture QUALITY by putting a filter on a lens - any filter. You say you wanted sharpest wit most contrast, the lens ALONE will give you the sharpest with no contrast..any filter can only lessen sharpness and contrast,(even if inperceptably) - not add to it

I suspect what's happpened here is that I have misunderstood your posts to mean that you want the best image with or without a filter, where pewrhaps you mean , that you are definitely going to use a filter and that from the choices of filter availabe you can see no advantage to the morre expensive ones

It seemed to me from your previous posts that you thought that there were advantages to image quality by using a filter over the lens without filter.

Nonetheless the test you linked IS meaningless, sorry because a UV filter should NOT add any colour cast , it should do what it says on tjhe packet - filter out UV rays; UV light give a haziness and slight blueness to images, OVER DISTANCE.

So it can only normally be seen in landscape pics or pics that include some distant objects in the field of view- The worst possible example of a UV test is a close up shot of anything.

If you prefer the slight warming effect of a filter then opt for the Skylight filter instead, which does the same job as a UV filter but more so (effectively)

Finally, with digital cameras, the tone of the image produced by either UV or skylight filters is fairly irrelevant as these can be adjusted in post processing

[I Simonius]

>:( :twisted: :evil: .............:D

This is a more meaningful page from fStopJojo, than the test of his you previously linked uumode,

http://www.pbase.com/fstopjojo/image/45039261

[blue_max]

So, the filter may, or may not, make a difference to the image quality. It may, or may not, make a difference if you use a top quality one. This may vary if you use more extreme conditions. Perhaps one needs to buy just one and do ones own experiements. Hey, come back and show us all the difference, as it effects every one of us – and let's try and come to some 'real' conclusions, rather than hypethetical.

What is certain, is that if you damage a filter, it can be replaced reletively cheaply and the lens does not need to be sent away.

It's amazing that this issue has not been resolved - especially as most of us spend our time in photoshop looking at pixels. We can tell whether a lens is better, or worse, than the next, but we can't demonstrate that a filter makes any difference.

That's the challenge folks!

Graham

[I Simonius]

So, the filter may, or may not, make a difference to the image quality. It may, or may not, make a difference if you use a top quality one. This may vary if you use more extreme conditions. Perhaps one needs to buy just one and do ones own experiements. Hey, come back and show us all the difference, as it effects every one of us – and let's try and come to some 'real' conclusions, rather than hypethetical.

What is certain, is that if you damage a filter, it can be replaced reletively cheaply and the lens does not need to be sent away.

It's amazing that this issue has not been resolved - especially as most of us spend our time in photoshop looking at pixels. We can tell whether a lens is better, or worse, than the next, but we can't demonstrate that a filter makes any difference.

That's the challenge folks!

Graham

I don't think fStpJojo is claiming that these tests are the final words on the matter

There are many obvious problems with his test but rather than pick holes in it I take it as his POV. That test wouldn't be good enough for me.

If I were to do such a test to differentaiet between such small variables (which I don't have time for so don't ask :D :D ) I would use tripod mounted camera with cable release & mirror lock up, set the a good hyperfocal DOF , shade the lens, use a medium to wide FL, shoot RAW, and view on a calibrated monitor. (just converting the results to jpg and posting on the web to be viewed by different monitors would be enough to introduce such margin of error to make the whole enterprise worthless even then)

So the only way is to make subjective assessments as fStpJojo has done, or use an MTF test.

[blue_max]

I don't think fStpJojo is claiming that these tests are the final words on the matter

There are many obvious problems with his test but rather than pick holes in it I take it as his POV. That test wouldn't be good enough for me.

If I were to do such a test to differentaiet between such small variables (which I don't have time for so don't ask :D :D ) I would use tripod mounted camera with cable release & mirror lock up, set the a good hyperfocal DOF , shade the lens, use a medium to wide FL, shoot RAW, and view on a calibrated monitor. (just converting the results to jpg and posting on the web to be viewed by different monitors would be enough to introduce such margin of error to make the whole enterprise worthless even then)

So the only way is to make subjective assessments as fStpJojo has done, or use an MTF test.

I certainly wasn't suggesting the test was a definitive answer.

If one has to go to the above mentioned lengths to be able to tell any difference, would it not be reasonable to assume, that in effect, it makes no difference.

If one had to quantify the actual difference, even when working to those lengths, may it not be in the order of fractions of 1%. Surely, there are many other factors that can have much more impact on image quality, such as exposure, actual copy of lens etc.

If you want to use a filter for protection, it will not make any difference. If you are the sort of person who can tell whether a filter has been used or not (in a blind test - must be impossible!), then you should definitely not be using one.

Graham

[I Simonius]

I certainly wasn't suggesting the test was a definitive answer.
SNIPIf you are the sort of person who can tell whether a filter has been used or not (in a blind test - must be impossible!), then you should definitely not be using one.

Graham

Agree, for most users it boils down to whether they want to protect the lens or not, that's all.

But for those who fork out for L primes and use the images at 100% it can make a difference, albeit a small one, but at that level small differences make exactly that, and it can be that that does, make a THE difference, that is, be it everso small, the difference made, making ALL the difference. That's the difference. :lol:

[uumode]

What I am saying is that you don't get a better picture QUALITY by putting a filter on a lens - any filter. You say you wanted sharpest wit most contrast, the lens ALONE will give you the sharpest with no contrast..any filter can only lessen sharpness and contrast,(even if inperceptably) - not add to it


I thought that in some cases (not all cases) that putting on a filter would help contrast and sharpness in circumstances where the lighting diminishes it for the normal lens coatings. (like people putting on sunglasses) i.e. filters out the light - atmospheric haze/glare whatever, and makes things appear sharper and clear?- which is what I think I am seeing in the tests.

But I agree, any additional lens element or filter technically will diminish optical quality - it's the law of physics.

[I Simonius]

I thought that in some cases (not all cases) that putting on a filter would help contrast and sharpness in circumstances where the lighting diminishes it for the normal lens coatings. (like people putting on sunglasses) i.e. filters out the light - atmospheric haze/glare whatever, and makes things appear sharper and clear?- which is what I think I am seeing in the tests.

But I agree, any additional lens element or filter technically will diminish optical quality - it's the law of physics.

For a sunglasses type effect you would need to use a polarising filter- UV won't get you that sunglasses effect. polarisers will. You need a 'circular' polariser for DSLRs

-atmpspheric haze/glare yes UV and skylight filters will improve image quality provided there is haze /glare to be filtered out, i.e.which is actually diminishing image quailty
There wasn't any in those pics on the test you linked to - hence they are no help in deciding whether they affect UV/haze/glare

There IS haze/glare to be filtered out potentially in the second set of pics that fStopJojo did but it is not relevant because it is outside the DOF
If he had focussed so the distance was sharp then you might have been able to see the difference, because haze/glare is most obvious in the distance

[blue_max]

Agree, for most users it boils down to whether they want to protect the lens or not, that's all.

But for those who fork out for L primes and use the images at 100% it can make a difference, albeit a small one, but at that level small differences make exactly that, and it can be that that does, make a THE difference, that is, be it everso small, the difference made, making ALL the difference. That's the difference. :lol:


This could become very pedantic, so I'm not trying to score points here, but...

Can you show me any comparison where there is a difference with and without. Any at all. Any difference whatsoever, Any pixel that has been altered because of the filter.
As I say, of all the photographers who work night and day round the globe and all that has been written about the pros and cons of uv filters, it should not be hard - or should it?

I find myself taking this position, not because I believe it, but because there are people who dismiss them and are making claims about them, which are not proved.

If it's down to personal opinion, then it can't be claimed as fact. How many stops of light can the camera resolve? Is it about 8? How much do people think that the filter will alter the light?

If the debate is about lens protection or not, each to their own. I use L lenses and filters - but losing image quality does not keep me up at night.

Graham

[I Simonius]

This could become very pedantic, so I'm not trying to score points here, but...

Can you show me any comparison where there is a difference with and without. Any at all. Any difference whatsoever, Any pixel that has been altered because of the filter.
As I say, of all the photographers who work night and day round the globe and all that has been written about the pros and cons of uv filters, it should not be hard - or should it?

I find myself taking this position, not because I believe it, but because there are people who dismiss them and are making claims about them, which are not proved.
snip
Graham

I cannot show you any copmparison because I have only had my DSLR a few months and haven't taken a shot deliberately to demonstrate this. But you, or I, could quite easily, provided the conditions were right.

What I can tell you is that if you take shots that are hazy in the distance from UV, a UV filter will cut some of the haze. This is fact, not conjecture.

However I'm not going to go out to prove it because the main reason I use them is for protection.

That's all from me on this; my original point was simply that the first linked test was meaningless. I am not too interested in getting into the minutae of filter effects. ;)

[blue_max]

I cannot show you any copmparison because I have only had my DSLR a few months and haven't taken a shot deliberately to demonstrate this. But you, or I, could quite easily, provided the conditions were right.

What I can tell you is that if you take shots that are hazy in the distance from UV, a UV filter will cut some of the haze. This is fact, not conjecture.

However I'm not going to go out to prove it because the main reason I use them is for protection.

That's all from me on this; my original point was simply that the first linked test was meaningless. I am not too interested in getting into the minutae of filter effects. ;)

Simon, I'm not expecting you to show me anything, Or anyone else for that matter, that was the point - endless examples of how one lens was less good than another, but none 'revealing' the damage that was supposedly being done by a uv filter. In fact, I think you are saying that a filter would be an asset now. Has your position changed or am I reading this wrong?

Anyway, can we agree not to state as fact, that a uv filter damgages the image quality unless a proved fact.

Graham

nb this is a debate and not a personal attack. No photographers were hurt during the making of this thread! :lol:

[uumode]

Anyway, can we agree not to state as fact, that a uv filter damgages the image quality unless a proved fact.



Can we not assume that the tests done by fstopjojo were fairly controlled and are certainly more controlled than normal shooting in the field, and if no visible degradation of the image is detectable under those circumstances then those filters tested have negligible impact?

We can talk all we like, but you have to credit fstopjojo for actually having gone out to practically prove a point as far as humanly possible outside a lab. I viewed his results and come to form my own conclusion from his specific results WITHOUT the prior knowledge of which image was produced by what, and I chose the S & W filter. As far as I am aware, no one else in the blind testing chose the L lens without filter (or very few).

[blue_max]

Can we not assume that the tests done by fstopjojo were fairly controlled and are certainly more controlled than normal shooting in the field, and if no visible degradation of the image is detectable under those circumstances then those filters tested have negligible impact?

We can talk all we like, but you have to credit fstopjojo for actually having gone out to practically prove a point as far as humanly possible outside a lab. I viewed his results and come to form my own conclusion from his specific results WITHOUT the prior knowledge of which image was produced by what, and I chose the S & W filter. As far as I am aware, no one else in the blind testing chose the L lens without filter (or very few).

Choosing the cheap filter is actually proving it does make a difference. :confused: If there is not universal concensus, then either there is no difference or nobody can actually tell.

Maybe like religion, you just have to believe.

Graham

[uumode]

Choosing the cheap filter is actually proving it does make a difference. :confused: If there is not universal concensus, then either there is no difference or nobody can actually tell.

Maybe like religion, you just have to believe.

Graham

According to the law of physics it shouldn't be technically be possible for a cheap filter on an L lens to produce a better image, but subjectively it has for me. Just as the law of probability says if you flip a coin 100 times, it should end 50/50 but ironically it's impossible to achieve (well I've tried and never got ;-))

For me, I'm anticpating receipt of the S & W filters so I can compare it with my Hoya Pro 1 and keep the findings to myself (for fear of being labeled a madman) as it simply and couldn't be possible for a cheap filter to improve the image quality ;-)

Thanks all for a lively debate :-)

sayonara

[Wavy C]

Tnx for the advice. I've bought a couple of cheap uv filters for my favourite lenses because everytime I'm out shooting it seems like they pick up little specks of dust and I'm always a bit concerned about things like water splashes etc. My only aim is to protect the lenses - I'm not expecting any improvement in performance. However I've noticed on some shots there might be a little more in the way of flare or lower contrast perhaps due to reflections in certain situations. Just wondered if any others had noticed anything similar. It's difficult to tell if the filter is to blame or simply the lighting conditions at the time.

Even so, I think I'll keep using the filters for everyday use. If I'm doing a really critical shot I guess I can always screw the filter off for those.

[blue_max]

Tnx for the advice. I've bought a couple of cheap uv filters for my favourite lenses because everytime I'm out shooting it seems like they pick up little specks of dust and I'm always a bit concerned about things like water splashes etc. My only aim is to protect the lenses - I'm not expecting any improvement in performance. However I've noticed on some shots there might be a little more in the way of flare or lower contrast perhaps due to reflections in certain situations. Just wondered if any others had noticed anything similar. It's difficult to tell if the filter is to blame or simply the lighting conditions at the time.

Even so, I think I'll keep using the filters for everyday use. If I'm doing a really critical shot I guess I can always screw the filter off for those.

You could of course do your own quick test, with and without and see if you can tell which is which.

Graham
(Wonder if anyone actually changed their opinion through this thread :lol: )

[csnudelman]

You could of course do your own quick test, with and without and see if you can tell which is which.

Graham
(Wonder if anyone actually changed their opinion through this thread :lol: )

Good idea, really good idea. Now, if someone could just lend me a filter.....

[xuxu1]

Graham
(Wonder if anyone actually changed their opinion through this thread :lol: )
Nope, i did´nt :p

ED

[blue_max]

Good idea, really good idea. Now, if someone could just lend me a filter.....


I will get a selection in the post, please confirm this is the correct address.

Non Believer,
Sceptical Cottage,
Doubting Lane,
Dubious,
Unconvinced RUS URE

:lol:

Graham

[uumode]

I forgot to mention that I use filters to protect the lens,
as I don't use lens caps.

Otherwise the 'real world start up time' of my SLR is very slow compared to my Canon S45 point and shoot, which is probably twice as fast.

[csnudelman]

I will get a selection in the post, please confirm this is the correct address.

Non Believer,
Sceptical Cottage,
Doubting Lane,
Dubious,
Unconvinced RUS URE

:lol:

Graham

If you are addressing me I don't understand. Sorry, old age I guess.

[rklepper]

If it were simply a matter of the number of pieces of glass the answer would probably be use it only as a safety feature. The more complicated answer is that not all glass is created equal. Look into a fish tank once and see what happens to light as it passes through a cheap piece of glass. Higher quality glass will bend light less (a process called refraction). If you have a high quality piece of glass you should use a filter of the same or greater quality. If the filter refracts light to the same degree or less than the lens glass there can be no degradation of image quality
(absolutely). If on the other hand the filter refracts light to a greater extent than the glass in the lens there will be a degredation of image quality. Pure glass has a refractive index of 1.5. You should be able to get the information from the lens and filter manufacturers to help you in choosing a filter if you are concerned about degredation of image quality. By the way expensive does not neccessarily equal better quality.

Also air has a refrative index of 1.00029 so the air between the lens and the filter will refract light to a lesser extend than the glass so it will not effect the image quality.

[Wavy C]

I did my own quick and totally non-scientific test (photographed a bottle).

Perhaps surprisingly, I *think* I did notice a slight difference. The contrast might have been slightly greater with the filter in place, but difficult to say if that was solely down to the filter or if the light had changed slightly between shots.

I was more interested in 'real world' shots, however. Does anyone find that a filter, for example, causes more flare etc in certain lighting conditions? They don't appear to make much difference to me, so I'll probably keep them on my lenses, but just a little worried that they might affect some shots in certain situations.