Cheap/expensive filter???

[fmw]

coatings and reflections can be an issue where differences occur ...

Not in our test, Alex. We sent 6 pro photographers to put a number of filters through their paces. We asked all of them to try to produce flare. All of them were able to produce ghosting, with or without coating and none of them were able to produce visible flare, with or without coating. We were never able to tell a coated filter from an uncoated one in the results. Nor were we able to tell an expensive one from a cheap one. In the case of UV filters we were never able to tell a filtered image from a non filtered image except in those instances where the photographers generated ghosting with the filters. It takes extreme lighting right into the lens to produce ghosting, as you know. If you need to shoot that type of light, simply remove the filter.

It is possible that some flare could exist because of the filter but it was certainly not visible under a 16X loupe or in a transparency projected full screen. It is not hard for me to see flare in a zoom lens adjusted to the same focal length as a fixed focal length lens. The fixed lenses are always contrastier. It is impossible for me to see it by adding a UV filter and was impossible for the other 5 pro photographers in the test as well.

This filter business is an old myth. It needs to go away. I've tried but I have no credibility. Perhaps someone with credibility will run the tests one day and be done with it.

 

[dsp921]

I have actually run the tests, however. Flat glass is flat glass. Filters can cause ghosting. I've never been able to get them to cause flare. It is impossible for a panel of professionsl photographers viewing their own images to tell a cheap filter from an expensive one. Sorry, this is not opinion, this is the result of testing. The person to whose article you link is stating opinion. I won't bore you with the details but the brand and price of a modern filter is irrelevent optically and, yes, this includes plastic filters that are flat and not scratched.

A "panel of professionals" is also opinion, fill me in on how the actual tests were done, because people looking at their images is not a scientific test. Like it or not, your tests are simply the opinion of the people viewing the images. I've worked with optics a long time and do actual tests, and these tests don't rely on opinions of so called experts. Unless you are actually using test equipment to measure thickness, density, flatness, reflections, refraction, etc, your opinion is no more valid than anyone elses, and definitely not fact. Try a simple test, throw quality filters on a white background and to the same with cheap glass, any of those look a bit yellow to you?

 

[fmw]

Actually it wouldn't bore me to read the articles. I have a doctorate in material science. Post references please.

Sorry, I've never written articles about our tests. We did them all just for our own knowledge about 10 years. We took on severl photographic controversies including filters. Even though I know I'm right, you have my promise to never mention filters again on the internet. Honestly, it doesn't matter to me whether people use filters or not or what kinds of filters they use. I try to provide credible input but it is obviously not credible. I'll give it up. Throw out those cheap filters. Take care.

 

[fmw]

A "panel of professionals" is also opinion, fill me in on how the actual tests were done, because people looking at their images is not a scientific test. Like it or not, your tests are simply the opinion of the people viewing the images. I've worked with optics a long time and do actual tests, and these tests don't rely on opinions of so called experts. Unless you are actually using test equipment to measure thickness, density, flatness, reflections, refraction, etc, your opinion is no more valid than anyone elses, and definitely not fact. Try a simple test, throw quality filters on a white background and to the same with cheap glass, any of those look a bit yellow to you?

Not at all. The testing was "blind." It fit all the parameters of scientific testing as laid out by the Physicist among the photographers in question. He was convinced by the results and even designed the testing method. He also has a Phd in physics and, besides doing photography, designs digital spectrographs. He's pretty good at optics also.

Each one made shots with each filter. The shots were numbered so they could be matched to the filters used in the shots. The panel viewed the images without knowing which was which. We had each photographer vote on every image. I'm talking about results that were random or statistically random. The votes were guesses, not opinions, because the photographers couldn't see differences. It isn't an opinion that they couldn't see any differences. It is a statistical fact that they couldn't see any differences.

Testing flatness, reflection, refraction etc. is fine and could produce mathematically meaningful data. But I'm telling you a panel of pro photographers wouldn't be able to see those differences so they are insignificant for practical purposes.

We did not test any "cheap glass." We tested cheap photographic filters and expensive ones. The collection was assembled from the camera bags of the photographers themselves. None of the clear UV ones had a visible color cast. The skylight filters did have a visible but subtle warming effect. Polarizers had differing abilities to filter polarized light. Colored filters had different color values. But there was no difference in image quality - softness or contrast. There was no flare. Perhaps there are some clear filters with a yellow color cast. We didn't test any.

I promise. I'll never mention it again. I'll just continue using protective filters and avoiding high priced filters. Let's just say it makes me happy. Let's hear it for Tiffen - plenty flat and made in the U.S.A.

 

[The_Traveler]

Without any rancor, can you see why it is difficult to accept data from tests done ten years ago on 10 year old equipment, old filters on unknown photographs made in unknown conditions by unknown photographers that goes against what published experts said?

 

[dsp921]

I promise. I'll never mention it again.

Same for me.

Have a good holiday.

 

[fmw]

Without any rancor, can you see why it is difficult to accept data from tests done ten years ago on 10 year old equipment, old filters on unknown photographs made in unknown conditions by unknown photographers that goes against what published experts said?

Not when the published experts are stating opinion instead of test results. They aren't even stating opinions based on their own observations. They are usually offering up common beliefs. Run the test for yourself. Make images with and without a protective filter. Make them with a Tiffen and a B+W. Then tell me you can see the difference. It may not be scientific but it will at least convince you.

I've been fascinated by a fellow named Ken Rockwell that operates a photo related blog. Much of what he says is just plain wrong and, in some cases, just plain stupid. Yet he is used as an "authority" by many people on the internet, simply because he has the blog and is willing to write into it. He has no credibility with me at all even though he appears to have some to other people who don't seem to know any better. He says some things that are right but I see far too many that are not. I see links to his site relatively often designed to prove a point. They make me smile. Good for him. I hope he's making some money from it.

I doubt seriously that filter technology has changed much in 10 years or, I should say, I haven't sensed any change. Perhaps the Chinese have put a lot of inferior product on the market. It's possible. I really don't know. I am pretty sure that there haven't been any meaningful changes to Fuji Velvia 100 in the past 10 years. I just keep buying Tiffen filters in my own happy ignorance.

The photographic world is full of experts with opinions. It isn't as bad as the investment industry experts, however. They are proven to be wrong as often as they are right. At least photographic experts as a group are right more often than they are wrong.

 

[lee_M]

This comes up all the time. Filter vs. no filter, cheap vs. expensive. I've said in other threads that all glass is not equal and all filters are not the same, some filters aren't even glass. I've worked with optics for more than 20 years (laser applications mainly), but I don't expect that to matter to anyone, I'm just another screen name on the internet. There are people with a lot of internet credibility that have written about this, do some research and decide for yourself. Here's a start:
http://www.bythom.com/filters.htm

Sorry! Thats a bit sh!!ty mate!
Yes i could of done a search on this site but not been very good with the internet and VERY new to this forum and photography, i though it would be better for me to simply ask the question!! and get to know a few people on here!!
I wont bother in the future, :x layball:

 

[darich]

I've got a Canon 5D and L glass and my polarizing filters were both under £25 each.

As has been said flat glass is just that....flat glass and it's not difficult to make to a good standard.
Having used my £25 filters for over a year i've not had any problems or complaints.

I'd definitely pay the prices for a quality lens or a certain brand but for a filter i'm very reluctant. Besides it's almost like a gaurd for my expensive lens so i don't want to spend loads of money for it to get scratched.

 

[lee_M]

I've got a Canon 5D and L glass and my polarizing filters were both under £25 each.

As has been said flat glass is just that....flat glass and it's not difficult to make to a good standard.
Having used my £25 filters for over a year i've not had any problems or complaints.

I'd definitely pay the prices for a quality lens or a certain brand but for a filter i'm very reluctant. Besides it's almost like a gaurd for my expensive lens so i don't want to spend loads of money for it to get scratched.

Thanks mate! great reply
Could you find a Link to the filter you are using so i could have a look at it:mrgreen:

 

[dsp921]

Sorry! Thats a bit sh!!ty mate!
Yes i could of done a search on this site but not been very good with the internet and VERY new to this forum and photography, i though it would be better for me to simply ask the question!! and get to know a few people on here!!
I wont bother in the future, :x layball:

That was a simple link with more information. Your response was uncalled for, get thicker skin

 

[lee_M]

Why do i need thinker skin mate!??

this is a photography forum! what planet are you on!
You don't have to reply with a message like that

 

[darich]

Thanks mate! great reply
Could you find a Link to the filter you are using so i could have a look at it:mrgreen:

I've bought 3 polarizers from Scottish Sterling on Ebay.
I only have two lenses but one one occasion i slipped while taking a photo in a river and thumped by 20D and 24-70mm L off a rock. The lens ring was dented and the filter destroyed since it wouldn't rotate. I was glad that i hadn't spent a fortune.
All three filters i've bought from the above company arrived quickly and without any trouble.

Good thing is, you're in the UK too so postage and currency will be no problem and you could even phone them if you were unsure. They've got excellent feedback as you can see (only 7 negative responses in nearly 20,000 this year) so I'm sure you'd be fine to buy from them.

:thumbup:

 

[lee_M]

Your a legend mate thanks very much!
Thats the type of reply i was looking for!

 

[Alex_B]

huh, didn't expect this thread would create such emotions... after all it is only about glass

OK, I have to admit, with my filters I never got flare in extrem lighting conditions which would disappear when I remove the filter .. but then again I never seriously used cheap filters (except on cheap lenses, but then you don't really have a valid comparison).

However, the cheap filters had more sensitive surfaces (more prone to scratching) .. as for the poor imaging quality, this will be mostly due to the cheap lenses they were screwed onto.


so I am not really qualified to to comment here (and my materials science knowledge does not help me here, as it is about the impression of an image, and not about a measured spectrum which will of course differ from cheap to expensive)