canoneer

A better way is to compare histograms of the two images. They should match almost perfectly.

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

Actually, your "test" proves nothing. In order to really ascertain differences you need to bench test the lenses/cameras/filters. A simple test like what you posted is subject to too many variables beyond your control

lea001a Loc: Catskills Region in New York

As I recall, historically, the purpose of an UV filter was to eliminate or reduce drastically blue from haze in the atmosphere that was overly emphasized on the FILM recording of the scene or whatever was producing the blue haze. Typically, films was highly sensitive to blue produced by UV in the light. Recall if you can a scene in the Grand Canyon in early morning. WOW, remember the bluish overcast!

Digital sensors do not suffer from high sensitivity to UV light. There is no real need for an UV filter on a digital camera. But, if you must, get the best one made by B+W; you'll be satisfied by it's failure to alter the image in any way, especially optically.

cambriaman Loc: Central CA Coast

Have we settled anything? A lot of opinion expressed. A lot of theory expounded. One of the longer threads I have seen. As usual the original question was lost for a while until someone reminded the audience of what we were about. Is there an answer in this somewhere, JimBob?

photoman022 Loc: Manchester CT USA

I'm not going to venture a guess (okay, #2 had the filter). In the original photo the only difference I noticed was change in "skin" tone between the photos. #1 had a more orange cast throughout the face.

In the second photo crop, I had to look closely and it seems that photo 2 is a tad sharper in some areas but not in all of them! My eyes are not as good as they used to be, but the ribbon in photo 2 looked sharper, until I looked at it again, and then I couldn't see any difference.

I can't afford new lenses and the like so I will continue to use my UV filters!

SonnyE Loc: Communist California, USA

Oh, it's not worth doing that....

jenny Loc: in hiding:)

* * * * *
Since the subject has been debated ad nauseum, it is up to you to decide what you want to do. However, if aware of these many discussions, you should know that the UV filter is not one that was ever intended to be used for portraits or other close subjects.

Bear123 Loc: Wild & Wonderful West Virginia

Don't really see a difference that matters maybe some difference in brightness. Just curious to find out which one had the filter and which filter was used.

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

With these type images, I doubt you would ever see a difference. Try the same test at night with a candle or other source of light in the frame & you will see a ghost image of the light source in the frame. A more highly coated filter will minimize the reflection, but not eliminate it. In normal scenes, the effects just are not visible in most scenes. A filter as a form of protection is limited. It can prevent some things like fingerprints on the front element, but if a lens is dropped hard enough to shatter a filter, it's very likely that the electronics & mechanics of the lens will suffer... .

Basil Loc: New Mexico

I agree - up to each individual (also agree it's been debated ad nauseous). I used to use UV filters, but only as lens protection. I changed my opinion over time and now, my personal preference is to NOT use a UV filter, but rather use a lens hood (and be friggin' careful) for protection.

I still have several UV filters and I suppose if I were going to shot an event where lots of flying debris were possible (like a dirt bike race), I would put one on out of an abundance of caution. Otherwise, why spend $2k on a lens, then put a piece of crap glass in front of it?

Merlin1300 Loc: New England, But Now & Forever SoTX

First: I read most of the drivel <sigh> in all of the thread pages.
Yeah - - self punishment - - but there you are.
-
Second - to answer the question. In the photos taken, I can't tell the difference.
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Third: THANKS to Cholly for posting this link : http://youtu.be/P0CLPTd6Bds
EXCELLENT work by Steve Perry, and answered MANY of my own questions
Also - remember - scratches on the front element are extremely unlikely to produce ANY effect on the image captured.
I DO think the filters provide some protection against elements such as dust and salt sea spray, and WILL produce additional flare if a point light source is in the image.
Very interesting thread - and why most of us belong to the Hog.

lev29 Loc: Born and living in MA.

Thank you, Screamin Scott! If one refers back to my 1st post on pg 5, I believe I laid the ground work for an even graver, salient point: the original poster's point, assuming his was to show a lack of appreciable difference between the images purportedly take with and sans a clear filter, is NOT A VALID POINT, per se, in establishing that the filter makes no optical difference!

As we in the Sciences, especially those in the Medical field, say, "one, in a series of one ... " [this followed by, in our thoughts,] "this proves nothing."

However, SS, I cannot fully agree with your point as to the necessity of bench-testing every component in Jim Bob's system that created this pair of images. As I understand it, your particular point IS APPLICABLE WHEN attempting to elucidate the cause or causes of WHY the image pairs are DISSIMILAR, but not absolutely necessary, I believe, for proof that the pairs are indistinguishable from each other.

Was it you, SS, or someone else who doubted whether Jim Bob presented the image pair to be created with the only difference between the two being the use of a filter? No matter. My point here is that I'm inclined to give Jim Bob the benefit of the doubt. Whether he says there is a discernible or not, it cannot be verified without his giving us the exact materials & methods (aka M&M,) he employed and then someone would, we might hope, validate his findings.

As for Jim Bob's reply to my first post that my response is "borderline" relevant, I submit that he's just plain wrong. My 2nd, 5th, and 7th paragraphs are opinions, yes, but my response is quite GERMANE in pointing out the FLAWS in your unheralded but implied POV on the matter of lack of distinguishability between the two photos. Oh, I know: I'm creating an issue out of something you didn't actually write in your first post, eh?

My counter to such an evasive reply would be that you know you have a POV, what do you expect people to believe it is, and that if I'm so obviously wrong, then WHY DIDNT YOU DECLARE WHAT'S NOT YOUR POV or AGENDA? Or is it that you're conducting a self-styled Psychology Experiment?

No, Jim Bob, your credibility, per se, is not shot, YET! But labeling my points, as to how to prove the POV that the with/sans filter question, as irrelevant is ASININE! No sir, Jim Bob, in science one must eventually put or shut up. Your credibility is not at stake here. To me, it's the question of whether you present material that is worth my time to read that's at stake. But I suppose that that's just my opinion.

A magician is not obliged to reveal his methods for creating an illusion, but a credible scientist MUST do so regarding the conclusions reached! (I must concede, though, I don't know how necessary M&M are in the fields of Theoretical Physics and Chemistry.) Therefore, I submit that if Jim Bob NEVER reveals the truth about which is image is which followed by his methods, THEN it would be logical to surmise that he's either "full of it" or a very sloppy scientist, indeed.

Refutation, anyone? Agreement or modifications thereof, anyone?

Thank you,
lev29

Ralloh Loc: Ohio

Oh brother. Time to stop watching this topic. Adios.

CHOLLY Loc: THE FLORIDA PANHANDLE!

Papa, there is no way to know if the individual who started this thread even used a filter in the first place, and given his "agenda" in saying their presence does not affect image quality, that is a valid concern.

There are a number of factors involved in demonstrating the positive and negative effects of protective filter use... very few of which can be legitimately demonstrated by THIS example... even if a filter WAS actually used.

As to the question of protection... well, yes; a filter will keep your front element from getting dirty, with the cost of reduced image quality. But that is NOT protection from physical damage. Filters are NOT designed for OR are capable of protecting the front element of a lens from physical damage.

There is NO question about that. Thin, soft, cheap glass will NOT stop something capable of damaging the thicker, harder front element of even the least expensive kit lenses. Using filters for that purpose is the same as putting saran wrap in front of your car windshield and expecting it to stop rocks from cracking your glass. It's a waste to time, money, and effort.

CHOLLY Loc: THE FLORIDA PANHANDLE!

Perfect. :thumbup: