Nick Carver Photography Blog

Photography Tips, Tutorials, & Videos


UV Filter Use: Does It Degrade Image Quality?

UV Filter Use: Do You Need One?Ah, to UV or not to UV, that is the question. This can be a heated topic amongst photographers. Some argue that UV filter use will degrade image quality, others argue that it’s the best insurance you can get for your expensive lenses. There are merits to each argument and we’ll get to that debate in just a second, but first things first - let’s talk about the purpose of a UV filter.

The best UV filter on the market will do nothing for your photos. That’s the whole point. UV filters are used simply to protect the front of your lens. It’s nothing more than a clear piece of glass that you screw on to the front of your lens and then forget about. You leave it on all the time as insurance. Drop your lens or smack it against a wall when it’s hanging around your neck, the filter will break instead of your lens.

If you get a good quality UV filter, it will protect the front of your lens without affecting the image one bit. If you get a bad one, it might degrade image quality or create more lens flare. And why are they called UV filters? Well, it sounds better than “clear piece of glass to protect the front of your lens.” True, they are supposed to block UV light - and most of them probably do - but it doesn’t matter because UV light doesn’t have any noticeable effect on your photos anyway.

Now the argument in favor of UV filter use is clear (ha! puns...). Put a UV filter on the front of your lens and you got yourself a $40 insurance policy. Replacing a shattered UV filter is much more affordable than replacing a shattered front lens element. And believe it or not, they actually do protect the lens. When I first heard about the purpose of UV filters, I thought, “Come a single piece of glass is really going to do anything to protect the lens.” But they do. Of course it ain’t going to protect against a 5-story drop from a hotel balcony, but it’ll protect against those really frustrating “it just barely slipped out of my hands” kind of mistakes.

B&W UV MRC Filter

My UV Filter of Choice is the B&W UV MRC
Click Here to Purchase Yours from B&H

The argument against UV filters is, shall we say, untenable. Anti-UVers say, “Why would you put a $40 piece of glass in front of your $1,000 lens? A lens is only as good as the glass in front of it. You want to turn your $1,000 lens into a $40 lens? Huh? Do ya, punk?” Alright, maybe they’re not that hostile.

This argument is based in theory, not practice. Sure, it makes sense in theory that another piece of glass is just another chance for image degradation. But I’m betting the people spewing this logic have never actually done a side-by-side shot with and without the UV. This also sounds like the logic of someone who has never damaged a lens before. It’s easy to say “don’t get car insurance” if you’re never had a fender bender.

And by the way, I did do a side-by-side comparison with and without a UV filter. Can you tell which one had the UV filter and which one didn’t? Neither can I...

UV Filter Use: Do You Need One?

Below is a 100% magnification of the above image.
One of the samples below was taken with a UV, the other without a UV.
Can you tell which is which?

UV Filter Use: Do You Need One?

The bottom line is this: If you get a really poor quality UV filter, like the $10 Sunpak ones, then yeah, it might degrade the image a tiny, tiny bit when examined at 100% magnification on your computer screen (but still, I’m betting you won’t see a difference). Buy a good quality UV filter, like those made by B&W, and there is basically no chance of it degrading your photos.

So I generally recommend the use of UV filters to my students. If you want the protection, use one. I do.

What is ISO and What Does ISO Mean?

What is ISO and What Does ISO Mean?The Misconception:
What does "ISO" mean? Ask anyone seemingly "in-the-know" and they'll tell you "ISO" is an initialism for "International Standards Organization" and thus it is pronounced "eye-ess-oh." Sounds pretty convincing, but this is false.

Why This is Wrong:
There is no such thing as the "International Standards Organization." Go ahead, Google it. It doesn't exist. So then what does "ISO" stand for? Nothing. It's not an initialism or an acronym.

Allow me to explain...

Here's where the confusion comes from: although there isn't an "International Standards Organization," there is an "International Organization for Standardization." The International Organization for Standardization is a corporation based in Geneva, Switzerland that sets all sorts of international standards for manufacturing and engineering, one of which is film sensitivity in photography. Their whole deal is getting the world on the same page with standard regulations, measurements, and certifications.

Then what is "ISO?" It's this company's name, that's all. No different than "Pepsi" or "Honda." But "ISO" obviously is not an initialism or acronym because the correct acronym (in English anyway) would be IOS. So then what does ISO mean? Well, it's derived from the Greek root "isos," which means "equal" - like in "isotope" and "isosceles." And if you look at the website for the International Organization for Standardization, you'll find an explanation on why they chose this Greek root instead of an acronym to represent their company (source:

Because 'International Organization for Standardization' would have different acronyms in different languages (IOS in English, OIN in French for Organisation internationale de normalisation), our founders decided to give it the short form ISO. ISO is derived from the Greek isos, meaning equal. Whatever the country, whatever the language, the short form of our name is always ISO.

Couldn't have said it better myself.

The Truth:
So "ISO" is not an acronym. No doubt about that. It's just a company's logo written in all capital letters derived from the Greek root isos. And just like you wouldn't spell out "PEPSI" every time you ordered one, you shouldn't spell out "ISO" every time you talk about it. That's why "ISO" is correctly pronounced "EYE-so." No matter how many times you hear it pronounced "eye-ess-oh," and even though everybody and their mother says it "eye-ess-oh," it just simply isn't correct. Doesn't matter if a guy has been taking pictures for decades or working with ISO standards for 50 years, if he says it "eye-ess-oh," he's wrong.

And just for good measure, here's a video summarizing it all:

My Thoughts and Rants:
Alright, I'll be honest. For awhile I was guilty of thinking ISO stood for International Standards Organization and for years I pronounced it "eye-ess-oh." That was based partly on misinformation from an online resource (What?! You mean Yahoo Answers isn't always correct?) and mostly from my own assumptions. After all, it made perfect sense. But that's what happens when I assume. I make an ass out of u and me.

So I can't really fault people for saying it "eye-ess-oh." It's in all capital letters so it certainly looks like an acronym. And the majority of shooters say it that way even though it's incorrect. But hey, just goes to show you how quickly false information can become "fact."

My only rant on this is that a couple years back I saw on Yahoo Answers that someone posted a question asking what is ISO and what does ISO stand for. Some know-nothing do-gooder happily answered with "It stands for 'International Standards Organization.'" Seeing this error, I politely corrected the answer with the information I stated in this blog post. All was finally right in the world. But sure enough, a few days later I get a notification that someone has "improved" my answer. I go to check it out and some idiot changed it back to the wrong answer! 

Don't get your information from some dumb yahoo on Yahoo Answers. And don't let anyone try to correct you into saying it the wrong way. It's "EYE-so."

Everyone say it with me now: EYE-so!


The excellent video and audio production was done by my brother Blake Carver. Check him out at