UV Filter Degrades Image Quality

I know this has probably been debated ad nauseum...but it seems on my Nikkor

70-200 f2.8 with filter IQ is MUCH softer than without....Could be random

variation....your thoughts?

Probably not random variation...many lenses lose image quality when anything comes between the object and the lens, especially if it isn't of superb optical quality.

Mine is the Tiffen 77mm UV Protection filter....$30 version...does it make sense to use this on this caliber of lens?

Cr@p filter?

It is known that all filters degrade image quality. They are way overused--should only be used when that is the only way to get the picture. I am sure most of you disagree, but you do not have to tell me so.

I am not surprised at all as Tiffen filters are cr@p to be honest. Maybe they are making some special grade filters for hollywood I don't know, but those you can buy at the retail section are overpriced pieces of cr@p. Sorry I have to say this word twice, but that's exactly what they are. Buy HOYA, buy B+W, buy Nikon, but no Tiffen please.

cokin ?

OK...so I tested the Tiffen on/off my 70-200 VR using a tripod and shooting a newspaper...no doubt about it, the filter makes a difference....here's what's interesting...I put on my 1.7 teleconverter and re-tested...The 70-200 VR with 1.7TC at 200MM is sharper without a filter than the 70-200 VR alone with a filter...the Tiffen filter degrades more than a 1.7 TC!!

The above experiment is also true using a Promaster filter!!!

Why are people surprised to find that a $30 piece of glass degrades IQ on a $1,600 lens?

 

And then why do other people conclude that "all filters degrade IQ" based on the results from cheap filters?

 

Buy Hoya Super HMC or B+W. (Beware that Hoya makes cheap filters to. Stick with Super HMC.)

 

And throw the Tiffen in the trash.

I have a promaster filter on my 18-200 and did a test and found no insurmountable

difference between with and without. Don't have any Tiffen, thank goodness. I've had a

couple occasions where something bumped my lens while I was shooting and I was glad to

have that UV. If I could always go without it, I think I would.

I keep either B+W or Heliopan multi-coated UV filters on all my lenses for front element protection and have never noticed any image degradation. If your image quality is, indeed, suffering, Morgan, then this could be a wise investment. Good luck.

First of all, Morgan, I have locked your 2nd thread on this topic:

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00KYYw

Please focus this topic within this one thread.

 

If you actually see some serious degradation of your image quality as a result of a protective filter, that filter has to be really poor in quality or it is not clean, or perhaps there is some sort of error in your comparison.

Standard Tiffen filters are not coated. Also, many are glass laminate rather than solid glass.

You will see better performance using a filter that is muli coated on both front and rear

surfaces. Good filters cost more. Its just a fact of life.

All filters represent some degredation of IQ, no matter how much you spend on them. Sometimes the compromise is worthwhile if you need a polarizer or CC filter, but otherwise I choose to avoid them. The hood and lens cap adequately protect the lenses I use, and I have never had a problem.

So I asked a friend of mine who maintains some space telescopes at Stanford...he said filters that are not of similar quality to the lens have a degradative effect on image quality and this is really pronounced on space instruments...that's why they don't use filters on their telescopes. I've convinced myself, no more filters unless I need them for a specific reason. I'm hard on camera equipment in general and I'm sure I'll end up breaking both lens and filter within a year or two!

"The hood and lens cap adequately protect the lenses I use, and I have never had a problem."

 

 

 

There are many times when a filter should be used for protection, Anthony. In dusty conditions for instance, or when shooting on or near the ocean.

 

Here in Hawaii, the dust blowing around in many locations on the islands is volcanic in origin and extremely abrasive. Wiping this material from the surface of your front element by any common means will scratch the lens surface. Granted, volcanic dust is not something most people will encounter. However, even constantly having to clean the front surface of your lens in dusty locations will damage the coating of a lens.

 

While shooting in the parks of Paris on windy days, I have been engulfed in dust storms of crushed limestone particulate which the French use to pave pedestrian pathways and courtyards. After cleaning this material from my filter surfaces over a period of days, I noticed they were getting scratched. I then started cleaning them at the end of the day in a solution of warm soapy water and then rinsing.

 

I have always kept protective filters on my lenses. The only exception to this was in my studio, but even there, I often used corrective filters by necessity.

 

My recommendation would be to use a quality protective filter all the time, unless you can determine that it is absolutely unnecessary or undesirable in specific circumstances.

I would be willing to bet that if I posted two photos up here on photo.net, one taken with a filter, one taken without, that nobody would be able to tell which was which. A good UV filter with multicoatings won't change the optical performance of a lens to a degree that will be noticable under normal circumstances. I use UV filters on all my lenses and I've never had any optical problems with any of my photos.

 

For the last time, a good quality UV filter (I prefer and mostly use Hoya HMC Super but have some Nikon and one B+W, others prefer B+W or Nikon, all three are excellent) is a good thing to keep on the front of your lens. Why? Because it will protect the front element from getting dust, dirt, sand, and other foreign material on it. Why is that bad, you say? Because cleaning the front element of any lens can damage the coatings and scratch the surface of the glass unless it's done properly. And once you get a scratch on the coating, THAT will damage optical performance.

 

I clean my filters a couple times a year by taking them off. The front elements of my lenses are all pristine and don't need cleaning. I've seen lenses that people didn't protect with UV filters, and they have had chips and other damage on the front elements.

 

So you can go without a filter if you want to take a chance. I prefer to protect my lenses as best I can. I also recommend using a lens shade along with the filter, which I do. A hat or hand can act as a shade in a pinch, but I prefer to use a shade.

 

Dave

My F3 and 35-70mm fell off the rock ledge I had placed them on while scrambling, once, and tumbled about five feet before bouncing off some more rocks and coming to rest. I thought the lens was jammed, for sure, and that the body might be a write-off as well. The F3's finder had a pretty bad dent in it, though was still functional. To my surprise, though, the lens was fine. The Nikon 1-A filter that was mas mounted to it had its lip collapsed on one side and took some work to remove, but the lens was otherwise unhurt.

 

There's no doubt that the lens would've taken the brunt of that had there been no filter in place. What if that was my 17-35mm? Bottom line: Cheap filters suck, good filters won't hurt you, and is the point of it all worth spiting yourself on a <$100 filter on a several-thousand dollar lens? Be your own judge.

Robert wrote:

 

"There are many times when a filter should be used for protection, Anthony. In dusty conditions for instance, or when shooting on or near the ocean."

 

My reply:

 

There are some times, a slim minority. BTW, I shoot at the beach often and sometimes the salt spray is considerable; but I liberally wash the front element before wiping it with a micro-fiber cloth.

 

Dave wrote:

 

"I would be willing to bet that if I posted two photos up here on photo.net, one taken with a filter, one taken without, that nobody would be able to tell which was which."

 

My reply:

 

Let me choose what you shoot with them; namely shoot into the sun or a bright light source and lets see how well it does. More to the point, I could post a photo taken with a cheap lens or with a P&S camera and one with an expensive lens on a MF digital back and I doubt you could tell the difference of many subjects like deep DOF landscapes by viewing them on the web.

 

Anyway, I'm just offering my opinion based on my experience and my standards -- YMMV and no one is right or wrong here since everyone is different.

"My recommendation would be to use a quality protective filter all the time, unless you can determine that it is absolutely unnecessary or undesirable in specific circumstances."

 

Does anyone else see the backwards logic here? If you assume that one would like the highest possible quality (barring user error) of a photograph using your equipment, doesn't it make sense to only use a protective filter in the RARE conditions where you wish to sacrifice some quality for the sake of your equipment's longevity? Perhaps its just me, but on a day to day basis I never put my equipment in a position to be damaged. If i'm in a dusty area (calm, not gusting winds), I point my lens down or keep it covered by a cloth, but when shooting I can decide what will happen to my lens. The hard coatings on these lenses (Nikon at least) are VERY strong, and made to stand up to dust and repeated cleaning in the field. So i would say quite the opposite. Keep a high quality filter around IF you plan on shooting in or could encounter harsh lens-harming conditions. But otherwise your lens can take it. Use common sense.

I have mentioned this before. When I was a teenager just started to use SLRs, once I was changing lenses, a friend accidentally bumped into my elbow and I dropped the lens on concrete pavement. The impact smashed the lens cap and cracked the protective filter on it. The filter thread was badly damaged such that I had to bring the lens to a repair shop to have the filter removed. However, there wasn't even a scratch on the lens itself.

 

That was a Minolta 135mm/f2.8 all metal lens with a built-in hood that slides in and out, so the hood just slide in and didn't absorb any impact.

 

Essentially things can happen unexpectedly. As long as you have a good quality filter in front, I really doubt that you can see any degradation.

 

We have discussed the 200-400mm/f4 AF-S several times recently. That lens comes with a front protective filter that is removable (unscrew). I'd say it is very clear that even Nikon themselves recommend one on their expensive long teles.

Jim, I think for the vast majority of photos, for most of us, the filter doesn't degrade the

image, if it's a good one. In some cases, shooting into the sun and such, it does. I think it

makes much more sense to leave the filter on until you get into that situation, which is the

opposite of what you say. Then while you're shooting in those situations you're extra

careful.

 

I get my camera into situations where it might get bumped or something all the time, I am

very careful, but on at least two occasions, the filter has saved my lens when something

happened that I had no control over.

 

A cheap filter is another story, they can be put to very good use as a miniature frisbee...

Shun wrote:

 

"As long as you have a good quality filter in front, I really doubt that you can see any degradation."

 

Peter wrote:

 

"Jim, I think for the vast majority of photos, for most of us, the filter doesn't degrade the image, if it's a good one."

 

My reply:

 

There is a hint of qualification in these replies, but I will say without any qualification that filters always degrade (however negligible) IQ. The question is how much is acceptable or even noticeable, and there is no one answer to that.

 

My stock recommendation on this issue is to check out: http://www.bythom.com/filters.htm

Unless you have 100% crops in a controlled test to prove that the filter degrades your images, I don't believe it. Getting more flare would be more believable. There are lots of more important factors that would have a greater chance of degrading you image quality. To name a two

1. camera shake (especially a long zoom hand held)

2. focusing error.

 

I don't think I've ever seen solid evidence to back up stories of the filter boogie man. If your that convinced buy a top of the line filter or don't use on.