UV filters?

[InfiniteLoopy]

Hello all,

Up until now, I never use filters except for a polarizer when necessary. I've read that some photographers use a filter such as a UV on their lens at all times to protect it. Is that generally recommended?

Thanks,

 

[ComputersaysNo]

The only reason i use an UV filter is so that i can clean the frontglass with my T-shirt if necessary, without the risk of slowly polishing the frontlens over time. Other than that, there's nothing it does that photoshop can't do.

 

[InfiniteLoopy]

Hi,

I'm not looking for it to add any effects and I don't even like modifying in Photoshop. It was rather as a protection that I was asking.

 

[ComputersaysNo]

well, it does have some effect;

A typical UV filter in photography is transparent to visible light while filtering out higher ultraviolet wavelengths. Historically, some photographic films were sensitive to UV light, which caused haziness or fogginess, particularly with a blue hue. However, newer photographic film and digital cameras are highly insensitive to UV wavelengths. UV filters are sometimes referred to as L37 or L39 filters, depending on the wavelength of light that they filter out; an L37 filter removes ultraviolet light with a wavelength shorter than 370nm, whereas an L39 filter eliminates light with a wavelength shorter than 390nm.

Many photographers still use UV filters as protection for their lenses, due to their low cost and lack of effect on the exposure of the shot. However, UV filters (in particular filters lacking optical coating) may introduce lens flare and have an adverse impact on contrast and sharpness, especially when a strong light source is present

 

[glocke12]

I used them at first all the time to protect the front of my lenses, but than as I started buying more expensive glass I stopped.

A few reasons are:

I noticed flares in some shots caused by the UV filter..

In rare cases some users get reflections from the filter (http://www.flickr.com/groups/canon_50mm/discuss/72157603907741669/)

It seemed silly to put an inexpensive piece of glass on the front of
a $1000.00 + lens.

I have found that using the lens hood is sufficient to protect the lens from bumps.

Also, FWIW my lens cleaning procedure really consists of nothing more than dusting off the front of the lens with hurricane blower, and maybe once, twice a year tops cleaning the lens with a GOOD microfiber or lens paper and cleaning fluid. The one thing I don't understand are people that say they need to clean their lenses to remove fingerprints, oils, etc...You should never be touching the front element of your lens with your bare hand/fingers so there should not be any residue on there from your hands. Also, keep in mind that if you wipe the front of your lens with a cloth and there are dust/dirt/sand particles on your front element these may act like an abrasive and introduce "micro-scratches" into the coatings of your lens. This is why I use a hurricane blower 99% of the time, and only use cleaning solutions and lens paper/microfiber very rarely.

Be aware that microfibers differ in quality. If you get one to clean your lens dont cheap out.

 

[throttlemeister]

I used to use UV filters, then I started buying Canon L lenses and started noticing differences in color and contrast when the UV was attached. Ever since, I don't use a UV filter anymore.

 

[jabbott]

Up until now, I never use filters except for a polarizer when necessary. I've read that some photographers use a filter such as a UV on their lens at all times to protect it. Is that generally recommended?

It depends on the lens. For many Canon L-series zoom lenses, the weather sealing is not considered complete unless a filter is attached to the front. Here is an article that talks more about weather sealing. I use UV filters to keep dust from getting sucked in through the front of the lens, as well as to keep the front element pristine. If you are considering using a UV filter, here is a detailed review site.

The internal reflection issue mentioned in a previous post is something I've only seen with the 50mm f/1.4 USM. That lens isn't weather sealed anyway, so using a UV filter on it (and all other non-weather sealed lenses) is optional. In those cases, using a lens hood instead is a good idea to keep things away from the front element.

 

[fcortese]

Short answer, no to UV filters. As to "weather sealing" for Canon L lenses, Canon does not REQUIRE it only "recommends" it. I have heard from multiple pro photogs that UV filters are just money makers for the seller and the lens compnay.

 

[Padaung]

I used to always advise putting a UV filter on the front of a lens, but as others have said: as soon as I started getting more expensive lenses the filters definitely lowered the overall quality - especially regarding colours and contrast. That said, I never then repeated any tests with the very top of the range UV filters to see if they made a difference.

However, I'm currently doing a lot of work by the sea with sand and spray blowing around a lot. I'm finding a UV filter here invaluable as I'm constantly wiping the front and would rather have a UV filter damaged by this barrage of water, salt and sand than the multi coating on the lens. Once I'm out of this environment the UV filters will be back off.

Again, like others I find the lens hood protects enough from general knocks.

I guess the decision ultimately comes down to your personal preferences, and work environment.

 

[compuwar]

Hello all,

Up until now, I never use filters except for a polarizer when necessary. I've read that some photographers use a filter such as a UV on their lens at all times to protect it. Is that generally recommended?

Thanks,

Most of the filter manufacturers also make multi-coated plain glass filters, there are folks who swear by the "protection" offered. For me, I'd rather not lose 10% of my light from another glass->air surface and ~12-15lp/mm of resolution[1] for each and every shot.

Also, the front element of many lenses is simply a protective glass element rather than part of the optical formula and therefore may be economically replaced, and its condition isn't critical to most images. See for example http://www.lensrentals.com/blog/2008/10/front-element-scratches

Paul
[1] I am unable to find the citation that asserts the loss of sharpness, but I recall it was in that ballpark.

 

[Chappers]

Have to agree with what others have said about adding a cheap piece of protection over the lens, it does protect but downgrade image quality so I stopped using them.

 

[Ruahrc]

Can't say I entirely agree. I have conducted tests with my uv filter both on and off,'and I cannot find any discernible difference between having it on or off. It is possible that in some situations I would get some ormore flare, but as long as you have a quality filter most circumstances you won't be able totell the difference.

If one actually lost 10% of the light to the added interface, there would be a visible difference in equivalent exposures between having it on vs off. I saw none of that either.

If you are mainly interested in protection, a no color or clear glass would work just as well, possibly better. Some cheap UV filters don't block just UV, and can block some of the deep purples as well. The whole UV-blocking aspect is an old holdover from film days because film was much more sensitive to uv than silicon sensors.

So the main point is, if you do choose to protect, get a good quality multicoated filter to do so, and take the filter off if you are using any other filters (stacking can quickly begin to degrade image quality)

With my first lens I bought a UV filter, a good quality one. I use it all the time on it except when I am using a CPL. however, when I bought my second lens, a higher quality wide angle with a different filter thread size, I didn't bother to get an additional protection filter for it. I don't miss not having one. If I will start shooting in hostile environments I may pick one up later on.

Ruahrc

 

[flosseR]

I have to agree with Ruahrc, I too have shot with and without UV's and i'd be hard pressed to notice a big difference. HOWEVER, if you want to get a filter as a protection, which DOES help, make sure you get good ones. When I say good ones I mean the 60-100+USD B+W filters.

 

[VirtualRain]

I think protective filters have a roll to play when shooting in extremely harsh (eg. dusty or sea spray) conditions. For example, I wouldnt want to cover a rally race without one. However, most of the time I see no need for one. My lens caps and hoods provide plenty of protection. If I ever end up shooting in harsh conditions I would get an affordable UV filter just for that shoot... And possibly view it as a disposable item after the shoot if it did it's job and got scratched or scuffed in the process.

 

[InfiniteLoopy]

Thanks for all the replies.
I do have hoods on all my lenses and am careful with them.

I guess I'll continue as I've been doing, without filters.

 

[HBOC]

I don't waste my money on UV filters. The only filters I use are Singh-Rays or B+W ND filters, but haven't used even that in months, as shooting waterfalls in the rain is the best time (and it is always cloudy/rainy here in the winter/spring..has rained 13 days this month here in Portland).

As stated, UV filters I used back when I was shooting film as it actually would help with the light (film sensitivity) but that was very seldom when I did use UV filters as I didn't do much mid day shooting.

Here are a few threads on FM that I have responded to and are good reads..#1
#2

 

[compuwar]

If one actually lost 10% of the light to the added interface, there would be a visible difference in equivalent exposures between having it on vs off. I saw none of that either.

The optical design rule of thumb I've always been given is most air/glass interface lose around 10%of the light transmission due to the reflectivity of the glass- that's not likely to bias a camera's meter in most cases.

The numbers I've generally seen are about 4-8% given that you have two air/glass surfaces in a filter, that's 8-16% of the light, though I've seen measurements for a Helionpan digital UV filter of 1/3 of a stop quoted- but I don't shoot with UV or Skylight filters, so I'm going purely on reported measurements.

A lot depends on the coatings and the glass used- and of course the loss will vary with wavelength, but it's definitely there.

B+W's MRC-coated UV filters claim to only only lose 5% of the light (filter factor of 1.0) while their "Skylight" filter loses closer to 10% with a filter factor of 1.1.

http://www.bhphotovideo.com/find/newsLetter/filterIntro-revised.jsp

Filter factor is 1.0.

http://www.photofilter.com/hoya_factor.htm

Hoya's UV and Skylight filters both have a filter factor of 1.0. Again, that's generally a loss of 5% of the light- though they claim transmission loss of 3% for their HMC and .3% for their SuperHMC filters- so this is one place where spending lots of money on a filter makes a difference as the price is about double from one extreme to the other.

Personally, I'd rather eventually replace a front element if I ever need to than haul around about ~$800 of SuperHMC UV filters, which is what it would take to "protect" all but my big gun where the front element is simply a protective piece of glass and all filters go in the back. Anything else, I'd rather have that bit of light.

Quantaray Skylights are 1.1, I can't find a filter factor for their UV filters online, though I've heard their "Pro" line are re-badged Hoyas of some description.

Paul

 

[Laird Knox]

A UV filter makes a big difference on one of my D70s. Then again I've replaced the hot mirror so it now passes both IR and UV, but I'm just odd like that

The Milky Way sure is a lot more milky without any filtering.

 

[jackerin]

I don't use UV or any other protective filters, but I'm starting to see the benefit. I was shooting at a party and had the camera bag next to a table, I put the camera into the bag without the lenscap on and when I took it out later I had potato sallad smeared on my lens, apparently someone had caused a dirty plastic fork to drop into my bag, along with whatever was on it.

Could have been worse, but it was not cool to start rubbing potato sallad from the front element of my f/2.8 zoom, even if it's only a Sigma.

 

[compuwar]

I don't use UV or any other protective filters, but I'm starting to see the benefit. I was shooting at a party and had the camera bag next to a table, I put the camera into the bag without the lenscap on and when I took it out later I had potato sallad smeared on my lens, apparently someone had caused a dirty plastic fork to drop into my bag, along with whatever was on it.

Could have been worse, but it was not cool to start rubbing potato sallad from the front element of my f/2.8 zoom, even if it's only a Sigma.

The lens cap would have been a better protector.

Paul

 

[jabbott]

Hoya's UV and Skylight filters both have a filter factor of 1.0. Again, that's generally a loss of 5% of the light- though they claim transmission loss of 3% for their HMC and .3% for their SuperHMC filters- so this is one place where spending lots of money on a filter makes a difference as the price is about double from one extreme to the other.

This Hoya HMC UV-0 filter review shows a 97.1% transmission of visible light and 0.2% transmission of UV, which is in line with what you mentioned. The Hoya Super-HMC UV-0 filter isn't much different however -- it has a 97.3% transmission of visible light. That is still an impressive amount of transmission considering only 0.2% of UV gets through.

The reviewers used a Hitachi U-2900 spectrophotometer and claimed to have 0.3% accuracy with the device. The surprising difference I noticed with the other filters they reviewed is that many allow 97-99% light transmission but their ability to block UV wavelengths greatly varies from 99.8% to as low as 68.5%.

Don't forget that 63% of all statistics are made up, so all of this could be fabricated.

 

[compuwar]

Don't forget that 63% of all statistics are made up, so all of this could be fabricated.

The test looks like a reasonable apples-to-apples comparison. The discrepancy between their and Hoya's numbers could be valid, or it could be process-related- as they really don't describe how they measure the light and under what conditions it's very difficult to tell- (Neither do Hoya- the fault could lie in either direction.) Reflections tend to affect off-axis light more, and it could be that Hoya lines up a light and tests straight through, for example. The DSLR's hot mirror is also going to block some UV, so it's really difficult to say with any certainty that the amount of UV blocked is going to make a bunch of difference without a lot of testing- and that might even be camera-model specific but if your main goal is protecting the front element, then Hoya seemingly wins hands-down. I'd probably still go with the extra coatings though, since I don't know where the measurement discrepancy is. But as I said, I have yet to have to replace a front element- so I'd rather have the light, even at 3%.

Paul

 

[Ruahrc]

It's a little OT but I also found lenstip's polarizer comarison to be an informative read.

 

[glocke12]

I don't use UV or any other protective filters, but I'm starting to see the benefit. I was shooting at a party and had the camera bag next to a table, I put the camera into the bag without the lenscap on and when I took it out later I had potato sallad smeared on my lens, apparently someone had caused a dirty plastic fork to drop into my bag, along with whatever was on it.

Could have been worse, but it was not cool to start rubbing potato sallad from the front element of my f/2.8 zoom, even if it's only a Sigma.

Don't want to sound like a jerk, but you need to take better care of gear and be more attentive of where you put it when not using it.

 

[The Mad Kiwi]

I don't use UV or any other protective filters, but I'm starting to see the benefit. I was shooting at a party and had the camera bag next to a table, I put the camera into the bag without the lenscap on and when I took it out later I had potato sallad smeared on my lens, apparently someone had caused a dirty plastic fork to drop into my bag, along with whatever was on it.

Could have been worse, but it was not cool to start rubbing potato sallad from the front element of my f/2.8 zoom, even if it's only a Sigma.

Too funny, you'll only do that once.

I use UV filters ocassionally if I'm shooting at the beach and it's windy. Other than that they just degrade the image. They're a hangover from the film days when some films were slightly sensitive to UV light and they would actually improve the image by removing some of the UV scattering from haze.