I don't use protection filters except in extreme conditions. Never had any lens damaged or scratched. My daughter once thrown whole content of a baby food jar to my lens, but it was easily cleaned with distilled water and did not leave any traces. Since I started using Zeiss lenses, I even stopped using polarizers.
It's exactly what it's stated to be. An example of the mentioned phenomena.
BTW, I have to agree acetate (resin) filters are the pits! They were sold to me as being "optically superior" (to glass?) by a shop clerk but when I tested them... oh my goodness! I got them cuz I couldn't track down any glass IR filters locally. They were IR so I didn't know if it was my lenses or what. Then I tried a UV of the same make and wow - how terrible!
Left with B+W MRC UV filter. Right without. This is a crop. The 35Lux ASPH is quite good when it comes to CA but its still there. The filter made it worse. Not as bad as Luka's sample but its still there. Is it enough to bother me? It depends on the trade off and what I'm shooting. Its quite impossible to add another layer of glass in front of your lens and have zero degradation or diffraction of light transmission.
Yes, its possible that the focus is out. I have some other controlled test on tripod but I can find those shots right now. Some are worse than this shot. Really, my experience is that I see this degradation of IQ on my more expensive lenses, especially on my M mount lenses. On my Nikon lenses I don't see this. It could be a combination of lens and sensor, not sure.. just speculating.
edwardkaraa wrote:
The flare thing is total BS. Many tests and comparisons have been done. There may be flare with the filter, but when you remove the filter, guess what, the flare is still there, probably slightly less, but there nevertheless. Same goes for ghostings at night. .
I am primarily a night photographer in winter, and shoot a lot of trains (railroad.) I've had many terrific shots ruined by flare caused by a stupid filter on my lens, including MRC coated. When I quit using filters, my keeper rate soared. I honestly think filters can do more damage to a lens than they prevent, although I will use one on rare occasions, such as shooting in waterfall spray. Even then I've not had any damage to a lens because I had no filter, but it made lens clean up faster. Filters are very thin and flimsy and I consider them as only able to offer impact protection from marshmallows. Lenscaps are nearly bulletproof.
i voted never even though i agree there are occasions where it would seem that a filter could be helpful (high winds and sand). since i don't bother carrying them normally, i don't have them to use in such situations. on the few occasions i've tried them (mostly blizzards) i've always noticed ghosting and other image degradation.
i've never had any lens damaged and i have a great deal of difficulty imagining a frontal impact situation where a filter would help rather than hurt. as far as i'm concerned their only use is keeping dust off the lens during it's tenure with whoever owns the lens before me. on the rare occasion i need to clean a lens with something other than a rocket blower, i usually remove the front element to clean it.
i also don't use hoods unless the lens has a built in one (woo leica!), too bulky and awkward. if i need one i can improvise (but i kinda like that kinda flare). my lenses are always protected by old school metal screw caps when i'm not shooting with them. btw, does anybody know of a source for used screwcaps (or have some they want to get rid of)? i like the ones from the 50 years ago better than the ones currently available (sorta like my taste in lenses).
FlyPenFly wrote:
Denoir: Are you sure the focus is the same? The left looks slightly out of focus compared to the right, especially the details on the roof.
No, I'm not sure as I'm a complete novice who has never done a photo test of any kind before in my life Of course I'm sure. The focus wasn't moved and it was shot at f/6.7 so the DOF is large to start with. The left one is not out of focus, but the detail has degraded.
A filter, any filter, including a high end Leica one results in a degradation of quality - primarily resolution. You won't notice that with an AA equipped camera that smears the details anyway but it does become evident when you use an AA free camera.
At f/8, no filter on the left, filter on the right:
That is an interesting theory, Luka. It may explain why I don't see the effects of the filter, having tested on A900 which has an AA filter. The AA filter by blurring the fine detail equalizes the results. On the positive side, you can use UV filters on your M lenses to reduce moire
denoir wrote:
Edward, yes there are actually filters designed with that in mind - they're very popular with the video DSLR crowd who have real moire problems
As for lens hood yes (the 90 Cron AA has a built in one).
I'm a bit disappointed that you used the hood
Otherwise I have no explanation to that evident loss of contrast, very puzzling
I have noticed similar behavior from my ZM 85/4 with filter/without hood when the light hits the filter glass directly reducing the contrast. Without filter the front element is a bit recessed so it doesn't suffer from that. However, once I bought the hood, no more problems with this kind of lighting.
The loss of contrast is so extreme to my eyes that I would be very surprised if anyone used any filters after seeing these results. But then again, I would also not recommend to anyone getting a camera with an AA filter either
I think filter quality matters. The Hoya HD filter in question is crap. The Leica filter produced much better results. As I said, if you want to see really bad degradation in quality, try a plastic Cokin filter
Hoya HD filters are actually really good filters....It's Hoya's best filter line, and from all reviews I've seen, they are outstanding, with really high quality coatings and stronger glass than most filters.
Just lets you know what sort of degradation most people experience and don't realize it by using them.
And I still have yet to ever see a single instance where a filter saved a lens in a drop. (blowing sand...yes. Salt spray.....yes. Flying dirt and debris....yes. Drops? Nope.) People always insist "I dropped my lens, and look, the filter shattered, but the lens was fine. The filter saved the lens!" There is no correlation there. The filter is going to break if you drop the lens from any real height. However, that means NOTHING about whether or not the lens will break. The impact absorption capabilities of a rigid filter ring with thin glass is next to zero. All having a filter on does when dropping your lens is expose your front element to shards of shattered glass. If your lens is safe and the filter shattered, your lens would have been safe WITHOUT the filter. About the only time this isn't the case is if you happen to drop your lens in the woods, and the front element glances off a stick or something, where the filter would have taken the impact and deflected things.
For the money I've saved by not having filters on all my lenses, I've already paid for about 10 front element replacements, so if it happens that one in 10,000 chance, I have no regrets. And the fact is, a front element replacement isn't that expensive. It's usually about $100 or so...about $40 more than the cost of a good UV filter. And since if you break or badly scratch a UV filter in 'protecting' the lens, you need to replace that....it is actually a wash to replace a front element vs. purchasing good filters for all your lenses.
Lenscaps are nearly bulletproof.
Of course I'm sure. The focus wasn't moved and it was shot at f/6.7 so the DOF is large to start with. The left one is not out of focus, but the detail has degraded. 
