Lens Filter Selection: ND, UV and polarizer

[SpinnignCone]

I'm currently in the process of upgrading to an SLR from my Cannon S5 IS P&S and trying to get some initial gear.

I'm looking to get 3 filters a protection filter a polarized filter and a ND filter and was looking for suggestions.


for the protection filter it seems most people get a UV filter but i cant seem to find any photo results or users who can claim a significant enhancement on a digital camera. so seems a waste to spend extra on uv filtering i don't need. however i do want a multi-coated filter to prevent flare. Can anyone recommend a good quality protection filter. I'm looking for 77mm (i intend to get sizing rings rather than mes with multiple filters)

For the polarized filter I'm trying to figure out if getting a linear filter will affect the auto focus on the Rebel XSi (EOS 450D) I'm familiar with the physics behind polarized filters and have even been guilty of trying to hold my sunglasses in front of my point and shoot but i cant seem to find any consistent information about the AF issue on this model. i would just get a circular one but they are expensive and i figure i might e able to find a nice used linear one on the cheap. overall I'm looking for recommendations i intend to use this mostly for scenic views and in bright light.


last I'm looking for an ND filter. i do lots of hiking and have been fustrated with trying to achieve that "soft water" effect in brighter conditions. i have a few really nice ones from some very overcast days but i just dont have the aperature on that camera for bright light and on the SLR i think i could stop it down but most of the cheaper lenses (particularly the super zoom series) tend to get their best sharpness in the f/8-11 range (shallow DOF not the biggest issue) so i figure an ND filter would be a nice option. does anyone have recommendations for brands or levels of ND I'm looking for something that can get 1/10 - 1/4 shutter speeds in moderate to bright light around f/8 at ISO 100


all in all any help would be nice in tryign to balance cost with quality (id rather spend the extra few bucks to not have to buy new filters later)

[Colin Southern]

Hi SpinnignCone - welcome to the CiC forums - nice to have you with us.

I'm looking to get 3 filters a protection filter a polarized filter and a ND filter and was looking for suggestions.

OK - here we go.

for the protection filter it seems most people get a UV filter but i cant seem to find any photo results or users who can claim a significant enhancement on a digital camera. so seems a waste to spend extra on uv filtering i don't need. however i do want a multi-coated filter to prevent flare. Can anyone recommend a good quality protection filter. I'm looking for 77mm (i intend to get sizing rings rather than mes with multiple filters)

Modern digital camera sensors don't respond to UV light - so UV filtering per sec isn't beneficial. However, UV filters are commonly available and don't attenuate the light - so they become the defacto choice for front element protection. Some manufacturers do make clear filters purely for protection, but you'll probably find that they have higher reflectance than quality UV filters. Personally, I fit Heliopan slim SH-PMC filters to all of my lenses - alongside B+W they're generally regarded as having the highest-quality optics, but I prefer them to B+W because the slim varients have front threads, allowing you to stack additional filters. Off memory these have a per-side reflectance of 0.2%, pretty close to as good as it gets, although in extreme contrast situations, ghosting can stil be an issue (the easiest solution being to simply remove it when shooting in these conditions).

For the polarized filter I'm trying to figure out if getting a linear filter will affect the auto focus on the Rebel XSi (EOS 450D) I'm familiar with the physics behind polarized filters and have even been guilty of trying to hold my sunglasses in front of my point and shoot :rolleyes: but i cant seem to find any consistent information about the AF issue on this model.

You need to get a CPL filter for the reasons mentioned. Linear polarisers will affect the AF on any camera that uses split prisim AF (ie "most of them")

i would just get a circular one but they are expensive and i figure i might e able to find a nice used linear one on the cheap. overall I'm looking for recommendations i intend to use this mostly for scenic views and in bright light.

A Linear will cost you more - because after you've bought it you'll then have to buy a CPL. As with just about anything in life, you get what you pay for - Heliopan make a very nice 77mm CPL, but unless they've recently upgraded it then it doesn't have front threads, and it doesn't have the SH-PMC coatings.

last I'm looking for an ND filter. i do lots of hiking and have been fustrated with trying to achieve that "soft water" effect in brighter conditions. i have a few really nice ones from some very overcast days but i just dont have the aperature on that camera for bright light and on the SLR i think i could stop it down but most of the cheaper lenses (particularly the super zoom series) tend to get their best sharpness in the f/8-11 range (shallow DOF not the biggest issue) so i figure an ND filter would be a nice option. does anyone have recommendations for brands or levels of ND I'm looking for something that can get 1/10 - 1/4 shutter speeds in moderate to bright light around f/8 at ISO 100

The very best that money can buy is the Singh-Ray Vari-ND from www.singh-ray.com. It allows you to dial in any attenuation from 2 stops to 8 stops, but it's not cheap. Failing that, if you want to shoot on a "sunny 16" day at F8 and get a shutterspeed down to 1/4 of a second then you're going to need in the region of 7 stops of attenuation - which isn't really practical - you'll probably find it better to go for a quality 5-Stop ND and stop down as low as she goes. Yes, you will be diffraction limited - yes the lenses arent as sharp in that region anyway, but with correct sharpening you should still be able to get a perfectly acceptable result.

all in all any help would be nice in tryign to balance cost with quality (id rather spend the extra few bucks to not have to buy new filters later)

We're all looking for a bargain, but "I want the cheapest, so long as it's the best" just isn't a reality in photography. I only purchase top-of-the-line components for professional use - so I might have to rely on others to chip in here with recommendations for lower-grade equipment. If you get a chance, have a look through my gallery at pbase.com/cjsouthern - the majority of my work includes water, so you might find something there that you'd like to emulate and I'll be able to tell you how I did them.

Does this help?

[SpinnignCone]

thanks for the info. mostly confirmed what i already suspected. the Singh-Ray Vari-ND looks great and would love to get it but at $360 its a bit too much right now and it appears to be a rare in the 3rd party markets.

for now i might skip the UV i think i can manage without the added protectionf or a while untill i get some better lenses but might spring for a good polarized filter the the coated B+W 77mm filters seem to go for round $150

[Colin Southern]

You're welcome.

To be honest, I often feel a sense of frustration when I hear the common reaction to the Vari-ND (ie it's cost) because I know how damn good they are (I have two - 77mm & 82mm), and I just know how much you'd love it if you ever find a way to beg-borrow-steal the money. I do wish it were cheaper - but I guess that's the "price" of a top-quality item, unfortunately.

For water shots it's a dream - usually you'll want control of both aperture (for depth of field) and shutterspeed (for water effect) - with the vari-ND you simply set the aperture and shutter speed you want then twist the Vari-ND to get the exposure right - VERY simple, VERY easy - whereas with anything else you have to make compromises and it can mean a lot of mucking round. Keep in mind also that once you have one, you have one for life - so long as you're careful with it and don't scratch it of drop it, it's going to last forever - literally.

With regards to UV filters - the "protection" angle usually invokes responses more akin to religious wars - my position is that they give you a cheap insurance policy (like seatbelts) - contrary to popular utterings by the nay-sayers they DON'T degrade image IQ in any detectable way, with the exception of extreme contrast situation for which they can be removed before hand - and when you DO get sand or salt crystals from evaporated sea water / mist on them then it's easy to run them under the tap to remove it whereas wiping a front element is lible to scratch it and running a lens under the tap isn't recommended (even an L-Series!). So my advice is to not lose any sleep over it - but don't forget about it altogether either. Accidents do happen and if you damage a lens in a situation where a filter would have saved it then you'll be kicking yourself.

Regarding CPL filters ... I have a couple of expensive Heliopan ones, but I just never seem to have a need for them - so they stay in my bag unused. I'm not saying that others don't use them either, but I'd be interested in hearing from others as to how much they do use them just to get an idea. In your situation - if it's water-related shots then I wouldn't be at all surprised if a Vari-ND would be on your lens most of the time, and a UV or CPL probably not at all, but that's just me - you may well be different too.

Hope this helps!

[William W]

In your buying decision and following on from Colin's suggestions, (especially for the soft water effect on sunny days), you should consider the CP stacked on the outside of the ND.

This is one of the reasons why slimmer filters are usually better, especially when you are at the wider FL.

***

I (almost exclusively) use Hoya Pro.

However the Singh-Ray Vari-ND is sublime, exceptional quality and, from a technical standpoint brings to a new dimension the exposure bracketing of the running water scenes, waves, rivers, loosing people etc scenes: as one can retain the A, T, and ISO – I think this point even Singh-Ray overlook in their sales propaganda.

I use a UV on my lenses for "protection" - but I do have a couple of 'Skylight' in my kit which serve equally as well, actually the slight colour boost is noticeable, usually.

I remove the UV ('protection') in circumstances which create (or might create) flare, or veiling flare.

***

You will find there are two schools of thought about "Protection Filters" and the argument from each camp never varies.

My view, from my experience (excluding the Flare scenarios) I have not been able to see any degradation on a 11 x 14 or 20 x 24 print on well exposed image with a lens using a reasonable quality UV filter - compared to the same scene taken without the filter – in this regard, though I love the theory, I am a ultimate practicalist – it is the end product which counts - not labs tests.

WW

[William W]

It appears Colin and I, as well as responding at the same time were copying each other's notes in class . . .

WW

[William W]

"Regarding CPL filters ... I have a couple of expensive Heliopan ones, but I just never seem to have a need for them - so they stay in my bag unused. I'm not saying that others don't use them either, but I'd be interested in hearing from others as to how much they do use them just to get an idea."


My experiences:


Very useful for my swimming coverage, especially outdoor pools, and indoor pools late in the afternoon or early morning - as most indoor pools here have glass around the side, or fold-back "doors", thus direct light in and on the water’s surface . . . and also for open water events etc.

The Photographer's viewpoint, for some events cannot be controlled - i.e. not always am I free to roam around the entire pool - and for open water . . . well if I am not in the boat, it's difficult to swim with a 70 - 200 and a 300 hanging off my neck . . .

I do not use a CP for scenes and the like very much at all (perhaps I am lazy just not to consider it I think) - though - on another forum, yesterday - I was working through a problem with a chap who had a night scene of a Road Bridge in what seemed to be an industrial area of a city - he had PP problems with the sky - density and colour - he believed there was light pollution, (from air pollution). I suggested he attempt the same shot with CP - those comments / thread would be easy to find, for those interested in the details.

WW

[Colin Southern]

In your buying decision and following on from Colin's suggestions, (especially for the soft water effect on sunny days), you should consider the CP stacked on the outside of the ND.

You're up early today Bill

To put a slightly different twist on the classic "Waterfall / Sunny Day" theme, I find that often the best solution is simply to avoid shooting the likes of waterfalls in bright sunlight altogether.

Case in point - a few weeks ago I had the boat on one of our local lakes and I whizzed up to Whiskey Falls with the camera. Although I'd previously shot the falls with "OK" results ...



... I was trying to find the exact location a collegue had shot it from. Thought I'd found it - so thought I'd have a crack at it in full sunlight. Cut a long story short, it just didn't work - I had in excess of 10 stops of attenuation - couldn't see anything through the viewfinder - hellishly bright sun pouring down on the scene (lots of harsh shadows) - all-in-all a total waste of time (other than confirming the location). So it you're after world-class waterfall shots then nothing beats (at a minimum) an overcast day (for soft shadows) - and if it happens to be early or late in the day then it makes things oh so much easier.

On a side note, this was shot with the Vari-ND - piece of cake ...

[Colin Southern]

It appears Colin and I, as well as responding at the same time were copying each other's notes in class . . .

WW

... and again!

[SpinnignCone]

Thanks for the replies. still shopping around to see what i can find in what price range

as far as the ND filter goes i would love to have it and would likely enjoy it but since I'm starting from scratch it makes more sense to put the money towards lenses right now than a filter of that price. once i get a couple good lenses and get a feel for how much i'm going to get into photography can consider investing in something like that

as for the protection filter I'm more of the school that it will be safer to clean and is easier to replace compared to a lens (almost scrathec my point and shoot twice). as for quality looks like the coated ones pretty much don't affect quality in any appreciable way. perhaps if i worked for National Geographic but i don't so i care more about the safety factor


actually a thought occurs to me has anyone tried a combination of a linear and circular polarizer stacked to act as a variable ND filter? conceptually you could go from ~0-50% transmission...

[Colin Southern]

Sounds like you've got a bit of a plan, which is always a good thing

What lenses have you got for the 450D at the moment?

[Dave Humphries]

actually a thought occurs to me has anyone tried a combination of a linear and circular polarizer stacked to act as a variable ND filter? conceptually you could go from ~0-50% transmission...

I haven't tried this, I'll see if I can find my old LPL from film days and try with newer CPL and let you know (unless someone beats me to it). It'd be good to save $360 ...

However, a couple of thoughts are;

1. Max transmission is going to be around 3.5 to 4 stops down, so by my maths, 6 - 8% rather than 50% (one stop = 50%, so that's 50>25>12.5>6.25 for four stops), then you twist and it goes down to 0% as you say
2. It will stop most AF working (as possibly will a lack of light)
3. Composing with it on is going to be tricky
4. Flare might be an issue shooting into sun

OK, it was 4 thoughts; I can't count (so be sure to check my maths!!!!)

Sadly, I think Colin's right (he may have said it in another thread), you get what you pay for ..

Cheers,

[SpinnignCone]

Sounds like you've got a bit of a plan, which is always a good thing

What lenses have you got for the 450D at the moment?

Heh none right now :-D still waiting for my SLR in the mail. for now im starting with the XSi kit lens which i have read isn't half bad and has IS. ill use that to get a feel for things and be able to better judge the reviews for other lenses.

once i get going there I'll also have a better idea of how much I'm willing to stretch my budget for the right stuff. I've been eyeing a few different lenses but am mostly looking for a good walkabout lens, probably the superzoom type. true they are jack of all trades-master of none types but its nice to not to have to change.

i am considering the filters up front since they can add a value without costing too much and will continue to be useful as i upgrade the lens, if nothing else its something to put on the wish list and budget for.

[SpinnignCone]

I haven't tried this, I'll see if I can find my old LPL from film days and try with newer CPL and let you know (unless someone beats me to it). It'd be good to save $360 ...

However, a couple of thoughts are;

1. Max transmission is going to be around 3.5 to 4 stops down, so by my maths, 6 - 8% rather than 50% (one stop = 50%, so that's 50>25>12.5>6.25 for four stops), then you twist and it goes down to 0% as you say
2. It will stop most AF working (as possibly will a lack of light)
3. Composing with it on is going to be tricky
4. Flare might be an issue shooting into sun

OK, it was 4 thoughts; I can't count (so be sure to check my maths!!!!)

Sadly, I think Colin's right (he may have said it in another thread), you get what you pay for ..

Cheers,

could be its been a while since my college physics class and was basing the 50% off of the maximum transmission of a pol lens (iirc they should kill half the light if they receive un polarized light in an ewual dispersion)

and while you get what you pay for in a amature/prosumer setting a ghetto but functional variable ND and a polarized filter for half the price of just the good variable ND itself well you get my drift

besides if it does work ok it offers even more range than the Singh-Ray Vari-ND you could probably turn them to just above 0% and photograph welding or perhaps get some crazy shots of the sun. at any reate please give it a try if you can and report back im very interested to see how it works out


EDIT: btw thought i should go back and mention that shooting directly at the sun even with the filters ican be dangerous (unless you use the "live-View" lcd). just like looking at a solar eclipse its not the brightness but the radition outside the visible specturm (like UV) that can blind you.

[Colin Southern]

besides if it does work ok it offers even more range than the Singh-Ray Vari-ND you could probably turn them to just above 0% and photograph welding or perhaps get some crazy shots of the sun. at any reate please give it a try if you can and report back im very interested to see how it works out

I haven't done any experiments myself, but from what I've read from others, as you push the attenuation more and more you end up with colour shifts.

[rc53]

actually a thought occurs to me has anyone tried a combination of a linear and circular polarizer stacked to act as a variable ND filter? conceptually you could go from ~0-50% transmission...

See this thread

http://forums.dpreview.com/forums/re...hread=29592761

for extensive overview of filters.

Stacking circular and linear polarizers can be made to work, but often it seems there is a magenta shift.

[bockey]

On UV filters. I always have a UV filter on my lenses. Over the years (50 with SLRs) I have damaged two UV filters and 1 lens hood but the only lens damage was when camera + lens fell lens down and wrecked the zoom cam. I have never seen any deterioration due to a (clean) UV but you have to be more careful of a direct light source on the lens.
On NDs. I have no experience of the variable ND. I have a ND16 (4 stop) and use it sometimes.
I use my camera and slide duplicator to scan my old slides and here I use a 4X ND and my macro lens so I am not using f22 with diffraction effects.
On Polarisers. plane polars result in both AF and exposure meter not working. 2 polars together do give an ND effect but most will give a colour cast as it gets denser (top grade ones may be OK). If using 2, the circular one MUST be put on the lens.
I don't use my polariser for skies now as Photoshop can do the job; but for shaded landscapes such as the waterfalls and in Australian fern gullies, even on dull days, they are great for reducing reflections off leaves and improving colour saturation.

Note: a circular polariser consists of a plane polariser plus a half wave retarder which spins the polarising angle and the light can get through a half silvered mirror. To check if a filter is a CPL look throught it at its reflection in a mirror. Lens side of filter must be towards mirror. If the reflection of the filter is black no matter which way it is turned, it is a CPL. The mirror reverses the direction of rotation of the light so it cancels the incoming light.