What filter first: Polarizer or GND?

[Daniel Salazar]

Hi, I'm about to buy my second filter. My first priority was to protect my lenses, therefore I got UV filters.

I like the B + W filters, no professional reason, just because they are done in Germany and Germany is closer to Switzerland than Japan

Now I've saved enough to buy a filter to improve my day photography and I would like to get either a Pola or a ND filter. The most of my pictures are taken when I'm with the family, therefore it's not so easy for me to go out either at dawn nor at dusk.

Now I'm planning to go to Vienna on vacation next Easter and I would really like to have a filter that might help me to avoid having washed out pictures.

Any ideas? Colin I know you like the Vari filters, however the only GND filters they have are the ones you have to use with a holder and not the one with a ring.

Cheers,
Daniel

[Colin Southern]

Any ideas? Colin I know you like the Vari filters, however the only GND filters they have are the ones you have to use with a holder and not the one with a ring.

Hi Daniel,

The "ones you use with a holder" allow you to move where the filter appears relative to the top of bottom (or side) of the image (ie "they're adjustable").

Screw-in type are practically useless, as the split only ever occurs at the centre of the composition which (if you're guided by the rule of thirds) is seldom where your horizon is (or where brighter portion start). I wouldn't waste my money on them - if you can't get ones that slide, the next best thing is to use a tripod and shoot two overlapping exposures and do a digital GND with a mask in photoshop.

B+W are great filters - the only catch is if you get the slim varients to minimise vignetting with WA lenses, the B+W ones don't have front threads (unless they've recently changed), whereas the Heliopan SH-PMC ones do (and they're also of the highest quality, and made in Germany :)

Hope this helps!

[The Blue Boy]

Hello mate,

I would say it really depends on the effects you are trying to achieve, then budget. Personally I went for a polarizer. I bought a hoya and it does a good job on the rare occasion that I use it. My next (set) will be ND filters. The reason for this is as I live in a city with great architecture, I want to take shots where I can blur out the people (and the police!) As for protective filters, well, I think this is a personnal thing too. I don't bother with them as a rule but if I'm on the beach.... yeah I'll either stick the UV or the Skylight on. I hope this helps.

[Dave Humphries]

Yes Daniel, I'd say a CP is most verstaile, like Mark, it's what I have; it polarises and is about 2 stop ND, although not graduated, admittedly.
Also as a screw on, less bulky and easier to use, although this latter aspect better on lenses which don't twist the front element when focusing.

[Colin Southern]

Mark just reminded me of something I forgot to mention ...

GND filters and CPL filters are worlds apart - different tools for different jobs. CPL filters - in a nutshell - remove glare, be it from water and/or other non-conductive surfaces. Great for allowing you to see into water - or for reducting the glare on, say, plant foliage (thus leaving more saturated areas) - and of course for making the sky appear darker (although they don't work well at wide angles - you'll get very uneven skies).

A "side effect" of CPL filters is that they generally attenuate the light by around 2 stops (although some newer ones only 1 1/3 stops) - so they can be used as a 2-Stop ND filter in an "emergency".

I've got two very expensive Helipoan CPL filters, but can't remember the last time I used them.

At the end of the day it all depends on what you need - if the issue is lack of dynamic range (eg "sky too bright for the rest of the shot") than a CPL filter won't really help that much, whereas if you need to reduce glare then GND filters won't help at all. Horses for courses :-)

Hope this helps!

[Daniel Salazar]

Thanks for the feedback. The issue is that going to Vienna on vacation and I don't know, which filter might be better a ND or Polarizer considering the light, I might be taking pictures at noon, and perhaps I'll just take my monopod.
Now as Mark mentioned, (thanks for the tip I didn't know) with a ND I could blur distracting objects when taking pictures, otherwise I'll always have a group of tourist in the middle of all my pictures.
Cheers,
Daniel

[rc53]

As Colin says, one effect of Circular polarizers is to act as a neutral density filter; ND filters are useful when you want long exposures in brightish light -- for rivers, waves on the sea etc. Graduated ND filters are useful when the sky is 'too' bright by comparison to the rest of the image -- but the useful ones are rectangular, and fit into a slotted holder, so you can adjust what part is NDed and what part isn't.

And, the effect of a ND filter can be mimicked in post-processing with a graduated filter. The effect of a polarizer can't really be mimicked.

So, I'd suggest a polarizer first.

You might consider if you want later to add graduated ND filters -- if so, consider a slot system -- they come in various sizes to fit larger or smaller lenses. If you get a round polarizer you can always thread a slot filter onto the front of it, though there may be the risk of vignetting.

[rc53]

Now as Mark mentioned, (thanks for the tip I didn't know) with a ND I could blur distracting objects when taking pictures, otherwise I'll always have a group of tourist in the middle of all my pictures.
Cheers,
Daniel

Yes, sort of; but you will need very long exposures for this, and a very solid tripod.

There are better ways of removing people you don't want; in Photoshop CS3 extended you can 'stack' a series of images into a smart stack, then run the median filter -- this gets rid of people very well [Originally this was designed to spotlight differences in images for forensic purposes]. I don't have CS3 extended, so haven't tried this -- the extended version is much dearer. Here's a small video showing this:

http://www.jnack.com/adobe/photoshop/fountain/

[Daniel Salazar]

WOW, thanks! unfortunately I don't use Photoshop just aperture and PSE 6

So about the filters, then I understand that might be better first to get a Polarizer than any other and then either a ND or a GND.

Thanks!

[Colin Southern]

Hi Daniel,

Reading through the last few posts I was a bit "concerned" that you might be getting the impression that a CPL is some kind of "Magic Wand" - at the end of the day it's primary purpose is to simply filter cross polarised light. Full stop. End of story.

So ...

... if you having issues with glare then a CPL will help, but that's about all.

To be honest, I'm a little confused by the references to the "blurring of distracting objects" - all I can think of is that most CPL filters give about a 2-Stop attenuation thus allowing you to open up your aperture by two stops to have the same EV at the sensor. Opening up two stops with give you a narrower depth of field which will blur things in the distance a wee bit if your aperture is already fairly wide, but it's not going to make that much of a difference to the average shot. Alternatively you could retain the same aperture and extend your shutter time by two stops - but all that's probably going to achieve is getting you more motion blur (which might be a good thing or a bad thing depending on what your trying to achieve).

Not trying to talk you out of it - just wanting you to be clear about what it does, and how it does it, so you can make an informed choice. CPL filters arguably have their greatest use around water - I shoot around water a LOT - and still I never use a CPL - my two are by far my least used filters. I'd be interested to hear how much others use theirs.

Hope this helps,

[Daniel Salazar]

Hi Colin, thanks for the info. I know that a CPL won't be the solution to everything, I'm also aware that the best efect can be obtained when using exactly when sun is exactly over my head, when is not 90° then the sky might have some darker areas.

What I want is easy, due to the fact that I'll be taking pictures of the city during the whole day, I would like to take pictures without a blown up sky and also without a too dark building or monuments, therefore I though that I could solve it using either a Polarizer or a ND filter. Or I could just meter the whole scene pointing to the main object using matrix metering and then compensate the exposure if I see a blown out sky or underexposed object?

Cheers,
Daniel

[rc53]

McQ has recently added a section on selection and use of filters on the CiC tutorial page.

[Colin Southern]

What I want is easy, due to the fact that I'll be taking pictures of the city during the whole day, I would like to take pictures without a blown up sky and also without a too dark building or monuments, therefore I though that I could solve it using either a Polarizer or a ND filter.

ND filter won't do anything - yes, it cuts the highlight by a given amount, but it also cuts the shadows by the same amount so the only thing that happens is you have to lower your shutter speed or increase your aperture to compensate. On AE modes it won't affect exposure at all. A GND filter is different - it'll make all the difference in the world for what you want - but - you need to get the dark bit of the filter over the bright bit of the scene, and screw in ones generally present 2 problems; (1) The split is only ever in the centre (but the bright part of your scene usually isn't), and (2) It's pretty hard to see even a 3-Stop split through the viewfinder on a bright day.

A CPL filter on a medium to slightly wide lens *may* darken the sky a bit, but personally I wouldn't rely on it as a device to compensate for dynamic range issues. I'll test it to see if I get a chance sometime soon.

Or I could just meter the whole scene pointing to the main object using matrix metering and then compensate the exposure if I see a blown out sky or underexposed object?

Pretty much - it really all depends on the scene - if you're trying to photograph a building with some dark shadow areas and you're shooting towards the sun then something is going to have to give; whereas if the sun is behind you then it's usually not a great issue to capture the range of levels that you want.

PS: Did you realise that your signature is appearing twice - you've got show signatures turned off in your profile, but it looks like you're typing yours manually and also telling the system to add it - so everyone who has view signatures turned on sees your twice. Let me know if you need any help with this.

[Daniel Salazar]

PS: Did you realise that your signature is appearing twice - you've got show signatures turned off in your profile, but it looks like you're typing yours manually and also telling the system to add it - so everyone who has view signatures turned on sees your twice. Let me know if you need any help with this.

Thanks, I've changed.

About the filters, I'll better wait. And if I get one for my 18-250 mm, which I'll use, I'm definitely getting some GND as you recommended me once.

@ rc53 thanks for the advice, I haven't check all the tutorials.