should i remove the polarising filter for dusk/ nightshots ?

Joined: 26 Jul 2004 Posts: 37 Location: Sydney, Australia

Generally i always take shots like this

CAMERA -> POLARISING FILTER -> SKYLIGHT FILTER

From what I understand ever extra bit of glass (filter) added in front of a lense takes away some light so should i remove the polarising filter for dusk/ nightshots ?

Posted: Tue Sep 21, 2004 7:31 am

I think it should be CAMERA>SKYLIGHT>POLARIZER. The skylight you can leave on all the time as a lense protector with no loss in exposure.

In general you can do away with the polarizer for night shots, though there might be rare, specific cases where you'd want to get rid of reflections, like a store's window display (humm?). Otherwise you're just making the exposure longer.

Joined: 01 Sep 2003 Posts: 323

nb wrote:

Generally i always take shots like this

CAMERA -> POLARISING FILTER -> SKYLIGHT FILTER

From what I understand ever extra bit of glass (filter) added in front of a lense takes away some light so should i remove the polarising filter for dusk/ nightshots ?

Extra glass on the camera also will affect sharpness and resolution!

The Polarizing filter should only be used when you need to darken a blue sky or cut some unwanted reflections, or in some cases to change the look of the haze.

The Skylight/UV filter is to attenuate the UV part of the spectrum which records as blue on film. It will make distance haze more white as your eye sees it rather than bluish. This filter should NOT be used to 'protect' a lens... that's what your lens cap is for!

You should NEVER have both filters on your camera since the polarizer will also attenuate the UV portion of the spectrum!

Joined: 01 Nov 2003 Posts: 2751 Location: Luxembourg

What Orrin said...
I never supported the use of a UV filter for protection but I've always been fighted on the forum :)

A cheap lens doesn't produce the greatest pictures to start with and when you put some glass or plastic filters in front of it then you worsen the quality.

And if you have an expensive lens and payed thousands of dollars to get the sharpest exposure ever then there is no point of putting that filter to degrade the quality back to the cheap lens level...

I don't know, each his own mentality but if I am worried for my expensive lens, better go get the cheap on from the beginning since the end result will be the same.

Posted: Tue Sep 21, 2004 5:03 pm

I’ll admit up front that I’m an “old schooler” and I’ve always heard and read that you should put a “protective” filter on and leave it there to avoid scratches, dust, moisture, etc., from getting on your relatively soft lens. It’s easier and safer to clean/replace a filter than have to worry about damaging the lens coating or the lens itself, and a Skylight/UV filter really doesn’t have that much effect on the picture anyway.

So I went gooleging and son-of-a gun, Orrin and fadi are absolutely right- after looking at dozens of sites the consensus is that any filter or glass in front of the lens degrades image sharpness (except for the filter manufacturer sites and, of course, they swear up and down they don’t). The consensus also says that the use of more than one filter at a time is a definite no-no and can cause all kinds of problems (chromatic aberrations, etc.). Bottom line- pretty much everyone agrees that you should never put a filter on unless you need it.

Well, they don’t call me Goofup for nothing, and I learned something new.

Joined: 26 Jul 2004 Posts: 37 Location: Sydney, Australia

thanks people

I kind of expected that answer, but wanted an *expert* opinion to back up my own guess

Posted: Wed Sep 22, 2004 5:48 am

nb wrote:

thanks people

I kind of expected that answer, but wanted an *expert* opinion to back up my own guess

mmm... interesting

Posted: Wed Sep 22, 2004 9:21 am

Fadi wrote:

I never supported the use of a UV filter for protection but I've always been fighted on the forum :)

Agreed. ;-)

Joined: 17 Aug 2004 Posts: 172 Location: Pittsburgh, PA

In regards to the UV thing, I was wondering.. I recently dropped my 18-70 and it chipped the lens. Now I didn't have a filter on there, but the way it landed on its side, I'm not sure that one would have helped. Has anyone ever broke a lens with a filter on it in an "everyday" way?

I guess perhaps the extended length of a filter might have caused the pressure to be put elsewhere besides the glass, but my filter seems small and I can't help but doubt it.

Posted: Wed Sep 22, 2004 10:26 am

I'm paranoid about damaging my lens and when I'm walking around with the intent to take pictures then I always have my lens cap off. For that reason, I always protect the lens with a filter despite that fact that I may be compromising image quality.

just my two pence

Joined: 01 Nov 2003 Posts: 2751 Location: Luxembourg

why not leave the lens cap on until you decide to stop and shoot?

Posted: Wed Sep 22, 2004 10:48 am

fadi wrote:

why not leave the lens cap on until you decide to stop and shoot?

yeah... I know what you're saying... and it makes sense. But old habits die hard. I actually did that a couple of months ago with my dimage and ended up losing the lens cap... slipped out of my hands unbeknown to me at the time, and by the time I had noticed I was without cap I'd walked on some distance. Retraced my steps but couldn't find it. Sounds a bit daft I know and lens caps arn't all that expensive anyway (I don't think... never checked it out).

What I tend to do when I reach a site of interest is take my camera from the bag and then straight away remove the lens cap. I suppose I do that so that I think I'm all ready for action. I suppose that for some types of photography you don't need to be poised for that rare moment when an opertunity presents itself. And just this weekend, I was walking around the Forest of Bowland, not far from where I live, and nearly caught the front of my lens on the bolt of a farm gate. Very silly indeed... and I didn't have a filter on the lens because I'm just trying it out at the moment.

I'll have to have a good think about this before I change the way I work. I'll keep my filter on my lens for the time being.

cheers

andy

Posted: Fri Sep 24, 2004 10:40 am

I'm with Shaun and Fadi on this. I never leave a filter in place. I put my lens caps back on when not shooting. I have lenses that are 35 years old with nary a scratch on them.

I almost never clean my lenses--but I will dust them with a camels' hair brush once in a while. Finger prints will damage a lens and must be cleaned as soon as possible. I don't recall ever having put a finger print on any of my lenses.

I think most lenses are scratched during frequent cleanings.

The skylight filter thing is a result of camera salesmen trying to get a few extra bucks in sales.

It's sort of like the car salesman trying to sell you "glazing" to protect the finish on your new car. A waste of money.

Skylight filters are even worse. A waste of money. A waste of resolution. An invitation to flare.

Other than that I have no opinion on this subject.

Posted: Fri Sep 24, 2004 6:18 pm

Maybe you film guys can tell in your pictures, but for me, shooting digital, it just doesn't matter (I did some test shots just to find out for myself, blew them up 400%, and I couldn't tell any difference). If it doesn't matter in my pictures, I'm keeping my filter on.

But that's just me.

Posted: Mon Sep 27, 2004 1:44 am

Well, you National Geographic photographers are right. My B+W Skylight filters -- including the really big ones in front of my really big glass - do indeed degrade the image slightly. But not so's anybody'd notice who I sell to.

But, some imbecile linesman sticking his first down pole up my 300mm does bad things to my 300mm f2.8 front element. Or, ever been in a crowded hallway full of news photographers, or hanging over the rail of a racing sailboat on Long Island Sound? Where you want to rinse the salt off the lens about every three frames?

This is the difference between the different types of photography here. If your very expensive front element is never in jeapardy of physical damage, then don't spend another $100 or more for a B+W Skylight.

I truly do not mean this as a put down of those who don't. I'm just explaining why I do spend the extra, and have been glad I did.