Lens Filters

[4073706]

I am seriously thinking of investing in a system to allow me to add filters to my lens (FUJI HS20).

Polarising / Variable ND / graduated etc

I have no experience with filter systems except for the mind boggling prices and a polarised filter i got a few years ago.

What system would you / have you invested in?

 

[astroNikon]

There's been tons of filter questions lately.

The biggest obstacle is what budget do you have ?

General Overview --> Choosing a Camera Lens Filter

And here's DBJ's setup and info on the square filters --> http://www.thephotoforum.com/forum/...ity-filters-why-you-need-them-landscapes.html


I currently use just polarizers and ND filters and use B+W screw in.

BUT, for landscapes and more versatility your really need to use square filters and a lens setup and in the above thread. Lee & Cokin are the big ones out there.

 

[4073706]

Thanks for the links.

I will do a lot of reading before investing.

 

[TCampbell]

Consider the following shot:



I've placed the boxes for these filters in front of them so that you can see what they are. On the left is a "cheap" UV filter. On the right I have a "good" UV filter.

Ignore, for the moment, that these are UV filters and your question is about ND filters, polarizers, etc. What I REALLY want you to see is the glass.

On the left, the cheap filter doesn't have good coatings. Try to look "through" the filters to the black matte board. The cheap filter definitely looks like there is glass in that ring.

Meanwhile, on the right, the "good" filter's glass is nearly invisible. It almost looks as though I've put the filter ring on the black matte board with no glass inside it.

THAT is the difference between a good filter and a bad filter. The bad filter WILL DEGRADE the quality of your shot. If you can see light bouncing off the surface of the glass... it's because the light you can "see" didn't actually pass "through" the filter. The glass is transmitting less light and reflecting more light. What you want is glass that transmits more light and reflects as little as possible.

If the filter can "reflect" light, then it also means that when it's on your lens, it can create "ghosting". Ghosting happens when light bounces off the front element of your camera lens, hits the inside surface of your filter, and bounces off that surface AGAIN and back into the camera. You get a weak "ghost" artifact of a subject (which paranormal researchers love to declare as something else) - when in reality it's just the physics of light and low quality glass.

Good filters have anti-reflective coatings, high transmission of light in the visible spectrum, and "even" transmission of all visible wavelengths (it he filter allows more "reds" to pass through than "blues" then it will end up applying a warm color cast -- you don't want your filter doing that.)

These same properties will apply to all filters regardless of type... neutral density filters, graduated neutral density filters, circular polarizers, etc.

 

[4073706]

B+W XS-Pro Nano 58mm Digital Neutral Density Filter - Price: £161.95

Tiffen 58mm Variable Neutral Density Filter - Price: £93.83

Hama 58mm Variable Neutral Density Filter - Price: £22.25

Is there roughly 800% difference between cheapest and most expensive?

 

[TCampbell]

The B+W "XS Pro" refers to the threads on the filter. XS is "eXtra Slim". These are intended for use on wide-angle lenses where the thickness of the filter ring might actually show up in the corners of the image as vignetting. The "FPro" is their standard ring.

Polarizing filters aren't good for wide-angle lenses because of a banding problem which is really the result of how the polarizing effect works. Light is blocked by the filter based on it's angle of polarization as it tries to pass through the filter. But wide angle lenses can gather light from an angle far enough off the center of the lens axis that the amount of polarization achieved in the center of the image will not be the same as the amount of polarization achieved at the edges of the image. The result is uneven polarization.

When you use a "variable" neutral density filter, it's actually two polarizers stacked together. As you rotate the angle of the front polarizer relative to the back polarizer you can massively cut the amount of light that can pass -- thus getting "variable" neutral density just by how you rotate the filter.

But this has a drawback. Since the variable ND effect is adjusted using two stacked polarizers and polarizers have that interesting side-effect when used on wide angle lenses, stacking two polarizers can give you an "X" shaped darkening pattern when used on wide angle lenses.

A non-variable ND filter doesn't use polarization at all... it's just tinted glass. That means it gets perfectly even reduction in light in all parts of the image and it doesn't matter if it's on a wide-angle lens.

So while I do have circular polarizers, I really just use them to cut reflections and not as neutral density filters. I carry non-variable 2-stop, 3-stop, and 10-stop ND filters in my bag.