Filter basics

Introduction

Since the earliest days of photography filters have played a necessary role in enabling photographers to control the imaging processes. Today, working in colour and in particular utilizing digital image processing techniques, do filters still play a role and if so which ones are necessary and useful?

Colour Enhancing Filter Vs. PhotoShop

   

Unfiltered                                                                    Lee Enhancing Filter

The image above was taken with a medium-formatRollei 6008iand300mm f/4 Schneider Apo-Tele-XenaronKodak 100VS film. The lighting conditions were bright-hazy. The one on the left is without filter and the one on the right was taken through aLeeColor Enhancing Filter. Neither frame has had any correction other thansharpeningandlevelsin PhotoShop. Specifically, there is no colour correction applied — just the straight output from myAgfa Duoscan.

As can be seen the filtered frame on the right has considerably punched-up reds and yellows (which is what a colour enhancer is supposed to do) but it also has an unacceptable magenta cast.

The frames below are versions of the frames above. The one on the left is the un-filtered image but with +15 Red and +15 Yellow colour saturation increases inPhotoShop.

 

Unfiltered – colour boosted                                        Lee Enhancing Filter – magenta corrected

The frame on the right is the one taken through theLee Enhancing Filter, but with the magenta cast removed (+50 Green).

So what do you think? I realize that the limitations of on-screen display and the smallish image sizes make the comparison difficult. It’s even difficult when comparing large screen images and 8 x10" prints.

But, the print on the left which is unfiltered, with colour that was saturated using PhotoShop, is cleaner with more pleasing colours than the enhancement filtered but magenta-corrected one on the right. My take therefore is that the use of a colour enhancing filter is largely redundant if you will be processing your images digitally prior to output.Even if you are using traditional printing means then you will have to correct for a major magenta imbalance that seriously compromises the benefits of the filter to begin with.

Lee / Sing-Ray / Tiffen Colour Enhancer Comparison

I’d been told that theSing-Raycolour enhancing filter does not suffer from this magenta cast. Fortunately in mid-October ’99 on a shoot in theEastern Sierrawith photographerSteve KossackI had the opportunity of comparing theLee,Sing-RayandTiffenenhancers. ClickHEREfor that review.

Cokin Blue / Yellow Polarizer

Within the vast family of Cokin special effects filters there is just one that catches my fancy, the#173 Blue / Yellow polarizer.  This articles explores how and when to use this special effects filter.

PalmPilot Software for Photographers

On location software tools can be invaluable. The small size and efficiency of thePalmPilotwhen combined with these programs provides photographers with some invaluable tools.

Pocket PC Photography Software

Windows for Pocket PCs has finally come of age and has become fully competitive with Palm computers. In 2001 the hottestPocket PCis theCompaq Ipaq 3600. It has a bright backlit LCD screen that unlike most of its competitors is highly visible in daylight  — ideal for outdoor photographers.

There are excellent programs available that makes this a must-have tool for photographers.

Polarizers

The use of polarizing filters to darken the sky is generally well understood by outdoor photographers, but using them to minimize reflections on water and foliage is less familiar. This tutorial shows how.