Luminous Landscape Forum

Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: William Chitham on October 19, 2017, 07:38:46 am

Title: Nisi Polarising Filter Suitable For Copy Work?
Post by: William Chitham on October 19, 2017, 07:38:46 am
I'm looking for a decent polariser to use with a borrowed Phase One kit (SK LS 80mm f2.8 / p65+) for copying artwork with cross polarised light. I was considering a Lee 100mm square "circular" glass filter but for less money I could have a complete Nisi V5 pro kit with filter, holder and a selection of lens rings. Has anyone used a Nisi for this kind of work? In particular I am concerned about sharpness and colour casts.

Thanks,

William Chitham.
Title: Re: Nisi Polarising Filter Suitable For Copy Work?
Post by: Alan Smallbone on October 19, 2017, 10:05:07 am
I did some testing with a spectrophotometer of various filters. The Lee round 105mm and the Nisi polarizer did not have any color casts. The Lee square filter did have a slight bump in the blue and red spectra, so it gives a slight color cast.

Alan
Title: Re: Nisi Polarising Filter Suitable For Copy Work?
Post by: William Chitham on October 19, 2017, 11:03:48 am
I did some testing with a spectrophotometer of various filters. The Lee round 105mm and the Nisi polarizer did not have any color casts. The Lee square filter did have a slight bump in the blue and red spectra, so it gives a slight color cast.

Alan

Thanks Alan, that is encouraging.

William.
Title: Re: Nisi Polarising Filter Suitable For Copy Work?
Post by: BobDavid on October 31, 2017, 02:40:43 pm
In the past, I've had success with B + W polarizers. I cannot see the difference between circular and linear polarizers. I'm sure there are subtle differences, without instrumentation I do not detect differences.

The biggest issue with fine art repro is that artists often use several brands of media. One manufacturerer's paint may have different refractive properties than another brand. That's when things start to get a bit tricky. And then there are artists who like to mix metalic media with paint. That type of artwork requires a few exposures: one for the paint, and another where the polarizer filters on the lights are rotated 90 degrees to cancel out polarization so the metalic areas become visible.

Fine art repro is as much a science as it is an art. It's a combination of playing by the numbers and having a "feel" for the printer, ink set, and print media. My experience is that professional artists who sell work to earn a living will usually accept pleasing color. Achieving accurate color can be time-consuming and costly. Water color, pastels, and pencil drawings are easier to reproduce than most acrylic and oil paintintgs.

It's a given that every aspect of the process from capture to final print stays inside a well tuned color managed workflow.