[toni-a]

I am getting ND filters for christmas, although I rarely needed them before, since I rarely shoot in plain daylight, but this might change.

There are several god ND filters, however I am wondering would a variable Nd be abetter solution, if yes which one ? otherwise I am getting the classical ND 

[JJ_SO]

The variable ND filters basically are two polarizers which are crossed in the orientation of their polarization when fully closed. Like you, I also thought "why getting specific ones with several ND steps, but instead one for all occassions?"

 

Maybe the one I chose is of lesser quality (the "big brands" like B&W, Hoya, Cokin, Lee or Format Hitech don't offer them afaik), but there's a big colordrift the more I close it.

 

Color drifts can also be an issue with bigger stoppers. I was not doing more research into it, but I wonder if the big stoppers sometimes just stop the (for humans) visible light but let pass the infrared range. I'm also looking forward to the answers of the other members, as I'd like to biy a good "big stopper" but not spend a lot of money to one with color drift (Formatt hitech in my case, they have 150×150 mm sizes)

[obican]

All the big stoppers I've tried had color shifts too. 

[JJ_SO]

How do you deal with it?

 

The simplest way is going black and white. I tried a color checker, but when the grey was okay, other colors looked plasticky.

[obican]

I have absolutely no idea  

[stoppingdown]

I confirm, they DO have a strong cast, even the high quality ones. I'm using them too rarely, and this is a fault of mine, but I've used them enough to tell you that they need some work to get a good colour picture (as you said, B&W is easier).

 

First I tried a medium quality stopper, and was appalled at seeing the strong colour cast - so I thought it made sense to spend more money, and bought a Lee Big Stopper (the smaller, for mirrorless, but same glass). It still has a strong cast, as you'll see by the images I'm going to attach (curiously, I did something with the Big Stopper just the past Saturday).

 

With Lightroom, it was a big problem: while most of the cast can be corrected with white balance, it's not enough. Lightroom allows colour channel correction, but it's fixed. With Capture One... it's much easier because you can pick the colours that need correction and selectively fix their hue.

 

Another approach would be to shoot a reference with the ColorChecker Passport and create a specific profile for the shot. This works, but it requires more work, the most annoying stuff being that you need a clamp to keep the color target in a fixed position.

 

So, my current approach is: shoot without the filter, to get a visual reference for what the final rendering should be; first apply strong white balance correction to the photo with the filter, and then selectively adjust the remaining colours that aren't good yet. For my limited experience, this is the fastest way.

 

I'm going to attach: a colour reference (not exactly from the same perspective, but it works), the post-processed final photo, and the unprocessed photo straight from the camera.

[Brightcolours]

Stoppingdown, is it not easier just to set the white balance when the filter is mounted?

 

On ND filters, my 9 stop Hoya ND filter (ND400) only has a slight cast compared to most ND filters (slightly more yellow/green, or less magenta?). 

[JJ_SO]

My Hoya ND 8 behaves also very well. It's the big stoppers, for which I had to set up an own white balance value. Stoppingdown, then hint for Capture One is a good one. Although Aperture also has a color correction for 8 different colors in saturation, hue and brightness (I can colourpick 4 reds an 2 blues, i.e.). I used it on the picture with the big stopper, but having used a colorchecker passport would have made things easier... 

[JJ_SO]

Funny, someone at my local dealer appear to read this forum:

 

I just got their usual advertisement mail offering 12% rebate for NiSi filters and holders. Like usually when I sniff new gear they dragged my attention.

 

Until I read the prices: holder for 150×150 mm: 170.- francs. ND 1000 filter (10 stops), made of glass, nano coated and with the (usual) statement of "very low color cast": 260.- francs  :wacko:

 

I'll take a dozen. Glass breaks so easily... 

[stoppingdown]

My ND64 from Marumi is good as well - it needs only very slight corrections.