vari-ND vs. ND kit

Looking at ND options. I have never owned NDs before. Is it possible to stack ND filters (as in adding a .3 in front of a .6 to drop 3 stops) ?? Or would doing this have a negative effect on image for some reason?

It seems cheaper to go with a small Tiffen kit than buying 1 very expensive variable ND for $400+

Thanks for any input you guys have.

You can stack them. That is why most matte boxes have multiple stages. You are however better off keeping stacking to a minimum as you are adding another optical element into the mix.

Even stacked you would probably get better images than from a variable ND due to how a variND works.

Stacking ND & other filters is common practice, but as Adam says, in certain situations doing so may increase the likelihood for unwanted flares or other issues. But used carefully, stacked filters can be a great technique.

Vari-ND filters can be very convenient. Most of the relatively inexpensive vari-ND filters are terrible and cause optical problems of various sorts. One of the best-regarded vari-ND filters is made by Heliopan.

Most ND & vari-ND filters block visible light more than infrared, which results in color cast issues. There are IR-cut filters available which address this issue, such as the Hoya IR/UV cut filter. There are also combination ND IR cut filters.

Cheers.

A new, less-expensive alternative is the ND Fader from Genustech, available in various diameters. This filter has been getting very positive reviews:
http://www.genustech.tv/home/nd-fader-c ... ystem-77mm

I bought this Genus ND Fader. I am very pleased with it.

You also have to look out for reflections when stacking to many filters. I believe some pro Matteboxes filter tray's are able to tilt to avoid reflections

Have a look at the new Genustec Eclipse. It's said to be as good as the heliopan if not better. It's also cheaper!

Keep in mind, a Vari ND is always and Pol at the same time. This can have some negative effects on your shoot.

Have a look at the new Genustec Eclipse. It's said to be as good as the heliopan if not better. It's also cheaper!

Keep in mind, a Vari ND is always and Pol at the same time. This can have some negative effects on your shoot.

Am I correct in thinking that you need to add an IR filter in front of these variable ND filters to be safe from infrared pollution?

Rick Lang
Sent from my iPad using Tapatalk HD

Have a look at the new Genustec Eclipse. It's said to be as good as the heliopan if not better. It's also cheaper!

Keep in mind, a Vari ND is always and Pol at the same time. This can have some negative effects on your shoot.

Am I correct in thinking that you need to add an IR filter in front of these variable ND filters to be safe from infrared pollution? -- Rick Lang

Yes, both traditional ND filters and vary-ND filters influence the affect of infrared on exposure. As the ND value is increased, a higher percentage of the exposure results from IR light instead of visible light.

Once the ND value goes above about .9 ND, the IR pollution can become quite apparent. For example, certain black fabrics will begin to take on a reddish hue.