Please excuse my ignorance about this stuff, but in looking over Tiffen's site regarding ND filters (their PDF isn't loading properly) I found myself confused insofar as what our 1/8 and 1/64 translates to in 4x4 filter lingo. Anybody know? Am wondering if, in full mountain sun, I should have a stronger ND along with me, stronger than what is native on our camera, that is. But I'm not sure what I've got already, when looking at how they rank them.

Just curious.
Thanks yet again,
Marcia

P.S. The tech guy at Panasonic that I'd called for another reason had no idea.

Fractions with ND refer to usually how much lighted is block. 1/8 = 7/8th is blocked, 1/8th comes through etc.

Each f-stop move either doubles or halves amount of light, so 1/8th gives you two stops of ND and 1/64th gives you 4 stops, more or less (unless my math skills from 5th grade have deserted me :)

Thanks much. Makes sense when you put it that way, even though I think I've more than likely forgotten my 5th grade math and then some. ;-)

One last thought, are there any issues with ND filters that I should know about? I'd never use gain even if it was available in 24p as I hate how it looks, but as opposed to boosting, since ND only restricts the amount of light, however strong a filter I use, it won't effect picture quality in some unforseen way, will it? (Can't think of how it could...)

Sorry Stephen, we gotta send you back to 5th grade math... :)

1/8 = 3 f-stops (1=1/2 the light, 2=1/4, 3=1/8) and 1/64 = 6 f-stops.

1/8 = ND.9

The 1/64 is the same as using two ND .9's.

I don't think you'll need a stronger ND, the existing 1/64th will turn an f/16 scene into f/2. If you do decide to get an external ND, I'd recommend a .6, not a .9, because you've already got two .9's built into the camera.

Barry:

Thanks teach :)

I knew I was screwing something up. And to believe I once took calculus and trig though I could not tell you want those actually are...

stupid is as stupid does...