View Full Version : A question about the ND filters


David Warrilow
July 9th, 2003, 12:48 AM
Hi,

I've been following with great interest the first hand encounters with the hd1 and hd10. Thanks to all those on the front line for giving the rest of us your experiences.

One of the objections to the camera was how fast bright areas in a scene clip out - and one of the proposed solutions was to put ND filters of varying density in front of the lens. I can see how the decrease in the amount of light entering the lens will allow a slower shutter and a wider aperture on the camera - but how do the ND's lessen the rapidity of the ccd clipping out? If you expose a scene properly with the nd's on the front, slower shutter and wider aperture - won't the bright highlights clip out just the same? If not, why not?

Thanks again for all the feedback.

best,

DW

Steve Mullen
July 9th, 2003, 01:19 AM
If the physical CCD is being overloaded the ND will stop that.

But, you are right -- an ND only lowers average brightness. The contrast ratio can still be too great to handle.

A polarizing filter cuts reflected light which usually seems too bright. So it should work.

I think they also cut sky and water brightness so could be a big help.

Please, someone try this and report.

Robert Jackson
July 9th, 2003, 07:55 AM
<<<-- Originally posted by Steve Mullen : If the physical CCD is being overloaded the ND will stop that.

But, you are right -- an ND only lowers average brightness. The contrast ratio can still be too great to handle.
>>>

Has anyone tried Tiffen's line of contrast-reducing filters? I've been wondering if they might be the answer to some of these latitude problems.

-Rob

Steve Mullen
July 9th, 2003, 02:47 PM
<<<-- Originally posted by Robert Jackson : <<<-- Has anyone tried Tiffen's line of contrast-reducing filters? I've been wondering if they might be the answer to some of these latitude problems.

-Rob -->>>

Hi think they work via a very fine mesh -- which in HD is going to look like chicken wire.

Joe Russ
July 9th, 2003, 05:08 PM
<<<-- Originally posted by Steve Mullen : <<<-- Originally posted by Robert Jackson : <<<-- Has anyone tried Tiffen's line of contrast-reducing filters? I've been wondering if they might be the answer to some of these latitude problems.

-Rob -->>>

Hi think they work via a very fine mesh -- which in HD is going to look like chicken wire. -->>>

actually, there is no such chicken wire problem. i used a low contrast filter on my previous camera (sony trv950) and ive had one on my hd1 since last week. im currently using a Tiffen Low Contrast 2 filter. thats the contrast filter that raises the level of dark areas and leaves highlights and mids alone. so it doesnt affect blown out highlights, but you can fix them in post and with better contrast of lighting (if you can control your lighting).

Jay Nemeth
July 10th, 2003, 03:45 AM
The polarizer certainly helps to reel the sky back in, as long as you're off axis to the sun. A full set of NDs is a necessity with this camera so that it can be forced into a 60th of a second outdoors. I find that even if you don't lock the exposure, it's good to leave the bias in -1 or -2 to avoid blown out highlights.

This camera is not for the timid or casual user. You must hold it's hand and coerce it into doing what you want. It is very similar to shooting reversal stock for motion pictures. Better to underexpose a little than see the not-so-gradual clipping of the whites.

Tomorrow I'll shoot some tests with the Tiffen Ultra Low Contrast and some Warm SFX filters. With film, the Low Contrast filters effectively "flash" the dark parts of the image revealing detail that would be lost otherwise. I'm interested to see if the same holds true here.

Jay