8mm Forum: 2/3 of a stop neutral density filter

This is topic 2/3 of a stop neutral density filter in forum 8mm Forum at 8mm Forum.

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Posted by Michael Wright (Member # 1387) on November 30, 2009, 07:32 AM:

Hi, one of the above is recommended by Kodak to use Ektachrome64 film in a super8 camera that only accepts 40asa film. Has anyone actually seen one of these for sale? I certainly haven't MIKE

Posted by Bart Smith (Member # 780) on November 30, 2009, 08:06 AM:

Hi Mike,

I've looked into this in the past, the simple answer is no!

It would be easier for you to get a different camera that will read 64 correctly.

Posted by Michael Wright (Member # 1387) on November 30, 2009, 08:10 AM:

Thanks Bart.

Posted by Steve Klare (Member # 12) on November 30, 2009, 08:12 AM:

The problem is if the camera meters through the lens, the 2/3 stop ND filter won't actually compensate the exposure, it will just reduce the light available. This will work if the filter reads the light seperately from the lens, then the metering system will allow 2/3 of a stop of excess light, which the filter will remove and bring you back to where you want to be.

I experimented with a camera that allows for exposure compensation and tried exposing 64T at 40 and 64ASA under the same conditions, the results weren't very different and neither was visibly better than the other.

If you try a test cartridge in a 40 ASA camera, you will probably like what you see.

(You just need to be sure you are actually getting 40 ASA and not 160.)

Posted by Claus Harding (Member # 702) on November 30, 2009, 08:18 AM:

Posted by Bart Smith (Member # 780) on November 30, 2009, 08:42 AM:

The Eumig Mini 3 doesn't have TTL metering, so a 2/3rd stop ND over the lens would work.

If you could get hold of one!

Posted by Steve Klare (Member # 12) on November 30, 2009, 09:03 AM:

Have you tried it filter-less, Bart?

There's a theory out there that a little overexposure will tighten up the grain and may actually be a benefit. At least in my K40 adjusted eyes the 40 ASA exposed 64T was still a little on the grainy side.

Otherwise a half stop ND will at least get you in the neighborhood.

Posted by Douglas Meltzer (Member # 28) on November 30, 2009, 09:10 AM:

Michael,

You would need a 0.2 ND filter. What filter diameter does the camera accept?

Doug

Posted by Bart Smith (Member # 780) on November 30, 2009, 09:20 AM:

My advice would always be to try one cart and see how people get on with it. The accuracy of the internal meter is an unknown anyway.

There is precious little light here in the UK at the moment anyway, so 2/3 stop overexposure might be just the ticket.

I've seen the results of running 64T in 40/160T only cameras many many times as I telecine it, very often it is perfectly OK, but sometimes it can be too washed out.

Many people (especially beginners) try to film in too low light levels anyway, so it can be a positive when you take into account all the swings and roundabouts!

It is possible to get 0.2 ND polyester filters, but I don't remember seeing glass screw-in ones. Unless you want to spend a LOT of money!

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