Movie film problem

Hi all, so here is my deal. I have a couple of old movie cameras, a Tower Varizoom and a Bell and Howell Zoomatic that use double 8mm film. I have some Fomapan 100 I want to try but..... the cameras light meters are only calibrated to a max of ASA40, the Fomapan is rated at ASA100, my light meter tells me I would need to use F45 (at 16fps), both cameras have a max. F22 aperture, How can I make this work? Would a ND filter do the trick and if so, how would I calculate the strength of the filter? Any help would be appreciated. Steve

It's been a while, and I've only used them on still cameras, but as I recall ND filters are marked according to the wider f stop they require -- i.e. an ND2 filter would call for an exposure at f/11 instead of the metered f/16. Contrast, etc. remains the same. I can't think of any factors that would apply to cinematography that wouldn't apply as well to still photography. Nothing wrong with your plan as long as you can find the right filters. Good luck!

ND filters are marked according to several systems of notation; this wikipedia article has a good chart:

Neutral-density filter - Wikipedia

In common photographer-speak, "N3" is 1 stop, "N6" is 2 stops, "N9" is three stops, etc.

Probably a 1,5 stop ND filter(if available...it may exist) would be good for your application, assuming the camera meters are not through-the-lens.

Use your external light meter unless you trust the camera meter. You may have to sacrifice a roll of film to test the system.

ND filters are marked according to several systems of notation; this wikipedia article has a good chart:

Neutral-density filter - Wikipedia

In common photographer-speak, "N3" is 1 stop, "N6" is 2 stops, "N9" is three stops, etc.

Probably a 1,5 stop ND filter(if available...it may exist) would be good for your application, assuming the camera meters are not through-the-lens.

Use your external light meter unless you trust the camera meter. You may have to sacrifice a roll of film to test the system.

 

This is where I get lost, all the math. First, I am using a Gossen Luna Lux, that is what is telling me I need f-45. So, going by Steve logic, that means I need to stop down 3 stops to get into a usable range, (reading the numbers right off my trusty Gossen light meter) f45-f32-f22 and finally to f16 which is within the Bell and Howell range. Does this make sense? I am assuming these are full stops,( I have never seen anything calibrated for smaller than f22 ). Thus is seems to me that an ND9 (3 stops) may do the trick.

You have suggested an ND1.5 so I am wondering what I am missing here. I looked at ND charts, f-stop charts and read their explanations, but now I think I know less than I did before. The way the values are expressed is confusing and seemingly not uniform, as an example I found on the same chart, I noticed that an ND6 expressed as an ND102, ND 0.6 and ND 4 (using the wikipedia chart suggested by Fred), also the ND 1.5 you suggested expressed as ND 105, ND 1.5 and ND 32 all with a fractional transmittance 3.125%. As I understand this that means that only 3.125% of the light is permitted through? I should have stayed in school.

I do have a ND-6 filter, might that be close enough to give me a starting point?

ND filters are marked according to several systems of notation; this wikipedia article has a good chart:

Neutral-density filter - Wikipedia

In common photographer-speak, "N3" is 1 stop, "N6" is 2 stops, "N9" is three stops, etc.

Probably a 1,5 stop ND filter(if available...it may exist) would be good for your application, assuming the camera meters are not through-the-lens.

Use your external light meter unless you trust the camera meter. You may have to sacrifice a roll of film to test the system.

 

 

Thank you for the reply, it looks to me like this is a mathematical nightmare, or I am overthinking it.

ND filters are marked according to several systems of notation; this wikipedia article has a good chart:

Neutral-density filter - Wikipedia

In common photographer-speak, "N3" is 1 stop, "N6" is 2 stops, "N9" is three stops, etc.

Probably a 1,5 stop ND filter(if available...it may exist) would be good for your application, assuming the camera meters are not through-the-lens.

Use your external light meter unless you trust the camera meter. You may have to sacrifice a roll of film to test the system.

 

 

Wait a minute, I just turned a haircut into brain surgery, is there any reason I couldnt hold the ND over the eye on my light meter? If it gets me in range on the meter it should be about right over the lens. That seems like it should get me in the ball park.

is there any reason I couldnt hold the ND over the eye on my light meter?.

 

Sure that would work but it is too easy. You wouldn't have the fun of making yourself bat crap crazy by trying to do all the math.

I presume you mean R100, the reversal film. f/45 sounds a little worse than I would expect.

 

For 16 fps, the shutter has to be faster than 1/16, and if you include time to move the film, probably 1/30.

 

So using sunny 16, that would give about f/32, so only one stop from f/22.

 

But for a slightly cloudy day, or more cloudy, you should be within the range of your camera.

 

Otherwise, 1.5 stops of ND over the lens, not over the meter, and set the meter for 40.

 

For a negative film, one stop over should be fine. Not usually for reversal film.

well.... I am not sure what I did wrong (I think I read the wrong scale) but it appears I misread my meter. I finished up a test roll of Fomapan R100 yesterday under shady sun, the meter, when read correctly said f16 at 16fps (no filters) so thats the way I went. I had the camera set for manual aperture so it seems to me I should have a valid starting point, f16 being well withing the range of this old Bell and Howell. Am I correct to think that in manual, meter and manual aperture should be (more or less) in agreement?

I presume you mean R100, the reversal film. f/45 sounds a little worse than I would expect.

 

For 16 fps, the shutter has to be faster than 1/16, and if you include time to move the film, probably 1/30.

 

So using sunny 16, that would give about f/32, so only one stop from f/22.

 

But for a slightly cloudy day, or more cloudy, you should be within the range of your camera.

 

Otherwise, 1.5 stops of ND over the lens, not over the meter, and set the meter for 40.

 

For a negative film, one stop over should be fine. Not usually for reversal film.

 

 

 

I think this might be another case of me making much of little. Thank you for the reply.