Borrowing a Beaulieu...

[chas_ucla]

Well, wouldn't you know...a colleague from work casually mentioned at lunch that he used to sky-dive in the '70s with a Beaulieu 4008 attached to his helmet via a custom-mount...

He's not using his ZM 2 anymore so I asked if I could borrow it for a couple of weeks...and he said, "yes"!!

Since the Beaulieu has a 62mm lens, I thought I'd buy a 62-55mm step-down ring so that I could use my still-camera filters on it. I just ordered 55mm multi-image and center-focus filters (so I can use these for my still cameras after I return the Beaulieu)...I'm curious if anyone has ever used special effects filters like these on their Beaulieus...if so, how were the results? Is there anything I need to look out for?

Chas

[GREATwarEAGLE]

Vignetting. Especially since you're stepping down. Unless you plan on cropping in post, watch your wide angle shots carefully.

[chas_ucla]

Thanks. Yeah, I heard about vignetting issue...but I heard that's mainly a problem if you are stepping up, not down. But I plan on not using any wide angle shots for the fx filters so I think I'm ok...

[GREATwarEAGLE]

Also - the FILTER FACTOR

the following is verbatim from a film book:

All filters absorb some light, and compensation must be made for the loss of light to avoid underexposing the film. The filter factor is the number of times exposure must be increased to compensate for the light loss. Each time the filter factor doubles, increase the exposure by one stop. Manufacturers supply filter factors for each of their filters.

[MovieStuff]

<BLOCKQUOTE><font size=2 face="Verdana, Helvetica, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="Verdana, Helvetica, sans-serif">Originally posted by GREATwarEAGLE:

All filters absorb some light, and compensation must be made for the loss of light to avoid underexposing the film.</font></td></tr></table></td></tr></table></BLOCKQUOTE>

The easiest way is to simply use the camera meter and take a reading through the lens, which will automatically take into account the density of the filter(s).

Roger

[GREATwarEAGLE]

Most of the people here unfortunately rely on the meter in their camera - the result of a low/no budget.

But, if you take filmmaking seriously, and want to spend the rest of your life doing this, then perhaps you should consider buying an incident/reflected light meter. Like a Sekonic. No they're not cheap. But if you wanted cheap - you'd be shooting video. Right?

That's when the filter factor becomes something you need to think about. Otherwise, what Roger said will work - if your camera's meter does.

[MovieStuff]

<BLOCKQUOTE><font size=2 face="Verdana, Helvetica, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="Verdana, Helvetica, sans-serif">Originally posted by GREATwarEAGLE:

But, if you take filmmaking seriously, and want to spend the rest of your life doing this, then perhaps you should consider buying an incident/reflected light meter.</font></td></tr></table></td></tr></table></BLOCKQUOTE>

You can also do the same thing with an incident meter by holding the desired filter over the meter. When I get a new filter in, I generally don't rely on the published filter factor that comes with the filter. Instead, I place the meter on a copy stand and take a reading with and without the new filter to see what the difference is in stops. I make a note of that for reference in the field. If I have several filters that I'm going to use at once and I'm shooting on Kodachrome where a little bit goes a long way, I will stack the filters and do a meter check in the field, just like with the copy stand. I have found that what the math works out to be and what the reality of the reading ends up being is often off by a quarter stop, on occasions, when using multiple filters.

But I agree that an incident meter is generally best and one should get used to using it.

Roger