DIY Light Meter Concept

So, just thought I'd make a new blog entry saying that I intend to build a light meter.

A CdS 'sensor' (light dependant resister or photo resistor) is pretty cheap, about $1, so I'm going to try and experiment and build a low-light meter.


Sekonic's seem to stop metering somewhere really lame, my Gossen Luna Pro SBC is several stops better, and goes down to EV -5, so I'd be looking at improving upon that essentially, a number of more stops.

 Would be handy.

16mm Motion Picture Film Developing Tank Mk1 aka "Missile Launcher"

Okay so the first developing tank is completed, it has numerous problems in operation, though isnt expensive to make, is a pain in the arse to actually use, I have already learned a lot and have a number of refinements for the heliacal-spiral type, though I'm 'putting my money' on a simple 2D spiral type.

Ultimately I want to construct something that has semi-automatic loading of up to 1000 ft in lengths in both 16mm and 35mm formats, which I have a few ideas for the future for.

Anyway, I've posted a video on vimeo detailing on putting this first version together, I will post chemistry mixing for ECN-2 and other videos in the future, such as other tank versions, and actually processing ECN-2 film, and B&W motion picture reversal stock.

http://vimeo.com/12522602


Video journal of the "missile launcher" (since it likes to launch the inner tube like a missile if you dont tape the end cap on when using it).

This shows construction of the first 16mm ~100ft I built (ended up being 86.5ft in this one).

There are problems with this design I didn't know about or think of until I went to use it.

This design takes a long time to construct, is very difficult to load.

I would also recommend if using the heliacal-spiral type like this desig of mine, to have the spiral track cut into a tube (perhaps a wooden solid cylinder?) about 0.5cm+ deep so the film can be crank-wound on.

Currently, at the moment I recommend a 2D spiral type on a base board that gets placed into a bath, a spiral may seem hard to make, but you can do it with vertical rods (nails, dowel, otherwise, etc) rather than two tracks at bottom and top like a 35mm/120 roll hand processing tank for still film.

If your film needs to touch against something (such as the rod 2D spiral type or rack processor, or this tank in the video) wind it on so the emulsion side is not touching anything, then it is perfectly fine.

I'll make a new tank and show a video, as well as mixing up useable formula for processing ECN-2 at some point.

I'll be scaling up my final design when I find the perfect design after building enough 100ft tanks for 400ft and 1000ft and 35mm as well.