SPECTRA COMBI-500 LIGHTMETER

I recently found that very classic light meter (1960's), see title.

It came in a very good shape and is working perfectly (compared to my other light meter and D800 camera). It was packed in its fancy leather case with, at first sight, all the accessories.

But apparently one slide is missing, it's the X100 one. This one is needed to work in high daylight.

Does anyone here can help me out?

Perhaps, a drawing with the pattern of the holes of that slide could do, so I can make one out if a tin sheet...

Thanks,

I bought a Sekonic Lux meter, based on the same design as their Studio 398 light meter. It came with a multiplier slide that was insufficient for full sunlight (>100K Lux). So I made another slide by calculation, using less holes and of a smaller diameter. It worked fine and to an acceptable degree of accuracy.

The amount of light admitted by a round aperture is inversely proportional to the square of its diameter, and obviously directly proportional to the number of holes.

So to reduce the amount of light to 1/100th, you could have a slide with a single aperture 1/10th the diameter of the open receptor, or with 4 holes 1/20th the diameter, or 16 holes 1/40th of the receptor diameter, etc. Or any combination of diameters and number of holes to match the original pattern as closely as possible. (1 x 1/20th and 12 x 1/40th for example)

Luckily, drill bits are available in almost any size, and a photographic light meter only needs to be linearly accurate to +/- 12% in order to be within 1/6th of a stop of 'correct'.

Remember that the slide needs to be blackened, and that spray paint will partly block small holes! A self-coloured material like thin black plastic sheet is going to be your best starting point.

Thanks Rodeo_joe, that's exactly what I did, as somebody send me a template.

Now I can fully use this Spectra, regardless its clumsy ergonomics, it's fun to use...

Even the CDS cell is still working with two WeinCells!