Spot meter ground glass for macro

[brighamr]

Hi

Is it possible to spot meter off the ground glass ?

The idea would be to first make a reading of a tray card and then one off the ground glass of the same gray card and work out the difference factor
then apply that to further readings off the ground glass

Am i missing something

I could use an exposure disk etc but I am doing macro and its to small to get my light meter in
and also not much is in focus which is how I like it

thanks

robin

[Sevo]

For many pro grade meters there were on- or off-meter accessories for ground glass metering. In my experience the most useful common type would be the Minolta Booster or Booster II (for the Autometer/Flashmeter series), as these detach from the meter and have a sufficiently small (about 4mm diameter) spot - most meter mounted attachments use the reflected light optics of the meter, which tends to result in poorly defined "spot" sizes of 1-2cm. As LF use in studios has pretty much ended and Ansel Adams never wrote about the TTL zone system, these (originally priced like a good lens) are in a buyers market today (with a bit of patience, less than $100 ought to buy you a compatible Minolta meter and Booster I probe kit). Watch out that the ground glass attachment (a aluminium cone with a acrylic disc on the narrow front) is not missing...

One step up from that would be the Sinar probe systems that do true TTL metering in front of the ground glass rather than behind - these have a even smaller spot size, no issues with light loss at the ground glass, and are barely more expensive than the above by now. But they are mostly a option if you want to use them on a Sinar with probe back (not that rare - they shipped all cameras with it from the F2 on). There were "metering cassettes" to be used in place of the film holder to hold the probe wand on other cameras, but these are rare (indeed exotic in any size other than 9x12/4x5), and they will only fit cameras that take modern "International" holders (i.e. pretty much nothing preceding WWII) and don't block the probe slot (a issue with many collapsible press and travel cameras).

[BrianShaw]

Am i missing something

I think the only thing you are missing is the question mark (and other sundry punctuation).

Other than that, I suspect your plan will work just fine.

[Sevo]

The Calculite XP is small, solid state, reliable and has a ground glass probe for metering the way you ask. It also meters down to the light of a quarter moon - very sensitive. They are excellent meters for this use.

The original poster seems to be in London though - I don't think Calculites were ever distributed outside the US, the few I've ever seen here came to Europe second hand via ebay.

[Drew Bedo]

I have a Sinar Booster-1 probe that works with my Minolta Autometer IV F. This is a focal plane spot probe designed to work with any standard spring back view camera.

Broncolor has had a similar set-up too.

An older system was the Sinar-Six probe, based on the Luna-Pro meters.