Calibrating Apertures (on LF lenses)
So I can't be the first person to ask this, but i can't find anything in the search (maybe I'm just searching for the wrong thing).
Anyway, I have a few LF lenses, all bought second-hand, and I'm not sure if their real apertures are the same as the ones written on their scales.
Specifically, I've got a 65/8 'Technika' Super Angulon in #00, a 90/8 'Technika' Super Angulon in 'Compur Electric 1' (#1), a Xenar 105/3.5 in #0, and a 180/5.6 Symmar-S in #1.
The 180/5.6 is the most dodgy-looking, for a start the aperture scale on the shutter only goes down to 6.8, when the aperture is fully open it's off the scale, and there's also a sticker on it that says 'Rodenstock Quality Seal'. So it's definitely not the shutter it came in. All the shutters work (even the Electric one that I had to hack together a battery holder for), and the times all sound right, it's just the apertures need calibrating.
So what's the best way to calibrate them? I'm just going to put a white sticker around the shutter and marking my own aperture-values on that, but it's how to take the light-readings to know where to put the marks that I'm wondering.
What I've got available is a Gossen Digisix (it does both reflected and incident), I've got my Toyo-View, I've got any number of slrs with TTL metering (probably the most accurate would be the digital on live-view), and I've got a nice plain evenly-lit wall in my house.
I've previously calibrated my Soviet MF TTL-Prisms by mounting a long-lens on my tripod, attaching the dslr via adapters and taking light readings, then attaching the MF-body and setting the prism accordingly. (sometimes I've used the digisix instead of dslr).
But how can i do that with LF? I can get the reflected/incident reading on the wall easily enough, say I get something like iso100, 1/30s, f/8.
But then how do I get the TTL reading through the LF lens to calibrate? Obviously I can get a film-holder-board with an EF mount on it, set camera to iso100 Av, and move the aperture until I get a 1/30s reading, ergo that must be where f/8 is (although it won't be focussed to infinity, and I'd prefer not to have to buy anything I wouldn't use after this).
I was thinking the best way is to use the digisix somehow through the LF lens. Should I use it on incident or reflected (ie dome or not?). And then how do I know when I'm at the correct spot to get 1/30s at f/8? Won't the light being read be 'different' because it's already gone through an f/8 lens? Maybe I hold a grey-card at the film-plane and reflected-meter off that (whilst pointing at the wall that gave me the first reading of iso100, 1/30s, f/8)?
Any other methods that can use the stuff i've got lying around? (I'd rather not take a bunch of test shots, I doubt my developing is anywhere near calibrated)
(ps, please don't say Sinar Six, I can't afford one of them)