Opinions on GG probes/sensors?

I've got an old L-718 Sekonic that has served me well over the years. In looking at an old ad from that era, I see that they made a pinpoint attachment for reading from the GG. Part of my intrigue is that I have an old style Copal on a Super Angulon without the proper ƒ stop band attached. With the Sekonic's reflective window attached and held to the GG, I feel that my measured hand markings are basically correct so that's not really that big of a deal but the whole thing has me thinking about how useful these would be for bellows factor, etc?

Sekonic responded right away today about the probes still being in stock and B&H lists them, too.

• B&H # SEFOAL718
• Mfr # 401-804

Does anyone have much experience with this method? Is it accurate, overkill, an answer to a question no one even asks?

I have one for my Minolta Flashmeter III and rarely use it. It's mainly useful for studio work with strobes, where you have a very bright light source so that you have enough light to spot meter accurately off the glass and can shield the groundglass easily from stray light. It also has other attachments that I've never used for doing things like metering through a microscope camera or at the film plane of a 35mm camera (which entails not having film in the camera) or through the eyepiece of an SLR.

It depends on how you work..

if you do lots of close up work where bellows extension needs to be taken into account then they are a joy to use.

I have a Minolta one I use with a Autometer V - mine came without an instruction book, but once I worked out how to calibrate the probe it has made measurements quick and accurate

I've got the Sinar/Gossen unit that links up to a Luna Pro SBC or an Ultra-Pro, and I love it. Its everything nice about a spot meter, except its all in-camera, so you can be completely sure of composition and bellows factor, even if it is only a small degree.

Hello !
I've a Gossen probe apt to connect to a Luna-pro. Used a couple of times and now it's sitting in it's drawer.
IMHO it's of no use if you do landscape work as I do.
If you do studio or close up work, they are a joy to use and allow to precisely measure the difference between highlight and low light zones to check for rendition... Worth a peanut load of wasted film, don't you think ?
Having seen the Sinar system in use I can second it's a marvel... But an expensive one.