If you go ahead and search the internet you'll find an article about the AE that pretty much discounts the radiation as trivial. Short of living with it in your pocket it's not going to do anything!
I've got two in my house right now, building a couple cameras. They are unique lenses that are very interesting to me. Still doesn't look like a Schneider 300/5.6 on 8x10.
My blog about shooting film in south GA:
I don't mean to perpetuate the tangent this thread is taking, but my friend was worried about taking road trips and sleeping in his van close to ULF lenses containing radioactive glass. I arranged for his lenses to be tested by the Director of Radiation Safety at the university at which I work.
IIRC, the radiation exposure you would receive after staring directly into the glass for an hour from ~6 inches away was similar to that you would receive during an hour of commercial air travel. The metal barrels shielded the radiation considerably. The ground glass would probably provide additional shielding while composing as well. In short, the Director told my friend that he should simply limit his close contact with the glass. My friend was reassured.
Back on topic: if you're leaning towards 8x10, someone just posted a Rodenstock 300/5.6 for $300.
The results indicate that it's not worth worrying about. The alpha and beta can be stopped very easily and the gamma is not bad as long as distance is increased... worrying about the radiation will do more harm than the radiation itself!
But it's still radiation... the less of it you get, the not bad it is It's like driving and speed. The slower you go, the fewer the chances of fatalities in accidents... so is the best thing to do not travel by vehicles at all?
So, Serge. I'm curious how your thoughts evolving on the topic of 4x5 vs. 8x10.
I'm sorry to hear that, John. I don't want to come across as casual about radiation. I simply wanted to put the radiation emitted by lenses in perspective by comparing it to other exposures we willingly and perhaps naively accept as "safe." The more we have learned, the less radiation the medical field uses for imaging procedures. There was a time when X rays were deemed safe by "experts" and used for everything from acne treatment to even sizing your feet in a shoe store. Times have gladly changed, but perhaps not soon enough for you.