Yes, I was wrong about 20 to 40 stops. I should have said it was a factor of 20 to 40.
Does the Hasselblad use Bay 60? If so, the cost of a B+W, Heliopan or Hoya filter is going to be very high -- probably more than $200.
I ordered a Bay 1 B+W infrared filter, and it took about four month to arrive. I think these are made in small batches, probably when enough orders have been received.
I'm planning to use it with some Efke infrared in 127 format and a Baby Rolleiflex.
It's better (cheaper) to use a B60/67mm adapter and then a "normal" 67mm filter.
With Rollei IR, I use a 715 Heliopan.
Well, thanks for all the advice guys... I guess at this point, my only option is to use the film with my standard red filter and see how it comes out... at least, until I get a proper IR filter...
You can use a #29 dark red and do OK.
Be sure to read the articles here, which were very helpful to me in figuring out this film and showing the effects of the combos you talked about