infrared film focusing in a Rolleiflex

[jpa66]

I just got an infrared filter for my Rollei and wanted to know if there are special "tricks" to focusing. My 'flex doesn't have a red dot on it, and I was wondering if I need to focus as if it did, or just focus as normal. I ask this because the filter is a Rollei brand infrarot, and I have heard that this filter compensates for the IR light, so no adjusting of focus is necessary. Is this the general consensus, or not?

Thanks,
Jan

 

[Captain Boar]

You can take a bulb and focus on it with and without filter to mark the difference between the distances.
The red dot for my 2,8c with Xenotar is between 5,6 and 8.

 

[Dan Daniel]

Although this doesn't answer your question about the Rollei infrared filter and its need for offset, I will post this image of the focus scale of a Minolta Autocord with its infrared pointer. It should give you some idea of the basic offset. This camera has a 75mm lens-