<p>As far as I know, the only difference between the PQ and PQS lenses is the maximum shutter speed. I don't think there is any difference between them in terms of optical formula or coatings. I think you have two options:<br>
1) Find someone to make a custom adapter to fit Exacta66 lens onto a Rollei.<br>
2) Experiment with different films, filters, and different grade papers to achieve a close as you can to your desired result.<br>
If you are using the Hy6 with a digital back, then it might be the sensor that is the issue. In which case, try a film back for the Hy6.<br>
Regards,<br>
Rif</p>