Planostar 0.79 reducer spacing tolerance

[Anne S]

Does anyone know the tolerance if I use a SX694 with a Planostar 0.79 reducer, the  3 inch one, on an Altair Wave 102mm super triplet? The recommended spacing is 57mm. The above ccd is approx 15mm diagonal. I gather the smaller the chip, the more tolerance as to distance. I need 59.5mm to run an OAG in the imaging train.

Thanks

Anne