Hello Bill, Stephen and Jim,

Thanks for your answers, it's clear to me now! I wil leave it on J2000 then!

Regards,
Albert

On 27-9-2013 7:36, Albert van Duin wrote:
> Hi Bill,
> I have a question about coordinate systems in Guide9.
> My mount is using Jnow natively, and so does CCD-Autopilot5. MaxImDL
> can also be switched to Jnow.
> I would like to use Guide9 in that mode too, because positions can be
> off by a few arc minutes now.
> In the Guide9 "settings-formats" menu I can choose between:
> J2000
> B1950
> Mean of da... (last part illegible)
> Apparent
> Other___
> Which one do I choose?
> Thanks.
> Best regards,
> Albert van Duin