I have been doing photometry with an ST9E. I replaced an AO-7 with an AO-8. For some reason, the ST9E won't work with the AO-8. I don't want to invest too muchy money in an old camera, so I have been looking at an SBIG STT 8300M. This is an ABG, BUT appears to be linear to around 50,000 ADUs. However, the pixels are small and have a full well of about 25, 500e. I am worried this might mean that many comparison stars would quickly reach the 50,000 non-linear point. I'd appreciate anyone's thoughts/guidance on the issue.