Re: Image Quality
This is actually a pretty good example of the creeping privatisation of the NHS, and the negative effects of doing so. The motivations of private companies (in this case, the "contractor") and medical professionals are quite different.
The contractor will almost certainly have been chosen either as the lowest quote, or as the only quote (in which case, the outsourcing has probably been put in place specifically to give work to that organisation, not because of clinical need).
Private companies are motivated by profit, so the person doing the scans will be the cheapest available, and thus will have been trained to the minimum standard required to do the job. Spending any more money on someone more qualified, or on more training will be seen as wasted cash.
Medical professionals, however, are motivated by a desire to try and help people. They will want to do the best job possible, to save them having to repeat the job later, and to make sure they don't miss anything and potentially get sued. The private individual doing the retinography doesn't have this worry, as it is their company that gets sued, not them personally.
In theory, outsourcing such tasks gains an economy of scale (e.g. multiple NHS trusts using the same outsourcer). In practice, it doesn't save costs, but instead ends up with corners being cut to maximise the bottom line. In the end, this make the people who put that outsourcing in place very rich, at the expense of everyone else.