In article <32631B48.1F3A@pop.mil.adfa.oz.au>, stevemci@pop.mil.adfa.oz.au says...

>I am aware that there are marked differences between the various camera
>lens manufacturers - and assume that similar differences exist between
>lenses for enlargers.

The differences are not quite so apparent, maybe since enlarging lenses
are (or should be ;-) used at optimum apertures, where the differences
among good lenses made by the major manufacturers are minor.

>I am interested in peoples opinion of the various brands - mainly in the
>35mm film, 50mm lens area. [...]

If you use a good model 75-80mm lens for 35mm (with appropriate condenser setup, if using condensers) made by Schneider, Nikon, Rodenstock, etc.,
the results should be about equally excellent at f8-11 with any of them.
Using a longer than normal lens provides the benefits of more even illumination, more even sharpness, more space for dodging/burning
operations, and maybe a bit less of a problem with film flatness...

>Another Q - Do enlargers all use a standard screw thread diameter? or is
>it possible to buy adapters for the non-standard dias? [...]

Lens boards with various hole sizes are generally available to fit various size lenses.
Hope This Helps