I have been wanting to successfully record an exoplanet transit for some time and have "spoilt" some attempts by simple errors; e.g. got the fov wrong, UT and civil time mixed up and transferring details to paper for use in the observatory wrongly.

Eventually, I managed to record the transit light curve of  HAT-P-54b, which orbits a 13.5 mv host star of 0.645 solar masses and a radius of 0.617 solar radius.  The planet has a documented period of 3.7998 days and is thought to be a Hot Jupiter of mass 0.944 Mj.  The magnitude drop at transit minima is  ~0.023 with a total  duration of ~ 1hr 47min.

AstroImageJ was used to process both the images and model the light curve. AstroImageJ is free and I can highly recommend a course, given by Denis Conti via the AAVSO, on its use.

Using and fixing both established values together with the predicted time of minima I obtained;

an O-C of the minima of -2.06 min and a transit duration of 1:57:38 (hh:mm:ss)

Allowing the same variables freedom I obtained;

an O-C of -2.04 min and a transit duration of 1:47:38 (hh:mm:ss)

Mass of the planet HAT-P-54b was determined to be ~1.07 Mj.

There would appear  to be a 2min difference between the observed and calculated minima.