There's no need to even check the sightglass. Drain the oil (w/filter removed), put the plug back in along with the new filter and poor in 4.5 quarts of oil and you're done.
5 quarts is for a DRY engine. Do I have to explain dry?
like I said, some people claim to be experts on stuff.... maybe if the factory service manual was available for the 2015 models they could actually read those figures, so you may need to explain it to those people...
personally, the sightglass is only there for visual verification during the periods btween oil changes, that the level is adequate....
the correct figure is in writing, and I can verify from all the oil changes I have done since 7/7/07, that the figure is correct.
to blindly dump MORE oil than that figure tells is a bit silly...less maybe, but never more.
for giggles... dry means " totally devoid of any oil, I.e. a completely rebuilt engine, or new engine, that never had oil, thus the oil cooler and oil passages are all empty.
that's where the extra pint ends up.
and oil is checked with the bike sitting on the wheels, on a level surface, and held in a vertical manner... but that's outlined in the manual also... I believe its in the owners manual also, but nobody reads those either, because they all owned soo many bikes they know more than the manual...
draining the oil on the centerstand works, as the oil pan is now sloped forward towards the drain hole....
but unless all you do is run the engine in the garage, with it on the centerstand, that sightglass reading will be showing too full when the wheels are actually on the ground. So by all means DO compare it, makes sense to me....
kinda like whining because the tire pressure sensors say you have a different amount of air than you do when checked with a gauge...
ride safe and have a nice weekend.