Single Lens Reflex

For years they let us see the view
through any type of lens,
for portraits or landscapes anew
and fashionista trends.

The key design ingredient
was pentaprism glass
which rendered more expedient
a route for light to pass...

for when the shutter blocked the scene,
in previous designs,
we also knew the focusing screen
helped us sight the lines...

and by that screen glass we could see
the scene unlike before,
with new optical liberty...

photographers adore!