Pupil Size Gauge  Maximizing the aperture of your telescope requires that you consider your personal optical equipment!
When you are choosing the eyepieces to use with your telescope, do you take your eyes into account? Many folks don't realize that the maximum size of your eye pupil is what determines what your optimum low power eyepiece should be. By using a lower power eyepiece than the optimum, one effectively shrinks the aperture of the scope. Since pupils tend not to open as widely as we get older, it is clear that one needs to adjust to get the maximum performance out of our equipment (personal and purchased).      You can search the net and find many references on the importance of pupil size in determining your optimum low power eyepiece, here are two good ones:	Sky & Telescope, "A Pupil Primer" When does your 8" telescope deliver less light than a 3"? The second one gives an indication of how important paying attention to this can be! It also has a nice chart of pupil size vs scope speed (F/?) if you don't like the math.
I have a 14" F/4.7 and reasonably good eyes for my age (59). My exit pupils measure about 4.5-5.0. I find that my best, ie brightest images come with a 23-24mm eyepiece with that telescope(both by calculation and experience). Even if I had 7.0 mm pupils (about the best the normal young person could expect), ~ 32 mm would be the maximum for this scope. To use the 30-50mm eyepieces effectively one needs an F/10 or higher scope. Several people put out pupil gauges to test your eyes. The second article tells you how to make one and use it. Mine are adjusted to let in as much light as possible since they are meant to be used in the dark.  They aren't hard to construct and so I have. It is basically a series of holes on clear plastic at measured distances apart. Hold your eye close to the scale (too close to actually focus). You move your eye up and down the scale until the holes seem to just touch, and read the distance between the holes. If you do that in a bright room, you will find that your pupils contract considerably (mine are at ~2.5mm). If you do it with just enough light to see the holes, with dark adapted eyes you will get a measure of what your eyes really do under a night sky. Take it with you when you observe and see how dark adapted you get under different nighttime conditions. If you would prefer not to make your own, I have made these available at $5 including shipping. The picture shows it printed on white paper background so I could scan it in. The tester is on clear plastic so you can see through the holes. Also, since I relearning to program computers, I have put a free program on the download page that will calculate the match between your maximum pupil size and over 200 eyepieces. It will also estimate how much light will be lost if any in the combination of its exit pupil in your telescope and your eye.  It also calculates their FOV while its at it.  I will send you a copy (Windows and/or Linux format) on request. Whether you make your own or buy one here it is important to match your scope to your personal pupil parameters. It may be the easiest and cheapest way to start using a larger aperture instrument!	$5 includes US shipping; Email for international shipping