Can I see the edges of the visible spectrum at home?

So we can modify light outside of the visible spectrum via sophisticated lenses with the result being a new frequency inside the visible spectrum.

What I would like to do is different. I would like to explore (with my eyes) the edges of the visible spectrum i.e. red and violet. Ideally, I would love to have a light bulb, which emits light of any frequency required. That way I will make it red, and then decrease the frequency until it becomes invisible. That is, I am curious how sharp is the drop-off in our eyes' transfer function with frequency.

Trouble is, I don't have any laboratory equipment. All I have is an oscilloscope, breadboard and basic knowledge of controlling LEDs.

Is this feasible? I would expect a compromise solution as well, e.g. wait for a rainbow and look at it's edges.

• Those aren't "lenses" which cause frequency conversion. Meanwhile, you need to learn about black-body curves, wavelength distribution from LEDs, and so on before asking a question like this. – Carl Witthoft Nov 21 '15 at 15:13

• And how would he know whether he can't see a given $\lambda$ or it just isn't there, or isn't bright enough? – Carl Witthoft Nov 21 '15 at 15:14
• Indeed a similar experiment. However, either this noise generator is not functioning correctly, or my system of braowser-wireing-amplifier-speakers is not, because at max volume, I can hear 1Hz (as a pulse about once a second). – Vorac Nov 21 '15 at 13:57