I'm not a spectroscopist, but, I know a fair bit about spacecraft data reduction. CRISM is a spectrometer that's very sensitive, but it needs more light than it can get by just riding along with the spacecraft, so it slews in the reverse direction of motion (that's why CRISM images have that hourglass shape). Despite that, it STILL has some light issues ...
TheSkyLive's Mars information page has graphs of its distance and apparent magnitude from Earth.
If you set the same year range for each, you can see how the quantities are related.
They provide similar pages for all the planets and selected comets and asteroids.
Not quite what you want:
Following is a list of all close encounters when Mars has approached, or will approach Earth closer than 56.00 million km .. during the first 3 millennia A.D. (1 AD to 3000 AD).
Also, the maximum apparent magnitude may be a few days from the closest approach. See: The cycle of close and far Martian oppositions
(Much of this echoes what antlersoft says in their answer)
For a phone photo through the eyepiece that looks about right to me!
The size... the brightness... both are as I expect.
What you could try is to use the manual mode of your phone's camera and set the ISO down to minimum (100) and the shutter speed down to something like 1/60s.
Take a few shots, ...
It's very difficult to get any kind of picture just holding your phone up to the eyepiece, and the picture you posted is overexposed and probably motion-smeared, but other than that it's what you'd expect.
Planetary observation is a learned skill; planetary detail is usually very low contrast. Mars is a small target and you have to use lots of magnification,...
Per this article, the most recent volcanic activity on Mars might be less than 1 million (Earth) years old. Pyroclastic deposits in Elysium Planitia were dated thanks to impact craters and were found to be very young.