Hi,
I guess we don't get notification if anyone leaves a reply or asks a question on our photos, so I did not know you asked this.
I think it will be a bit harder with the kit. This was a 30 second exposure as it was. And with everything else the same, going from f/1.4 to f/2, then f/2 to f/4 is 4x more light getting to the sensor w/the f/1.4 lens than an f/4 lens. You'll need to increase ISO, and that's going to increase the noise incredibly high with a 30 second exposure. You'll definitely need to shoot RAW and rely on the tool not getting rid of the star trails, get rid of the specks of noise aggressively.
Whether the newer plastic fantastic, or older MF fast 50's, they're all pretty affordable. I'd recommend you get yourself one, set it to infinite focus, and shoot away.
Filmstrip
m8o's Photos - Nature - "Milky Way"
