Canon EOS Rebel T5i ISO Test on Orion, Andromeda, and the Pleiades

I just got the Canon EOS Rebel T5i for Christmas, and I used it for the first time last night! I was able to photograph a few popular celestial objects, and I wanted to make some test sets to see the level of noise at ISO higher than what I was using previously (Rebel XT only goes up to ISO 1600).  What do these night sky objects look like at ISO 3200, ISO 6400, and ISO 12800? All of these tests are with single frames on a fixed tripod in 25ºF clear weather about 20 miles outside a large city.

Andromeda (M31) shot at ISO 3200, 6400, and 12800

Orion Nebula (M42) shot at ISO 3200, 6400, and 12800

The Pleiades (M45) shot at ISO 3200, 6400, and 12800

As you can see the noise goes up a great deal between ISO 3200 and ISO 6400, but I think the jump in noise from ISO 6400 to ISO 12800 is a deal-breaker when it comes to using it for astrophotography. I think I'll try stacking some images to reduce noise in the 3200 and 6400 range.

Hopefully when I get my motorized EQ mount set up I won't have to resort to such high ISO to reveal faint deep sky objects, but this was a fun little experiment using fixed-tripod techniques I'm already familiar with!

Canon EOS Rebel T5i