Astrophotography with EF-M Prime lenses (PIC)

Marco Nero wrote:

noisephotographer wrote:

The other two lenses (28mm + 11-22mm) were both shot at maximum apertures for their respective lenses because they needed every bit of light.

It could make more sense to shoot at 22mm f/5.6 instead of 11mm f/4.

22mm f/5.6 captures twice as much light from distant objects than 11mm f/4. (22/11 x 4/5.6)² ≈ 2

A 22mm crop of the 11-22mm at 11mm f/4 is equivalent to 22mm f/8 on a 6 megapixel Aps-c camera. Though it wouldn't be as bad as one would expect because the low resolution (6 megapixels) gives a read noise advantage. Therefore it's possible that it could perform better at 11mm f/4 despite capturing less light per object.

Oh GOD! I don't want to go out there again in the cold... but that observation you've made actually piqued my interest. I will certainly try this soon if nobody else with the 11-22mm lens wants to give it a go. I think this might have merit enough for an experiment. Anyone want to give it a whirl?

That's why i used tracker to compensate the low signal from wide angle lens vs normal lens by exposing longer.But doing long exposures (3-8 mins range) introduce another problem: sensor heating! It will make the read noise more nasty even shooting at low iso, so even using tracker, I will still go for 22mm, doing mosaic instead of using long exposure with 11-22mm, waiting to try out the magnificient 32mm when I get the hold of it.

If you remember my shot last year using 11-22m, ISO 2000, 2 mins exposure x 4 shots, camera was so hot that the last shot was full of noise.