Proper "rule" for pinpoint stars with M43

Giiba wrote:

OutsideTheMatrix wrote:

Giiba wrote:

OutsideTheMatrix wrote:

Giiba, I see that you put 14/3.5 in there! So do you find there is about the same amount of trailing with the 7-14 at 14mm and the 14-42 at 14mm?

If you could do so, would you do one for the 14-42 at 42mm and the 40-150 at 40mm please? Thanks!

I was just toying for the score. As far as the spreadsheet is concerned 14 is 14 is 14 but in reality there can be slight fov differences between lenses of the same focal length. But that shouldn't change max time significantly.

40mm, 42.5,mm and 45mm are all 6s after rounding so 42 will be as well. I plan to add the 40-150/2.8 only the score would differ based on aperture.

I was wondering how much the difference would be between the 42/5.6 of one lens versus the 40/4 of the other lens. I thought your score might relate to how many stars can be captured based on the aperture of the lens

That's the theory behind the score, the higher the score the fainter the object that can be imaged. I've used the standard formula created by the astro folks:

Clear Aperture Area x Angular Area x Max Exposure Time

What a given score will image would be better asked in the astrophotography forum.

As for varying score based on changing aperture, my spreadsheet assumes use at max aperture. But basically, stopping down one stop will half the score.

Thanks!  Do you also find that when you get to ISO 3200 the star colors seem to become pale, regardless of shutter speed? I think this has to do with reduced dynamic range.  I've been keeping ISO at between 800-1600 to keep star colors rich regardless of the shutter speed.