[ALREADY DONE, M only] Bracketing: More than 30s shutter (w/o opening aperture)

[Marsu42]

I only discovered this yesterday when doing night-time shots - when doing a bracket 0+-+- or 0++ when the slower frames are more than 30s, the camera automatically opens up the aperture to still reach 30s which the bad effect on sharpness and ability to merge frames because of different dof.

Ml can do bulb timing, so it'd be great if the slower brackets could still be shot with a smaller aperture, but more than 30s shutter speed? That would also be a distinct advantage over Canon bracketing.

[a1ex]

Sounds like a bug, was in M mode? if so, how to reproduce?

[Marsu42]

Sounds like a bug, was in M mode? if so, how to reproduce?

It was Av mode with 0+-+- bracketing, 1ev steps, 7 frames, shot with f8 - the +1 frame was 30sec @f8, and then the +2 & +3 frames were also 30sec but with 1 and 2 stop larger apertures resulting in a sharpness loss & changed dof.

[a1ex]

In Av mode it won't go past 30 seconds, try M.

[Marsu42]

In Av mode it won't go past 30 seconds, try M.

Ok, thanks - though I think this information deserves a big red warning in the help menu since the changed aperture is hard to spot when shooting.

[a1ex]

... that's how Canon firmware works.

[Marsu42]

... that's how Canon firmware works.

Yes, I understand that now - I just assumed that *ML* bracketing automatically works around that problem just as it is able to do bulb timing. But if I was the only one with this knowledge gap and everybody else has worked it out I'm fine :-)