I am so excited that I got the Sigma 30mm f/1.4 for my birthday. It is really sweet, though I find I'm stepping forward more after using the 50mm for 9 months now. I'm used to a tight crop, but glad to be able to get more than 1 person in a shot now.
So here's my issue and I feel really dumb. My low light photos are sucking - as in too much noise and often out of focus faces. Technically, I understand why. I'm using Program Auto + Auto Focus, so the aperture shoots to the max (smallest number), the ISO bumps up and the shutter speed compensates to those values. I get it, the depth of field is too shallow, the ISO is too high.
I'm not talking super low light concerts - just indoors somewhere, at night or without much natural light. For the most part, the exposure is great - not too light or dark - but I'm not getting anything that resembles "crisp".
I've experimented with manual focus and that seems to help a little, but often times I don't have time for manual, so I need to rely on a quicker change of numbers.
Do you have a rule of thumb for your indoor shots where you don't want the DoF to be too shallow?
In using the calculator on
this page, I think I would need to bump up to 2.8 to get one face clear and 4 to get 2. (They always say aperture = 2x the people, right?) But then what's the benefit of having the 1.4 if only taking a photo of a domino on a table is going to benefit. I think I am missing something.
Edited to add - this problem was noticed mostly with the 50mm f/1.8 lens. According to the calculator I linked above, the problem should be less so with the 30mm lens. I haven't shot enough with the new lens to compare.