Bob Krueger
New member
I'd like to ask what many of you will no doubt consider to be an elementary question. I'd just like to clarify what I think to be the case with ISO expansion on an EOS 1DMkII.
I have toyed with activating the ability to shoot at the lower expanded ISO (50) in the menu several times at the races so that I could shoot a moving race car in daylight at a relatively slow shutter speed (for wheel and background blur) and a decreased depth of field (sometimes there is signage in the background that detracts from the shot if it is too clear). The main thing that has kept me from doing this is reports of a reduced dynamic range at the expanded ISO settings, but I think I should see what I think myself about this by trying it and seeing what happens. It's only one stop, but sometimes that's enough to make a difference, and since these are images of race cars, not portraits or something, the reduced dynamic range may not be as destructively important for me as it might be for some others. Optionally, of course, I could just use an ND filter on the front of the lens, but for as often as I might want to use this option that route might not be worth the cost of the filter or the hassle of installing/removing it.
Anyway, here's my question. If I enable the expanded ISO feature in the menu, and leave it enabled all of the time, the dynamic range limitation will apply to only frames shot at the expanded ISO setting, correct? I could leave that feature activated for easily selecting and de-selecting ISO 50 without going back to the menu and still shoot at other ISOs (100, 200, 400, whatever - except 3200, of course) with absolutely no difference in the dynamic range results from what I would get if that feature were not activated, right? That is my impression from the little I have read on the subject. I'd just like to confirm that is correct. I would not want to leave the expanded ISO feature activated if it were going to negatively affect the quality of frames shot at "normal" ISO settings.
Not that it matters, I suppose, but I shoot RAW all the time.
I have toyed with activating the ability to shoot at the lower expanded ISO (50) in the menu several times at the races so that I could shoot a moving race car in daylight at a relatively slow shutter speed (for wheel and background blur) and a decreased depth of field (sometimes there is signage in the background that detracts from the shot if it is too clear). The main thing that has kept me from doing this is reports of a reduced dynamic range at the expanded ISO settings, but I think I should see what I think myself about this by trying it and seeing what happens. It's only one stop, but sometimes that's enough to make a difference, and since these are images of race cars, not portraits or something, the reduced dynamic range may not be as destructively important for me as it might be for some others. Optionally, of course, I could just use an ND filter on the front of the lens, but for as often as I might want to use this option that route might not be worth the cost of the filter or the hassle of installing/removing it.
Anyway, here's my question. If I enable the expanded ISO feature in the menu, and leave it enabled all of the time, the dynamic range limitation will apply to only frames shot at the expanded ISO setting, correct? I could leave that feature activated for easily selecting and de-selecting ISO 50 without going back to the menu and still shoot at other ISOs (100, 200, 400, whatever - except 3200, of course) with absolutely no difference in the dynamic range results from what I would get if that feature were not activated, right? That is my impression from the little I have read on the subject. I'd just like to confirm that is correct. I would not want to leave the expanded ISO feature activated if it were going to negatively affect the quality of frames shot at "normal" ISO settings.
Not that it matters, I suppose, but I shoot RAW all the time.