Last Saturday's wedding speeches were so 'romantically lit' that even after I'd secretly and slowly turned the chandeliers up full it still meant that the next 52 minutes were going to be shot at +18dB of gain up and f/2.8 - to allow me some zoom on the Z1 without under-exposure.
So for the first time ever I used 1/25th sec shutter speed. This allowed me to drop the gain to a more acceptable +12dB. The camera was solidly mounted and zooms and pans were slow and gentle and it's only when the speakers were arm-waving that the slight jerkiness becomes noticeable. And then only to the likes of you and me I suspect.
Any thoughts?
tom.
Any chance of posting a few seconds of arm-waving to illustrate the extent of the effect, Tom? (I suppose this is a lazy way of saying: I must try this myself. :) )
Hi Tom,
Scenario 1.
Shutter speed of < 1/25 can be accommodated at 25fps (ignoring interlacing) with each frame different.
Scenario 2.
Shutter speed of >1/25 will mean the image will be written to 2+frames.
I would have expected shutter speed of 1/25 to fall into scenario 1, and be not so much jerky, but perhaps blurred (on arm moves etc).
As you are saying it's jerky I wonder if 1/25 falls into scenario 2 because the
sensor requires a wee bit of a fraction of a second to discharge.
Lets call this period 'D'.
That would mean slowest shutter speed possible with minimum jerkiness is 1/25-D.
As we know 25 fps(or 24?) is the slowest rate before human eye detects individual frames. So jerkiness implies scenario 2.
Unless of course you (or Alan) knows different.
1/25 is fine unless there's significant motion. And under those conditions, that's exactly what I'd have done.
I should now tell you I was shooting SD DV at 50i, so I'm thinking that 1/25th sec was in fact one field doubled, so giving the very slight jerkiness. 'Cut to' cam was an FX1 running at 1/50th sec, but I see no loss of resolution in the Z1's footage so can it really be one field?
tom.
If the FX1 was shooting at DV, then running 1/25 wouldn't change the resolution.
Is that something to do with the fact that it's downconverting from the chips to the tape Alan? On my VX2000 the drop to 1/25th sec gave a very noticeable drop in resolution and was never worth the stop gained.