Better lowlight with 30p than 60i...?

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filmguy123

Veteran
So as I've been trying to find the best settings for my camera, I often find myself needing to shoot 60i for live event coverage in order to maintain faster auto-focus in lower indoor light conditions.

However, I have been disappointed, as I cannot get the shutter speed down as much in 60i... am I doing something wrong? In 30p I can get down to 1/30 and even 1/15 if really needed (although it gets blurry then), but in 60i... I cannot??

Is there a way to get the best of both worlds - the faster 60i auto-focus and the better lowlight in 30p (thanks to shutter speeds)?? Am I missing something??
 
This is my stupid question of the day... is there any difference between 30p and 30pn on an HVX as far as light sensitivity?
 
so 30p has better low light in general... hmm ok. That's a bummer because 60i is better in auto-focus on low light, right?

Is there any possible way to get better low light in 60i? Like using the shutter speed (I can't get the shutter as low in 60i as in 30p, why?)
 
filmguy123 said:
so 30p has better low light in general...
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On an HVX. Not necessarily true on other cameras; for example on an EX1 or DVX they both are a stop faster in 60i than 30p.

That's a bummer because 60i is better in auto-focus on low light, right?
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Autofocus is always faster in 60i or 60p. The faster the frame rate, the better the autofocus functions.

Is there any possible way to get better low light in 60i? Like using the shutter speed (I can't get the shutter as low in 60i as in 30p, why?)
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Because if you're shooting 60 fields per second, you cannot have a shutter speed slower than 1/60th. You can't have an exposure time longer than your frame rate, that'd violate the space-time continuum.

Now, here's where it starts to get funky: you can choose 1/30, or even 1/15, in 60i mode. When you do that it changes the way frames are accumulated; at 1/30 you get 30 distinct frames per second, at 1/15 you get 15 frames per second (so each frame is repeated 4 times). But, it's possible that the autofocus will still be updating at 60 frames per second; just that the frames will be accumulated before being written out. I'm not sure about this, but it might be worth a try. Just put the cam in 1080/60i mode, and choose VIDEO CAM mode, then turn the shutter on and select one of the low speeds, and see if that gives you what you're looking for.
 
Oh wait, hmm... ok so the reason I couldn't get 1/30 or 1/15 in 60i mode, but could in 30p mode, was that to get those shutter speeds in 60i for some reason I have to switch the camera to VIDEO CAM mode (like you mentioned)... but in 30p I could get those shutter speeds while staying in FILM CAM mode.

SNAP... I could have gotten much better low light at this last wedding I filmed had I known that... oh well, next time.
 
Slow shutter speeds are only possible in VIDEO CAM mode. FILM CAM limits you to the same shutter speed as your frame rate, so 1/30 for 30p, 1/60 for 60i.
 
Oh I see - got it! That makes sense.

Besides controlling the shutter using shutter degree angle, is there ANY other benefit to using Film Cam mode for other stuff?
 
If you use the framerate hack, the 350 degree shutter becomes nearly a 1/2 sec shutter speed, something you can only do in film cam mode, I believe.
 
Right, I've used that and its awesome! But other than controlling the shutter in angle degrees, is there anything else about FILM CAM mode? Features or causing a different image? Or does it basically just change notation for how the shutter operates (also, then of course, allowing like you mentioned 1/2 sec shutter in the framerate hack)

?

Thanks so much!
 
Also Barry: you mentioned 1/30 in 60i being 30 distinct frames each second. Does that mean that it is recording 30 distinct fields (each field repeated twice?) for 1/30 shutter? Does this make it more like progressive footage in a way?

How is 60i at 1/30 shutter different than 30p at 1/30 shutter, technically speaking?
 
FILM CAM disables interval, pre-record, loop record, and stop-motion. It enables variable frame rates (in 720p mode) and the film-style syncro scan shutter.

1080/60i at 1/30 probably results in field doubling, similar but lower in res than 1080/30p. Don't know, though, as I haven't tried.
 
Thanks Barry, now I know you said you haven't tried, but I did a lot of indoor low-light shooting like this the other day.

I shot 480/60i at 1/30 shutter speed, or 1/60 shutter speed when lighting was better. The footage at 1/60 looks... "faster" whereas the motion at 1/30 has a different, slower feel (perhaps more filmic?) - that must be because shooting 60i at 1/30 shutter is actually shooting 30p??

Why is it lower resolution than shooting true 30p?

Also, do you know if this is the case? Have you or could you confirm it? I don't really know how to go about confirming this, you are much smarter with that than me! :) haha.


Finally, you said it was possible that at 1/30 in 60i mode that the auto-focus would be updating as fast as at 1/60 shutter - in my shooting, it was hard to tell. Do you know about this, and why or why not that may be the case? How could I test it?

Sorry for the many questions and if anything is redundant. I'm just really curious to know how all these settings work and interact with eachother...

Oh and also, if shooting at 1/30 shutter at 60i, and the fields are doubling, does that mean i could or should use, in FCP, the DVC PRO HD frame rate converter? (also, I know this is kind of off topic for this post, but when DO I use that frame-rate converter? Would I use it shooting 480i/30p, since it is actually recording two identical frames per second? or 720p30p, not native mode? Or both?)


Thanks Barry for all your help and sorry if its too many questions!!
 
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