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iPad and iPhone Shoot - Lines on screen

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Raphael Rogers
iPad and iPhone Shoot - Lines on screen
on Sep 19, 2011 at 3:33:42 pm

So I shot an iPad and am going to be shooting video of an iPhone and I'm getting some lines on the screen of the iPad. I lit with LEDs and tried multiple shutter speeds but can't seem to shoot the devices without getting the classic monitor lines. Any ideas on how to either fix this in after effects or shoot with different settings? I'm using a 5D to shoot. Thanks!


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Kevin Camp
Re: iPad and iPhone Shoot - Lines on screen
on Sep 19, 2011 at 4:55:08 pm

i'd be surprised if the ipad doesn't have a refresh rate of 60hz... i can't imagine a mobile going higher, and i can't imagine a modern device that is expected to play media going any lower...

does the 5d have shutter angle control? if so, it should yield more precision in shutter timing than shutter speed which is normally limited to multiples of the frame rate.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW


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Raphael Rogers
Re: iPad and iPhone Shoot - Lines on screen
on Sep 19, 2011 at 5:07:23 pm

Well looking up shutter angle it says you can calculate it like this:
Shutter Angle = fps x 360degrees / Shutter Speed

so are you saying that the shutter angle should be a multiple of 60 then?


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Kevin Camp
Re: iPad and iPhone Shoot - Lines on screen
on Sep 19, 2011 at 6:01:46 pm

kind of, but if exact shutter speeds aren't giving you what you need... ie. shooting at a shutter speed of 1/60 still doesn't work with the ipad's refresh rate, then try adjusting the shutter angle.

a more simple way to look at the relationship of shutter angle to shutter speed is:

shutter speed = shutter angle / 360 * frame rate

so if your frame rate is 29.97 and your shutter angle is 180, then the effective shutter speed is 59.94. that's pretty close to what i think the refresh rate of the ipad is, so if that doesn't work, you could try tweaking the shutter angle until it gets better and you have a lot of small increments to use with shutter angle (like 200 or 175, etc..) vs shutter speed where you can jump to 1/30 or 1/120.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW


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Michael Schmidt
Re: iPad and iPhone Shoot - Lines on screen
on Sep 10, 2012 at 4:51:26 pm

I'm having this same issue.

I have a shoot coming up this weekend, and we discovered this on our test today.

Raphael, did Kevin's suggestion work? Or did you resolve it some other way? I'd love to know what you did.

Like you, I am shooting with a DSLR, the Canon 7D. No problem with iPhone4 images, but definite lines on the iPad1. Being a 1st generation iPad, I am going to try to source an iPad3, because the resolution was upgraded from 1024x768 to 2048x1536. I'm hoping that might help.

I'd love to hear your advice, Raphael and Kevin.

Thanks!


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