C100 strobing at DVinfo.net

Kathy Smith · January 21st, 2015, 05:31 AM

Hi,

I am trying to figure out how to avoid strobing effect with my C100. Or maybe it's called flickering. I use 24p frame rate. If I'm following someone for example, or panning how do I make the flickering go away. I probably need a higher frame rate?

Darren Levine · January 21st, 2015, 07:08 AM

Faster frame rate is the only way to mitigate strobing, which is just a basic affect of movement on lower fps/higher movement.

check this out Panning Best Practices

Daniel Epstein · January 21st, 2015, 07:58 AM

Darren's link is very useful. Strobing is definitely a part of the 24 frame experience. There is a reason TV went to 30 frames a second even though we all love the film look. What shutter rate are you using? The faster it is the more stutter you will see. I have a producer who wants motion on as many shots as possible so we use 29.97 for her projects as she likes fast moves which strobe too much at 24. The way you shoot also makes a difference. Panning seems to create more issues than moving forward or back. Also some displays have more trouble with 24 frame rate than others so you may be seeing a playback issue as well.

Kathy Smith · January 21st, 2015, 08:58 AM

Quote:

Originally Posted by Darren Levine

Faster frame rate is the only way to mitigate strobing, which is just a basic affect of movement on lower fps/higher movement.

check this out Panning Best Practices

This is very helpful but it only talks about panning, I am experiencing this when turning the camera using glidecam for example. I suppose that would do the same thing

Gary Huff · January 21st, 2015, 03:18 PM

Quote:

Originally Posted by Kathy Smith

I suppose that would do the same thing

It's exactly the same even if the move looks a little difference. This applies to all motion.

Kevin Lewis · January 21st, 2015, 05:45 PM

Kathy, I too shoot with the C100. I typically use a shutter speed of 48 and never have an issue. You may see some strobing on the Lcd or your playback monitor, but do you actually see it in your final rendered video?

Kathy Smith · January 22nd, 2015, 04:16 AM

Quote:

Originally Posted by Kevin Lewis

Kathy, I too shoot with the C100. I typically use a shutter speed of 48 and never have an issue. You may see some strobing on the Lcd or your playback monitor, but do you actually see it in your final rendered video?

yes, I see it on the actual video. I will make a clip to show later today

Kathy Smith · February 3rd, 2015, 03:38 PM

OK, I just did a test. Here is the resulting video. I am seeing some kind of flickering when or I don't know what to describe it, it's the most pronounced when looking at the etches of things. Am I moving the camera a too fast?

Kevin Lewis · February 3rd, 2015, 04:10 PM

You are not panning to fast. To me it looks like you are using incorrect render settings or perhaps shooting 24pf and not handling it properly in post.

Kathy Smith · February 3rd, 2015, 05:10 PM

Quote:

Originally Posted by Kevin Lewis

You are not panning to fast. To me it looks like you are using incorrect render settings or perhaps shooting 24pf and not handling it properly in post.

Kevin,
What render settings should I be using? These are the settings I always use. I am importing this to FCXP. I am pretty sure I'm shooting 24p, but I'll double check tomorrow.

Gary Huff · February 3rd, 2015, 05:25 PM

Quote:

Originally Posted by Kevin Lewis

To me it looks like you are using incorrect render settings or perhaps shooting 24pf and not handling it properly in post.

If she was shooting PF24, there'd be interlaced lines.

Kathy, what is your shutter speed? 180 degrees or 1/48 if you are shooting 24p?

Frankly, to me it looks like you're moving the camera too fast.

Kevin Lewis · February 3rd, 2015, 09:35 PM

The first time I watched in SD now that I re-watched in HD, it looks much better. Make sure that if you are shooting 24p that your shutter is set to 48. When you export, make sure that you are not exporting as anything other than 24p. If you are shooting PF24, make sure that your NLE is not picking it up as interlaced footage. It also looks like you are using the auto focus. If you are, make sure you try re-shooting with it off. Its hard to gauge properly with things going in and out of focus. When I shoot 24p with my c100 panning to quickly is not an issue. I don't change the way I pan just because i'm shooting 24p. Now that being said, you cant go whipping the camera around but you should certainly be able to follow a moving object without an issue provided that you are using the correct shutter speed. You can also try resetting your camera to the factory defaults in case you inadvertantly changed a setting.

Gary Huff · February 3rd, 2015, 10:11 PM

Quote:

Originally Posted by Kevin Lewis

Make sure that if you are shooting 24p that your shutter is set to 48.

Actually, just set it to 180 degrees. You can do that on the C100 and it ensures that your shutter speed is always correct no matter the frame rate. Only change it for those instances with lighting that strobes in the frame.

Quote:

When you export, make sure that you are not exporting as anything other than 24p.

Unless you are shooting 30p or 60i. Just make sure your export matches your footage.

Quote:

If you are shooting PF24

Neve, ever, ever shoot PF24.

Quote:

When I shoot 24p with my c100 panning to quickly is not an issue. I don't change the way I pan just because i'm shooting 24p.

If that's the case, then judder simply doesn't bother you. You should always adjust the speed of your camera moves depending on your frame rate (60i can handle a lot, then 30p, and 24p is dead last). For proper 24p panning, the rule of thumb is that it should take 7 seconds to pan an entire frame's worth of information (so anything on one edge of the frame should take 7 seconds in your pan to reach the other side). Doing it faster than that causes judder, and you either live with it, pan slower, or use a faster frame rate.

Jon Fairhurst · February 3rd, 2015, 11:56 PM

That's awesome, Gary, I just responded to you in another thread and quoted the 7 second guideline, then I read your post here quoting the same. :)

For completeness for the other readers, when whip panning or tracking a subject, one can go faster. It's those pans on static backgrounds that really show the judder. Of course, very fast whip pans will show skew due to rolling shutter, but that's another topic.

FWIW, I did a pan of almost exactly 7 seconds across a building recently and I still noticed the judder. One reason is that I accelerated at the start and decelerated at the end, meaning that the speed mid-pan would have been a bit too high. But also, it's not like judder occurs at 8 seconds and is invisible at 6. It's more of a soft threshold. There's still judder at 6 seconds, but most audience members won't notice it. Once you know to look for it, you can't not notice it...

Gary Huff · February 4th, 2015, 07:43 AM

Most people simply won't notice, so I wouldn't sweat judder too much, just something to be aware of.

For the best example of this that I have seen recently, check out the graveyard scene in The Good, The Bad, and the Ugly when Tuco is running through it. He is running full tilt, the camera is locked on him and panning with him, and the background becomes this crazy ugly blur, almost like something out of 2001.

January 21st, 2015, 05:31 AM	#1
Kathy Smith Major Player Join Date: Oct 2010 Location: NY, NY USA Posts: 519	C100 strobing Hi, I am trying to figure out how to avoid strobing effect with my C100. Or maybe it's called flickering. I use 24p frame rate. If I'm following someone for example, or panning how do I make the flickering go away. I probably need a higher frame rate?

January 21st, 2015, 07:08 AM	#2
Darren Levine Major Player Join Date: Apr 2010 Location: NJ/NYC Posts: 563	Re: C100 strobing Faster frame rate is the only way to mitigate strobing, which is just a basic affect of movement on lower fps/higher movement. check this out Panning Best Practices __________________ C100 - GH4 - NYC Shooter www.DarrenLevine.com

January 21st, 2015, 07:58 AM	#3
Daniel Epstein Trustee Join Date: Jan 2006 Location: New York, NY Posts: 1,267	Re: C100 strobing Darren's link is very useful. Strobing is definitely a part of the 24 frame experience. There is a reason TV went to 30 frames a second even though we all love the film look. What shutter rate are you using? The faster it is the more stutter you will see. I have a producer who wants motion on as many shots as possible so we use 29.97 for her projects as she likes fast moves which strobe too much at 24. The way you shoot also makes a difference. Panning seems to create more issues than moving forward or back. Also some displays have more trouble with 24 frame rate than others so you may be seeing a playback issue as well.

January 21st, 2015, 05:45 PM	#6
Kevin Lewis Major Player Join Date: Feb 2009 Location: Philadelphia, pa Posts: 705	Re: C100 strobing Kathy, I too shoot with the C100. I typically use a shutter speed of 48 and never have an issue. You may see some strobing on the Lcd or your playback monitor, but do you actually see it in your final rendered video?

February 3rd, 2015, 03:38 PM	#8
Kathy Smith Major Player Join Date: Oct 2010 Location: NY, NY USA Posts: 519	Re: C100 strobing OK, I just did a test. Here is the resulting video. I am seeing some kind of flickering when or I don't know what to describe it, it's the most pronounced when looking at the etches of things. Am I moving the camera a too fast? Strobing - YouTube

February 3rd, 2015, 04:10 PM	#9
Kevin Lewis Major Player Join Date: Feb 2009 Location: Philadelphia, pa Posts: 705	Re: C100 strobing You are not panning to fast. To me it looks like you are using incorrect render settings or perhaps shooting 24pf and not handling it properly in post.

February 3rd, 2015, 09:35 PM	#12
Kevin Lewis Major Player Join Date: Feb 2009 Location: Philadelphia, pa Posts: 705	Re: C100 strobing The first time I watched in SD now that I re-watched in HD, it looks much better. Make sure that if you are shooting 24p that your shutter is set to 48. When you export, make sure that you are not exporting as anything other than 24p. If you are shooting PF24, make sure that your NLE is not picking it up as interlaced footage. It also looks like you are using the auto focus. If you are, make sure you try re-shooting with it off. Its hard to gauge properly with things going in and out of focus. When I shoot 24p with my c100 panning to quickly is not an issue. I don't change the way I pan just because i'm shooting 24p. Now that being said, you cant go whipping the camera around but you should certainly be able to follow a moving object without an issue provided that you are using the correct shutter speed. You can also try resetting your camera to the factory defaults in case you inadvertantly changed a setting.

February 3rd, 2015, 11:56 PM	#14
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	Re: C100 strobing That's awesome, Gary, I just responded to you in another thread and quoted the 7 second guideline, then I read your post here quoting the same. :) For completeness for the other readers, when whip panning or tracking a subject, one can go faster. It's those pans on static backgrounds that really show the judder. Of course, very fast whip pans will show skew due to rolling shutter, but that's another topic. FWIW, I did a pan of almost exactly 7 seconds across a building recently and I still noticed the judder. One reason is that I accelerated at the start and decelerated at the end, meaning that the speed mid-pan would have been a bit too high. But also, it's not like judder occurs at 8 seconds and is invisible at 6. It's more of a soft threshold. There's still judder at 6 seconds, but most audience members won't notice it. Once you know to look for it, you can't not notice it... __________________ Jon Fairhurst

February 4th, 2015, 07:43 AM	#15
Gary Huff Inner Circle Join Date: Jan 2013 Location: Austin, Texas Posts: 2,006	Re: C100 strobing Most people simply won't notice, so I wouldn't sweat judder too much, just something to be aware of. For the best example of this that I have seen recently, check out the graveyard scene in The Good, The Bad, and the Ugly when Tuco is running through it. He is running full tilt, the camera is locked on him and panning with him, and the background becomes this crazy ugly blur, almost like something out of 2001.