High Shutter Strobe Effect?

diego1235467

diego1235467

Well-known member
I'm trying to decide wether to trade my DVX for a T2i. I like to use high shutter speeds for fast paced "28 days later" shots.

Is this not possible with a T2i?

What about shooting at say 1/1000 in 60p for slow mo?

I REALLY love shooting at high shutter speeds with my DVX, and making the switch is freaking me out a bit.
 
But I've heard it causes strange distortions and artifacts in the image. At least that's what I understood :-/
 
When used in the wrong situations, a faster shutter speed will result in stroby looking images. There will be less motion blur which means you'll get sharper images (great if you want to pull frame grabs from fast moving scenes) but the bad side is that the images will appear to stutter across the screen in incremental jumps rather than as one smooth movement. This will be less pronounced in 60p, so you can get away with a higher shutter speed.

You have full control over the t2i's shutter speed so as long as you know when and how to use different speeds then you will be able to get the effect you want.
 
I only use a high shutter speed for slow mo and action scenes. Well, also for shallow DOF (on my DVX), but that won't be necessary on a T2i.

I guess I should be fine, then.
 
diego1235467 said:
I'm trying to decide wether to trade my DVX for a T2i. I like to use high shutter speeds for fast paced "28 days later" shots.

Is this not possible with a T2i?

What about shooting at say 1/1000 in 60p for slow mo?

I REALLY love shooting at high shutter speeds with my DVX, and making the switch is freaking me out a bit.
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Where did you hear/read that fast shutter speeds are not possible on the T2i?
 
diego1235467 said:
But I've heard it causes strange distortions and artifacts in the image. At least that's what I understood :-/
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What distortions? What artifacts? Where did you read/hear about these problems?

There is rolling shutter skew that is apparent with fast motion and shaky handheld shots. This footage is also likely to have compression artifacts because there's so much image detail that's changing so quickly. Whatever distortions and artifacts there might be, they are not dependent on shutter speed. They will be there regardless of shutter speed as long as you shoot the same way. The bottom line is that you should avoid shooting fast motion or shaky footage with this or any other HDSLR.
 
ydgmdlu said:
What distortions? What artifacts? Where did you read/hear about these problems?

There is rolling shutter skew that is apparent with fast motion and shaky handheld shots. This footage is also likely to have compression artifacts because there's so much image detail that's changing so quickly. Whatever distortions and artifacts there might be, they are not dependent on shutter speed. They will be there regardless of shutter speed as long as you shoot the same way. The bottom line is that you should avoid shooting fast motion or shaky footage with this or any other HDSLR.
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http://www.dvxuser.com/V6/showthread.php?t=209464

http://www.dvxuser.com/V6/showthread.php?t=208745

http://www.dvxuser.com/V6/showthread.php?t=208407

http://www.dvxuser.com/V6/showthread.php?t=205539
 
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You can use as high a shutter speed as you like, it's just you'll see rolling strobing when you use certain shutter speeds with certain light sources.

If you're shooting the majority of your stuff outside in the bright daylight, without other light sources, then you'll see no strobing. However, if you're shooting all your high shutter stuff indoors, you'd better plumb for some HMI's or another camera...
 
So high shutter speeds with sunlight won't give me those weird lines? Still, the more I hear of these types of problems, the more I'd rather keep my DVX.
 
As far as I'm aware, the strobing is to do with the frequency at which mains current runs, being around 50hz for America and 60hz for Europe. This is visible to the camera's sensor in the emitted light from a light that is not correctly wired to protect against this phenomenon. So, users are directed to use a shutter speed that is not at the same speed as their mains electric, but as close to the 180º rule as possible (that is, to double the frames per second you're shooting at.)

There are lights you can buy that will not exhibit this problem, but they are very expensive because of all the extra circuitry involved and because of the specialism of the product (film industry = licence to print money)

In short, it's better to err on the side of caution and only shoot very high shutter speeds during daylight, unless you have very expensive lighting equipment.
 
Ok, thank you. If I were to use high shutter speeds, it would likely only be outside. I'll try to save up for this cam, and maybe they'll make more progress with DSLRs by the time I have enough.

If anyone else has opinions please share them.
 
C2V said:
http://www.dvxuser.com/V6/showthread.php?t=209464

http://www.dvxuser.com/V6/showthread.php?t=208745

http://www.dvxuser.com/V6/showthread.php?t=208407

http://www.dvxuser.com/V6/showthread.php?t=205539
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I know all about that, and have seen those threads, thanks. The issue is not caused by shutter speeds. Shutter speeds are coincidental. The real issue is caused by the flickering of ballasted light sources and the way that an imaging sensor captures light. No flicker, no problem. Remember in the old days when CRT monitors dominated, you could point a camcorder at a monitor/TV and see a similar sort of rapid scrolling or refreshing effect? So it's not entirely the camera's fault.
 
diego1235467 said:
So high shutter speeds with sunlight won't give me those weird lines? Still, the more I hear of these types of problems, the more I'd rather keep my DVX.
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I saw your post in one of the threads that the other guy linked. In that thread, Barry explained the issue very clearly.
Barry_Green said:
And outdoors you can do that without worry. But outdoors is one of the few places you can. Problem is, we see people all the time trying to shoot at 1/250th, everywhere -- and you just can't do that without causing this artifact frequently.
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I'm surprised that it didn't click for you until just now. If it were such a big issue, do you honestly think that a bigger deal wouldn't have been made about it by now?

DSLRs have many little issues that have been discovered and discussed again and again here and elsewhere. People have found ways to deal with them, and the cameras' popularity hasn't been abated. For some reason, even professional videographers and cinematographers are starting to use them on productions with considerable budgets (where equipment costs are largely considered negligible). The season finale of House was shot entirely with 5Ds. 7Ds are being used on SNL. There's at least one Hollywood movie heading for wide-release that was shot entirely with Canon DSLRs. George Lucas invited some of his famous buddies to screen some test footage at Skywalker Ranch, and they were all impressed. Robert Rodriguez shot a music video with his personal (and quite fancy) 7D rig. A friend of mine, who's a shooter for small production company in Los Angeles, said that seemingly everyone over there is using them now in a variety of capacities.

So whatever problems that DSLRs have as video cameras (and I would be the first to speak out about them), they are still clearly able to be effective in a wide variety of situations. You know what? A $40,000 RED package will have problems. A $5,000 per day Panavision Genesis will also have shortcomings. Film has its own difficulties (which personally make me prefer digital formats). Film is even vulnerable to that flickering/scrolling line problem at certain shutter speeds with certain light sources because it also uses a rolling shutter. Just ask Barry, who's shot 35mm film for many years. The bottom line is that you should pick the right tool for the job, or at least avoid the most wrong tools for the job. Sure, you can't use high shutter speeds with CMOS cameras like DSLRs, Sony XDCAMs, Canon VIXIAs, or REDs when lighting with ballasted light sources. But you know what you can't use with a DVX100? Shallow DOF.

Being mindful of known issues is one thing, but blowing things out of proportion due to your fear, uncertainty, and doubt, to the point where you either ignore or don't mentally process other people's clarifications, is definitely another thing. I would worry much more about rolling shutter skew and aliasing than scrolling lines. Those are much more commonplace.
 
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BTW, apparently CCD cameras may not be immune to the flickering issue with ballasted light sources. Here's what I just found on this page: http://www.cybercollege.com/tvp019.htm

When taping under fluorescent lights, it's advisable to stick to a 60th second (normal) shutter speed. Using a faster shutter speed typically results in a flickering effect in the video as the chip exposure interval interacts with the normal flicker of fluorescent lights.
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Why don't you take your DVX100 into a room with fluorescent lights and see if you can capture some flickering on tape?
 
Ah, When I went back to read the threads I saw Barry's posts. I also have no idea how it didn't click for me. And I went through those threads more than a few times each.

I think I will give it a shot. I hardly ever film indoors, it'll be an interesting experiment.

And I'm not scared or anything. It's just I want to familiarize myself with these issues, and see whether or not a DSLR fits my style of cinematography, budget, etc.

I'm skeptical because I love high shutter speeds (apparently not an issue anymore, thanks for the clarification), handheld camera, etc. Much of my style could potentially be hindered by a DSLR. And yet I am still very attracted to them.

Thanks again for the help.
 
ydgmdlu said:
BTW, apparently CCD cameras may not be immune to the flickering issue with ballasted light sources.
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CCD cameras don't flicker, but instead they exhibit a color shift. It almost looks like automatic white balance hunting. It's been a frequent question here, but it's nowhere near as prevalent as the number of times it comes up on the DSLRs, mainly (I think) because shooters with professional video cameras are used to the idea of just plain not changing the shutter speed, whereas those with stills cameras are far more likely to (especially because the stills camera doesn't include any built-in ND filters, so without resorting to external filtration, you pretty much *have* to go changing the shutter speed to get appropriate exposure outdoors).
 
i would lean towards that being a shutter issue, because i can replicate the same issue with both my nikon d50 and nikon d300 in a fluorescent only environment. the d50 is a single chip ccd whereas the d300 is a single chip cmos; but the results can be basically the same; no different than shooting a television in 60i/50i at 1/24th or 1/25th vs 1/48th or 1/50th; the final product will differ.

Try a longer shutter speed, and try something equivalent to a multiple of your native regions' hertz. Fluorescent lighting is difficult at best with photography; with videography, the problem is multiplied if one does not understand the base issue.

practice shooting with a fluorescent light at very fast shutter speeds with video, and be sure to note them. Do the same with still shots and it wont be the same exact issue, but is basically the same problem. the best way to understand what you are up against is to get used to working in that environment; Barry has a much better explanation and understanding than i do, but i have a general concept.

practice and learn where your camera will falter, and you will learn how to avoid encountering those issues again. Personally, i cannot shoot IR with my (FAR FAR FAR more sensitive and 'better' CMOS sensor equipped) d300 at ALL compared to my D50 (which is ccd); i learned that by playing with a Hoya R72, both digital bodies, BRIGHT daylight and my 50mm f1.4D lens. I always assumed the d300 would trounce the d50 in IR due to its enhanced ISO's, however assumptions do not always translate to facts.

practice play and make mistakes; that is experience.
 
I haven't followed the four links you posted -- so I'm responding only to you.

I approached the 7D with the conventional wisdom of 1/50th for video -- period. I discovered I didn't especially like the 1/50th look on video, and that higher shutter speeds weren't looking bad and weren't resulting in a "strobe." (shooting at 1080/24p)

Yesterday, for example, I shot some magnificent outdoor footage at 1/4000th. At 1080/24p -- no strobe effect.

My point here is that it's more complex, there's more too it, some high shutter works, some may have issues -- it's definitely NOT a 1/50th or nothing deal with the 7D.

All that being said -- I can't imagine that replacing a DVX with a T2i is a good idea. But, that's got nothing to do with high shutter.

Good luck!
 
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