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First DSLR experience screw up


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#1 Alex Zustra

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Posted 10 November 2010 - 12:47 PM

I recently had my first experience actually shooting with a DSLR and it was rather disappointing. It was a 5D. The rolling shutter showed up on a small, slow pan even (luckily I was just playing at this point). I was shooting a little interview/talking head bit, and knowing about the infamous aliasing/moire, I made sure to tell the subject not to wear any tight patterns. He arrived, we did a quick test and I popped it into the computer, and there was a terrible moire pattern all over his jacket. I walked back into the room about to (politely) scold this guy for not listening when I realized it was just the FABRIC of his jacket, which was nothing out of the ordinary. I had read all about the problems with these cameras but I never expected it to be this bad. To top it all off, we were short on time, and my instinct was to ever so slightly soft focus the guy, which seemed to work until I looked at the footage later at proper size, and much of it is just unacceptably out of focus even though it looked fine on the camera monitor.

What would you do/should I have done in this situation? I feel like I would at least look like less of an idiot had I just focused and dealt with the moire. The average eye-brain is at least more forgiving of that than out of focus shots.
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#2 Peter J DeCrescenzo

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Posted 10 November 2010 - 10:21 PM

Hi Alex: Some 5DM2 users have reported success sharpening the video slightly in post after having purposefully shot scenes slightly out of focus. YMMV.

The 5DM2, 7D, T2i and other cams tend to record somewhat more alias/moire artifacts than the Panasonic DMC-GH1. The new GH2 model seems to record even fewer of these artifacts than the GH1, probably because the GH2 has more capable internal hardware & software processing.

The more expensive Panasonic AF100 looks like it will record fewer of these artifacts than any of the DSLRs, probably because it has an internal OLPF & processing optimized for HD video, not high-res stills. That's great if you only want to shoot video, but a moot point if you want a camera that can shoot both.

In future, shooting with your 5DM2 with the assistance of a full HD 1920 x 1080 monitor for playback on set should allow you to see many problems when they occur. You can then make adjustments immediately (wardrobe, focus, focal length, lighting, diffusion, and so forth) by carefully watching results of your changes on the monitor.
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#3 Gabe Spangler

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Posted 11 November 2010 - 02:07 AM

I've had moire show up on clothing that has a visible knit pattern, not even tweed, corduroy or intricate stripes or patterns, just a knit pattern. It's the fine detail that does it. I've had moire show up on blades of grass. You did a test and the moire showed up. The best thing to do would have been to approve the article of clothing days in advance. The second best thing to do after confirming the moire in monitor would have been to have the guy change into something else, even if it meant a trip home or whatever.

I'm gonna go ahead and say NEVER defocus your shots to account for moire or aliasing; you'll always end up with useless footage or footage only useable on the Net at a very small resolution. These cameras don't have the resolution to do that. Even in focus, they lack the sharpness of true 1920x1080 cameras and obviously don't come close to the detail of a 4K camera.

The simple fact is, until Canon solves the moire and aliasing issue (if ever), these cameras have serious limitations that you must work around. For planned shoots, you must approve and test everything ahead of time. I think you learned your lesson there.

The more light you have on something prone to aliasing, the more likely it is to show up, which is why intricate patterns in sunlight are murder. If you are having an issue with a shirt or whatever and you have no time to make changes, try reducing the amount of light hitting your problem area. Having a dark area is way better than having the dancing rainbows all over your footage.
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#4 Edgar Dubrovskiy

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Posted 11 November 2010 - 05:27 AM

Changing lenses or the distance to the subject can help. Had this on a music video recently, decided to drop a head to toe shot and just shot waist up. Not good.
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#5 Sherman Johnson

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Posted 11 November 2010 - 11:17 AM

Hi Alex, the camera's Sharpness setting would be the first thing I would check. I've been fortunate to rarely have to deal with moire and aliasing issues on the 5D/7Ds, but I tend to keep the camera's sharpness pretty low. And in the times I have had an issue, usually reducing the sharpening by a level or two has made a difference. Another idea might be to try some light diffusion filters - SoftFX, Classic Softs, GlimmerGlass. I've personally never tried diffusion for this, but in a pinch, it'd be worth a shot. And then lastly, I might suggest taking advantage of the 5D's larger sensor and try to limit the focus as much as possible to your subject's face and thus avoid the problem jacket - obviously this is easier done in certain shot sizes and is also an aesthetic choice.
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#6 Alex Zustra

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Posted 11 November 2010 - 07:30 PM

Thanks for all the replies. I have been reading up on DSLRs forever since I've been debating buying one, so I knew to turn the sharpening down, which clearly failed. In some cases the soft focus method worked beautifully, the depth of field on that sensor is just so shallow that he would go too soft if he moved a little bit. Having the face out of focus and a shoulder sharp is new to me, ha. I've had some success since the shoot sharpening in post but this obviously isn't desirable. It's mostly going to be for web viewing, so maybe it won't be as noticeable after being encoded, and I'm definitely giving him 720P files.

Edgar-
Are you saying that longer lenses/more distance can increase the problem? How so? If that's the case, I was only a few feet from the subject. This didn't help though, obviously narrowing my DOF even more, but I desperately needed to throw the hideous tie dye background of focus as much as possible.
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#7 Ram Shani

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Posted 13 November 2010 - 02:09 PM

for this kind of situations i use my caprock filter 1.4 on my 7d
it's great help
also i tested with Dior 10denir black net behind the lens that work very nice
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#8 Phil Rhodes

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Posted 13 November 2010 - 06:03 PM

Are you saying that longer lenses/more distance can increase the problem?




I really don't understand why people find this so complicated.


If you attempt to shoot fine details with a Canon DSLR, particularly fine repetitive detail, you are likely to see aliasing. Whether that's fine repetitive detail on a clapboard barn half a mile away or fine repetitive detail in the weave of someone's shirt, if the size of the pattern that lands on the sensor interacts with the size of the photosite groups on the sensor, you will have a problem. It's nothing to do with lenses or distance, it's to do with landing fine patterns on the sensor - however you do it.


P
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#9 Edgar Dubrovskiy

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Posted 15 November 2010 - 06:22 PM

But surely by swapping to a longer lens/coming closer you make the fine print less... fine. Thus solving the aliasing. That's how I solved it couple times at least - by avoiding making the small pattern even smaller.
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#10 Phil Rhodes

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Posted 15 November 2010 - 09:40 PM

Yes, change the size - but you can do that in any number of ways.

The reason I labour this point is that there's too many people out there who are under the impression that the mere fact that it's a "long" lens directly causes aliasing somehow, which of course is balderdash - it's about the size of the pattern. If using a long lens, whatever that means in context, makes the pattern the right size, then it may cause aliasing. A short lens is just as likely to cause aliasing by reducing the relative size of a pattern.

It's not about lenses or any other optical component, it's about the size of the pattern as you shoot it.

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#11 Hal Smith

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Posted 15 November 2010 - 09:46 PM

for this kind of situations i use my caprock filter 1.4 on my 7d
it's great help
also i tested with Dior 10denir black net behind the lens that work very nice


Have you got any screen grabs of the Dior in action?
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#12 timHealy

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Posted 05 January 2011 - 07:40 PM

he couldn't just take off his jacket? or give him a different one?
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#13 John Sprung

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Posted 05 January 2011 - 08:03 PM

But surely by swapping to a longer lens/coming closer you make the fine print less... fine. Thus solving the aliasing.


That works, but so does going to a wider lens, making the fine pattern too small to resolve. Try it with a zoom lens, you'll see that there's a worst place to be as you run through the focal lengths.




-- J.S.
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#14 John Sprung

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Posted 05 January 2011 - 08:14 PM

The simple fact is, until Canon solves the moire and aliasing issue (if ever), these cameras have serious limitations that you must work around.


Right, and there are two ways they might accomplish that:

1. Provide an extra OLPF that you put in only for motion work.

2. Increase the speed of the electronics to be able to read the whole chip fast enough for motion.





-- J.S.
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