How to shoot the top of Houses (roofs) & Avoid Moire = Is it possible?

V

vision_filmz

Carbonite Member
Recorded some roofs today just for testing and it seemed almost impossible to record a moire free image on a wide shot. Medium and Close shots were better, but wide was rainbow moire city.

Someone must know how to get around this problem?.........
 
If you have a T3i and a 10-22mm or an 11-16mm ultrawide zoom you can hit the 3x crop and it's gone. You'll end up with a full frame equivalent of a 50mm at that point, but it's a way better option than getting nothing.

Outside the T3i, a GH2, 5n or D7000 is the only option as said above :)

Cheers,
Pete
 
c3hammer said:
If you have a T3i and a 10-22mm or an 11-16mm ultrawide zoom you can hit the 3x crop and it's gone. You'll end up with a full frame equivalent of a 50mm at that point, but it's a way better option than getting nothing.

Outside the T3i, a GH2, 5n or D7000 is the only option as said above :)

Cheers,
Pete
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Pretty cool trick, I know there must be other people that might have theirs as well. Also using another camera is not an option due to obvious reasons.
 
David W. Jones said:
Sorry but we are not mind readers, so we are unaware of the obvious reasons.
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Judging by your horrible second post which was un formative in every sense you still continue to troll this thread? Please, you have Nothing to contribute here so move along. If you have a Canon camera on a shoot and you have to do a scene like this then "No Other" camera can be used because there is none available.

Many times in this "Music Industry" a lot of things are done on the fly and no time to prepare.......

So please step away from your computer and get some fresh air as there is a "real" world.
 
You can try a chroma blur in post.

You could also bring the footage into After Effects, mask off the problem area, and then apply a very specific color correction that only affects the dominant chroma in the moire. Also, try a very modest Camera Blur effect on the brick, if it's warranted.

Hope that helps!
 
Avoid Moire

Avoid Moire

Hi,

A few tricks

1. Take a soft screen (maybe a cut of panty hose) or something really light, and stretch that across the lens (a pro version is out there where u can put inside the camera and it is like a screen filter for the sensor. The idea is still the same.

2. Get a standard cheap filter / lens protector and put little drops of nail polish on it.

3. In post, I can also use NUKE and just filter it out using matrix and noise removal nodes, though other software doesn't have those nodes, the concept is almost the same is just use filters to wack it out (in some cases works fine)

good luck!

Tim
 
The moire and aliasing were some of the big reasons I dropped the Canon Cameras and jumped to the GH2. Never seen the kind of horrible moire that I got with them....
 
vision_filmz said:
Judging by your horrible second post which was un formative in every sense you still continue to troll this thread? Please, you have Nothing to contribute here so move along. If you have a Canon camera on a shoot and you have to do a scene like this then "No Other" camera can be used because there is none available.

Many times in this "Music Industry" a lot of things are done on the fly and no time to prepare.......

So please step away from your computer and get some fresh air as there is a "real" world.
Click to expand...


Yes in the real world a carpenter knows when to switch hammers during a job.

Many of us keep multiple cameras in our kit because we know each one has things it excels at, and each has it's own specific weaknesses. Hence my comment on the right tool for the job. Sometimes a 150w fresnel is a better choice than a 1K open face.

You may not like my comments, but some others may use them to their advantage and not make the same mistakes that you have. The next time you are on a shoot thinking hey in the music industry there is no time to prepare we do things on the fly, remember the 7 P's... piss poor prior planning prevents positive production performance.

Good luck!

Dave
 
David W. Jones said:
Yes in the real world a carpenter knows when to switch hammers during a job.

Many of us keep multiple cameras in our kit because we know each one has things it excels at, and each has it's own specific weaknesses. Hence my comment on the right tool for the job. Sometimes a 150w fresnel is a better choice than a 1K open face.

You may not like my comments, but some others may use them to their advantage and not make the same mistakes that you have. The next time you are on a shoot thinking hey in the music industry there is no time to prepare we do things on the fly, remember the 7 P's... piss poor prior planning prevents positive production performance.

Good luck!

Dave
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Rarely if Ever do I shoot any scene of a shingled roof. In a perfect world having multiple cameras would be ideal. It's not about poor planning, as 90% of the time I have never ran into this problem. Heck using Sony f3 footage I still see moire and aliasing on some shots...... Now my final comment towards you is, get off your high horse buddy. Your attitude and lack of professionalism towards this subject would make any client reference your name and avoid your company.

This is a small world, remember that....
Thanks to those who provided great comments on options regarding this matter.
 
David, it appears that you are making the assumption that the original poster has the options of switching cameras, which will may also necessitate switching accessories and other gear.

In the real world, not everyone, I would even go as far as to say most people who are posting in the APS-C area of DVXuser at least, don't have the budget to support 3-4 cameras that are up to date with the current standard of technology so they can address specific situations as they arise. Most likely they have to work with what they have and find workarounds for problem areas.

The original poster is asking for help with the gear that he owns. Perhaps one "change your gear" comment is helpful, but once that is evident that is not an option, it is more helpful to assist him with what he does have to work with. If one has the knowledge and is inclined to reply, they should offer actual assistance, don't you think?
 
I think it is more than reasonable for someone with a Canon APS-C camera to come to a forum asking questions about working around the known issues of a Canon APS-C camera.

Telling them to switch cameras, while viable, is counterproductive.
 
David's not on a high horse, he's making a reasonable suggestion -- use the right tool for the job.

Now, if you simply can't change cameras, and have to work with what you've got, then there are three things that I can think of that you can do with a Canon to minimize the aliasing in that worst-case scenario:
1) Absolutely unquestionably do NOT use 720p mode. Use 1080p mode instead. It'll still have the problem, but to a lesser degree.
2) Shoot at f/22 or deeper (f/32 if your lens provides for it). The diffraction that results will help minimize the moire.
3) Shoot slightly ever slightly out of focus. No I'm not kidding, this is what you have to do. Aliasing happens when the lens passes too much detail for the sensor to resolve. Defocusing just a little bit lowers the amount of high-frequency detail being passed through the lens, and this can help the sensor resolve the amount of detail it's being fed. Of course, this is really the same thing as #2 but arrived at in a different way.
 
Barry_Green said:
Now, if you simply can't change cameras, and have to work with what you've got, then there are three things that I can think of that you can do with a Canon to minimize the aliasing in that worst-case scenario:
1) Absolutely unquestionably do NOT use 720p mode. Use 1080p mode instead. It'll still have the problem, but to a lesser degree.
2) Shoot at f/22 or deeper (f/32 if your lens provides for it). The diffraction that results will help minimize the moire.
3) Shoot slightly ever slightly out of focus. No I'm not kidding, this is what you have to do. Aliasing happens when the lens passes too much detail for the sensor to resolve. Defocusing just a little bit lowers the amount of high-frequency detail being passed through the lens, and this can help the sensor resolve the amount of detail it's being fed. Of course, this is really the same thing as #2 but arrived at in a different way.
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Thanks for this advice - I am new to DSLR shooting, but already being aware of the moire issue, I was preparing for just such a circumstance. My approach was going to be the old-school "shoot through a sock" technique suggested above, I understand that TV people used to use it to glamorize older subjects by smoothing out wrinkles etc. , but I think I'll test shooting slightly out of focus. I am really good at ^%$#! my focus so it might work out great for me.
 
Barry_Green said:
David's not on a high horse, he's making a reasonable suggestion -- use the right tool for the job.

Now, if you simply can't change cameras, and have to work with what you've got, then there are three things that I can think of that you can do with a Canon to minimize the aliasing in that worst-case scenario:
1) Absolutely unquestionably do NOT use 720p mode. Use 1080p mode instead. It'll still have the problem, but to a lesser degree.
2) Shoot at f/22 or deeper (f/32 if your lens provides for it). The diffraction that results will help minimize the moire.
3) Shoot slightly ever slightly out of focus. No I'm not kidding, this is what you have to do. Aliasing happens when the lens passes too much detail for the sensor to resolve. Defocusing just a little bit lowers the amount of high-frequency detail being passed through the lens, and this can help the sensor resolve the amount of detail it's being fed. Of course, this is really the same thing as #2 but arrived at in a different way.
Click to expand...

Wait Barry, dosen't point 2 and 3 kinda contradict each other?

I have found you minimize more moire with a shallower DOF rather than a deep DOF. Also if you use FCP there is a filter you can download somewhere(forgot the name), like Jordan Scott Price suggested above in after effects, the filter will put a chroma blur over the affected areas of the picture and help reduce the color moire.
 
2 & 3 are largely the same thing. Diffraction causes the whole image to become softer (which could arguably be called "out of focus"). It's just a different way of getting there.

The key thing is -- pinpoint-sharp imagery is going to alias on a Canon. Period. Whether it creates moire patterns depends on how regular and repeated the detail is, but it's going to alias. The Canon can only resolve around a 720p image, so feeding it 4K worth of data through a sharply-focused lens is asking for aliasing problems. Defocusing a little bit can drop the total resolution the lens is passing down to a tolerable level that the sensor can handle.

Going to f/22 may increase the depth of field but it will also blur the entire image. It's too deep of an f-stop for the tiny pixels in a 7D, and results in diffraction, which blurs everything.

If you can put the rooftops in shallow focus so that they're blurry, that will eliminate the aliasing entirely. If you need them to be in focus, the problem is that you can't have them TOO in-focus or they'll alias like mad, so that's when you either defocus a little, or go to f/22 or f/32 to bring in some diffraction which will take the edge off and keep there from being too much detail. It's not a magical cure-all, but it does seem to help some.
 
Don't you think David was just being humorous? Or pedantic? He's commenting on the phrase "obvious reasons", which isn't helpful for the problem at hand, bit is helpful for refining overall communication skills…
 
Excellent post Barry and yes I know that an argument never helps anything......

Very good suggestion on shooting to f/22 to help with this as I never knew that!! Please everyone lets stay away from the negativity, maybe I took it the wrong way, maybe I'm wrong or maybe it's just one of the frustrations I have because of the limitations of this camera.

Regardless I think we should always help one another. While Dslr camera has a disadvantage it also has many advantages specifically speed, cost, and ease of use (to a degree). Hopefully in 2012 we can see some new cameras by Canon within their dslr line updated.

Thanks a lot
 
I post rarely but read religously this board and just wanted to chime in and say big thanks to all the people who come through with practical real-world information in this thread and elsewhere. I have learned so much since i've discovered this place and just feel bad i can't offer back anywhere close to what i've gotten. I think lots of us working with "entry-level" gear understand that these cameras have serious shortcomings, but for whatever reason its what we got and i'm sure i speak for many when i say we appreciate the help in getting as much as we can out of it. btw: this is DEFINITELY not a dig at anyone--i love the lively conversation and the big-picture dialogue that happens here too!
 
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