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New Contributor
Posts: 4
Registered: ‎12-23-2012

T4i Aliasing questions because I must live with horizontal lines

I am the photographer, videographer, and webmaster for a model railroad club, and as such, I have to deal with many horizontal lines and miniature brick textured surfaces. I have read Barry Green’s article at DVXuser: a detailed article on moire.

The following 8 second clip on YouTube represents an example of some of the worst case situations I have to record. The brick structure center right and the locomotive louvers demonstrate aliasing issues: moire example

I am using a Canon T4i with the 18-135 IS STM lens and this clip was shot with these parameters,
Tv( Shutter Speed ) 1/125
Av( Aperture Value ) 6.3
ISO speed 1600
Image Size 1280x720
Frame Rate 59.94
Picture Style Faithful
Sharpness 0
Contrast 0
Saturation 0
Color tone 0

All of the club’s videos to date are uploaded to YouTube.

I have read that manually focusing to create a slight blur rather than autofocusing is one suggestion to minimize moire. Since these videos, in many cases, are “set clips” which can be prearranged, I was thinking of buying this focus follower http://www.dslrsolutions.net/products/ to accurately preset multiple focus points for an appropriate blur.

There is one unanswered question about using this focus follower because I heard that the lens manual focus design is unable to identically repeat itself - does anyone have any experience with that issue for the Canon 18-135 IS STM lens?

I have Cyberlink’s PowerDirector 11 which I can use to post process clips to improve overall sharpness.

I was also thinking that tilting my tripod a small amount might create fewer “horizontal” lines.

Does anyone have any comments on these ideas or other suggestions for me to try?

Thanks,
George

Frequent Contributor
Posts: 78
Registered: ‎11-11-2012

Re: T4i Aliasing questions because I must live with horizontal lines

Sorry I am having trouble to understand your question well in first place but well my suggestion as understand it:

1- Consider using a manual old lens with focal length you need. Any 42mm screw lens, Nikon, Pentax or Olympus old lens can be attached to Canon's EOS EF, EFs mounts easily via a single dollar priced adapter (Infinity adapter not macro).

 

2- Use of prefocus zone is surely the right way to go. I would think the kit you mention should help. If interested to make one yourself, check this tutorial that is made by a genus young person who is placing DIY extremely useful tutorials on line since age of 13. A serious note: Don't fall in love with her or take you number go to end of lineSmiley Happy and more importantly, if you like what she does, make sure to send a donation.

LINK

 

3-  If you have any problem with "Moire" then pay attention to free solution available to you after that millions of dollars( if not billions), paid by Nikon to research in making of D800 or Canon's target in the most wanted  list currently. All you need to understand is the difference between D800 and D800E. There is plenty of literature out there and I leave the joy for you to research and find your way as to how you can modify your current tools to get close to what Nikon did to build "E" version of D800.

Frequent Contributor
Posts: 57
Registered: ‎11-19-2012

Re: T4i Aliasing questions because I must live with horizontal lines

Mosaic Engineering makes an optical anti aliasing filter for DSLR video. It is designed for people shooting video who are experiencing moire/aliasing beyond what the built in filter can handle. http://www.mosaicengineering.com/products/vaf/txi.html
New Contributor
Posts: 4
Registered: ‎12-23-2012

Re: T4i Aliasing questions because I must live with horizontal lines

Thank you Samsen - Ritwika has a lot of useful educational videos.

 

George

New Contributor
Posts: 4
Registered: ‎12-23-2012

Re: T4i Aliasing questions because I must live with horizontal lines

Thank you Scatterbrained - I think this will be a helpful purchase.  This review/endorsement adds to your suggestion:

An effective anti-aliasing filter for the Canon 5D Mk2

 

George

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