7d and guitar strings
 

Just wondering if this redish halo effect is an issue for anyone else when sheeting narrow black lines such as guitar strings and if so, does anyone have any workarounds or ways to limit the effect?

Shot with the neutral profile setting with sharpess at -2 and contrast all the way down in 1080 24p

http://img42.imageshack.us/img42/3351/image1iu.jpg

caprock filter -- http://www.caprockdev.com/antimoire.htm

Have you noticed much loss of image quality or light gathering
 

The site mentions some loss of image quality but I'm wondering if anyone has some practical experience with how much =please quantify if possible Thanks

With a shallow DOF, and by keeping the strings slightly out of focus, you can avoid aliasing on guitar strings, as you can see here....

Melissa Fairy

As a non DSLR user, I'm amazed that they are so bad at this kind of thing (I saw some similar pictures of a grill on a car with the same problem).

I do know that I couldn't consider buying a camera that cannot shoot such simple things without unwanted very obvious artefacts like this!

DvSLRs have two primary artifacts: 1) aliasing, and 2) rolling shutter. Both can be ugly, so the key is to learn how to avoid the problems.

To avoid aliasing, it can help to use a diffusion filter in front of the lens, though this won't eliminate it fully. As long as your main subject isn't wearing clothing with fine patterns, just keep the other items slightly (or more) defocused. That eliminates the problem 100%.

If you absolutely can't keep the an aliasing background item from being in sharp focus, snap a photo. You can use After Effects to replace the aliasing building video with the clean building photo. It's extra work, but can save a shot.

The main thing to avoid is aliasing clothing. If you're shooting a documentary, you will lack control of the scene and might have to soften things in post. If you're shooting a narrative piece, let the art director know.

For rolling shutter, get good support equipment and manage the camera movement. When tracking an item, you can move the camera a bit more, but with a stark pan, go slow. You can always speed it up in post.

If you know what to avoid and develop the skills to avoid it, shooting with a DvSLR is very rewarding. Take a look at Philip Bloom's pieces - or the season finale of House. You just can't get that look with a small chip camcorder. And to get "the look" without aliasing or rolling shutter means multiplying your equipment budget by ten times or more.

If a shallow DOF look isn't important to you, there are many traditional, small chip camcorders that can do the job. But for shallow DOF on a budget, I'm happy to take the steps to work around the limitations.

I played around a little bit with a Caprock. It does indeed clear up moiring. The resolution loss seemed more apparent on test charts than on real subjects. Seems like a good product. Be aware you need a set of them, it's not one size fits all.

I cannot predict when moire will or won't appear and I'm skeptical that anyone can despite claims to the contrary. The wise solution is investing in a good external LCD and catching it on the spot, as opposed to trying to predict it based on various conditions. You might be able to predict it 80% of the time, or even 99%, but that 1% you miss can be ruinous. The 7d's built in VF isn't large enough to consistently spot moire.