Thom Hogan says:
"More on Moire
Feb 16 (commentary)--A recurring question in my In Box right now has to do with what subjects trigger moire.
Moire happens when your sampling frequency (sensor pitch) begins to coincide with the captured detail frequency (subject pitch). As you pass the Nyquist frequency, problematic artifacts are produced, moire and color fringing being common ones on Bayer systems.
However, nature is pretty random with frequencies while man isn't. Even things that look like exact patterns, like bird feathers or tree rings, usually aren't. They have some randomness to them much of the time, and thus when you shoot natural objects, the tendency to get large patches of moire is relatively low. It's possible, certainly, but in my experience, I've not photographed anything in the natural world where I've had an image ruined by moire. A few here and there that need some post processing touch up, but ruined, no.
That's not exactly true in the man-made world (especially the Western cultures). Buildings tend to have all kinds of repeating patterns. We typically build on grids and we use products that have fixed sizes. Exactly the type of thing that can trigger moire. Same thing applies to the clothes we wear: many are made with repeating weaves with fixed size threads. Another common problem occurs with hair, where you don't get large blocks of moire, but you do get color fringing and artifacts on edges.
It's not a coincidence that most of the moire examples you see in articles about it are one of three things: test charts, buildings, or fabrics. I have a screen door at my office that does a very nice job of showing moire when I need a sample.
So the question you have to ask yourself before removing the AA filter on a camera is this: what do I shoot? Is it things that tend to occur in nature and mostly randomly, or is it things that have man-made, non-random components to them? If the former, it's going to be rare that you have to worry about post processing moire, and it's also not likely to be large and highly destructive moire, at that. If the latter, you're going to encounter moire a lot more often, and it can be over very large areas and occur in ways that are much more difficult to remove visually.
That's a gross simplification, of course, but it's a good starting point from which to base a decision."
I have a 1:2 chance of getting the D800 or D800E (pending CFO approval), was thinking about getting D800E for the additional acuity. But as an urban person who enjoys the occassional foray into landscape, I think the above analysis is pushing me towards D800. For argument sake, what would be your take on this issue of moire?
It might, afterall, be academic if CFO turns down the request for new capital investment for what amounts to a high-depreciation low-return hobby. He he.
"More on Moire
Feb 16 (commentary)--A recurring question in my In Box right now has to do with what subjects trigger moire.
Moire happens when your sampling frequency (sensor pitch) begins to coincide with the captured detail frequency (subject pitch). As you pass the Nyquist frequency, problematic artifacts are produced, moire and color fringing being common ones on Bayer systems.
However, nature is pretty random with frequencies while man isn't. Even things that look like exact patterns, like bird feathers or tree rings, usually aren't. They have some randomness to them much of the time, and thus when you shoot natural objects, the tendency to get large patches of moire is relatively low. It's possible, certainly, but in my experience, I've not photographed anything in the natural world where I've had an image ruined by moire. A few here and there that need some post processing touch up, but ruined, no.
That's not exactly true in the man-made world (especially the Western cultures). Buildings tend to have all kinds of repeating patterns. We typically build on grids and we use products that have fixed sizes. Exactly the type of thing that can trigger moire. Same thing applies to the clothes we wear: many are made with repeating weaves with fixed size threads. Another common problem occurs with hair, where you don't get large blocks of moire, but you do get color fringing and artifacts on edges.
It's not a coincidence that most of the moire examples you see in articles about it are one of three things: test charts, buildings, or fabrics. I have a screen door at my office that does a very nice job of showing moire when I need a sample.
So the question you have to ask yourself before removing the AA filter on a camera is this: what do I shoot? Is it things that tend to occur in nature and mostly randomly, or is it things that have man-made, non-random components to them? If the former, it's going to be rare that you have to worry about post processing moire, and it's also not likely to be large and highly destructive moire, at that. If the latter, you're going to encounter moire a lot more often, and it can be over very large areas and occur in ways that are much more difficult to remove visually.
That's a gross simplification, of course, but it's a good starting point from which to base a decision."
I have a 1:2 chance of getting the D800 or D800E (pending CFO approval), was thinking about getting D800E for the additional acuity. But as an urban person who enjoys the occassional foray into landscape, I think the above analysis is pushing me towards D800. For argument sake, what would be your take on this issue of moire?
It might, afterall, be academic if CFO turns down the request for new capital investment for what amounts to a high-depreciation low-return hobby. He he.
