Question about sharpness and aliasing.

H

harmonica44

I have the Canon T2i. A lot of sites online, say to keep the sharpness turned down to zero, cause adding sharpness, in camera, leads to aliasing. And some people disagree, saying although that's true, with the sharpness at zero, there is not enough detail in the end result.

I did some comparison tests, and I found with the sharpness turned to zero, then applying a sharpness filter in post, there are certain details you don't get back. There is detail in eye close ups especially when noticing sharpness in camera, compared to post. So I guess it's matter of judging how much sharpness to go, or whether it should be turned up at all.

I like adding in camera, cause it helps me pull focus. But I don't have to if it's bad for aliasing. I turned the sharpness all the way up to 7, which really helps for pulling focus, and the picture looks really sharp with a lot of detail at end. A close up of a mustache, and you can see all the little thin hairs, compared to adding sharpness in post.

However, is 7 too much for most viewers, or most TVs? On my TV it looks good, however, I do not notice this aliasing people are talking about. What am I suppose to be looking for? Is it for certain TVs only? What are your opinions on sharpness and what should be done about it?

Thanks.
 
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Use magic lantern for "focus pulling". Sharpness all the way up will not look good on anything,except perhaps the lcd of the dslr. At least to my taste. Aliasing happens at the point of focus at certain patterns,i.e stripped shirt. You can avoid it by shifting focus but it is not always possible
 
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I have my sharpness turned all the way down and can still get really sharp images - even with the crap kit lens.

I will sometimes add a small bit of sharpness back in Final Cut, though, depending on what the scene is. I shot something recently and used the sharpness filter to bring out more details a bit, and it definitely did the trick just fine.

The truth is, though, that unless you get a Canon 5D MK III, you won't be able to avoid aliasing in camera or in post. Philip Bloom explains this a bit more in-depth on his review of the 5D MK III, which seems to be the only Canon camera that doesn't have moire and thus aliasing. Even the Blackmagic cameras have moire, which is disappointing.
 
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Okay thanks. Is their any reason why you turn it all the way down? If aliasing is unavoidable, with all these cameras, then why do you still turn it all the way down, then add later, as oppose to shooting with it to begin with?
 
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harmonica44 said:
Okay thanks. Is their any reason why you turn it all the way down? If aliasing is unavoidable, with all these cameras, then why do you still turn it all the way down, then add later, as oppose to shooting with it to begin with?
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I have it turned all the way down because it's the only way to avoid the nasty aliasing/moire - I also do it to allow more freedom in post in determining how much I want to sharpen it, rather than just picking a number on the camera and hoping it'll look good.

Of course, there's still aliasing and moire happening, but it's greatly reduced when you shoot with sharpness all the way down.
 
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Every single thing I've ever shot with my 5DmkII, other than my initial tests, has been with sharpness all the way down. This isn't because of aliasing - it's because the in-camera sharpening creates visible artifacts like fringing around high-contrast areas, even at one notch up from it's lowest level. Personally I find those kinds of artifacts distracting, giving it more of an 'electronic' or 'video' feel, and I prefer the smoother look with sharpening turned off. If I want it to look sharper I do it in post because you have a lot more control to tune it without creating visible artifacts - but honestly I don't find that I need to do it very often. Some people don't seem to be as sensitive to those artifacts and prefer to use in camera sharpening - you really just need to do some tests and then compare them at full res on a good monitor. You definitely shouldn't be doing it just to make focusing easier - if it's strong enough to change what you're seeing on the camera's LCD then it's going to be way over-sharpened at full res in your finished product.
 
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Okay thanks. Some people are saying to shoot at +2 sharpness, saying that's the best without looking too digital. I guess I don't find them as distracting, as long as the shot is well lit. What is this 'fringing' exactly? I'm probably just missing it.

I can shoot with it at zero, but the image is so dull looking that I am worried it will not look like their is enough detail, like something is wrong. To me, it literally looks like the camera is not in full focus and is a bit off, even though it's just the sharpening, compared to adding +2 to compare. I ask a friend's opinion, and she said it looks a little dull, but if that's the way it's suppose to be done than I will do it. It just looks dull to me around areas like hair in close ups.

In this test, the first take is at zero, and the second is at +2. Notice how my thin mustache hairs are more sharp and clearly defined.

https://www.youtube.com/watch?v=b8fivMlyh34&feature=youtu.be

But I guess the first one at zero, is more of a film look and is more acceptable to have if that's so...
 
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H44 - Any sharpness added in-camera is a destructive editing process. You cannot simply roll it back after doing this, as you have just discarded important data in the sharpening process, and introduced edge artefacts as described above. As a general rule, the least amount of jiggery-pokery your camera does to the image before writing the file, the better.
 
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harmonica44 said:
In this test, the first take is at zero, and the second is at +2. Notice how my thin mustache hairs are more sharp and clearly defined.

https://www.youtube.com/watch?v=b8fivMlyh34&feature=youtu.be
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This has absolutely nothing to do with the sharpness settings in the camera at all. In the first shot the camera is focused on the tip of your nose. The depth of field is so shallow that your mustache is out of focus. The second shot is focused about half an inch back (bridge of your nose in focus, tip slightly out), so your mustache is more in focus than the first shot.
 
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Okay thanks, that makes sense. But I did other tests, with hair, and eyes and such. Even if you add post sharpening, you cannot make hair look as sharp compared to in camera. I don't see what data is being recorded that would be missing, when it looks like their is more data recorded with the sharpness up.

But if shooting with no sharpness is the way to go, then I will do it.
 
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Even though cameras and visuals are not my area of expertise* I would like to remind H44 and everyone else that you are working with an imperfect piece of equipment. The Canon T2i and all other DSLRs are cameras manufactured for the taking of still photographs, and they have been co-opted into recording moving images. Using DSLRs definitely opens up some creative doors for low/no/mini/micro budget filmmakers, but, as with all similar situations, you must deal with the issues brought about by those compromises; you will not get everything that you want.












* My wife is a very experienced photographer and does graphics for a living, so I'm not a total ignoramus when it comes to visuals.
 
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harmonica44 said:
Okay thanks, that makes sense. But I did other tests, with hair, and eyes and such. Even if you add post sharpening, you cannot make hair look as sharp compared to in camera. I don't see what data is being recorded that would be missing, when it looks like their is more data recorded with the sharpness up.

But if shooting with no sharpness is the way to go, then I will do it.
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Like I said before - you've got to look at it yourself and make a call. If you prefer the look with sharpness turned up, then shoot that way.

Just make sure you're not making the same mistake you made with the sample video you posted. You're obviously shooting with the lens wide open in that shot and you have less than an inch of depth of field. Even the slightest movement of your head is going to change the apparent sharpness of everything in your shot.

If you really want to evaluate the effect of sharpening on the picture you should do your tests in bright light where you can stop down to somewhere around 5.6-8, and shoot a subject that is at more of a distance from your camera. That way you can be reasonably sure that the differences you are seeing are the result of the sharpness settings and not due to having insufficient depth of field.
 
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Okay thanks. I am going to do tests in sunlight next, or just light bright enough in doors. Is aliasing and moire those waves, you sometimes get around lights, in the image? If so, I have shot with the sharpness turned down, and still have that sometimes. I have expiremented with different picture profiles in the camera to get the best look and so far the best one I have come up with is this:

LANDSCAPE

Sharpness +2 (or maybe 0, if that's better. not sure on this one)
Contrast -2
Saturation 0
Color Tone 0

I was thinking maybe the Color Tone should be turned to +2 to get more of a film look, but it only works in daylight. In tungsten light the skin tones are too green per say.
 
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Alcove Audio said:
Even though cameras and visuals are not my area of expertise* I would like to remind H44 and everyone else that you are working with an imperfect piece of equipment. The Canon T2i and all other DSLRs are cameras manufactured for the taking of still photographs, and they have been co-opted into recording moving images. Using DSLRs definitely opens up some creative doors for low/no/mini/micro budget filmmakers, but, as with all similar situations, you must deal with the issues brought about by those compromises; you will not get everything that you want.
Click to expand...

yes I'm strongly agree with you, but I love Canon Rebel T2i.
buy.gif
Canon's Rebel T2i is an incredible camera—everything a first DSLR should be. for the price, it's easy to use, and perhaps most importantly, And for anyone just getting into DSLR photography, the power to package ratio is phenomenal. That said, it still feels like an entry-level DSLR, for better and worse.:D
 
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