personal lighting study

[modernhorse]

Hi all -

I've been meaning to do this for a long time. One of the things that my mini movie work proved to me was/is that I need to work on lighting. I've started this thread so that I might gain as much input into the process as possible from anyone who wants to comment.

 

This first exercise is supposed to be an outdoor setup, I'm going for afternoon sun. I understand that this isn't the most interesting from a character and modeling standpoint, but that is not my intent here.

 

Thanks for any thoughts.

 

Doug

[Dearmad]

Warning, strongly worded opinion ahead, NOT meant to offend. And remember, it's JUST my *opinion.*

 

The lights seem too hot in this shot. The shadows appear to have been considered the enemy in this shot. Shadows are not evil, they are your friends.

 

The lighting on the "head" makes it appear as if he's standing *very* close to a *very* bright thing... and it must hurt.

 

The self shadowing on the "guy" is far too minimal to enhance contour. This is due to poor choices in lighting angle, and/or too manyu lights killing out each other's strengths.

 

The shading (not shadows, but where colors should be richer due to variance in light levels) is very very flat.

 

The highlights are too white without some sort of bloom to help define them; they look flat as they are now. But I wouldn't push for bloom, I'd push a look that says: "proper exposure" before I went there.

 

 

Not addressed to you, but in general, all the pixelated shadows I'm seeing from almost everyone's skyrigs and multipasses... just look plain bad. It's like dropping back to 1994 and using POLYray or POVray again. And the complexity of a skyrig (which by its nature ha many light sources) is clearly too much for most people to handle well.

 

I don't understand why it's such a common error in CG for people to start with 10 lights and try to make that work... as if you had any chance of figuring out how to make all those variables come together. Also, critiquing an image where so many lights are used bbecomes VERY hard unless you're some sort of lighting god who can discern where the sources aare....

 

I've been a professional photographer, and have worked in theater design; I have a better chance of figuring out a light setup of 10+ lights better than most people in this forum, yet, I wouldn't approach with initially more than 2 lights ever. Rather, it is simpler (read: still REALLY HARD) to start with one light. Try to make it work, then *add* one more light, figure out what it does... try to make them both work, then add another... Then STOP, why on earth is 3 lights not working? That's WIERD! (There are good reasons why it might not, but I suggest figuring out why before moving on.)

 

I *sincerely* hope I haven't offended you.

[Dearmad]

I just can't leave off like that- you've my admiration for setting out a task before yourself and deciding to learn about it. That deserves accolades, man.

 

There's a link I should send you once I find it about lighting... it's very well written.... Will edit when I find it.

 

Here it is:

 

http://www.itchy-animation.co.uk/light.htm

 

It's been updated since I last read it- it's even MORE thorough now. The guy knows his stuff!

 

And a thread about it:

http://www.hash.com/forums/index.php?showtopic=10028&hl=

[oakchas]

Peter,

i don't know about the original poster, but I would not take offense to what you are saying... and thank you so much for the link...

 

I've copied the link and am sending it to myself at home so i won't forget it.

I've learned something here.. and I appreciate it.

 

Charlie

[robcat2075]

The first thing that struck me is how fuzzy the shadows are for sunlight. The sun is a rather narrow source of light; it would take a very wide source of light to cast the shadows we see in this pic.

 

But as Peter noted it's great that you want to improve in your lighting skills. Let's see what v2.0 looks like!

[modernhorse]

Thanks very much for the pointed replies. No offense taken at all (one would have to wonder why anyone would post here if they were that thin skinned ).

 

Actually, this isn't a skylight rig. I started out with one light, added another. I think I'll take your advice Peter and reduce it down to one again and solve the shadow(s) issue and then move on. I'm on it and thanks again.

 

Oh and thanks also for the link. I was actually reading this before I started this scene. More reading is in order.

 

Doug

[modernhorse]

Okay -

Here's an update.

 

Robcat - the strange shadows occured from not using enough rays cast for the shadow (i was using a setting of 5 on raytraced shadow). I've since discovered that setting it to '1' is better than 5. I tried one at 16 and it was still too grainy and way upped render times.

 

I also did some more reading and following tech reference I tried a bluish tint on my sun light and it just made it look cold. The current setup is two lights. One sun to the right. And one rim in front of the character.

 

Thanks for the help so far. It's been very helpful.

 

Doug

[Dearmad]

If it's in front of the character it's not a rim. That could be a key or a fill. Which purpose does it fulfill? Not so important to get the terms right, anyway.

 

This looks much better. It's decently lit. From here I'd say you need to decide *why* you want the scene lit to make the *how* part final:

 

what mood? (happy discovery of blocks at midday?)

 

what's unimportant? (the orange block is not what I was looking for...)

 

what's important? (THERE'S my YELLOW BLOCK!)

 

what colors should be brought out? which blended in?

 

how do you want the shadows to help the scene? (maybe oprange block should be repositioned to be half in the guy's shadow and half out?)

 

how do you want shading to help the scene? (fake some radiance to the yellow/orange blocks?)

 

how do you want highlight to help the scene? (Yellow block just glistens beautifully... that's why I was looking for it!)

 

do I need a rim light to seperate my character from the background?

 

 

So, for example, if the YELLOW block is the key piece, then maybe a fake radiance light (colored yellow) will help, aim it a little at the guy across the block so it looks like yellow light reflected from it off the sun. A subtle effect noticed unconsciously most likely. Probably a no-shadow light and not very bright at all...

[Dearmad]

Also, try out the z-buffered shadows, sometimes you can get very sweet results from them. I quite like them.

[Dhar]

::: keeping a mental note: rim light = front of character::::

 

This is valuable info.

[Dearmad]

What?

[Fishman]

::: keeping a mental note: rim light = front of character::::

 

This is valuable info.

Better reread your notes. Light in back of character = rim. Light in front of character = key.

 

This is a good discussion. I love Peter's lighting in his Ravel film, so this is a great insight into his mind. Doug, thanks for being the sacrificial lamb on a subject that so many of us have no clue about, but are ashamed to admit it.

 

Scott

[ypoissant]

I agree with most of Peter's comments. His expressive use of light, in particular, I agree completely.

 

Indeed, it is a godd advise to start exploring with as minimal number of lights as possible. Unless one have experience with lighting, it is better to start with one main light to get the most expressive basic lighting setup. Then add secondary lights like a fill light and then a rim light. After that you can add bounce lights to help get the mood and enhance relationship between the objects and characters. But beware that too many lights can truely kill a scene by making all objects appear flat. Secondary lights should be used parcimoniously and subtly.

 

I agree only partially with the comments concerning skylights however. I also find it odd that several beginners starts by putting a skylight rig in their scene without even understanding how to manage even one single light. But that is not a reason to dismiss skylight rigs altogether. Skylight rigs can make the objects in a scene appear much less flat because of the ambiant occlusion effect. But that is if the skylight rig is used correctly and with the proper settings.

 

It is true that skylight rigs are not easy to use. Finding the proper babance between a skylight rig light intensity and color vs a sun light intensity and color to get the right mood can require a lot of experimentation. Skylight rigs are not magic wand that one can use to automagically get a cool clay look. So skylight rigs are not for beginners. Most of the beginners I saw trying to use a skylight rig did it the wrong way and had big difficulties in setting them right.

 

The bottom line is it is better to start with the basic 3 light setup. Learn what is this beast that is a light first. How it works, how it is adjusted, what it does. etc. first. Then move on to more complex light setups.

 

BTW, this was not a comment addressed specifically to you Doug. I know you didn't use a skylight rig in your scene. And bravo for setting yourself such a learning goal. I invite to move your effort in lighting in the Radiosity forum so that we can follow your progression and advise as you go. And have everybody inerested in lighting learn at the same time.

 

About your setup, Doug. 1 ray cast lights will produce way too harsh shadows. You could use z-buffer shadows but that have the potential to make your objects look floaty.

 

Instead of using only one ray on your sun light, you would get better results by using like 5 rays but reducing the size of your sun light. The shadow smoothness is controlled by the light size. From the softness of your first shadows, I would say that your sun light is very very large. You could easily reduce its size to at least 10% its current size.

[Dearmad]

I didn't mean to sound like I was dismissing skylights, but I do stand behind the notion that people ought to lay off of them until they have a grasp of how to light a scene without them- that is, if they want to ever have a decent and true grasp of lighting and not just go for solutions driven by a formulaic approach.

 

I've seen some beautiful skylight rig images, but they number about 1% of the total output I see involving skylights.

 

Also, I would add that adding multiple rays to your raytraced shadows is something I've found in practice to be the *last* step of the process. The time it takes to render and the fidgety details involved to get it "right" are truly not worth it until you have your scene's lighting basically completed and under control. The shadow will fall where it is falling with 1 ray- only have less of an edge to it- just know that and work without it.

 

However, I've yet to see multiple ray cast shadows that look very good in renders that don't last a week. And there are multiple other approaches to softening and/or lightening a shadow, *if* the shadow needs to even be softened (penumbra spread thicker) or lightened (so details hold up inside the shade).

 

In a lot of dramatic images, having one (maybe even more) shadow with crisp delineation is compelling. And with the cheat of no-shadow lights, we can add a key or rim light without fear of introducing more shadows that we cannot control. Also, adding lights just to lighten shadows cast by other lights is helpful:

 

http://www.hash.com/forums/index.php?showtopic=3676&st=0

 

See the image attached to the first post I made in that thread- while the shadows are easier on the eyes, their outlines are still strong- this doesn't look bad, and involves no multiple raycasts, z-buffers, etc...

 

Working to get that ultra soft penumbra is often a waste of time when there are other fundamental problems with the lighting to an image.

[modernhorse]

Again, I thank you all for your very informative input. This is a tremendous help to me.

 

Yves as you said here in your post ;

I invite to move your effort in lighting in the Radiosity forum so that we can follow your progression and advise as you go. And have everybody inerested in lighting learn at the same time.

 

I guess I've been under the mistaken notion that the Radiosity forum was for developing Radiosity renders. Would you like to move this thread or should I start a new one? Either way I'll take this discussion over there if it's more appropriate.

 

Thanks again all.

 

Doug