THE SMA FORUM ARCHIVE
Posted by olwynn, on 2005-10-20 07:44:09
Forced Perspective for faking larger sets
Hi All, I hope I'm not being too forward, but I'm planning my first film and trying to do as much on paper as possible in order to keep cost down. I hope that I can spark some interest from the more knowlegable set builders out there...
The project is set in medevil europe somewhere ... leaning toward Venice, but scared by the water scenes ;). Anyhow, the actual location isn't really important, what I worried about is that the film is calling for some outdoor shots in a medevil town/city and I am hoping there is someone out there with experience in planning these kinds of sets. I have written the outdoor scenes to only be at night, so limited visibility will be one ally, I'm wondering if anyone can offer some tips on faking perspective with that many man-made structures about.
I have read the Aardman book and seen the tutorial with the kilometer long pier that someone posted the link for, but neither really seems directly applicable. I guess what I'm mainly looking for is a planning method to help me keep the sets smaller and more in budget for an indie filmmaker, but I still would like the effect of a 'money shot' :P. I am currently working with a 1:6 model, which ends up about 14" tall.
Thanks in advance
Posted by Strider, on 2005-10-20 08:12:42
Not sure what kind of shots you have planned (or maybe you haven't planned them yet), but I know you can get away with a lot just by using some flat cutouts for the distant buildings. Especially since it's a night scene.
A while back a friend and I were messing around with a video camera (live action miniature shots). I had a few great looking rocks (clinkers actually, look like lava rocks) and wanted to create the effect of a mountain range. I set the rocks up in the foreground, right behind them I placed a few cigarettes with various objects above them to 'baffle' the smoke, so it built up and came out in sheets rather than rising in thin strings like - well, like cigarette smoke. And finally behind that I propped up a big sheet of corkboard made for bulletin boards. I broke the top edge off raggedly so it was shapes like the skyline of a distant mountain range. And behind [b]that[/b] was a sheet of white posterboard. I had a bright halogen light hidden behind the corkboard to flood the posterboard with light that completely burned out the video camera, so the edge of the 'mountains' was sort of hazed out a little. When I had it all set up, I took the camera and did a slow hand pan across the front of it all, my friend laughing at me the whole time because he couldn't see what I was seeing through the viewfinder. But when I played it back to him a few seconds later, he was amazed... it looked incredible!
The key was the backlighting.... the corkboard became a dark silouette and you couldn't tell it had no surface detailing on it. I've thought about doing a nightime city shot with a few layers of silouetted buildings, with lights in between each layer. Anyway, it's something to consider. You'd want to build a few parts of close buildings... maybe an archway or two that you can see the distant silouettes through.
Posted by olwynn, on 2005-10-20 09:30:24
Strider and Jim
Thanks for the speedy advice. Jim, I'm writing down that book list right now to go and accost the librarian here at Sheridan. After I've got the treatment mailed to myself, I'll post a copy online with some of my character development work if you like. Strider, I was thinking that using cutouts was probably going to be the way to go, just wondering whether there was any kind of formula for fudging perspective or if it all had to be eyeballed in camera.
thanks again both of you
Posted by Jim Aupperle, on 2005-10-20 09:02:50
Sounds like a great project, I love the effects you can get in camera with trick perspective. There's very little written on the subject but some of the best information can be found in Eugene Lourie's autobiography "My Work in Films" (you should be able to find a used paperback edition for under $10). Lourie was an art director, film director and visual effects designer for many years in Hollywood and Europe. I think you'll be stunned when you see the behind the scenes shots of the hanging miniatures he created for The Adventures of Captain Fabian and there's also a great photo of the hanging FG miniature for Crack in the World with Lourie standing in. Other films are covered besides those two. I don't recall just how much detail the text goes into but I think there's a significant amount of information there. He does discuss using a miniature in the BG to expand the set and how he was able to do a dolly move with the live actors in the FG and yet still maintain correct perspective through the shot.
Another book you might find helpful is Peter Ellenshaw's "Ellenshaw Under Glass" where he has information on the trick perspective shots in Darby O'Gill and the Little People (this books costs some $$$, think it was about $80).
The trick perspective sets in F.W. Murnau's "The Last Laugh" are discussed in "Film Architecture - from Metropolis to Blade Runner" edited by Dietrich Neumann. I think it's out in paperback now.
I've never seen anything written about it but there's a set in Carol Reed's "Odd Man Out" that looks to use trick perspective on a street scene. If you get the DVD check out chapter 10 at about 52 min. into the movie.
I can't find my copy just now but check out "The Thief of Bagdad" (1940s version) for ingenious hanging miniature shots of the city.
hope this give you a place to start and best of luck on your project
Posted by Jim Aupperle, on 2005-10-20 10:30:45
If you're not already well versed in it you might want to study up on using the hyperfocal distance in setting your focus on trick perspective shots. You want to hold both FG miniature and your BG image in the same focus so the trick is finding that point between the two to set focus so the depth of field will carry the scene and keep everything acceptably sharp (the words "acceptably sharp" are key in doing trick perspective work).
"The Hyper Focal Distance is the focus point, such that anything between half the distance to the focus point and infinity is in focus."
Sometimes it isn't necessary to even have everything all the way to infinity in focus so you can then move your set focus slightly closer to the FG. If your FG model is three feet away and the buldings you're matching to are 50 feet away then 3 to 50 feet is the distance to hold acceptably sharp. As a very general rule you'll end up setting the camera's focus about 1/3 of the way of the distance to your main subject behind your FG miniature.
You can also do split screens so that a FG miniature appears behind a real hill on location. Splits can be done in camera if you're working with film, in post production if video and by using the Schufftan process if you're a purist and masochist.
"The Schufftan process was developed by cinematographer and special effects pioneer Eugen Schufftan, who was best known for using the process in Fritz Lang's Metropolis (1927). It involved scraping away the silver on part of a mirror and placing the mirror at a 45-degree angle to the camera. The action was then photographed through the clear portion of the mirror while the silvered portion reflected the artificial background, combining the two into a single image."
Oh, by the way, the miniature set behind the dancing corpse in Evil Dead 2 was built in forced perspective just to save space on the stop motion stage. I gave Jim Belohovek a rough sketch and a general idea of what we needed and he built a wonderful miniature (as he always did) where even the house diminished in perspective. No live action in that shot but the idea is much the same. If you're building a model in forced perspective always keep in mind where your horizon is as well as all vanishing points.
This sounds like fun.
"I have written the outdoor scenes to only be at night, so limited visibility will be one ally"
Richard, I just noticed the above remark in your first post. Something to keep in mind is that sun light is your best ally in doing trick perspective work. Otherwise you must light your set to a deep enough f-stop to hold everything in focus and usually low budget films can't afford to set up that much light. Perhaps day for night? Don't want to change the look of your film but just something to keep in mind.
Posted by DaveHettmer, on 2005-10-20 09:51:56
Here's a quickie example to get you started until you can get your hands on Jim's references...
You can do a lot with 2D things that are painted "right" if the camera doesn't truck much. Strider's corkboard mountains are a good example. Accounting for atmospheric haze is important. As objects become further away, details become mushy and there's less contrast. Things in the distance are often purplish, for example. If you have an image of a building that's just right, you can project it onto the surface (foamcore, luan, etc) at the scale you want, trace it and then paint it appropriately.
This sort of thing is done in stage productions, too. This page has pictures of a set I co-designed, and it has cutout of the White Tower in the back of the set.
This page has an example more in the style of The Wizard of Oz where the 2D cutout was painted with forced perspective and atmospheric haze (it's the part with the gate and bushes behind the wall):
Posted by Boy Oyng, on 2005-10-20 11:57:04
I remember having similar questions when I first joined the board. I, too, was looking for a formula, and I could never find one. Here's a link to that discussion, just in case you might find it useful. I certainly found the suggestions helpful.
I still intend to figure out (which means, ask some math-capable friends) some kind of easy-to-use formula and post about it. Three years later, it's still on my "to do" list. Nevertheless, among the best advice I got in the responses--advice I initially resisted a little--was the "eyeballing it" suggestion. And one conclusion I reached that I still believe is valid: the audience's minds WANT the scene to make sense visually, so you can get away with a fair amount of imprecision as long as the basic cues are correct.
One thing that wasn't clear to me from your post: Are you trying to integrate live action with miniatures, or is this all miniatures/stop motion?
Posted by olwynn, on 2005-10-20 12:49:34
Thanks everyone for the suggestions... I am currently reading that old thread and it sounds like Venice may not be the best location for more that the water. Perhaps I can make better use of the hilly terrain in Tuscany to assist, many precipitous dropoffs ... actually, they could add drama to the outdoor scenes that were called for, and the hills in the villages there would assist in breaking the perspective into planes.
I'm not finished looking for a perspective rule based solution ... I'm off to talk to one of the instructors here Brian, who teaches an advanced perspective course that I can highly recommend - 2,3, curvalinear and spherical perspective. You haven't seen anything until you've seen a warp pan which looks around a room 360^ and then pans up to the ceiling as well ... the man is a laser. Anyhow - more about the project:
The night scene is unfortunately, pretty much built into the story and I would not like to limit the film by worrying about technicalities just yet. The project is an all stop-mo film about an alchemist who brings a small tin doll to life, satisfying his yearning to prove his intellectual dominance. Unfortunately, when he attempts to show the puppet to the world, he discovers that it has a mind of it's own.
Cheers, more later when I've taken some photos of the concept work.
Posted by Jim Aupperle, on 2005-10-20 11:57:49
I just assumed that in your project you wanted to mix live action with forced perspective sets but now that I look over your first post again I think your plan is to do an all puppet animation film (your mention of the Aardman book). Most of what I was talking about, outside of the set we did for Evil Dead 2, related to trick perspective with live action. So, what's the plan? Hmmmm, now I see Boy Oyng has the same question. His link to the earlier discussion here on SMA.com does seem to cover it all and even back then there was the question about do we mix with live action or is it for an all puppet self contained set. Wish we had a better way to index these topics.
Posted by Jim Aupperle, on 2005-10-20 13:50:43
The night scene is unfortunately, pretty much built into the story and I would not like to limit the film by worrying about technicalities just yet. The project is an all stop-mo film about an alchemist who brings a small tin doll to life, satisfying his yearning to prove his intellectual dominance. Richard
As long as it's all a stop motion miniature anyway then there wouldn't be any problems doing a night shot. When I thought you were intending a live action production with forced perspective sets the scale of lighting such live action sets concerned me. I once needed to match lighting on a live action exterior for some background pates (Robocop 3) and used a 10,000 watt HMI lighting unit to light up a parking lot. On Addams Famly Values I used an 18,000 watt HMI for a large scale live action miniature of the Addams' house at night. With smaller stop motion sets and time exposures none of that is a problem. I guess our forced perspective shot of the cabin in Evil Dead 2 does come closest to what you have in mind. The thing that's still true for what you're doing is to watch that your horizon and vanishing points are correct.
Posted by Nick H, on 2005-10-20 20:41:19
A cityscape where you are looking down a long street, with all the buildings parallel, needs accurate perspective. Your eye can follow along the lines to the vanishing point, and it shows if it's not right. But a medieval town with odd shaped buildings at odd angles is much more forgiving, just put smaller buildings further back. And a landscape with rolling hills is dead easy, you can only judge how far away the next hill is by the scale of the buildings on it, so just about any scale will look right. If it's a lot smaller, then it must be a lot further away. If you can't see all of the ground in between you don't give anything away. It also gives you a way to have gaps in the set so you can get in and animate, since they are hidden by the hills in front. A Tuscan landscape would look brilliant!
Natural landscapes like forests are also easy, since trees and rocks can be smaller or larger anyway, you don't have to go by any mathematical rules. Even if you put a bigger tree further back than some smaller ones it won't look wrong, it will just look like a bigger tree.
Ideally you'd have 3 or 4 diminishing scales without too big a difference between them, but I've gotten away with a 1:6 foreground with a 1:24 scale set behind. That's a big jump, down to 1/4 the size in one step! It looked like a wide angle shot where the perspective is exaggerated (In Good Riddance album at my Picturetrail site). I had to avoid seeing the ground up close. A middle size of 1:12 would have been better, but I was out of time and trying to avoid making more sets. It was a night shot, using a fairly lurid blue to suggest moonlight. In the wide shot of the 1:24 set, the very furthest buildings on the horizon are actually painted on the sky backcloth.
I've done a Venice set (seen in O Pollo Mio at Stopmoshorts >Archives> Past Events), and most of it is more rennaissance than medieval in style. It's a night shot too, but doesn't show sky. Yes, that water is a pain! I composited it into one establishing shot to show it, then framed it out and just suggested it by rocking the boat and throwing ripple light up onto the buildings. I've got more to build and a lot more to shoot for the real film it was made for.
Posted by Pjotr Sapegin, on 2005-10-22 03:59:31
I was working as FX in the old days, and that´s´how we did it:
First thing which arrived on the set was the camera. Using the camera, we would build the "modell" of the modell - a primitive paper/carton set, wher we would establish the right size of things and right degree of perspective destortion.
First we would choose the optick.
Then we would take a shot of the sketch with our video-assist, and have it on the monitor. Then i would draw a copy-scetch on the surfice of the monitor-screen, repeeting the pictuare taken.
Then we would swich the camera to "live" and begin to build the paper-modell of the set, correcting the perspective by the lines of the scetch drawn on the mnitor.
Then we would take the elements of paper-modell to the workshop and build it in wood.
Posted by Nick H, on 2005-10-24 01:49:26
Did you make individual buildings with a normal shape, or did each building have converging lines? I have always avoided those, partly because the building only looks good from one angle. I like to re-use my buildings in different positions. And partly, because every horizontal line, like a row of bricks would have to be made smaller as it goes towards the back. It would take much longer to make.
But that is a good idea, to arrange the boxes to fit the sketch on the monitor!
Posted by olwynn, on 2005-10-24 14:53:02
Thanks everyone for the advice - it looks like there is no fast an easy way to plan something like this much in advance other than to have solid storyboard sketches and to plan from them. I am thinking that I will likely blow up my storyboard sketches and try printing them to acetate ... If I can put the acetate on a platen between my viewpoint and my intended set, I can probably estimate the convergence fairly well. I can see the point about avoiding distorting the individual buildings - it would definetly increase their complexity and decrease their reusability. I have made some loose appointments to speak with professors here, so if they provide any tricks, I'll try to summarize them here.
Thanks again everyone