Simulating sky with a projector

[tom mann]

I've always wanted to simulate atmospheric conditions with model photography.  Backdrops look usually fake, and photoshopping in a real background sometimes looks contrived. 

A few years back I used a LED flashlight (which has a blue tint) and waved it onto a white backdrop during a long exposure to simulate a sky.  The upside was that the colors looked good, and the light would reflect off the backdrop onto the model to make things like grab irons and railings look thinner.  The downside was that the all the images resembled ones taken at twilight or early morning when there is not enough light for the subject.

For the new layout, which is focused on photography and not on operations or even running trains*, I brainstormed another possibility:  a projector throwing a sky image.  This is the first test with an image I took somewhere in the Caribbean:



The projector is mounted up high and angled down so that the horizon of the image is behind the building.  The land part in the original image is masked out and is now is just a solid grey color.

More experimentation is necessary of course.

*so effin' sue me ;D

[Sokramiketes]

I forget now, did the NSR article have before/after comparisons of blue flashlight vs no flashlight?

Once you figure out how to focus the projector you might be onto something...   

[tom mann]

I forget now, did the NSR article have before/after comparisons of blue flashlight vs no flashlight?

Once you figure out how to focus the projector you might be onto something...   

No comparisons in the NSR article, it was just a flat white piece of posterboard behind the models.

Projector was focused, aperture on camera did not allow for proper dof.

[Sokramiketes]

I forget now, did the NSR article have before/after comparisons of blue flashlight vs no flashlight?

Once you figure out how to focus the projector you might be onto something...   

No comparisons in the NSR article, it was just a flat white piece of posterboard behind the models.

Projector was focused, aperture on camera did not allow for proper dof.

Any chance you have a comparison photo?  I'm curious as to how it makes grab irons look smaller... is it above the model as well as behind it, thus allowing for a reflection of the sky onto protruding parts of the model?

What the projector should give you is an illuminated sky, which should look cool.  No matter how you light a flat, painted backdrop, it's not going to have that 'glow'.  Should be neat when you iron out the details.

[wm3798]

Cutting edge stuff, Tom...  It'll be interesting to see how it jives with full layout lighting.  I suspect that it will end up washing out a lot of the projected sky detail, but with proper aiming... maybe not.

I wonder if there's a lesson to be learned from my sloped ceiling?  Would it make more sense to reverse the image and project it up from behind the benchwork onto a 45 deg. sky?



When it's lit right, you really don't get the feeling that it's a "backdrop" because it actually slopes out over the layout.  The reflection of the light also bounces off the 45 down onto the layout, giving you some of those highlights that you're looking for.

Now, I'm not telling you to move the layout up to the attic... but it's something to think about!

Lee

[tom mann]

Any chance you have a comparison photo?  I'm curious as to how it makes grab irons look smaller... is it above the model as well as behind it, thus allowing for a reflection of the sky onto protruding parts of the model?

What the projector should give you is an illuminated sky, which should look cool.  No matter how you light a flat, painted backdrop, it's not going to have that 'glow'.  Should be neat when you iron out the details.

Essentially, what you are doing is bouncing light off of the backdrop forward, partially lighting the scene from where the source of the light is supposed to be. (if it was the real world).  This "glow" wraps around detail parts, making them look thinner.  In my article, look at the handrails of the ATSF unit - they look 1/2 the thickness.

This isn't meant for full layout lighting - I can't afford the projectors for that and Lee is right, multiple projectors in the same room would be too much light.

When I was a kid, the Jan 1988 issue of MR was eye opening.  It was the one with the darkened street and the recreation of the Nighthawks painting.  Modeling the atmosphere is something that I always wanted to do.  The photography article touched on it; the layout will allow me to explore the ideas further.

[tom mann]

Same sky, but a light orange foreground to look like a sunset-y color.

[Ed Kapuscinski]

Wow. Now lets see that with some equipment.

[DKS]

Wow. Now lets see that with some equipment.

That's what she said...

[tom mann]

Wow. Now lets see that with some equipment.

You mean a $35 billboard isn't enough? ;D

[Sokramiketes]

How many real billboards have you taken a photo of that resulted in blurry clouds?   

[tom mann]

How many real billboards have you taken a photo of that resulted in blurry clouds?   

crap, you guys are gonna make me break out helicon, aren't you?!

[Philip H]

Not me - since I prefer to spend my $$ on things other then computer programs . . . .

[Sokramiketes]

How many real billboards have you taken a photo of that resulted in blurry clouds?   

crap, you guys are gonna make me break out helicon, aren't you?!

Well, you said the background was a vacation photo, why don't you just photoshop it into the background?

[tom mann]

How many real billboards have you taken a photo of that resulted in blurry clouds?   

crap, you guys are gonna make me break out helicon, aren't you?!

Well, you said the background was a vacation photo, why don't you just photoshop it into the background?

Well, the whole point of this is to not use photoshop.  I want to have the projector be a source of light (modeling the sun), and the reflected background light be the sky.