Photo overlays

[dreamrod]

I use this technique a lot and can compare the model to a reference photo this way. The attached is an example of the first test shot of a Mustang II comparing the kit hatchback to a coupe. I proceeded to build the coupe based on this photo among many others.

I have a couple screen shots of how to make overlays using GIMP software. GIMP is free software available at www.gimp.org it's real good software. Basically you open the background photo (reference photo of your own or from the for sale ads on the net etc) then try and duplicate the shot while taking a photo of your model. I watch the roof pillars mostly for alignment. I usually can do a good match after the 10th or 12th try. YOU HAVE TO USE A TRIPOD. If you don't you will never be able to narrow down the camera position. If the foreground is too big you're too close. Back off the camera. If the car isn't the right angle I just rotate the car. Too much roof and hood then lower the camera. Each time I have to scale the model too the reference photo and then make the overlay. I usually just measure from a distance the have in common like fender tip to fender tip. I could go on and on. I will address any questions right here.

bob sifferd

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[dreamrod]

This is an overlay of two web photo to match each other. The point of the photo was to compare the roof of the Mustang to the roof of the Cougar to see if the match completely. Turns out they do.

First I found the smaller of the two photos by measuring the distance between the wheels centers. I don't like to enlarger photos. So I use the smaller one as a base. Only on TV does enlarging anything help out detail. I found the Cougar was the smaller. The Cougar has a 111" wheelbase and measures 288 pixels between the wheel centers. So if 111/288 you get 0.3454 inches per pixel. The Mustang has a 108" wheelbase which comes out to 280 pixels. I scaled the Mustang down to that distance. Then overlaid the Mustang onto the Cougar.

Does this type stuff interest anyone?

bob sifferd

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[dreamrod]

I meant to say come to 0.3854 if anyone is checking my math. You take .3854 x 108 and that's comes to 280 pixels for the Mustang. Phew !

bob

[virgil]

This is some great info!! I have been throwing around the idea of doing overlay pics to make it look like i am setting in, or driving the model...lol. I will be using this formula when i get the GIMP downloaded into my puter. Thank you!!!

Virgil

[dreamrod]

I did this photo using an overlay. It's the only car I have still in one piece. The first photo was taken of the car setting on some fake asphalt focused on the model. The second photo was taken with the asphalt and car removed and the background in focus. There is little editing to do as you only have to erase the blurry background from the car photo. Using a graphics program (GIMP, Photoshop etc) use the background as the bottom layer and the car as the second layer. Erase the blurry background from the car layer and only use the shadow from the fake asphalt. The asphalt was made from 1/4" foam core sprayed primer black, then over sprayed with primer red and finally with primer grey.

I use two tripod to do this. One for the camera and the second for the car. I take the picture of the car first and set the car and tripod aside. Then take the background photo. All this is done to get the background in focus. It will look like a toy otherwise.

To get perspective correct you must measure the camera height. Measure from ground to lens, lets call it 62.5 inches for this explanation. You divide that by your model scale. I'll call the scale 25 (hehe) So 62.5" / 25 = 2.5" So the fake ground has to be 2.5" below the center of the lens.

I could have stood in the photo behind the car or along side the car. I would have needed a helper to direct me into position. And yes in front of the car with a little more editing. But why obscure the car??

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[dreamrod]

Here's those photos
1. Macro photo of the car
2. Background
3. Overlaid with blurry background of macro erased.

www.modelcarscience.com/goldnugget/Macro.jpg

www.modelcarscience.com/goldnugget/Background.jpg

www.modelcarscience.com/goldnugget/Combined.jpg

[dreamrod]

A little higher resolution. Heck, I don't where the original stuff is.

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