Arch-Interiors: decent but wide focal length camera lens

[digitarch]

Hi, I´d like to do an architectural interior of a small room. To get (almost) everything in view I would need a 20mm-focal length which gives me real stretchy look on the very left and right image border. The vrayphysicalcam and the render setup camera type dialog provides lots of lense alternatives and settings. Does anybody have some favored settings to get decent "non-strechy" wide angle shots?
Matthias

[tricky]

Can't really get away from using a wide lens in these situations. The spherical/cylindrical cameras cause other distortions than are more problematic than just using a very wide angle lens. One trick is to make sure there aren't any 'features' close to the edges of your frame that will exhibit these distortions (i.e. keep furniture etc in the middle of your shot). Another way is to pull back out of the room and use a clipping camera and/or remove a wall from your model - treat it like a film set (ie it doesn't need to be physically 'correct' - just remove panels and imagine you are a film maker)

[super gnu]

yep.. thats the way to do it! pull the camera back out of the room, and either clip the foreground or hide the wall.. then you can use any cam angle you want.

[urbanite]

I also use camera clipping in small spaces and use 35, 50 mm camera to get less distorted furniture’s but the main reason is to give yourself freedom in composition aspect.

[Dariusz Makowski (Dadal)]

U can always rotate camera around and then stitch renders together... - bit longer and harder but I can avoid low mm distortions...

[digitarch]

ha, stitching several images, nice idea, would reduce the distortions at the very lift and right. We also use the camera-pullback and clipping, keep the walls not visible to camera but creating gi.
Tricky - i also had the impression, the other vray lenses helped in some places but created other problems....
Thanks to all,
Matthias

[Dariusz Makowski (Dadal)]

Heya

If I remember correctly canon 18/16mm lens for around £3k was able to fix the distortion to the curtain degree... I wonder if Vray could be tweaked like that a bit more... or use a blend of perspective and orthographic mode...

[plastic_]

The Canon 17mm tilt shift lens does the same as the Vray camera offset, or using the perspective correction modifier/Vray camera shift correction.
You can straighten the vertical lines that way, but there is still perspective distortion.
Rotating and stitching would be the same thing as de-fishing a spherical projection, you trade distortion at the edge with curved straight lines.

Clipping the front wall is the way to go, that's how they do it with photos too. Just look at some Ikea catalogue.

[chriserskine]

another option would be to render out the 360 image then convert that to a panini projection.
http://www.panoramas.dk/panorama/panini/vedutismo.html

this is pretty easy to do in pt gui. though there should be other ways to do it for free. (maybe hugin or panotools)

[Olli96]

In those cases i apply a fdd modifier to the objects close to the camera and move the points around till the object are looking normal agian.