Match Photo: which is the best camera / lens?

Avoiding cropping and avoiding perspective ‘correction’ or lens distortion fixing changes where the vanishing points are. they need to be in the right place.

Cropping shouldn’t affect vanishing points.

But it moves where the center of the image is.

I must be stupid, because I can’t see why that would matter.

I don’t think you are stupid but it does matter. Don’t agonize over it.

I don’t know why but I trust the documentation that says so. https://help.sketchup.com/en/sketchup/matching-photo-model-or-model-photo#choose-photo

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To go back to my original question, Why?

I’m calling bs on this. A crop is simply a smaller piece of the original image. It doesn’t change a thing.

It depends on how it’s cropped. If you can get a cropped image to work well, that’s great. I wouldn’t count on it, working for every cropped image.

That’s just a pivot. Tell me how you crop? Do you use perspective crop? No a sometimes a crop is just a crop, to paraphrase Freud.

Sometimes a crop doesn’t leave the original center of the image in the center of the final image.

I’m sorry, please tell me what that has to do with it. The original center that is.
Really, I’m all about learning.

Crop to your hearts content… then spend frustrating hours never matching your model with the image :slight_smile:

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Why? That’s all I wanted to know.

Paging @RTCool, Could you add any insight to this?

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As Dave explained, like pin cushion effects and tilt perspective correction, cropping shifts the image centre and the photomatch software assumes the image undistorted to perform the mathmztics…

How would the software know where your image centre was if the image was arbitaritly cropped…

Ps… 35 to 80mm lense range is probably the best

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Thank you. But that is not an explanation as to why you can’t use cropping. I also have all of the lenses you have suggested.

The software cannot predict where you have cropped the image and the raw image centre is an essential factor in perspective calculations… try matching a one point perspective with the image cropped
https://www.math.utah.edu/~treiberg/Perspect/Perspect.htm

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I know that Match Photo works bestwith uncropped photos. I accept that, but I’m still with c.j.ryan in asking why?
Implicit in Dave R’s explanation is the notion that the edge closest to the camera must be in the center of the image, so that the vanishing points are equidistant from that edge. But it’s easy to take a photo with the close edge off-center, so the vanishing points will not be equidistant from that edge. Conventional SketchUp wisdom says this photo should work in Match Photo as long as it’s not cropped. But I wonder why it won’t work in Match Photo even if it’s cropped.
So, to paraphrase c.j.–Why?

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Thank you David! You seem to be the only one that gets what I’m asking!

And how the heck does it even know it’s a cropped photo?