Match Photo: which is the best camera / lens?

I think the thing to look for is lenses that don’t have much pin cushion or barrel distortion. Those types of distortion make straight lines appear curved which, of course, SketchUp can’t do. The shorter the focal length the more likely you’ll see those distortions (Think of a fish eye lines, for example.) Longer focal lengths would be better.

The other important thing to consider is the location of the camera. ideally you would end up with a photograph in which the horizontal lines run to vanishing points that would be within the frame of the image. as the vanishing points move out to the right or left they get closer to parallel which can reduce the precision of the set up. Of course when you have horozontal lines running parallel, the vanishing point becomes ambiguous and you can’t establish where it in with the Match Photo setup.

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Thank you Dave

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It’s also best to work with photographs that have NOT been cropped.

I’ve seen that said before, but why is that?
Also some programs, PS comes to mind, can fix lens distortion.

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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