Topic: cropping versus zooming

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atrchi (Over 1 year ago)
I read somewhere that you should not crop photos, it confuses the synther.

But what about zooming (with a zoom lens)? This is physically equivalent to cropping isn't? 

I accidentally zoomed some of my photos and the results still seemed ok (but not perfect, in some places)... Could the glitches and imperfections be a result of the zooming?

atrchi (Over 1 year ago)
Just to be clear, I'm talking about zooming some photos to a different focal length than other photos in the same synth.
Nathanael (Over 1 year ago)
Hi again, ATR, 

Zooming is definitely welcomed and Photosynth will be able to handle it just fine, much the same as walking closer to something. 

There is a slight advantage that keeping your camera at the same zoom setting and actually moving the camera closer has over staying at the same place + zooming (just because moving will make things line up differently, and therefore help Photosynth calculate depth a little better) but either way, the images should match each other.

This is mentioned briefly in the video at this link between 13:42 and 17:48.
Nathanael (Over 1 year ago)
The only real consideration when zooming is to make sure you don't zoom so much that the object increases its size in the photo frame by more than a factor of two from the next nearest shot. That is to say, if you have a zoom shot where an object on a shelf fills up the photo frame, be sure that you have another shot (either zoomed less or actually walked over closer) where that object takes up half the photo frame. That way, you can count on them matching each other (as long as the two distances are within 25 degrees of rotation around the object of each other).
Nathanael (Over 1 year ago)
Getting back to cropping, though, several of us in the community had exactly your question just after Photosynth was released. Here's what David Gedye ( ) told us.

In that same discussion, Ken, from the Photosynth team ( ) suggests that there is a possible use for cropping: namely that if you don't have the option of going back and reshooting an environment to get bridging shots which will link some photos in your synth that are not matching each other (but which clearly picture the same subject but from slightly too large a distance difference), you can make a copy of the wider angle shot, crop it so that the scale of the subject is intermediate to the telephoto and the wide angle shot and the crop should be able to link to both the original wide angle shot and the close up.
atrchi (Over 1 year ago)
Nice to know it uses the EXIF data. Cool!