Hello,
when I open a TIFF file in Inkscape it has been resized from it's original 11x17 inches to 73.3x113.3 inches. If I open the file in other programmes it appears at it's original size. Has anyone got any idea why it would do this or how to stop it?

>Thanks

I don't understand why that happens, but here's how I fix it.

With the imported TIFF selected, look at the status bar (middle area at the bottom of the window). It tells you the size of the image. Then I enter those numbers into the W and H fields in the Selection tool control bar.

When you import an image into Inkscape, the dialog asks you if you would like to use the default import dpi or the dpi taken from the image.
Try if taking it from the image solves the problem for you.

I always use "From file" and the images are always smaller than they should be. Hhmm....when I switch to "Default Import Resolution" it makes it them the correct size!

Isn't that backwards? If it's not backwards, then perhaps something should change with the wording?

For me, it works as expected. Created an image in Gimp, with resolution of 100dpi, and size of 9.91 mm, and when I import into Inkscape, it's 9.91 mm wide (and the image itself is still 39 px wide, of course, which correspond to 35 px in Inkscape 0.91's 90dpi resolution).

Probably the files you use have a different dpi value than the one you expect. It's different from the one Inkscape uses, so a pixel point in the image does not correspond to a pixel in the Inkscape coordinate system (which it will if you use the other option). You can check with a raster editor, or using imagemagick's identify (https://www.imagemagick.org/script/identify.php) command.