View Full Version : ptgui and 2 shot nadir blending

07-25-2009, 10:52 AM

Anyone here using ptgui and can help me with my nadir blending..

i'm taking 2 nadir shots. 1 every 180 degrees
and when stitching with ptgui, it blends like it's only 1 nadir shot.
and i'm getting to much of the mounting bracket in the picture, and have to do to much photoshopping to get a perfect nadir..

i know it can be done. have seen nadir shots where you only see the tripod and a level bubble on each side..

if u dont understand what i mean look at this link..


i want the right side of the nn3 to be like the left side..

07-25-2009, 11:00 AM
Try masking out the tripod and NN3 entirely. You'll get a small black spot the size of the masked area.

John Houghton
07-25-2009, 11:37 AM
Yes, apply an alpha channel mask to each nadir image. If you aren't familiar with these, see http://www.johnhpanos.com/alphatut.htm.


07-30-2009, 05:57 AM
tnx for telling me to use alpha mask in photoshop :biggrin: was easy..

but now i got another little problem. not that big. but by the look of it it's looks like my mount settings is abit off..

the pictures arent a perfect mirror of each other. one is slightly offset towards one way that the other..
so when alpha masking and erasing from one picture. the NN3 gets abit higher on one side than the other..

it's not a big deal i still get the nadir shot to be perfect. but i just want to make it so i can do as little photoshop work as possible..

check the link to see what i mean..


camera is nikon d90 with nikkor 10.5mm fisheye
and settings is A: 58 B:86

and a link to the pano after processing it..


John Houghton
07-30-2009, 07:37 AM
What's happening is that the entrance pupil is moving when you rotate the camera between the two nadiirs. It should remain in the same position. You can check the panohead setup easily by doing the visual test illustrated at the end of section 3 of this tutorial: http://www.johnhpanos.com/epcalib.htm.