I've been trying for the last few hours to get Imagemodeler 3.5.2 for os X to work with higher-res images. I managed once to get the images calibrated (it's much more precise and i had to increase the 'good' tolerance) but, once calibrated, the program was so intolerably slow that i had to give up. I tried a couple more times, and got erratic results  (images were randomly cycling in the windows; images were not associated with their correct names, etc) and had to delete the prefs to restore normal behavior. Is this slowness inevitable? Have any windows people done hi-res images and not been frustrated? Is there any hope that this will be remedied in 4.0?

i tried turning off progressive calibration and it makes a big speed difference - you have to calibrate manually, but at least you can choose when you want a coffee break  

What's a reasonable quality threshold for a 6 megapix image? 1 pixel is nearly impossible to get aligned perfectly - but if I set the threshold to 1.2 pixels then at least my four cameras are green. Am i deceiving myself about accuracy? thanks

Hello,
 
  There is no real equation that gives you what is good or what is not good ... It does not only depend on the resolution in pixels, but also on your material and especially your lens distortion.
 
I recently tested a good quality lens on a 8Mp EOS 20D and get residual errors of 0.3 pixels max on a 4 image project.
 
Whith that known, I would say that the default preferrence values (1 pixels for green and 3 pixels for yellow) are good settings for :
- 3/4Mp with "normal" lenses
- 6/8Mp with a professionnal lens (few distortion)
 
 
Speeding up tips:
- remove "antialiasing" in the preferrence settings
- Lower the OpenGL texture size used for the images (Image plane size in the preferrences)
 
Calibration speed up :
- Remove progressive calibration (you already did it)
 
How many images do you try to calibrate ?
 
Best regards,
 
Stef

HI Stef -
 
I usually calibrate 4 images. I had also lowered the texture size, and i will try turning off antialiasing. Another question: when you say 'lens distortion' do you mean the distortion inherent in any lens, regardless of the focal length, or the distortion that occurs with a wide-angle lens?

Hello,
 
  I meant distortion of any lenses (including wide-angle lenses).
Undistorting the images can move the pixels a lot (As it is radial distortion you will have the most deformation on the borders of the images.).
If the distortion model is not perfectly found, it can lead to bigger residual (but that doesn't mean that the camera position and focal is wrong)
So, It's the couple Resolution+distortion that should guide you on residual min/max settings.
 
A good thing to do is to get a good estimation of your lens distortion (at constant focal: low zoom of your camera for example) by doing a special project easy to calibrate with good constraints in it. I used a portable chess game, that i could fold to an angle, to get at least 2 different planes with easy markers.
Take shots at constant focal, and the distortion obtained on this project can by used as "known" settings in further projects.
This leads generally in more precise calibration.
 
Best,
 
Stef