common mistakes¶

Here is a list of hints to find out why your reconstruction don’t fit with your expectations.

Transmission¶

the freeart transmission algorithm is considering that sinograms are the result of \(log(\frac{I_t}{I_0})\). But if this is not it for some reason and the sinogram is in fact the result of \(\frac{I_t}{I_0}\) then you sould uncheck the ‘Compute -log’ in the normalization tab.

detector position is taking into account so please make sur the one given is correct
solid angle is taking into account. You can force it to be force to one for all point sample (see reconstruction parameters tab)
absorption and self attenuation are taking into account. The value of those are saved for each pixel in \(g.cm^{-2}\) (see). And the calculation of the absorptions are also based on the voxel size !!! So a wrong value of it can bring either no effect on the reconstruction or a too important and bring reconstruction like no phantom or ‘fiew voxel reconstruction’.
damping factor: this is an important parameter for an art reconstruction. By default a plausible value is setted. But incoherent value can bring to strange behavior to. If too low then you might bring a ‘blur’ effect and the solution will never converge. If to hight you will have some really incoherent phantom.