The last time I put it under HPLC-SAXS it eluted in the void volume and it was too big for the camera length
I think you mean a distance between detector and a sample. At some beamlines this can be adjusted.
I also wanted to change the camera lenght in such a away that it would fit the data for the protein.
do you not see the Guinier region? in other words, why exactly do you want to change detector-sample distance?
I recall some work by Vestergaard and co-workers who studied fibrillation and saw fibrils up to 900A in Dmax, which was
actually at that time the max theoretical possible distance one could see:). Perhaps, this can be helpful and
perhaps you can consider a different beamline:https://www.embl-hamburg.de/biosaxs/cou ... rgaard.pdf