last night tried my homemade focal reducer with the 350d +lx90. shots were unguided . resampled in astoimage and stacked and processed in registax. m42 is 4 x30sec exposures and 1x60 sec exposure, omega centauri is 7 x30 sec exposures. all were at iso 1600. I'd like to try some guided shots but dont have a guide scope. i have an lpi but my laptop hasn't got an rs232 port so that option for the moment is out.
some months ago i posted that i was using a homemade focal reducer with the lpi. Its an 18cm focal length achromatic lens from the telescope of an old spectrometer. Its 25mm in diameter and is inserted intothe visual back of my lx90 before the t-mount,. seems to work ok with minimal vignetting and slight chroma on stars when photos are zoomed into.seems to give about 0.6F. I haven't tried shorter focal length lenses as i haven't access to any. I believe many people make focal reducers out of old binocular objectives.anyway pictures seem ok and it didn't cost anything which is a bonus.
philip
