Your TTL idea would be unnecessary on a refractor, so you must be thinking of using a Newtonian design. In that case I don’t think it would work because the image is reversed. I think the program in the O-GPS would be designed to shift the sensor in only one direction (the one that work with ordinary camera lenses of a refractor-sort of design). Not sure though.
Also, keep in mind that the maximum exposure time possible with the O-GPS/AstroTrack gets shorter and shorter as the focal length gets longer. A shorter exposure time with a longer focal ratio is the opposite of what you want for catching photons in astrophotography. Respectfully, Darren Addy On Fri, Jun 8, 2018 at 3:15 PM luiz felipe <[email protected]> wrote: > pretty much divided between the Vixen Polarie and the O-GPS 1. just > because if I get to use a small newtonian reflex, the camera will be > pointed at 90 degrees from the subject, and I don't think de astro > function of the O-GPS 1 can handle that. > > the Vixen Polarie is small, and seems able to handle both the APS > Pentaxes and a small reflex telescope - and as long as it's properly > aligned, the pics should be ok. > > as far as money goes, it's one OR the other, and that's why I'm looking > for advice. building a barn door star tracker is the third option, but > I'm not really with time to make a proper unit. toughts? ideas? > > thanks!!! > > -- > luiz felipe > luiz.felipe at luizfelipe.fot.br > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. > -- “The Earth is Art, The Photographer is only a Witness ” ― Yann Arthus-Bertrand, Earth from Above -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.

