Hi,
I've been thinking of testing a finder guider with a 1.25inch barlow? anyone done this?
theoretically, it changes the pixel scale from 5.6arcsec/pix to 2.8arcsec/pixel. (50mm guidescope with a qhy5)
the main scope pixel scale is 1.6arcsec/pix with a qhy8 and a 10inch F4.
I know the whole point of this thread was whether longer focal length guidescopes help or not. also that phd can do 1/5 sub pixel guiding.
but in testing, I've found that although my phd graph looked quite good, stars were elongated in RA.
it could be my mount not coping with the payload but I was expecting to see that in the phd graph, can't understand why it won't show
https://www.dropbox.com/s/jagwn011z280pgx/phd-2.png
hence the thought of using a barlow. will that work?
Thanks
edit: also came across this forum section that's dedicated to unguided imaging. there are some 10min unguided shots in there with round stars.
http://www.progressiveastroimaging.c...faf0837a6cea63