TiffsAndAstro

both photos are from same lens and camera. i previously had a pentax k-x and got better results stacking 100 x 5 sec subs untracked. this is what i mean from the untracked stack its not great but can see flame nebula and possibly start of horse head.

i think the result is awful, its the result of 103x30sec subs. i got a far better image with a pentax k-x with the same lens on a tripod stacking 100 x 5sec untracked subs. if its clear for a while this evening ill try playing more with fstop and iso values in test shots before setting it to run. ty again.

hey ty for the fast reply. tbh im very new to this (if you can't tell) and im reluctant to stop it down because it will reduce the signal and the light pollution. iso800 seems the best signal/noise ratio. in my focus tests i did drop iso to 100 and it looked 'normal' as i was expecting. i also dropped exposure time to 5 and 10 sec for checking focus and seemed ok then too. But if i can only take 5 sec exposures i might as well bin my tracker. in your experience, is this likely to be caused by light thin high cloud i can't see with my own eyes?

hi there, hoping for some thoughts on the 'final image' ill post below (not a lot more than a quick stretch) and an example of my exposures. Im thinking the answer is high thin cloud that i can't see with my eyes is reflecting light pollution? if this is the case - if i see a test exposure in future like my example below - just try another night? 30sec subs iso800 canon 600d/t3i (unmodified) and an old pentax m 50mm f1.7 shot wide open because im a noob. anyway result is here: and an example sub here: thanks in advance for any insights anyone can provide.

i don't disagree, what i meant was, i want to spend at least a couple of nights of clear skies just getting some experience first. just the idea of a two star polar alignment makes me want one, as i can't see to do this with a gti and synscan app. all the guiding and camera controls on top seem even better. but i want a few hours on the basics before i do that

ty for this, need more experience before considering an asi air

did this happen right after "un hibernating" your mount? mine's done it twice since i got it (two weeks ago). I think, to fix it, after un hibernating i do a one star alignment on something fairly near home. then it seems fine. i haven't updated my firmware since i got it two weeks ago and maybe that update might fix this possible problem?

i think i had a similar issue, it seemed to get a bit lost. i think i corrected it, but clouds came and i haven't seen the sky for like a week.

so an hour or two later it suddenly cleared up, so i set everything back up but this time i couldn't see any stars through the finder scope. checked the caps, RA axis was turned played with the focuser but couldn't for the life of me see any stars let alone polaris. so after some frustration i gave up and used a two star alignment with stars i've never tried to look at before and guessed. took 30 x 30 sec subs of whirlpool galaxy - couldn't see it in the stacked result, but i was impressed with how there was no trailing. so then i told it to go to ngc 237 (i think) and did 30 x 90 sec subs and again, couldn't see my target in the stacked results, but i was amazed how there was no star trailing. clearout says noi clear skies tonight, but bbc weather says 3 hours from 6pm so will have fun again with polar aligning then. all i can think of, as it was so easy to see and align on my first go at polar alignment is that there was a low of dew on the front of the polar scope but wasn't earlier on? there's a lot of top left to bottom right streaky noise on the final image - maybe high cloud? still, early days is is 30 x 90 subs. its crap, but stars look pretty trail free. not sure how tbh.

dunno why its b&w lol - i think i converted it from .cr (canon)? but when i stack them its worked out ok - dss and siril must handle. this was a 30 second exposure at 50mm on a crop sensor when i was trying to work out if it was even tracking stars look pretty round to me

ok i just had 45 mins clear ish skies. i boosted my tripod legs to max, bit wobbly but ok...and polar aligned pretty nicely (if i do say so myself) in about 2 mins. i was attempting a brigh star alignment when the clouds came. after watching another video, i'll try a 3 star alignment on ones i know best maybe orion. tbh im just happy polar alignment didn't seem as bad as i feared. at least as far as i got.

hey ty so much for that. yeah, its expensive and im trying to be cheap as i spent my cash on a gti rather than just a tracker ill have to see how i got on, only got the gti couple days ago and of course its been cloudy ever since. maybe polar alligning won't be too bad....

hope its ok to ask here. after tearing down my gti at the end of the night - should i loosen or tighten the clutches? also, unless im missing something, i need to limbo to use the polar scope to align?