milkyway

suma126 (Shane) · #1 07-10-2008, 03:39 PM

HI can any one tell me how to get more rounded stars .because the big bright stars are a odd shape thanks

cookie8 (Vincent) · #2 07-10-2008, 03:59 PM

HI Shane
That's interesting.I've not seen this field-rotation-like effect before. They doesn't look like coma either.??
I presume it was a piggyback DSLR shot on top of a motorised polar-aligned equatorial mounted refractor ( I can see the dew shield). How long did you exposed it for?

cookie8 (Vincent) · #3 07-10-2008, 04:05 PM

That's field rotation of a fork mount SCT if that's what you've piggybacked on. Solution are either a wedge or a field derotator.

iceman (Mike) · #4 07-10-2008, 04:23 PM

Hi Shane,

to IceInSpace!

Vincent is right - if you're piggybacking on an alt/az fork mount, you'll get field rotation like that. You'll need to get an EQ mount, or a wedge for your fork.

suma126 (Shane) · #5 07-10-2008, 04:45 PM

I did have a meade lx90 on a polar mount .camera is a olympus e300 with a small fish eye lens attached .exp 1x7 min was not auto guided

rat156 · #6 07-10-2008, 05:22 PM

Hi Shane,

The problem is polar alignment, if it's off slightly you'll still get field rotation. Try for shorter subs and stack them.

Cheers
Stuart

suma126 (Shane) · #7 07-10-2008, 05:39 PM

THANKS for all you help but have sold my meade lx90 and just waiting for my toy losmandy gm8 hope fully it will track better.

AlexN · #8 07-10-2008, 07:34 PM

Shane - No doubt about it, a GM8 will track better than an LX90

Matty P (Matt) · #9 07-10-2008, 10:05 PM

Interesting effect Shane.

What type of camera did you use?