Crescent Shaped Stars

[Leti Theobald]

Just wondering if this has happened to any of you and what would have caused so I don’t do it again.

Tonight whilst trying to image the M35 all my stars look like the below. I only did a 90 second exposure, which I usually do without an issue. Could this just be some bad polar alignment on my part? I’m not using any guiding just a HQE5 mount and a WO Zenistar 73 with a canon EOS. 
 

Any ideas? 

[newbie alert]

Seen them like that using a OAG and guidecam, just needed a slight spacing adjustment...

With my William optics 80 I had to use a adapter to produce the correct spacing...

Are you using a reducer?

[Leti Theobald]

1 hour ago, newbie alert said:

Seen them like that using a OAG and guidecam, just needed a slight spacing adjustment...

With my William optics 80 I had to use a adapter to produce the correct spacing...

Are you using a reducer?

I’m using the William Optics Adjustable Flattener 73A for ZS73 and I also have a Optolong filter 

[michael8554]

Hi Leti

To my eyes the stars appear to be elongated everywhere in the whole image.

Since the exposure was 90 seconds I'd say it's RA tracking. or Polar Alignment error.

Is that elongation in RA or Dec or both ?

Try a short exposure and stretch it, to see if it's the mount or the optics.

Michael

[Leti Theobald]

1 hour ago, michael8554 said:

Hi Leti

To my eyes the stars appear to be elongated everywhere in the whole image.

Since the exposure was 90 seconds I'd say it's RA tracking. or Polar Alignment error.

Is that elongation in RA or Dec or both ?

Try a short exposure and stretch it, to see if it's the mount or the optics.

Michael

It looks to be in both Ra and Dec. I tried a shorter 60 seconds exposure. It was still there but less severe.  I think I will just realign tonight and start again, hopefully it was just me doing some dodgy polar alignment last night!