Canon 200D - with Samyang 14mm - strange star shapes

[brenski]

I’d had a few issues with my Samyang 14mm F/2.8 lens. the “trident-shaped” glare to images (on my Canon 200d). (see image 1) prompted me to contact Samyang.
So, off it went to Samyang’s (Intro 2020) Service HQ UK. After inspection they concluded that there were problems with the lens – but as it was out of warranty, they could replace it with a shiny bright MkII version (complete with focus lock) for a reduced price.

However, after play-testing, images appear to have a curious (different) mis-shape to them (see image 2). I was assured by Intro 2020 that the MkII is a great lens, and I have contacted them, but while i await their reply, is there anything else i can try to be sure. could this be the camera itself? or have i just been unlucky with two lenses?

seems that even stopped down to F/4  (see image 3) there's still something going on.

am wondering if any of the following Canon 200d settings are likely to help, and if so, what should i opt for?

♦ Mirror Lock
♦ Lens Electronic MF
♦ Lens aberration correction ► Peripheral illum / Chromatic aberr / Distortion / Diffraction
♦ White Balance
♦ Colorspace
♦ Auto Lighting Optimizer
♦ Long Exp Noise Reduction
♦ High Speed ISO NR

or anything else "on camera" that may help?

Note: crops (below)) are not taken from edge of image.

 

 

[alacant]

20 minutes ago, brenski said:

crops (below)) are not taken from edge of image.

 

So we've no idea where the star is located within the frame nor the size of the crops...

Hence difficult to advise, but my guess is that I think for 14mm over aps-c, the only way you're gonna get corner to corner will be f8 or smaller. Or simply correct in software.

Cheers

Edited April 25, 2021 by alacant

[brenski]

the images are centre-ish of the image.

this evening i've tested the Canon 18-55mm kit lens - it produces nice round solid stars @ F/3.5.

so i'm veering toward this definitely being another Samyang issue

[michael8554]

If stars at the centre of the image are round, and the star distortions are more towards the edge and all pointing towards/away from the centre, then it's coma.

Others who have this lens can advise if coma is normal or not.

Michael

 

 

[brenski]

the stars in the crop are from the centre of the image

 

the distorted effect is consistent across the entire image