D500+samyang 135mm Optics advise

Started 1 month ago | Discussions thread
Flat view
Okky New Member • Posts: 21
D500+samyang 135mm Optics advise

Dear friends,

I need advise on my new purchase. I bought a new Samyang 135mm f.2 lens for my D500. I bought this lens to make a start with astrophotography as a beginner.

I have questions about the optics of my new lens. The situation is that I have 2 copies cause I had my doubts with the first copy.

I did use the following chart for my test http://www.graphics.cornell.edu/~westin/misc/res-chart.html

Focus in the middle:

Sharpness in center seems the same for copy 1 and 2. If I look to the corners then the corners of both copies are less then in the middle. 2 corners of copy 1 are noticeably sharper then copy 2. Other corners are more even with an slightly edge for copy 1.

I also notice a very light colour (seems purple) in the middle and corners of copy 2.

Focus on right down corner:

This time I focused on the right down corner. The corner of copy 1 is sharper. BUT I am very surprised to see that the center of copy 1 is blurry and copy 2 is sharp?!

The remaining corners is slightly sharper on copy 2 (not logical). Copy 1 seems to have a light green colour on the corners. Copy 2 seems to have light purple colour.

Which copy I should keep or is both not normal? I did read on the internet that is very normal that when focus on center the corners are less sharp.

Thank you

 Okky's gear list:Okky's gear list
Nikon D500 Nikon AF-S DX Nikkor 35mm F1.8G Tokina AT-X Pro 100mm f/2.8 Macro Nikon 200-500mm F5.6E ED VR Samyang 135mm F2.0
Nikon D500
If you believe there are incorrect tags, please send us this post using our feedback form.
Flat view
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow