[jsklee]

SIGMA 的是8mm
VIVITAR 的是7mm
why？

[h0001244]

I guess 8mm can fully utilize 36x24mm
once smaller than 8mm, say Vivitar 7mm, it will also have circular image as well.

[jsklee]

sigma 的8mm是circular fisheye, 不是diagonal fisheye

[h0001244]

of cos I know it's circular...... do you really understand what I mean by circular in 7mm?

[jsklee]

sorry, no

[jsklee]

The image produced by sigma 8mm is circular.

[jsklee]

http://www.syopt.co.kr/common/pdf/f=8mm.pdf

the above link suggests that the Samyang is designed for APS-C camera, but not FF camera?

[jsklee]

http://www.dyxum.com/dforum/test-driving-the-vivitar-7mm-fisheye_topic49327_page2.html

"Its just a rebranded OEM version made by Samyang in Korea (which is labelled as 8mm). Here's a review of the original:

http://www.lenstip.com/index.php?test=obiektywu&test_ob=160

All of Vivitar's current lens lineup are just OEM rebrands of Samyang lenses. Their 500 & 800 mirror, 85/1.4 and 7mm fish are all Samyang."

What is your opinion?

[jsklee]

http://kurtmunger.com/vivitar_7mm_f_3_5_fish_eye_reviewid166.html

This website suggests that both lens are the same and both of them are designed for APS-C cameras only.............that means it can't be connected to FF cameras? or like Sigma 8mm, these two lens can produce a circular image with outer areas being black?