Rokinon 8mm Cine Lens for Canon

[Terry VerHaar]

Need advice, folks: I just received my Rokinon 8mm Cine lens from B&H. It functions very nicely; focus ring and de-clicked aperture. However, my first tests with a Siemens Star indicates it to be a little "soft." Being as I have never worked with a lens this short before, I am not sure exactly what I can expect. It's true that, at this wide, it seems like there is very little difference between focus at 1 foot and at infinity, but, even with various focus assists, the end product is not as sharp as my other Rokinons (35 & 85).

Question to those of you who have more experience with wide lenses; can one/should one expect similar results as I get with the longer lenses? Or, is it pretty usual for lens this wide to be a bit less sharp?

Thanks in advance for opinions and advice.

I'll try to post some frames at some point for those who are interested.

 

[Terry VerHaar]

I have encountered an interesting phenomena with my 8mm: I have shot some footage of test charts at both 4K and 2K at some different apertures. In all cases, when I load the footage into RCX, I have a tall bar on the left of the histogram indicating a significant amount of pixels in noise. Yet, when I mouse around the frame, I can never identify the area that is this dark. It leads me to conclude that the lens is is vignetting the sensor on the edges (I saw that to be obvious when I switched to 5K) and producing "black" pixels outside the area of view, but which are showing up on the histogram. This does surprise me, though, as I didn't think the non-visible portion of the sensor would register in the histogram. Any thoughts??

Thanks.

 

[Terry VerHaar]

***crickets*** :smiley:

 

[Jason Ano]

I was curious to see if the new 8mm cine fisheye would be better than my 7.5mm for my GH2. That lens was indeed very soft and because of that, it was very difficult to judge focus. My other fisheye, the Canon 15mm, was very sharp in comparison, but unfortunately I sold it.

 

[Thomas Koch]

so it doses not cover 5K oh well, what can you expect from a really inexpensive 8mm!

Eventually, I think I will add this to my Kit. Terry do you have the 24mm Rokinon? I love my 35mm but haven't yet had a chance to test the 24mm. I'm for sure waiting for the cine version of it in any case.

 

[Richard Harrison]

Hey Terry I've been having the same focus issues/difficulty as you are. I even went so far as to call Rokinon to check my serial to make sure it was a legit lens and not some knock off.

At 5K I'm catching the lens hood on the left and right side of my frame but it's fine at 4K. Maybe post up a Redcine screen grab of what you're seeing?

 

[Tom C. Hall]

Samyangs are notorious for having their focus barrels uncalibrated. There is a method for pulling back the rubber grip and resetting infinite, I can't remember it now though.

 

[ray masi]

Nokia Windows Phone 8 phones

Nokia Windows Phone 8 phones

Samyangs are notorious for having their focus barrels uncalibrated. There is a method for pulling back the rubber grip and resetting infinite, I can't remember it now though.

Intended to do a last-ditch Nokia Windows Phone 8 phones, did not expect to be rivals Samsung Electronics grab the initiative: the latter is the first of its week released the world's first Windows Phone 8 operating system-based smart the phone ATIV S.
Lost priority, Nokia to rely on product performance, price advantage and marketing tool competitors a showdown. Of Nokia's new models in the key game of this round, whether across the threshold set by Samsung ray ban Intended to do a last-ditch Nokia Windows Phone 8 phones, did not expect to be rivals Samsung Electronics grab the initiative: the latter is the first of its week released the world's first Windows Phone 8 operating system-based smart the phone ATIV S.
Lost priority, Nokia to rely on product performance, price advantage and marketing tool competitors a showdown. Of Nokia's new models in the key game of this round, whether across the threshold set by Samsung:yikes:

 

[Dave Blackham]

Check you back focus and then re test.