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Rokinon 35mm Unusable at T1.5

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#1
Ben Corwin

Posted 05 February 2013 - 02:43 AM

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Hi everyone,

 

I just bought a Rokinon 35mm Cine lens for my GH3 because of how sharp everyone says it is wide open. To my utter disappointment, I found this not to be true at all. It is completely soft and unusable wide open. I am using a Kipon adapter with built in aperture blades (not that I used them) listed here:

 

http://www.amazon.co...l/dp/B004XGFIZY

 

Do you think that it has something to do with the adapter? I didn't have an issue when I used this lens on my Canon 7D. Any suggestions?

 

-Ben



#2
Julian

Posted 05 February 2013 - 08:31 AM

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Can you post some footage? If you don't have a problem with your 7D the suspect is the adapter. Try a cheap dumb adapter.


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#3
jgharding

Posted 05 February 2013 - 11:02 AM

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Try an aperture-less one I'd say... This adpator is for lenses with auto apertures, like Tokina 11-16 for example. Perhaps the widest aperture in the adapter is tighter than 1.5 at 35mm and causing issues? Or perhaps something to do with how the light is bouncing around in there...


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#4
Ben Corwin

Posted 05 February 2013 - 02:10 PM

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Can you post some footage? If you don't have a problem with your 7D the suspect is the adapter. Try a cheap dumb adapter.

 

I will try to post some footage. Any suggestions on a cheap adapter?

 

Try an aperture-less one I'd say... This adpator is for lenses with auto apertures, like Tokina 11-16 for example. Perhaps the widest aperture in the adapter is tighter than 1.5 at 35mm and causing issues? Or perhaps something to do with how the light is bouncing around in there...

 

Exactly my thoughts. It really seems like the light it getting bounced around in some way. It almost has the same look as the Voigtlander 25mm F0.95 wide open, but to the extreme.



#5
Julian

Posted 05 February 2013 - 02:18 PM

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I will try to post some footage. Any suggestions on a cheap adapter?

 

Just search for EOS M43 and you'll find plenty adapters. Like this:

 

http://www.ebay.com/...=item4d067f409b


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#6
Ben Corwin

Posted 02 March 2013 - 11:29 PM

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So I got a new adapter, but the results are pretty much the same. Has anyone else been having this issue with the Rokinon 35mm Cine lens on a GH3?



#7
andy lee

Posted 03 March 2013 - 02:13 AM

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once you get past f1.4 things to start to get soft and dreamy looking - thats Physics coming into play

I personally very rarely use lens past f1.4 due to this problem and the dof starts to get so small and unusable.

 

a good 35mm lens that is usable is a Carl Zeiss 35mm Flektogon f2.4 superb lens

I also use a Sigma 30mm F1.4 now this lens IS sharp full open at f1.4 - highly recomended

http://www.ebay.co.u...=item2ec68dcb16


Andy Lee
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#8
Julian

Posted 03 March 2013 - 03:07 PM

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So I got a new adapter, but the results are pretty much the same. Has anyone else been having this issue with the Rokinon 35mm Cine lens on a GH3?

 

Post some footage of both the 7D and the GH3..



#9
GravitateMediaGroup

Posted 03 March 2013 - 05:24 PM

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the rokinon 35mm is my most used lens



#10
MOONGOAT

Posted 03 March 2013 - 05:28 PM

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Maybe you got a defective lens. I have the same lens and adapter and it's pretty sharp at 1.4 (on a GH2)

 

I did this in about 5 seconds. Not exactly scientific, but it gives you an idea. 2nd is the 35 at 1.4, obviously.

 

vus46i9.jpg

 

VKi4fFj.jpg



#11
Ben Corwin

Posted 03 March 2013 - 09:00 PM

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Hey Everyone,

 

Thanks for all the responses. Here is what I captured... 

 

 

All the settings are set to -5 in the Standard setting. I expected it to be soft, but not this soft. 



#12
Ben Corwin

Posted 03 March 2013 - 09:03 PM

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Also note that this is wide open at T1.5



#13
Ben Corwin

Posted 03 March 2013 - 09:35 PM

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Here is another video transitioning between T1.5 and T2.0 on the Standard setting, but with everything set to 0 instead of -5.

 



#14
Julian

Posted 04 March 2013 - 10:44 AM

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This is both on the GH3? The second video looks perfect. The detail at T1.5 is fine, don't you think? Yes, it gets a bit better / more contrasty at T2, but that is normal.

 

The first video doesn't look very sharp indeed. Fact is that if you dial down sharpness all the way on the GH3 you get a softer image, but still, it looks a bit too soft maybe. It could be that the focus is a little off. Since your second sample looks fine, I don't think there's anything wrong with the lens.

 

So you say on your Canon 7D it is sharper?



#15
Ben Corwin

Posted 04 March 2013 - 03:12 PM

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Yes, both are the GH3. The only difference is that the second video has zeroed out settings whereas the first one everything is set to -5. I might just have to end up leaving the sharpness setting at zero.

 

Yeah I still feel like it's sharper on the 7D, but not by much. It's not as sharp as when I use my L series 50mm wide open at f1.2 though,  maybe I'm just spoiled with that lens : )



#16
BillPryor

Posted 26 April 2013 - 02:21 PM

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I bought a set of the Rokinon "cine" lenses for my Sony FS100. I unpacked the 35mm T1.5 first and when I checked it out on a product shot I was very impressed. It was as sharp as any lens I have, had excellent contrast and color. But then I started opening it up and it fell apart.

 

At T1.5 it was way too soft, and the color shifted so the whites had a slight yellowish case. The contrast also changed. At a T2-2.8 it was not as soft but still softer than f4, and the color and contrast still looked funky. Basically it is an F4 lens. Another thing is that when I compared it against my old Nikkor 35mm, which was much sharper wide open and had better color and contrast), the Rokinon was most definitely not 35mm. I didn't do any serious measuring but an educated guess says it's really 40-42mm.

 

I returned the set (24, 35 and 85) back to B&H and went into debt for more Zeiss glass. 

 

Since then I have read more than one post and had email from another person saying that apparently there is some serious variance in manufacturing. Some people get good copies, some get bad. I obviously had a bad one. If this is true, I guess I could have returned the lens and tried another. However, one other person I know has the 35 and says his is soft when opened beyond F4 too. I didn't check out the 24 and 85, just sent them all back. 

 

It was as big disappointment because I had read so many positive things about these lenses from reputable sources. I did read one lone comment about the color and contrast but ignored it since literally hundreds of posts praised the lenses. I guess it's the luck of the draw. I don't want to come out and condemn these lenses because so many people are happy with them. I'm willing to believe that I got a bad one. 






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