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05-29-2013, 08:26 AM   #1
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8mm Rokinon settings on K-01?

The A ring is at F8, but all the lightroom data shows f/3.5

I'm using Av mode. Do I also need to press the green button?

I'm wondering because I read this lens is super sharp, but even at 1/800 sec, they aren't that impressive, so I figured I was doing something wrong!!
I have tried all sorts of focus settings-- 0.3m, turn a little more, a little more, all the way to infinity.

Thanks!

This is at 1/800 sec, F8, 100% crop from near center

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Last edited by PBandJ; 05-29-2013 at 08:31 AM. Reason: added photo
05-29-2013, 08:52 AM   #2
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I suggest you look into tutorials on how to use manual and A-lenses.
I think that lens has an A setting on the aperture ring. Just push the button on the ring and set it to A, that ought to be the easiest thing. Now you control the aperture on the camera and not on the lens. And you can use Av mode.
If you don't have it set to A, then you need to enable "aperture ring use" in camera menu, and then use M mode. In Av mode, the camera will always use wide open aperture. In M mode it will use the aperture you selected with aperture ring, but it won't meter continuously, you need to use green button.
05-29-2013, 09:05 AM   #3
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Is this lens new to you?

Looks to me that the lens is faulty as everything in your sample shot looks equally blurred, not oof, with some odd artifacts around roof edges, etc.

How does it look on the lcd?

Better to post uncropped/unedited examples with intact exif.
05-29-2013, 09:27 AM   #4
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QuoteOriginally posted by PBandJ Quote
The A ring is at F8, but all the lightroom data shows f/3.5

I'm using Av mode. Do I also need to press the green button?
If you set the aperture ring in any position other than A, you are using the lens in total manual mode just like a K or M lens. In the Av mode, the aperture will remain wide open at F3.5 and the DOF will be narrower.The posted image looks out of focus. You can switch to M mode and use the green button, but you are much better off to use the lens in its A mode.

Set the lens aperture in the A position, the camera in Av and then use the camera to set the F-stop at 8. If you set the focusing distance on the lens somewhere around 1.5 to 2 m everything from .5m to infinity should be in focus (assuming that the distance scale is more or less calibrated correctly). You should be able to use focus confirmation also to get good focus.

This lens is very sharp at F8 if focused properly. It is a bit soft when wide open at F3.5 which, with the combination of incorrect focus, can give you an image like the one posted.

05-29-2013, 09:56 AM   #5
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The wide angle rokinons are known to be able to go past infinity. For instance I have one 8mm which I had to manually adjust the focus ring on, otherwise it went past infinity and everything was a blur regardless of the F stop. If you are using the aperture ring, I believe you would have to use Manual mode only with green button, since the mount is crippled. If I were you, id just throw it in A setting and use the dials to control the aperture from within the camera.
05-29-2013, 11:39 AM   #6
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1) What the previous comments said about 'A' lenses. If you are setting the aperture with the ring and using Av mode, it's going to stay wide open. So f/3.5 in the EXIF is accurate, and that could cause softness.

2) Make sure you set your focal length for Shake Reduction to 8mm. I've noticed that lens seems to be particularly blurred if the setting is wrong and SR is turned on.

3) Sharp focusing with that lens can be a challenge, because the hyperfocal distance is so wide, and focus peaking doesn't work as well with ultra-wide lenses. Be sure to zoom in (OK button) when focusing.

Last edited by THoog; 05-29-2013 at 11:53 AM.
05-29-2013, 12:09 PM   #7
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QuoteOriginally posted by THoog Quote
1) What the previous comments said about 'A' lenses. If you are setting the aperture with the ring and using Av mode, it's going to stay wide open. So f/3.5 in the EXIF is accurate, and that could cause softness.

2) Make sure you set your focal length for Shake Reduction to 8mm. I've noticed that lens seems to be particularly blurred if the setting is wrong and SR is turned on.

3) Sharp focusing with that lens can be a challenge, because the hyperfocal distance is so wide, and focus peaking doesn't work as well with ultra-wide lenses. Be sure to zoom in (OK button) when focusing.
Thanks, everyone! I will use A setting on the lens from now on and control in camera.

Yes - this lens is new to me. I hope I can get some better pics before my vacation ends!
05-29-2013, 02:00 PM   #8
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You can also just look into the lens iris to see if the behaviour matches the exif, if the lens gets stopped down to the set aperture or not.

05-29-2013, 11:06 PM   #9
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QuoteOriginally posted by Na Horuk Quote
You can also just look into the lens iris to see if the behaviour matches the exif, if the lens gets stopped down to the set aperture or not.
thanks, now I just have to sort out the focus. Mine stops at infinity, but turns a little past the closest- 0.3m iirc
Most things I want to photograph are at least a few feet away, so I figure that any setting in the 0.3-1.5m should work,
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