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03-17-2011, 10:56 AM   #1
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Anyone know about Samyang 28mm 2.8?

Does anyone know this lens? I am most interested in hearing opinions on IQ at around f16 for hyperfocal use.

"Samyang MC Automatic 1:2.8 f=28mm" written around the front glass. 52 filter thread. Seller mentions "macro"; I suspect that's written on the side of the lens. Aperture range 2.8-f22 with an "A" setting.

Samyang 28mm 1:2.8 Lens (Macro) for Pentax for a picture.

(I couldn't find any exact matches on PF and the larger web. There are many 28mm variants and I think Samyang does rebadging, so I've also searched Vivitar and add'l brands but struck out due to different filter sizes or aperture ranges.)

03-17-2011, 02:28 PM   #2
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I don't know anything about this lens but I'm not sure if it's a K mount since the aperture marking goes from left to right. Anyone please enlighten me.
03-17-2011, 03:35 PM   #3
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Almost looks like my sigma 28mm mini wide but I doubt there is any commonality
03-21-2011, 09:16 AM   #4
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Just posting to update those of you who replied (and maybe anyone else who is considering the same lens). I tested the lens and it was no good. I think it was a compatibility issue rather than broken but not sure.

The owner used it (infrequently) on his K20D in M mode. I was interested in using it in Av mode with hyperfocal focus (so I could click away without having to focus, letting the camera adjust shutter speed as needed).

The lens said k-mount and I confirmed there was no Ricoh pin. The lens mounted to my K-R without any problems.

I tried Av mode first. The lens had an "A" aperture setting and the camera showed an aperture setting (rather than "F---"). I tried a few test photos at different apertures but all were horribly overexposed. I tried playing with Ev comp. but still couldn't get a usable photo. M mode plus the green button was no better. The owner then tried it on his K20D in Av mode; same problem. The sun was at our backs so I doubt it was simply flare.

That was enough testing to conclude the lens wouldn't work for me. We didn't do any more testing to determine whether it was a metering incompatibility or a broken lens. The owner added that he used to use the lens in M mode but we didn't bother testing that. I wonder whether the reversed aperture ring as noted by Doanh indicates the lens was intended for a Pentax-like camera?

03-21-2011, 12:32 PM - 1 Like   #5
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QuoteOriginally posted by DeadJohn Quote
Just posting to update those of you who replied (and maybe anyone else who is considering the same lens). I tested the lens and it was no good. I think it was a compatibility issue rather than broken but not sure.

The owner used it (infrequently) on his K20D in M mode. I was interested in using it in Av mode with hyperfocal focus (so I could click away without having to focus, letting the camera adjust shutter speed as needed).

The lens said k-mount and I confirmed there was no Ricoh pin. The lens mounted to my K-R without any problems.

I tried Av mode first. The lens had an "A" aperture setting and the camera showed an aperture setting (rather than "F---"). I tried a few test photos at different apertures but all were horribly overexposed. I tried playing with Ev comp. but still couldn't get a usable photo. M mode plus the green button was no better. The owner then tried it on his K20D in Av mode; same problem. The sun was at our backs so I doubt it was simply flare.

That was enough testing to conclude the lens wouldn't work for me. We didn't do any more testing to determine whether it was a metering incompatibility or a broken lens. The owner added that he used to use the lens in M mode but we didn't bother testing that. I wonder whether the reversed aperture ring as noted by Doanh indicates the lens was intended for a Pentax-like camera?
to me, this sounds more like a stuck aperture or something rather than a compatibility issue. I have not seen any true KA mount lens over expose to that extent. When you say the camera showed an aperture value, did it range from F2.8 to F22 like the lens should?

Also, an aperture ring turning the wrong way would impact the aperture coupling for open aperture metering on non KA cameras only if the aperture coupling lever also turned the wrong way,

Do you have a photo of the mount? It might answer a lot.
03-21-2011, 03:51 PM   #6
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QuoteOriginally posted by Lowell Goudge Quote
When you say the camera showed an aperture value, did it range from F2.8 to F22 like the lens should?
Do you have a photo of the mount?
The e-dial showed the proper aperture range in Av mode.

No photo of the lens other than what was in my original link. It's a front photo that doesn't show the mount.

The level of overexposure seemed to stay the same regardless of aperture. At max f2.8 I don't think a stuck aperture would overexpose. The blades seemed to move smoothly. Maybe "overexposure" isn't even exactly what's happening. That's how it looked to me but maybe an inner lens had smoke or fungus haze. The lens looked clean but I was outdoors and couldn't control lighting to really examine the inside.

Anyway, I find this interesting because it might increase my knowledge of how lenses work but it's not something I need to solve. I am really hoping for a 24mm but those are much rarer than 28mm. I wish there was a current 24 prime smaller than Sigma's 24/1.8 (fast aperture and AF don't matter for my intended hyperfocal use).
03-21-2011, 04:37 PM   #7
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Any sample shots?

A couple of things come to mind

First the K20 is not the best metering camera and you might have an exposure error that can be offset with EV comp , or you had EV comp set to overexposed without knowing

Or

You may be suffering from reflections off the sensor. Any chance on sample Photos
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