Is this an issue with Samyang 12mm f2.0 lens shot on Fujifilm x-t30

Started 5 months ago | Questions
kolkataeye New Member • Posts: 4
Is this an issue with Samyang 12mm f2.0 lens shot on Fujifilm x-t30

Hi,

I am a newbie and was interested in architecture and astro-photography. So I have started with the Fujifilm x-t30 and a Samyang 12mm f2.0 lens. I have some questions on lowlight pics I have taken recently.

The below was taken at 1600 ISO, f2.0, 25 sec exposure. There is a string of diamonds on top of the trailer body. It wasn't there when I shot, so there is some effect that is coming up on the lens. Can someone explain what is the problem, please?

Berkshires, Masachussetts

I am seeing a couple pf strange effects on another shot.

Shot at ISO 4000, f2.0 and 1/30 sec. This pic has 2 unidentifiable effects on the skyscaper above the 3rd floor, one on left, other on right.

Can those be explained?

Copley, Massachussetts

There is a third question I have. It seems from this pic below that the focus is sharp at infinity and the center of the lens, while this slowly goes down as we move to the edges of the frame. The little waterfall lets flowing in the center are in sharp focus, but the focus is blurry on the waterfall lets at the edges of the pic. And they get progressively blurry as we look towards the edges.

Is that true of such types of lenses, or I have a defective lens? Can someone please explain?

I have till Jan 31st, to ask for a return / replacement. I really like the 12mm, f2.0, so if need be, I will ask for a replacement.

Looking for your valuable advice.

Shot at 1250 ISO, f2.0 and 1/15 sec

ANSWER:
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lehill
lehill Veteran Member • Posts: 6,015
Re: Is this an issue with Samyang 12mm f2.0 lens shot on Fujifilm x-t30
2

kolkataeye wrote:

Hi,

I am a newbie and was interested in architecture and astro-photography. So I have started with the Fujifilm x-t30 and a Samyang 12mm f2.0 lens. I have some questions on lowlight pics I have taken recently.

The below was taken at 1600 ISO, f2.0, 25 sec exposure. There is a string of diamonds on top of the trailer body. It wasn't there when I shot, so there is some effect that is coming up on the lens. Can someone explain what is the problem, please?

Berkshires, Masachussetts

The small bright specks just look like reflections off your shiny trailer. They occur in about the same location in each embossment of the trailer siding:

Reflection of distant light, lamp, or moon?

It's normal for a lens to be less sharp at the edges than the center. People pay big money for lenses that are sharp across the entire frame. It's extra difficult to make an ultra-wide-angle lens with sharp edges - I'm not sure if there are any UWAs that are sharp across the frame.

If you're worried about the lens. Follow the instructions here.

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Lance H

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Gerry Winterbourne Forum Pro • Posts: 18,590
Re: Is this an issue with Samyang 12mm f2.0 lens shot on Fujifilm x-t30
1

kolkataeye wrote:

There is a third question I have. It seems from this pic below that the focus is sharp at infinity

There isn't anything in the picture at infinity; that's a lot further away than anything in the picture.

and the center of the lens, while this slowly goes down as we move to the edges of the frame. The little waterfall lets flowing in the center are in sharp focus, but the focus is blurry on the waterfall lets at the edges of the pic. And they get progressively blurry as we look towards the edges.

Is that true of such types of lenses, or I have a defective lens? Can someone please explain?

Here is an extract from the ePhotozine review of your lens. It shows that resolution is much less at the edges than at the centre (although still classed as "good"), especially wide open. highres-Samyang12mm_MTF_1417442186.jpg (640×480) (ephotozine.com) This is a little bit more severe than on some other ultrawide lenses but is just the way things are; nothing to worry about.

I have till Jan 31st, to ask for a return / replacement. I really like the 12mm, f2.0, so if need be, I will ask for a replacement.

No reason to expect anything better than the one you have.

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Gerry
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Leonard Migliore
Leonard Migliore Forum Pro • Posts: 18,445
Do you have a filter on the lens?

You can get hot spots in strange places with light reflected from filters.

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Leonard Migliore

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OP kolkataeye New Member • Posts: 4
Re: Do you have a filter on the lens?

Thank you for the answer. I did not have a filter on the lens. So, do you think there could be any other reason?

OP kolkataeye New Member • Posts: 4
Re: Is this an issue with Samyang 12mm f2.0 lens shot on Fujifilm x-t30

Thank you for your answer. I cannot think of a light source at the time of the photo apart from (maybe) my phone. I'm not entirely sure whether my phone would produce a reflection like that though.

Thanks for the guide on checking the alignment of lenses. I will definitely give that a shot.

OP kolkataeye New Member • Posts: 4
Re: Is this an issue with Samyang 12mm f2.0 lens shot on Fujifilm x-t30

Thanks for your insights. By infinity I meant that the focus was at infinity since the objects in the photo were well over 30ft away from me.

I think I'll probably keep the lens then. I do like this lens very much, and believe it is great to play around with for a beginner.

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