Samyang 8mm question..please

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Samyang 8mm question..please

PanoTools NG mailing list
I have a friend that just acquired the Samyang 8mm fish eye..He is not stitching the images to make panos. He is using a Nikon D3100 camera which is DX.. OK so now my question.. He's using freeware to un wrap the images I am noticing that both the right and left sides of the image are quite soft and the center is sharp. Also the top and bottom are sharp  but as you move towards the R&L sides of the image start getting soft. I'm thinking this is in the software he's using or his process. Could the issue be that a setting is incorrect because he's using a DX camera? Sorry for being Mr Dumb on this .. but the show fits in this case. thanx.. /
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Re: Samyang 8mm question..please

PanoTools NG mailing list
Try downloading Ptgui trial and see what happens.



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Re: Samyang 8mm question..please

PanoTools NG mailing list
Thanks Richard.. I have PTGUI here. The shooter is in another state..  I'm
trying to see if he can send me the as shot file or get him to download the
trial version and try that.. He is a good shooter and really likes the
Samyang.. All the images I'm seeing are soft right and left and sharp
towards the center. I have sent him an email and am waiting for him to get
back to me with answers to a couple of questions..  So more later maybe..

 

jimbo

 

From: [hidden email] [mailto:[hidden email]]
Sent: Monday, June 08, 2015 6:31 AM
To: [hidden email]
Subject: [PanoToolsNG] Re: Samyang 8mm question..please

 

 

Try downloading Ptgui trial and see what happens.

 




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Re: Samyang 8mm question..please

PanoTools NG mailing list
In reply to this post by PanoTools NG mailing list
Am 08.06.2015 um 13:47 schrieb [hidden email] [PanoToolsNG]:
> I have a friend that just acquired the Samyang 8mm fish eye. He is
> not stitching the images to make panos. He is using a Nikon D3100
> camera which is DX.. OK so now my question.. He's using freeware to
> un wrap the images I am noticing that both the right and left sides
> of the image are quite soft and the center is sharp. Also the top and
> bottom are sharp  but as you move towards the R&L sides of the image
> start getting soft. I'm thinking this is in the software he's using
> or his process.

I assume you mean the unwrapped images and landscape orientation.
Furthermore I assume unwrapping was done to the maximum horizontal field
of view. In this case unsharp R&L sides are to be expected. The image
sides have to be stretched heavily in order to map the fisheye
projection to a rectilinear one. Using an 8mm fisheye on a DX sensor as
an ultra wide rectilinear lens means to throw away more than 3/4 of all
sensor pixels and stretch the remaining ones which inevitably causes blur.

Erik Krause


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RE: Samyang 8mm question..please

PanoTools NG mailing list
Eric.. Thank you very much.. Yes he going after the maximum horizontal field
of view.... and yes it looks pretty scary from blur.. So one more question..
If he shot the Samyang with FX rather than DX would he get better results
specifically less blur R&L

jimbo

-----Original Message-----
From: [hidden email] [mailto:[hidden email]]
Sent: Monday, June 08, 2015 9:24 AM
To: [hidden email]
Subject: Re: [PanoToolsNG] Samyang 8mm question..please

Am 08.06.2015 um 13:47 schrieb [hidden email] [PanoToolsNG]:
> I have a friend that just acquired the Samyang 8mm fish eye. He is not
> stitching the images to make panos. He is using a Nikon D3100 camera
> which is DX.. OK so now my question.. He's using freeware to un wrap
> the images I am noticing that both the right and left sides of the
> image are quite soft and the center is sharp. Also the top and bottom
> are sharp  but as you move towards the R&L sides of the image start
> getting soft. I'm thinking this is in the software he's using or his
> process.

I assume you mean the unwrapped images and landscape orientation.
Furthermore I assume unwrapping was done to the maximum horizontal field of
view. In this case unsharp R&L sides are to be expected. The image sides
have to be stretched heavily in order to map the fisheye projection to a
rectilinear one. Using an 8mm fisheye on a DX sensor as an ultra wide
rectilinear lens means to throw away more than 3/4 of all sensor pixels and
stretch the remaining ones which inevitably causes blur.

Erik Krause


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Re: Samyang 8mm question..please

PanoTools NG mailing list
Am 08.06.2015 um 18:13 schrieb Jim Bechtel:

> If he shot the Samyang with FX rather than DX would he get better results
> specifically less blur R&L

A bit, may be. FX pixel density is usually higher, but the stretching
still applies.

I suggest he sells the 8mm to someone who needs it for panorama and buys
a Samyang 14mm rectilinear instead.

--
Erik Krause
http://www.erik-krause.de


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