Hallöchen!
Louis Granboulan writes:
> [...]
>
> [...] The viewfinder shows 100% of the picture, including the
> corners, but there is almost no vignetting in the viewfinder.
> Therefore this vignetting is mainly caused by elements that are
> not between the subject and the main mirror… that's why
>> You can download a DNG sample at http://dl.free.fr/grImV4Y5M
>
> This seems to be mechanical vignetting.
Yes, it was the original view of the Pentax community, and is still often the
case, but I don't agree.
The viewfinder shows 100% of the picture, including the corners, but there is
almost
Hallöchen!
Louis Granboulan writes:
> [...]
>
> You can download a DNG sample at http://dl.free.fr/grImV4Y5M
This seems to be mechanical vignetting. I admit that d'Angelo's
polynomial may not work well for this. I know such an effect only
from one lens (the Sony E PZ 16-50mm). But there, the
Dear all,
>> I thought that I understood how it works, and that the ImageMagick command
>> below will do the same correction as the lens profile below.
>> > k1="0.0" k2="-0.156" k3="-0.711" />
>> convert IMGP4694.tiff -fx "Xi=i-w/2; Yj=j-h/2;
>> r=hypot(Xi,Yj)/hypot(w/2,h/2); s/(1-0.156
Hallöchen!
Roman Lebedev writes:
> [...]
>
> I'd expect that for not-broken-by-design situations, i.e. in
> 99.99% cases, the parametric formula is better in any regard. Do
> you plan on including these vignetting bitmap profiles into the
> lensdb.xml? If yes, how is it going to be made sure tha
On Mon, Dec 12, 2016 at 10:53 AM, Torsten Bronger
wrote:
> Hallöchen!
>
> Louis Granboulan writes:
>
>> [...]
>>
>> My idea was to use the Fx special effects of ImageMagick to
>> experiment with various correction formulas. But I have not been
>> able to reproduce with ImageMagick the effect of u
Hallöchen!
Louis Granboulan writes:
> [...]
>
> My idea was to use the Fx special effects of ImageMagick to
> experiment with various correction formulas. But I have not been
> able to reproduce with ImageMagick the effect of using lensfun
> profiles in darktable.
>
> [...] The page
> http://le
Torsten Bronger wrote:
> Have you tested which degree you need?
No.
I have been trying to see what is needed without experimenting by modifying
lensfun code, but I failed.
My idea was to use the Fx special effects of ImageMagick to experiment with
various correction formulas.
But I have not be
Hallöchen!
I don't speak for the project here, this is just my personal
opinion:
Louis Granboulan writes:
> [...]
>
> I propose to work on adding to lensfun the possibility of using
> another formula, with more parameters (higher degree polynomial).
Have you tested which degree you need?
> If
Hello again.
I ran calibrate.py but it did not give good results: the corrected pictures
show dark rings alternating with clear rings, because the interpolation with
only three parameters is not sufficiently precise to compensate this type of
vignetting.
That's why I propose to use a formula wit
Hello Karl,
I am aware of this thread, but it does not match my experience: there is almost
no vignetting in the viewfinder with my unmodified 60-250, which means that it
is pixel vignetting.
Anyway, my goal is to be able to compensate that vignetting with lensfun.
Regards,
Louis
> Le 4 déc. 201
Whoops, hit send too soon. :)
As the vignetting appears to be mechanical Lensfun should be able to
correct it, given profiling data.
I can't find an entry for this lens in the lens database; you're welcome
to submit profiling images to http://wilson.bronger.org/calibration for
inclusion in the
Hi Louis,
Greetings from a fellow Pentaxian! :)
As discussed on
http://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/304092-da-60-250-mod-ff-9.html
the vignetting for this lens is caused by a mechanical baffle at the
rear of the lens, and so the vignetting you're experiencing is
Dear all,
I use a "smc Pentax-DA* 60-250mm f/4 ED IF SDM" on a "Pentax K-1".
This lens is not designed for full frame, but its only drawback is a strong
vignetting.
This vignetting does not show in the viewfinder, it only shows on the sensor,
which means it is "pixel vignetting".
Pablo d'Angelo'
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