Re: [Gimp-user] GimpLensfun database

[Partha Bagchi <partha1b gmail com>]

On Sat, Sep 28, 2013 at 6:35 PM, Leonard Evens <len math northwestern edu>wrote:

> On Sat, 2013-09-28 at 17:57 -0400, Partha Bagchi wrote:
> > Here is something you can try. Copy the lens database from svn:
> > http://svn.berlios.de/wsvn/lensfun/trunk/data/db/ and put it the
> > appropriate location within lensfun-0.2.7. Rebuild lensfun and you
> > should have the D800 with 24-70.
>
> Thank you.  I may try that.  But I don't really understand why it should
> be that hard.  Presumably, the program darktable and the gimp filter
> gimplensfun are looking somewhere to find correction information.  If it
> is not in /usr/share/lensfun, where in the world is it?
It is in /usr/share/lensfun. It's just not up to date compared to the
database in svn. Cameras and lenses are constantly changing as you know. :)

> > Personally, I think you should fix lens distortion (if any) within
> > your raw editor rather than in Gimp, but that's me. :)
>
> I ordinarily work in darktable on NEF fiiles, but I somehow managed to
> nuke a whole bunch of NEF images and had to instead work with the jpeg
> images on my backup card.
OK, Have you thought about CNX2 unless you are Linux all the way?

> > BTW, curious where did you read that the 24-70 is the "standard" lens
> > for the D800? I have never heard of the D800 being sold with the 24-70
> > as a kit lens (or any lens for that matter).
>
> It is perhaps an exaggeration to call these "the" standard lenses for
> the d800.  When I was contemplating laying out a fortune for my D800,  I
> posted a query at Nikonians about which lenses I should consider given
> my needs.  The 24-70 and 70-200 lenses were both strongly recommended by
> several people.  Also, my Calumet salesman recommended those same
> lenses.   I think these lenses are common choices for use with the D800.
> They should definitely be in the Lensfun database, and if my reference
> above makes any sense, they are, so I am perplexed about why I can't
> find them.
Yes, that's what I thought you meant. I don't disagree with you. I was
commenting on your statement about the 24-70 being the standard on a D800.
Don't get me wrong. I think the D800 deserves the 24-70. That is in fact
one of my camera/lens combination. :)

> Fortunately, my lenses have very little distortions, so I may be able to
> avoid using corrections.
Unless you are shooting at 24 2.8, I would not worry about it. Of course,
if you are planning to make a large print then you might want to reconsider
shooting the picture again if possible.

> The 14-24 lens was also recommended, but I didn't think I needed it, and
> I had already spent enough money.  Later I got a 24 mm tilt-shift
> Rokinon lens which was something of a bargain for under $1,000.
try the sigma 10-20. You may be surprised.

> Perhaps I should explain that I have been doing view camera 4 x 5
> photography with 75 mm, 90 mm, 150 mm and 300 mm lenses.   I wanted the
> Nikon D800 to cover roughly that range.  24 mm is relatively short for
> 35 mm but not as short as 75 mm is for 4 x 5, so someday I may get a
> shorter lens for my D800.   One of my interests is architectural
> photography, and my 75 mm lens wasn't even short enough to photograph a
> building facade from across the street.   I had to stitch two images
> using hugin to capture that scene.   I think I can do the same thing
> easily, if the need arises, using 24 mm on my D800,
>
> If I feel a pressing need, I may get a shorter focal length lens for the
> D800, but given that I am 80 years old, that need may never arise.
>
>
> --
> Leonard Evens len math northwestern edu
> Professor Emeritus, Department of Mathematics, Northwestern University