Adjust for Wide Angle lens distortion

[Billh]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Is there a way in Photoshop to adjust for the distortion when
using a wide angle lens (e.g. 17mm)?

Thanks...

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

billh <billh@nospam.att.net> wrote:

> Is there a way in Photoshop to adjust for the distortion when
> using a wide angle lens (e.g. 17mm)?
>
> Thanks...

There's some software designed for panoramas and other image stitching,
called PanoTools. It's free, and it's being packaged by about a zillion
different people. One of the things it's designed to do is adjust for
lens distortion. There are PS plugin versions of it. Start here:
<http/panotools.sourceforge.net/>.

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

On Fri, 11 Feb 2005 08:33:15 GMT, billh <billh@nospam.att.net> wrote:

>Is there a way in Photoshop to adjust for the distortion when
>using a wide angle lens (e.g. 17mm)?
>
>Thanks...
>
Use freetransform and skew, and crop.

ken

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

"billh" <billh@nospam.att.net> wrote in message
news:420C6DAC.7BE5D2C7@nospam.att.net...
> Is there a way in Photoshop to adjust for the distortion when
> using a wide angle lens (e.g. 17mm)?

Yes, download the free PTlens plugin for Photoshop at:
http/www.epaperpress.com/ptlens/index.html
Also download the "PTlens helpers" and "Profiles" from their download
page.

Bart

 

[Billh]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Bart van der Wolf wrote:

> "billh" <billh@nospam.att.net> wrote in message
> news:420C6DAC.7BE5D2C7@nospam.att.net...
> > Is there a way in Photoshop to adjust for the distortion when
> > using a wide angle lens (e.g. 17mm)?
>
> Yes, download the free PTlens plugin for Photoshop at:
> http/www.epaperpress.com/ptlens/index.html
> Also download the "PTlens helpers" and "Profiles" from their download
> page.

Thanks Paul & Bart... Looks promising!

Bill

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Ken Ellis <kenellis@nycap.rr.com> wrote in
news:0hip011g74r2e0lht8a83j8dva7mmngv0g@4ax.com:

>>Is there a way in Photoshop to adjust for the distortion when
>>using a wide angle lens (e.g. 17mm)?
>>
>>Thanks...
>>
> Use freetransform and skew, and crop.

Hmmmm ... how?


/Roland

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Roland Karlsson" <roland_dot_karlsson@bonetmail.com> wrote in message
news:Xns95FAED4ED1580klotjohan@130.133.1.4...
> Ken Ellis <kenellis@nycap.rr.com> wrote in
> news:0hip011g74r2e0lht8a83j8dva7mmngv0g@4ax.com:
>
>>>Is there a way in Photoshop to adjust for the distortion when
>>>using a wide angle lens (e.g. 17mm)?
>>>
>>>Thanks...
>>>
>> Use freetransform and skew, and crop.
>
> Hmmmm ... how?
>
It's all there in "Help"
I tried it after seeing this post and it's just great for getting rid of
converging verticals.

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

On 11 Feb 2005 22:19:42 GMT, Roland Karlsson
<roland_dot_karlsson@bonetmail.com> wrote:

>Ken Ellis <kenellis@nycap.rr.com> wrote in
>news:0hip011g74r2e0lht8a83j8dva7mmngv0g@4ax.com:
>
>>>Is there a way in Photoshop to adjust for the distortion when
>>>using a wide angle lens (e.g. 17mm)?
>>>
>>>Thanks...
>>>
>> Use freetransform and skew, and crop.
>
>Hmmmm ... how?
>
>
>/Roland

If you can't get it with the help, let me know and i'll try to explain
it. It's fairly easy.

rgds

Ken

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Ken Ellis wrote:
> On 11 Feb 2005 22:19:42 GMT, Roland Karlsson
> <roland_dot_karlsson@bonetmail.com> wrote:
>
>> Ken Ellis <kenellis@nycap.rr.com> wrote in
>> news:0hip011g74r2e0lht8a83j8dva7mmngv0g@4ax.com:
>>
>>>> Is there a way in Photoshop to adjust for the distortion when
>>>> using a wide angle lens (e.g. 17mm)?
>>>>
>>>> Thanks...
>>>>
>>> Use freetransform and skew, and crop.
>>
>> Hmmmm ... how?
>>
>>
>> /Roland
>
> If you can't get it with the help, let me know and i'll try to explain
> it. It's fairly easy.
>
> rgds
>
> Ken

Isn't barrel correction one of the primary requirements? Is that in
Photoshop?
(Yes, it is in Paint Shop Pro, as is a rather handy perspective correction
tool).

Cheers,
David

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

"David J Taylor" <david-taylor@invalid.com> wrote in news:376231F5865icU1
@individual.net:

> Isn't barrel correction one of the primary requirements? Is that in
> Photoshop?

No it is not IMHO. You can correct perspective in Photoshop,
but not distorsion (without a plugin).

Some here wants to tell me how it is simply done in Photoshop.
If they can, then I stand corrected


/Roland

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

On 12 Feb 2005 10:45:19 GMT, Roland Karlsson
<roland_dot_karlsson@bonetmail.com> wrote:

>"David J Taylor" <david-taylor@invalid.com> wrote in news:376231F5865icU1
>@individual.net:
>
>> Isn't barrel correction one of the primary requirements? Is that in
>> Photoshop?
>
>No it is not IMHO. You can correct perspective in Photoshop,
>but not distorsion (without a plugin).
>
>Some here wants to tell me how it is simply done in Photoshop.
>If they can, then I stand corrected
>
>
>/Roland

I beleive you can acheive some similar results with the "sphere"
filter in photoshop - filter>distort>sphere (or spherize) where 0 is
no effect and +/- would debarrel and barrel ...lol

rgds

Ken

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Roland Karlsson wrote:

> Ken Ellis <kenellis@nycap.rr.com> wrote in

>>Use freetransform and skew, and crop.
>
>
> Hmmmm ... how?

You've been led to the well. Pump your own water.

--
-- r.p.e.35mm user resource: http/www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http/www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http/www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Ken Ellis <kenellis@nycap.rr.com> wrote in
news:vbur01p0g1cpdt5u5kmo6l7hdktfje0rq7@4ax.com:

> I beleive you can acheive some similar results with the "sphere"
> filter in photoshop - filter>distort>sphere (or spherize) where 0 is
> no effect and +/- would debarrel and barrel ...lol

Yes - you may be able to use that filter. It is not easy and
it is not certain that you can. You only have a slider for
amount - and lens distortion is somewhat more complex than that.
OK - I missed that filter.

But - that was not really my point. At least two posters claimed
that you could fix distortion easily with skew and distort. I
asked them to show me how.


/Roland

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Alan Browne <alan.browne@freelunchVideotron.ca> wrote in news:culgc5$7fc$1
@inews.gazeta.pl:

>>>Use freetransform and skew, and crop.
>>
>>
>> Hmmmm ... how?
>
> You've been led to the well. Pump your own water.

According to my knowledge you cannot use free transorm, skew and crop
to correct distortion. You have to have some kind of non linear
transform to do that.

So - I think that I have been led to a useless well.

Please show me that I am wrong?


/Roland

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

On 12 Feb 2005 22:10:43 GMT, Roland Karlsson
<roland_dot_karlsson@bonetmail.com> wrote:

>Alan Browne <alan.browne@freelunchVideotron.ca> wrote in news:culgc5$7fc$1
>@inews.gazeta.pl:
>
>>>>Use freetransform and skew, and crop.
>>>
>>>
>>> Hmmmm ... how?
>>
>> You've been led to the well. Pump your own water.
>
>According to my knowledge you cannot use free transorm, skew and crop
>to correct distortion. You have to have some kind of non linear
>transform to do that.
>
>So - I think that I have been led to a useless well.
>
>Please show me that I am wrong?
>
>
>/Roland


Well...With the free transform..etc you can approach converging lines,
etc; also you can rotate the pic like a 3d object and correct it that
way too...and the sphere filter will definately do what a debarrelizer
does (per se)...so betwean all that i suspect that you have to tinker
with them to get what you want....because what's to say what is
distorted..and what isn't. You'll make that decision when you pinch
and pull and tug on the thing; and change it...what "distortion" are
you trying to fix?

rgds

Ken

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Ken Ellis wrote:
[]
> Well...With the free transform..etc you can approach converging lines,
> etc; also you can rotate the pic like a 3d object and correct it that
> way too...and the sphere filter will definately do what a debarrelizer
> does (per se)...so betwean all that i suspect that you have to tinker
> with them to get what you want....because what's to say what is
> distorted..and what isn't. You'll make that decision when you pinch
> and pull and tug on the thing; and change it...what "distortion" are
> you trying to fix?

It sounds a lot more complex than the equivalent Paint Shop Pro 9 steps:

- step 1, apply barrel correction, needs one number

- step 2, apply perspective correction. Draw four lines on your picture
showing what elements comprise a rectangle, and tick Apply.

Perhaps it's easier than it sounds once you have experience of the tools
in Photoshop.

Cheers,
David

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Roland Karlsson wrote:

> Alan Browne <alan.browne@freelunchVideotron.ca> wrote in news:culgc5$7fc$1
> @inews.gazeta.pl:
>
>
>>>>Use freetransform and skew, and crop.
>>>
>>>
>>>Hmmmm ... how?
>>
>>You've been led to the well. Pump your own water.
>
>
> According to my knowledge you cannot use free transorm, skew and crop
> to correct distortion. You have to have some kind of non linear
> transform to do that.
>
> So - I think that I have been led to a useless well.

Not as far as I know. I've used Image|Transform|Perspective to correct
architecture shots from a 20mm lens. (Okay, that's not 'freetransform' but it's
in the same transform menu).

To be clear, it can correct for the perspective error; it cannot correct for
known 'flatfield' error of the lens.

http/www.aliasimages.com/images/ManoirLorraineLR00090010NC.jpg
http/www.aliasimages.com/images/ManoirLorraineLR00090010PC.jpg

Best to 'squeeze' the wide part to narrow than to stretch the narrow to wide.

Cheers,
Alan

--
-- r.p.e.35mm user resource: http/www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http/www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http/www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Ken Ellis <kenellis@nycap.rr.com> wrote in
news:ekit01p1h0pk2b4fr74j8u0qvu0nchdd7v@4ax.com:

> Well...With the free transform..etc you can approach converging lines,
> etc; also you can rotate the pic like a 3d object and correct it that
> way too...and the sphere filter will definately do what a debarrelizer
> does (per se)...so betwean all that i suspect that you have to tinker
> with them to get what you want....because what's to say what is
> distorted..and what isn't. You'll make that decision when you pinch
> and pull and tug on the thing; and change it...what "distortion" are
> you trying to fix?

I know how to fix distortion. I do it with panorama tools.
And I now know that there is a sphere tool in Photoshop,
although it looks more like a toy than a real tool.

I is just that some here said to me that I could use crop, skew
and free transform to do it. And when I asked how, they said
that it is now up to me as I have been led to the water hole.
I think it is sux big time to pretend being expert and pointing
at some tools - when you are wrong. And I also think it sux
big time to not admit that you are wrong.

Note Ken - that nothing what I write here fits you. Your replies
have been helpful. Others was just nonsens.


/Roland

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

Roland Karlsson wrote:

> Ken Ellis <kenellis@nycap.rr.com> wrote in
> news:ekit01p1h0pk2b4fr74j8u0qvu0nchdd7v@4ax.com:
>
>
>>Well...With the free transform..etc you can approach converging lines,
>>etc; also you can rotate the pic like a 3d object and correct it that
>>way too...and the sphere filter will definately do what a debarrelizer
>>does (per se)...so betwean all that i suspect that you have to tinker
>>with them to get what you want....because what's to say what is
>>distorted..and what isn't. You'll make that decision when you pinch
>>and pull and tug on the thing; and change it...what "distortion" are
>>you trying to fix?
>
>
> I know how to fix distortion. I do it with panorama tools.
> And I now know that there is a sphere tool in Photoshop,
> although it looks more like a toy than a real tool.
>
> I is just that some here said to me that I could use crop, skew
> and free transform to do it. And when I asked how, they said
> that it is now up to me as I have been led to the water hole.
> I think it is sux big time to pretend being expert and pointing
> at some tools - when you are wrong. And I also think it sux
> big time to not admit that you are wrong.

Tsk, tsk. See my other reply. And example. Imperfect though it is (not
knowing the lens distortion) it works.

Cheers,
Alan

--
-- r.p.e.35mm user resource: http/www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http/www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http/www.pbase.com/shootin
-- e-meil: there's no such thing as a FreeLunch.

 

[Guest]

Archived from groups: rec.photo.digital.slr-systems (More info?)

"David J Taylor" <david-taylor@invalid.com> wrote in news:378tn7F59eu60U1
@individual.net:

> It sounds a lot more complex than the equivalent Paint Shop Pro 9 steps:
>
> - step 1, apply barrel correction, needs one number
>
> - step 2, apply perspective correction. Draw four lines on your picture
> showing what elements comprise a rectangle, and tick Apply.
>
> Perhaps it's easier than it sounds once you have experience of the tools
> in Photoshop.
>

You are perfectly right. Photoshop has no built in distortion correcter.
It neither has any easy to use perspective correction. The method you
describe for perpective correction is several times more convenient.

If you have Photoshop, and want to work with it efficiently, you have to
get some plug ins.


/Roland