Re: A water side perspective & barrel distortion

"Joëlle" <frogsnwmail-ng@yahoo.co.uk> wrote in message 
news:48072cf6_2@cnews...
>
>
> "Tadjio" <Tadjio@PSP.Vista.uk> wrote in message
news:4807195b_2@cnews...
>>
> -snip-> Thanks, Joëlle, your suggestion worked a treat on my first one.
>> I struggled with the second one - original attached.
>>
>> To be honest, I have never managed Barrel Distortion
>> or any of the other 'distortion' tools very well,
>> including the DPP lens distortion tool.
>>
>> How do you set about it? Trial and error?
>> Should it be done before Perspective Correction?
>> Does the amount it fills the frame affect it,
>> as well as the focal distance?
>>
>> Any comments and hints are appreciated
>> (and a 'stab' at re-doing this image :-)
>> -- 
>> Tadjio
>>
>>
>>
>
>
> Apply Barrel Distortion Correction first, at about 23 ish.
> Then try something like the attached.
> It's easy to forget to line up the top and bottom when you've done the 
> sides, which of course then causes a problem.
> If you find the building looks a bit squat, just use the Deform or Pick 
> tool to pull it back into shape.
>
> With this particular building, there is something weird going on with the 
> right hand side, does it perhaps jut out further than the left?
>
> In one of my tries I selected the troublesome right, promoted it to layer 
> and straightened it out, you need to select using the Freehand or Edge 
> Seeker, rather than the Rectangular Selection box.
>
> Experimentation is the thing!
> :-)
> Joëlle
>

So it is trial and error.
I kept trying and got more errors last night :-(
It's difficult to interpret the effect of BD
before you straighten it with PC....

Thanks for doing that.
It's really the Barrel Distortion and other tools
that I don't know or use that well.
What does 'Preserve Central Scale' really do?
And what do the Strength and Result Sizes tell you?
Why did you choose 23 (and not 100)?

As to the building jutting out, I don't know,
but it must be over 300 years old and
belonged to a wealthy merchant
who would have insisted on getting it right :-)

I'm going out now but will try again later.
Merci bien.
-- 
Tadjio

"Tadjio" <Tadjio@PSP.Vista.uk> wrote in message
news:4807305a$1_2@cnews...
>
> "Joëlle" <frogsnwmail-ng@yahoo.co.uk> wrote in message 
> news:48072cf6_2@cnews...
>>
>>
>> "Tadjio" <Tadjio@PSP.Vista.uk> wrote in message
news:4807195b_2@cnews...
>>>
>> -snip-> Thanks, Joëlle, your suggestion worked a treat on my first
one.
>>> I struggled with the second one - original attached.
>>>
>>> To be honest, I have never managed Barrel Distortion
>>> or any of the other 'distortion' tools very well,
>>> including the DPP lens distortion tool.
>>>
>>> How do you set about it? Trial and error?
>>> Should it be done before Perspective Correction?
>>> Does the amount it fills the frame affect it,
>>> as well as the focal distance?
>>>
>>> Any comments and hints are appreciated
>>> (and a 'stab' at re-doing this image :-)
>>> -- 
>>> Tadjio
>>>
>>>
>>>
>>
>>
>> Apply Barrel Distortion Correction first, at about 23 ish.
>> Then try something like the attached.
>> It's easy to forget to line up the top and bottom when you've done the

>> sides, which of course then causes a problem.
>> If you find the building looks a bit squat, just use the Deform or Pick

>> tool to pull it back into shape.
>>
>> With this particular building, there is something weird going on with
the 
>> right hand side, does it perhaps jut out further than the left?
>>
>> In one of my tries I selected the troublesome right, promoted it to
layer 
>> and straightened it out, you need to select using the Freehand or Edge

>> Seeker, rather than the Rectangular Selection box.
>>
>> Experimentation is the thing!
>> :-)
>> Joëlle
>>
>
> So it is trial and error.
> I kept trying and got more errors last night :-(
> It's difficult to interpret the effect of BD
> before you straighten it with PC....
>
> Thanks for doing that.
> It's really the Barrel Distortion and other tools
> that I don't know or use that well.
> What does 'Preserve Central Scale' really do?
> And what do the Strength and Result Sizes tell you?
> Why did you choose 23 (and not 100)?
>
> As to the building jutting out, I don't know,
> but it must be over 300 years old and
> belonged to a wealthy merchant
> who would have insisted on getting it right :-)
>
> I'm going out now but will try again later.
> Merci bien.
> -- 
> Tadjio
>
>
>

Like everything, it is indeed try and try again.
I don't have Preserve Central Scale ticked, haven't seen any difference when 
I did and the 'oracle' says not to bother with it, so I don't.
On my images a strength of 22 or 23 works best, which I imagine is to do 
with the camera I use, some lenses distort more than others.

I know a lot of users of PSP, or any other program, prefer to have a tool 
'get it right', but the tool doesn't know what you want.
I like to experiment, it's fun and I always learn something along the way 
:-)

If that building is over 300 years old, bits of it might not be as 'true' as 
when it was built!

:-)
Joëlle