Author Topic: Aviod/Correct Wide lens distortion  (Read 5287 times)

2019-10-08, 10:29:36

petrorosengren

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Hello!

Is there a way to avoid wide lens distortion inside of Corona, or is post process the best way to go?

BR/
PR

2019-10-08, 10:39:35
Reply #1

romullus

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Hmm, what kind of distortions? Corona does not add any distortions, except perspective distortion, which is inevitable part of any focal length. The only option to reduce it, is to use narrower camera angle (longer focal lentgh).
I'm not Corona Team member. Everything i say, is my personal opinion only.
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2019-10-08, 10:46:56
Reply #2

petrorosengren

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Yes perspective distortion from a wide lens.
The architect is comparing with a view from Sketchup. I have not worked with Sketchup but it seems to show a view similar to a "Perspective" in max viewport.

2019-10-08, 10:51:48
Reply #3

romullus

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You can't "fix" perspective distortion without changing focal length. Not in 3ds max, nor sketchup and especially not in post. On the other hand if you're saying that perspective distortion at the same focal length looks differently in 3ds max, than it looks in sketchup, then it's worth investigating.
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2019-10-08, 11:11:07
Reply #4

petrorosengren

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Well, always ending up in wierd discussions with architects for some reson! Thanks for help :)


2019-10-08, 11:17:09
Reply #5

romullus

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No problem! Don't forget that you always have an option to increase focal length, move camera outside of the room and use camera clipping panes to see through walls. That would solve unwanted perspective distortion problem.
I'm not Corona Team member. Everything i say, is my personal opinion only.
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2019-10-08, 11:23:20
Reply #6

Juraj

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3dsMax 'perspective' view also has some kind of focal length, only by default it's usually 45 degrees of FOV (Field of View), which corresponds to 43mm +/- FullFrame sensor (35mm).

In Sketchup, the Architect can use type either FOV or FOCAL LENGTH, (either type "45 DEG", or "43 MM").

If both you and the architect type 28 MM wide-angle focal length, it will look the same. Rectilinear projection looks the same everywhere, that's basic geometry, but I understand you well, I fought with architects and clients who have extremely poor understanding of perspective for years... it boggles my mind ! Sometimes almost to what-the-fuck point :- O. That's life. Just keep educating and explaing :- ).

One more thing is 2-point perspective from Sketchup, which in 3dsMax you activate by "Autovertical tilt correction".

Also, perspective is the same, but it appears more distorted the taller is your composition. 28 mm in 16:9 ration looks less wide than it looks in 4:3. Some people can be confused by that as well.

No problem! Don't forget that you always have an option to increase focal length, move camera outside of the room and use camera clipping panes to see through walls. That would solve unwanted perspective distortion problem.

+1 Classic Archviz Fake :- ). Use with caution !
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2019-10-08, 11:29:05
Reply #7

romullus

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Use with caution !

Is it because of its unnaturalness, or is there some other hidden issues?
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2019-10-08, 11:34:07
Reply #8

Juraj

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Use with caution !

Is it because of its unnaturalness, or is there some other hidden issues?

No..it's because there are many ways architect, developer, and you, can be sued for deceit ;- ). It can be argued that wide-angle is more deceiving that longer focal length hidden behind wall, but both can be taken to extreme and really create wrongful illusion. In US/UK that can get you in trouble.

But also lately, after visiting some real locations, I am not sure I can say that here...but I almost felt guilty how much better I made it look in CGI... so now I am committed to not taking illusion very far. Architecture should be portrayed like it will exists, at least that is my current position. I don't hide or fake things when clients ask me now.
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2019-10-09, 13:21:00
Reply #9

mancdan

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Use with caution !

Is it because of its unnaturalness, or is there some other hidden issues?

No..it's because there are many ways architect, developer, and you, can be sued for deceit ;- ). It can be argued that wide-angle is more deceiving that longer focal length hidden behind wall, but both can be taken to extreme and really create wrongful illusion. In US/UK that can get you in trouble.

But also lately, after visiting some real locations, I am not sure I can say that here...but I almost felt guilty how much better I made it look in CGI... so now I am committed to not taking illusion very far. Architecture should be portrayed like it will exists, at least that is my current position. I don't hide or fake things when clients ask me now.

Architect: "We need to make this box room look big..."

Artist: "Ok. (Sets camera to 18mm) This ok?"

Architect: "No, it needs to look bigger"

Artist: "Erm, ok. (Sets camera to 12mm :S). How about this?"

Architect: "Go lower, we need to see everything and it needs to look big".

Artist: "Lower? Erm i er..."

Architect: "WHY DOES EVERYTHING LOOK SO DISTORTED!?"



2019-10-09, 17:13:18
Reply #10

Designerman77

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Use with caution !

Is it because of its unnaturalness, or is there some other hidden issues?

No..it's because there are many ways architect, developer, and you, can be sued for deceit ;- ). It can be argued that wide-angle is more deceiving that longer focal length hidden behind wall, but both can be taken to extreme and really create wrongful illusion. In US/UK that can get you in trouble.

But also lately, after visiting some real locations, I am not sure I can say that here...but I almost felt guilty how much better I made it look in CGI... so now I am committed to not taking illusion very far. Architecture should be portrayed like it will exists, at least that is my current position. I don't hide or fake things when clients ask me now.

Architect: "We need to make this box room look big..."

Artist: "Ok. (Sets camera to 18mm) This ok?"

Architect: "No, it needs to look bigger"

Artist: "Erm, ok. (Sets camera to 12mm :S). How about this?"

Architect: "Go lower, we need to see everything and it needs to look big".

Artist: "Lower? Erm i er..."

Architect: "WHY DOES EVERYTHING LOOK SO DISTORTED!?"


Yep... clients... especially Architects... who should actually have a basic knowledge of perspective, focal length, etc. :)))

Another issue is bad taste... Many people claim that aesthetics are only a matter of personal "taste"... a theory which I don't agree with at all.
As every artistic discipline and as every science, "beauty" has a grammar like language, music, mathematics, etc.
Otherwise there wouldn't exist such thing like a "beautifiul woman", that even a half bling recognizese as beautiful. :)))


2019-10-10, 21:16:13
Reply #11

petrorosengren

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3dsMax 'perspective' view also has some kind of focal length, only by default it's usually 45 degrees of FOV (Field of View), which corresponds to 43mm +/- FullFrame sensor (35mm).

In Sketchup, the Architect can use type either FOV or FOCAL LENGTH, (either type "45 DEG", or "43 MM").

If both you and the architect type 28 MM wide-angle focal length, it will look the same. Rectilinear projection looks the same everywhere, that's basic geometry, but I understand you well, I fought with architects and clients who have extremely poor understanding of perspective for years... it boggles my mind ! Sometimes almost to what-the-fuck point :- O. That's life. Just keep educating and explaing :- ).

One more thing is 2-point perspective from Sketchup, which in 3dsMax you activate by "Autovertical tilt correction".

Also, perspective is the same, but it appears more distorted the taller is your composition. 28 mm in 16:9 ration looks less wide than it looks in 4:3. Some people can be confused by that as well.

No problem! Don't forget that you always have an option to increase focal length, move camera outside of the room and use camera clipping panes to see through walls. That would solve unwanted perspective distortion problem.

+1 Classic Archviz Fake :- ). Use with caution !

Thanks for the explanatory answer. I need to check out SketchUp a little bit more.
There was no difference after all, just the architect who was "seeing" something differently when the textures where applied, compared to the clay view in SketchUp. :P

The most interesting discussion I ever had in this field, was a discussion of a colored wall with a IES light directed at it. Apparently the color did not match the specified RAL color in the spot where the light hit the wall...it was to bright :)
« Last Edit: 2019-10-10, 21:21:30 by petrorosengren »

2019-10-12, 13:00:32
Reply #12

Juraj

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Quote
just the architect who was "seeing" something
Quote
colored wall with a IES light directed at it...color did not match the specified RAL

:- ).

We all have to live with this, but I am always surprised by it too...even after 8 years.

My favourite is the combination of "nice afternoon warm light from sun, but keep the material color neutral"

¯\_(ツ)_/¯
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2019-10-12, 17:31:53
Reply #13

jms.lwly

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My favourite is the combination of "nice afternoon warm light from sun, but keep the material color neutral"

This, along with: "Show it on a strong, sunny day - but the shadows can't look too dark or harsh"...


2019-10-12, 18:01:14
Reply #14

ChrisMyatt

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I always enjoy, the glass is too reflective shout :)