Optical illusion or just plane butchery?
- Thread starter woodchipcharley
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Etaf
Established Member
measure the 2 diagonals on each side - just in case the square is out
measure the width top and bottom
measure the width top and bottom
The top rail is closer to your eyes/lens than the bottom rail.
woodchipcharley
Member
The width and length are spot on the diagonal is perfect on one side and 1mm out on the other side but this could be my measuring as using tape measure is making it difficult what sort of tollarance are we talking to cause this problem?
woodchipcharley
Member
So should I reduce the top rail dimensions by a couple of mm or just leave it? Thanks guys
woodchipcharley
Member
So should I reduce the top rail dimensions by a couple of mm or just leave it? Thank
Orraloon
Established Member
Provided the measurements and a square say its right then leave it. Remember perspective from school art. When the top is on then the eye will not be so drawn to it.
Regards
John
Regards
John
woodchipcharley
Member
Thanks. yes I remember althoughit feelslike a lif time ago, I am not sure how I feel about going to the effort of making it true and square to then undo that effort.
Etaf
Established Member
i was taught, many years ago 60/70's in fact, that on internal doors , because of perspective that the bottom hinge is 9" up and top is 6" down. So it most likely you camera or eye looking down slightly - if its all square and dimensions are within 1mm , must be OK
Etaf
Established Member
when i was a semi-pro photographer , you would see buildings tampering because of the angel of the lens - some cameras had a tilt function to compensate for this - i used photoshop to straighten when i took building landscapes
https://photographyskool.com/why-do...f tall buildings,to the cameras sensor plane.
you photo does not look square on - try taking the photo exactly square
https://photographyskool.com/why-do...f tall buildings,to the cameras sensor plane.
you photo does not look square on - try taking the photo exactly square
woodchipcharley
Member
Thanks for the reassurance 
woodchipcharley
Member
I remember the train track example in art , its just the first thing I've made in wood other than stud walls and wood carvings
Orraloon
Established Member
The pillars of the Parthenon have a built in taper so they look strait.
Regards
John
Regards
John
woodchipcharley
Member
Why would you say that hahaha
woodchipcharley
Member
I am just going to send it I think and remember to look up every time I walk past the end
Etaf
Established Member
J-G
Established Member
They don't have a 'taper' as such they are 'barrel' shaped - though the amount is slight so the effect is subtle.
Argus
Established Member
With regard to the curvature of classic columns, the word you're searching for is "Entasis".
All vertical columns have it to a degree .......Without it, they would appear to the eye as vertical pipes.
The downward converging parallels on those table legs is a phenomenon within the camera, where the plane of the two rear legs is at an angle to the focal plane in the camera.
Again, there's a word for it.......called the Scheimpflug Effect.
All vertical columns have it to a degree .......Without it, they would appear to the eye as vertical pipes.
The downward converging parallels on those table legs is a phenomenon within the camera, where the plane of the two rear legs is at an angle to the focal plane in the camera.
Again, there's a word for it.......called the Scheimpflug Effect.
Ttrees
Iroko loco!
Why are you using a tape measure, that's a builders tool for rough measurements mostly.
Furniture making techniques for your coffee table would be done with a rule and knife marks,
or not measured at all even, but four components planed to better tolerances instead.
You should be able feel within 1 thou of discrepancies. i.e...
The solution to this is having some hand planes for the job, and getting into a whole other realm of
refinement and precision which you couldn't get otherwise (without real expensive kit)
Have a look at the use of the shooting board, with someone skilled regarding the work,
like Rob Cosman for example.
He's as honest as you'll get regarding the work, (that's the important part)
but at the expense of interfiering sales pitches which some can't stand, that's his bag.
On the other end of the spectrum, there are a few prominent gurus on youtube who's income relies on keeping you as unskilled as is possible, but under the pretense of giving the answers,
or fooling you into thinking you already have the correct approach to things.
I won't mention who those guys are.
All the best anyway
Tom
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We actually "see"in a way that is closer to curvilinear perspective, our brain "corrects" this to rectilinear perspective. Sometimes ( in some shots ) cameras point this out to us. Take a length of wood, hold it horizontal in front of you, parallel to you, or even lay it down on the ground or a table this way.The centre is near to you than the ends, how does one depict this using rectilinear perspective ? We "correct" lenses for "barrel distortion", when in fact that "distortion" is closer to the reality of the physics of the scene that is in front of the lens, than the version in our brains of "correct".
No matter how you hold the wood , no matter the angle , as long as it is parallel to your visual plane and you a centered in relation to it, , the ends will always be further from you than the centre. Applies to the entire universe outside of you.
No matter how you hold the wood , no matter the angle , as long as it is parallel to your visual plane and you a centered in relation to it, , the ends will always be further from you than the centre. Applies to the entire universe outside of you.
