perspective correction - DPChallenge Forums

Panasonic LUMIX DMC-LX100

03/15/2012 08:21:08 PM · #1

i know i can apply in it advanced but is there a limit? im not using it to make some freaky effect, im using it to fix the image.

the picture will look normal but the original is quite off dues to my lens. it seems like i had to distort the image quite a bit to get it look straight.

spiritualspatula

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

03/15/2012 08:31:23 PM · #2

Yes/no.

This is along the infamous "is this creating an effect or not?" line and will be judged accordingly. That's the decision... does it create an effect not in the photo or significantly alter the photo. Submit for a check is your best bet.

GeneralE

Canon PowerShot S3 IS

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

03/15/2012 08:53:34 PM · #3

Correcting a lens distortion (perspective) should be legal.

Creating a "lens effect" is not.

If you are really concerned, send a before/after image attached to a ticket and list your editing steps and you can get a pretty accurate "informal opinion."

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

03/15/2012 09:11:58 PM · #4

it will never get approved in time. i already submitted it to the challenge. i didn't create any effect and anyone who looks at it wont suspect anything, only when you compare it to the original you'd know.

the image got warped quite a bit at first but i was able to tweak it so its not as bad.

its not like its going to ribbon anyhow.

GeneralE

Canon PowerShot S3 IS

03/15/2012 09:14:22 PM · #5

If it looks like a "normal photo" it should be fine.

Originally posted by mike_311:

... the image got warped quite a bit at first but i was able to tweak it so its not as bad.

AND it provided a valuable learning experience ... ;-)

Message edited by author 2012-03-15 21:15:58.

Canon EF 24-105mm f/4.0L IS

03/15/2012 09:16:26 PM · #6

it does, i just didn't want it to maybe have to get validated and someone say I distorted it too much.

when you correct perspective, the image can warp quite a bit. this is the first time i ever really tried to do it.

deeby

Canon EOS-60D

03/16/2012 10:00:30 AM · #7

I thought this was going to be about getting therapy.

Bear_Music

Samsung Galaxy S24 Ultra

Sony 24-70mm F4 Vario-Tessar T* FE OSS

03/16/2012 11:28:34 AM · #8

Originally posted by mike_311:

Generally, when we correct for extreme convergence (looking up at tall buildings) the correction leaves the building looking very "squat"; then we have to stretch the image in the vertical direction to restore reasonably accurate proportions. Accordingly, when you're shooting tall buildings that you know you're going to want to correct, it's a good idea to leave a LOT of excess image area around the subject building, because the perspective correction/stretching operation is going to GOBBLE away at the perimeters...

R.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

03/16/2012 11:32:25 AM · #9

Originally posted by Bear_Music:

Originally posted by mike_311:
it does, i just didn't want it to maybe have to get validated and someone say I distorted it too much.

when you correct perspective, the image can warp quite a bit. this is the first time i ever really tried to do it.

Generally, when we correct for extreme convergence (looking up at tall buildings) the correction leaves the building looking very "squat"; then we have to stretch the image in the vertical direction to restore reasonably accurate proportions. Accordingly, when you're shooting tall buildings that you know you're going to want to correct, it's a good idea to leave a LOT of excess image area around the subject building, because the perspective correction/stretching operation is going to GOBBLE away at the perimeters...

R.

i did notice that, luckily i had a lot to work with. i was able to adjust the perspective and then shift the center over to help straighten it.

but i will need to keep that in mind for the future.

GeneralE

Canon PowerShot S3 IS

03/16/2012 01:20:28 PM · #10

Originally posted by Bear_Music:

Like this? I found another method during the SF GTG in January -- this is stitched from three frames, panned vertically with the same settings. Pretty much the default settings using the demo (free) version of AutoStitch. Only "useful" here in Expert challenges though ...