determine camera angle from photo

[fadi3d]

Hi There,

i don't know if this is the right forum to ask this question but i sure hope anybody can help

 

i am trying to replicate this kitchen (attached) but i can't get the vray phys cam to give me the righ angle. i tried to determine the Horizon line so there is my cam target but still i couldn't get the right side to look elongated like this.

i hope someone can explain the sience behind such an issue (i gues it has to do with studiying perspective)

thanks in advance.

regards.

[chriswetzel]

Have you changed the camera lens at all? I imagine once you've got the camera location pretty close you will have to adjust the camera lens to duplicate what the photographer did in the shoot. Check the resolution of the original image to give you an idea of the aspect ratio.

[Scott Schroeder]

Use camera helpers. Place them at the known corners of say your kitchen cabinets, then generate a camera from using the helpers. Lowering your camera error gives you a more accurate result.

 

Watch how this video sets it up:

 

[Tommy L]

Looks like its a crop, which can throw off camera aligning. Add more to the left until that vertical construction line is in the center of the image. That might help.

[fadi3d]

@ Chris i did Check the resolution of the original image and matched it in the Vray frame buffer and max

@ Scott i will watch the video and try maybe this will work

@ Tom that is my guessing maybe it's a crop cause i usually get it worked out almost the same in other scenes.

thank you all for your help and maybe later i'll post what results i got so far

Cheers.

[Scott Dombrowski]

It looks to me like the photo was either taken with a tilt/shift lens or had its verticals straightened with the lens correction tool in Photoshop. Either way, that'll make it hard to match in Max. I don't use VRay so I don't know how their physical cams work, but in mental ray you can add a camera correction modifier to a normal camera to straighten out the verticals. Try adding a camera correction modifier (or whatever VRay equivalent there may be) to see if that gets you anywhere.

[fadi3d]

i decided to post my test so far maybe someone could see if i'm doing something wrong

@ Scott : i used the vertical shift correction in vray (somehing like the camera correction modifier in max)

but i don't know if what you mention is specific to mental ray

the problem i have is that the cabinets to the right although the right size (taken from the catalogue) in my render look smaller

(nearer to the viewer) wherein in the photo they seem a lot further

it's driving me nuts (or maybe i am nuts ???) i just wish someone with photographic skills would shed some light on the subject.

thank u all though for the goo thoughts.

Cheers.

[Scott Dombrowski]

Ok, seeing your render helps. It looks like in your rendering, the camera is further away from the window and uses a narrower lens (50mm or more?) and the camera in the photograph is closer to the window but uses a wider angle lens (20mm or less?).

 

Interestingly, Hitchcock played with this phenomenon in Vertigo. Move the camera and change the focal length at the same time, the apparent field of view stays roughly the same, but the objects in view will appear to expand or compress, depending on which way you're moving the camera.

 

Move your camera closer to the window and make it a wider angle. That should fix it.

 

Ninja edit: Also, the camera in the photograph is panned slightly to the right (look at the horizontal lines of the ceiling, the front edge of the counter at the stove, and the front edge of the rug). You may need to move your camera a little bit to the left and then pan back to the right to match those angles.

Edited March 5, 2013 by nauticus27
Added information

[fadi3d]

Man u made my day thanks a lot it is much closer to the photo now. i don't know why but i usualy stick with the

default focal angle as the alternative gives me weird results. but here the exagerated view is what gives the picture that kind of dramatic

impact (my guess)

Cheers man and i hope i'll post the final results soon make sure you check them

Regards