Photomontage Problem

[Sketchrender]

I am posting here also because i have no luck with the vray forum on here.

 

 

I have placed a number of cameras as per the drawings I have received.

Eg. Cam 11.2m and the image i have to montage into is says it is...

 

"an angle of 60 deg on the horizontal"

 

I have also placed the camera Target at 11.2m , as i am presuming this is what your suposed to do, to make the horizontal correct.

 

The buildings i am montaging are 1.5km away in a city.

 

I am using the a vray 1.5 ( the upgrade also for max 10) camera, and Max 2010.

 

The horizontal line is in the centre of my view port as it is suposed to be, I think.

But the Horizontal in the image I am montaging is way below it.

I am montaging over a montage to show a difference.

 

I know the montages are correct that i using as they have been done by a very good source, and confirmed by another company also.

 

So were am I going wrong.

 

I can not post the images as they are sensitive, sorry.

 

PS. 60mm camera lens, when I fiddled with it came out about 38 in the vray cam FOV

 

Help would be great.

 

Phil

 

The new camera selection tool in max 10 is very delicate, and very close together.

 

 

 

help would be appreciated.

[Claudio Branch]

 

help would be appreciated.

 

 

Unless you are showing up in a court of law under oath regarding the accuracy of your image, just eyeball the damn thing and be done with it.

[STRAT]

agreed with Claudio. just do your best to eye things up. camera matching is a complete art in itself, something you'll only master with practise.

[Sketchrender]

I know I can Eye ball it, but , I want it to be accurate.

Somemany different opionions on what to do, and what is correct.

I wish someone would do a tutorial on this and not with camera match.

 

Thanks anyway.

 

phil

[signet]

Hi

I am involved in the new 3DAS architectural visualisation book and have just completed writing a chapter on camera matching for stills and moving image sequences.

 

Its going to be a must have i think!

 

I am going to have a headscratch about what you have said as i dont quite understand your problem without seeing some images.

 

But if you mean the photo your matching has the horizon below the image centre and the vertical lines in the image are running parallel and do not converge, then its likely the photo was shot using a view camera.

if so you have to do some processing on the image to align the horizon back to the image centre and then keep your max camera horizontal as well.

 

you could fudge it though using the "gues vertical shift" and point you max camera up some....

 

but again to difficult to tell without seeing something.

 

Camera matching can be boiled down from an art into a science, and thus made easy

[signet]

also you have to remember if you are typing in a known lens...you have to also type in the aperture width/film back for the specific camera so that the lens you have been given information on will provide the correct FOV.

[jkletzien]

I agree with the other posts that without seeing...it is impossible to offer quality help.

 

That said, two things caught my eye in your post.

 

1. camera height - 11.2 may or may not be correct, if it is a datum from sea level than you're assured, but if there is topographic change that is in the real world, but not in your file, than it's not necessarily correct -that said at 1.5k, I think this hardly matters.

 

2. Horizon line - look in the photo where the lines of perspective all converge to horizontal - that is your height (and in a flat world) the physical horizon line - which I think you're confusing with the picture's horizon line -which is mechanically ALWAYS half way up the picture plane. If there is a discrepancy between the two, either the photo you have was taken looking slightly down or (in your case) up -or- it was cropped.

[signet]

i agree with Jons point about the horizon, but often with verified images an architectural photographer may use a Shift camera, this would mean that the camera is pointing completely horizontal and the image is not cropped but the horizon will be shifted up or down.

 

best way to nail this is get some details on the photography and find out if your working with a re-cropped image.

 

to get accurate camera matches you need to make sure the lens axis (what is the centre of the cameras lens) is aligned to the centre of the image.