Hello,
we got problems matching images photographed with Canon EF wide angle Lenses in Max. Even with various horiz./vertical shift settings, it does not match perfectly. Does anybody know where I can get the right distorsion settings for e.g. the EF 2,8/24-70mm ?
Kind regards
Ingo
probably because the real focal length isn’t really 24mm, as stored with the EXIF tags, but slightly different.
i remember from working with boujou that it was more accurate to calculate the focal length/FOV with boujou, than using the exif values.
i also read something on the web, but right now i can’t remember where.
it’s also a good idea to correct distorted images before using them for CG.
i’m not an expert on this topic, but last week i was talking with a very professional photographer who does really huge prints on buildings and stuff like that, with stitching, tilt-shift lenses, etc.
he said that DxO is the best software to correct distortion from canon lenses, before stitching panoramas.
Hi Marc,
thanks for answering, the weird thing is : The rendered image looks distorted, not the photographed one. It seems to be impossible to render a car like the photographed, which is the thing wa want to achive. In fact we need to manipulate the VrayCam to match the original camera, not vice versa.
Ingo
You could find some info about the camera here www.DRPeview.com
Dxo probably has distortion information for that lens.
I use PT Lens to correct lens distortion and and vignetting in PS. Maybe that can be used as reference?
Yeah id be correcting your photograph rather than trying to distort the vray camera to match.
Thanks for the answers, I know that it`s easier to correct the photograph rather the VrayCam, but there is no discussion with the client: in the image, the car looks good, in the rendering it looks not like it should be. We tried nearly any distortion setting possible. Am I the only one who has this problem, matching images 100% ?
get a better lens that has (almost) no distortion, like ef-s 10-22 
What camera are you using? if it has a smaller sensor size you need to take the crop factor into consideration.
also you say “It seems to be impossible to render a car like the photographed” so it sounds like you have a photo with a car in it.. and if you have the same car in 3d you can easily match that using max’s own camera matching tool.
/Thomas
If the OP is talking about this particular lens http://www.canon.co.uk/For\_Home/Product\_Finder/Cameras/EF\_Lenses/Zoom\_Lenses/EF\_2470mm\_f28L\_USM/index.asp then there is no better lens available. A quick google of this lens for reviews reveal it to be one of the best wide zoom Canon lenses ever made, and whilst I know little about your 10-22 I would guess that the fact that the 24-70 is f2.8 throughout implies it has superior optics, let alone that it costs 50% more.
To the OP, get this: http://www.dxo.com/uk/photo there is no better tool for correcting distortion, plus it’s cheap.
I’m with Suurland on this one. You don’t mention the camera you are using.
It maybe that your camera isn’t a 1:1 SLR equivalent, and therefore needs a scale factor. for example, the 400D needs to be multiplied by 1.6 to give you the 35mm slr equivalent.
Some more info on the camera itself might help clarify this.