First attempt of working with backplates. Raw render, will update with post production, and some other shots.
(http://i.imgur.com/b9ZTw1S.jpg)
Great angle shot, matches pretty darn well with the backplate. There are a few issues with the render but as an overall try it n see you have done really well.
Martin
Yessss, i saw some parts not rendered correctly but the image was nearly done, so i'll try to figure a way of hiding errors in PS. Here is take two. I want to add some smoke, and spinning effect on the wheel. Thank you Martin !
(http://i.imgur.com/Jcomn5K.jpg)
Post production: I have the feeling that i tend to darken the images too much. At the moment it feels right, but when i compare, i don't know what i prefer. Opinions ?
(http://i.imgur.com/RU3cOa2.jpg)
(http://i.imgur.com/A7eqBxg.jpg)
Since you ask for opinions:
The first one, low angle with rear wheel closest to camera could use some texturing to bring it into reality and match the backplate. Also, the backplate was shot with a low DOF, so you need to adjust the DOF of your render camera to match it. See where the ground closest to us is blurred a bit and becomes in-focus further away? That same effect needs to apply to your vehicle. Also, to me the lighting on the side of the vehicle doesn't seem accurate for the environment. There should probably be fewer harsh highlights on that side of the car.
On the next image, you've got the same depth of field issues. Car has no DOF but backplate has lots. Matching those up is vital. The reflections in this one seem to match better/be more appropriate. The headlights could use some detail/TLC.
On the 3rd image (with smoke) I'd suggest the smoke looks too opaque. I think in a darker environment, the smoke would be more subtle. I can tell you took the blur tool in post to try and fix the DOF issues, but it doesn't quite work like that. You've blurred the top of the car presumably because the backplate behind it is blurred (called a bokeh effect). However, in 3d space, the top of the car is directly over the middle of the chassis, so looking at the original backplate, the top of the car should be in focus, not blurred.
Looks like on your last edit, you began to address DOF issues, but I urge you to not do it in Post when trying to match the backplate, unless you're using a depth pass to do so.
I recommend watching some videos or reading up on Depth Of Field and once that's crystal clear, I'm thinking your renderings will improve quite a bit.
Hope that's helpful.
Thank you very much Will. I'm aware at my problems with DoF. I still don't know how to use depth passes but i will try to get better at it. Thank you for taking your time to see all this details... it helps me a lot.