Really is much easier if you have a tripod to do stuff like this.
Ill do a quite detailed reply, its quite useful to know this kinda stuff:
In terms of lining up your set nicely, get some measurements of things to build the set with.
If you have a grasp of the dimentions of things or atleast if you have a few things that have a definite size.
e.g. if you have a building, grab its width and height then you can use that to make a cube in maya to the same dimentions you can then be certain that you line up is accurate. Also try and measure things in relationship to eachother, so if you have a bench infront of a house measure the dimentions of both as best you can and then measure the distance between the two in x and z.
The panoramic mode on the camera is fine but faking the dynamic range in photoshop isn't ideal, if you can afford or borrow a cheap tripod i recomend doing that. Then you need to clamp your exposures to get a series in the range you need.
If your camera has the features needed do the following:
-decide on an apature to use, it wont really matter that much for general purpouses but remember the higher the apature the greater the depth of field (sharper thoughout depth). This needs to stay the same for each photograph.
-Then you need to vary the shutter speed by a stop for each position you are taking to aquire a panorama.
-so for example :
Position one take a photograph at f. 22 at 25 50 and 100/th of a second speeds (depending on the lighting, just if your camera can support changing frame speed on exposures thats ideal but you can do it by eye too)
Then tilt the camera up and do the same, three photographs- down and repeat, then rotate the camera across and do the same until you get full coverage.
Also its best to have these images as RAW, this will give you better quality down the line.
You then need to stitch and merge the photographs, autodesk stitches does this nicely if i remember, so it does nice things like stack the 3 exposures for you and treat them as a single image and then automatically stitch it togeather.
Once you have the exr or hdr exported from your stitching software (exr is industry standard) you will probably have black areas where you had no photographs, usually at the top and bottom.
You need to fill these areas or they will appear in your reflections and you can get bad lighting from the sky, from memory CS4 handles HDR very badly (clamped high values) but this might have changed in updates. Use nuke or another package to clone brush the dark areas so they are filled.
Be wary that you are dealing with a hdr image and its not the same as a jpg, the gamma curve IS NOT baked in, so for this image to work correctly in lighting you cannot compress this image.
This subject is also one of the most overlooked in CGI, its worth looking into:
But basically, all images need to be in linier space to work correctly, so for a jpg texture to appear correctly a gamma correct of .45 needs to be applied to it (can be done in hypershade with a gamma correct node) this removes the standard baked in 2.2 gamma correction from the image (so it looks nice for our eyes) so its mathematically correct.
This is all the more important for hdr, as its going to be lighting you scene etc.
If you want to see how an image properly you can use a LUT in your compositing software to apply a gamma to your display without damaging your composite.
Its not over yet!
To have this work nicely you need to do two more things:
Neutralize the image ( this is so the lighting is predictable)
Create a range of blurred/ scaled images for use in lighting / reflections.
To neturalize an image its best to take a picture of something thats 50% gray at the time you where taking your hdr photographs, a macbeth chart is ideal. Here
. Because you have a range of colors (or atleast grays) you can be sure of you can then tweak the color balance of your image to be normal, and more importantly use theis to perfectly tweak your IBL settings in maya to a gray sphere until it matches the middle gray part of the macbeth chart perfectly
Output 5 ish images of your hdr that are quite blurry to practically totally diffuse, this is for lighthing, you won't need sharp or large images to get nice results.
For reflections perhaps go for 2k images that range from very sharp to relatively blurry, you can then pick the ones you want for what your working with, there are tools to do this in mental ray too but it can be easier before hand, perfectly sharp reflections can look very odd and unrealistic.
End result is to get:
A filled in, netural set of high dynamic range images going from super small and blurry to larger and sharper for use in lighting and / or reflections.
The compositing side has more too it than this, these are the general steps needed to get nice, predictagble linier results from a hdr image.
FX supervisor - double negative