Your 5D Mk III can certainly shoot HDR, in fact it even has built-in HDR processing! Here is a short article and a video explaining how to set your settings for taking HDR shots.
I’m pretty sure @jamesstaddon has a 5D Mk III now, so he can probably help you with any specific suggestions with regards to camera settings. I have a couple of thoughts too. 🙂
- You’ll want a good high-quality wide-angle lens for this job! I’m not sure what gear you have now, but the lens will be one of the most important considerations for tight indoor shots. Again, James may have some tips here.
- I would recommend enabling the in-camera HDR processing so you can get some real-time feedback of what the end result will look like. It will save a JPG file, which is only useful for making sure you’re properly capturing the highlights. (Just make sure to set the camera to “save source imgs” so that you can process the RAW files manually.)
- If you have the latest version of Lightroom, you can process the HDR files completely in LR. I have an older version of LR, so I can’t test that feature, but I’ve heard that it works pretty well!
- I’m sure you probably know this, but definitely use a tripod for best results! It will help with composition and post-processing.
- Pay careful attention to lighting. (Especially indoors; you can’t really control outdoor lighting). Watch out for big color differences: i.e. warm light indoors and bluish light outdoors. Notice the color issues in the sample photo you attached… My advice would be to try to shoot at a “warmer” time of day, (golden hour?) or potentially use LED lighting panels or some sort of constant light source (not speedlights) to balance the coloring and lighting indoors/outdoors as much as possible. You’ll appreciate that work once you get into post-processing! 🙂 Of course, as a last resort, with selective editing you can also balance it in post-processing.
I hope that’s helpful, and I’m sure James will have some good tips for you as well.